The next time your toddler acts adventurous, shy, fidgety or cuddly, you might be able to blame the bacteria in his gut.
Researchers from The Ohio State University studied microbes from the gastrointestinal tracts of children between the age of 18 and 27 months, and found that the abundance and diversity of certain bacterial species appear to impact behavior, particularly among boys. The correlation exists even after the scientists factored in history of breastfeeding, diet and the method of childbirth -- all of which are known to influence the type of microbes that populate a child's gut.
Study authors say they aren't looking for a way to help parents modify the 'terrible twos,' but for clues about how -- and where -- chronic illnesses like obesity, asthma, allergies and bowel disease start.
"There is substantial evidence that intestinal bacteria interact with stress hormones- the same hormones that have been implicated in chronic illnesses like obesity and asthma," said Lisa Christian, PhD, a researcher with Ohio State's Institute for Behavioral Medicine Research. "A toddler's temperament gives us a good idea of how they react to stress. This information combined with an analysis of their gut microbiome could ultimately help us identify opportunities to prevent chronic health issues earlier."
Christian and study co-author, microbiologist Michael Bailey, PhD, studied stool samples from 77 girls and boys, and found that children with the most genetically diverse types of gut bacteria more frequently exhibited behaviors related with positive mood, curiosity, sociability and impulsivity. In boys only, researchers reported that extroverted personality traits were associated with the abundances of microbes from the Rikenellaceae and Ruminococcaceaefamilies and Dialister and Parabacteroides genera.
"There is definitely communication between bacteria in the gut and the brain, but we don't know which one starts the conversation," said Dr. Bailey, who is currently a researcher with Nationwide Children's Hospital and a member of Ohio State's Institute for Behavioral Medicine Research. "Maybe kids who are more outgoing have fewer stress hormones impacting their gut than shy kids. Or maybe the bacteria are helping mitigate the production of stress hormones when the child encounters something new. It could be a combination of both."
Overall, associations of temperament with the gut microbiome in girls were fewer and less consistent than boys. However, in girls, behaviors like self-restraint, cuddliness and focused attention were associated with a lower diversity of gut bacteria, while girls with an abundance of Rikenellaceae appeared to experience more fear than girls with a more balanced diversity of microbes.
To identify correlations between gut bacteria and temperament, researchers asked mothers to assess kid's behavior using a questionnaire which measures 18 different traits that feed into three composite scales of emotional reactivity: Negative Affect, Surgency/Extraversion and Effortful Control. Scientists looked at the different genetic types and relative quantity of bacteria found in the toddler's stool samples along with their diets.
The average gastrointestinal tract contains 400-500 different species of bacteria, and most of them belong to one of ten phyla of bacteria. Advancements in DNA-based methods have allowed scientists to identify bacteria in stool, along with the relative concentration of those bacteria -- giving them a much more accurate look at the diversity and composition of the microbial community.
"In the past, bacteria were cultured from samples in the lab, and scientists assumed that what grew was an accurate reflection of what was in the gut," said Dr. Bailey. "Now we can see that's not the case. All of the predominant bacteria that we found in our study have been previously linked to either changes in behavior or immune response, so I think we are definitely on the right track."
Similar to other child behavior studies, researchers separated their findings by gender to analyze temperament. Overall, the study found few differences in the abundance and types of gut microbiota between girls and boys.
While scientists believe that the microbiome is generally set by the age of two, there are dramatic changes in gut microbes that take place during and after birth, as babies pick up bacteria from their mothers during labor and through breastfeeding. Babies born via C-section will have different microbes than babies delivered vaginally.
However, the researchers found that gut bacterial composition wasn't impacted by delivery method, diet or length of breast feeding. The authors acknowledge that their study didn't delve deeply into individual diets, but looked generally at when food types were introduced and the types and frequency of food consumed daily.
"In this study, the associations between temperament and the gut microbiome that we saw weren't due to differences in the diets of children. However, it is possible that effects of diet would emerge if we used a more detailed assessment. It is certainly possible that the types or quantities of food that children with different temperaments choose to eat affect their microbiome. " said Dr. Christian, who also holds appointments in the departments of psychiatry, psychology and obstetrics/gynecology at Ohio State's College of Medicine.
Both researchers say that parents shouldn't try to change their child's gut microbiome just yet. Scientists still don't know what a healthy combination looks like, or what might influence its development.
"The bacterial community in my gut is going to look different than yours -- but we are both healthy. The perfect microbiome will probably vary from person to person," said Dr. Bailey.
Drs. Christian and Bailey are continuing to study how the gut microbiome impacts human health and behavior, recently publishing evidence that the babies of obese mothers have a different gut microbiome than babies of normal weight mothers. They are currently applying for an R01 grant to determine how this difference may predispose babies for developing obesity later in childhood.
Story Source:
The above post is reprinted from materials provided by Ohio State University Center for Clinical and Translational Science. Note: Materials may be edited for content and length.
Journal Reference:
Cite This Page:
Ohio State University Center for Clinical and Translational Science. "Toddler temperament could be influenced by different types of gut bacteria." ScienceDaily. ScienceDaily, 27 May 2015. <www.sciencedaily.com/releases/2015/05/150527091438.htm>.
Researchers from The Ohio State University studied microbes from the gastrointestinal tracts of children between the age of 18 and 27 months, and found that the abundance and diversity of certain bacterial species appear to impact behavior, particularly among boys. The correlation exists even after the scientists factored in history of breastfeeding, diet and the method of childbirth -- all of which are known to influence the type of microbes that populate a child's gut.
Study authors say they aren't looking for a way to help parents modify the 'terrible twos,' but for clues about how -- and where -- chronic illnesses like obesity, asthma, allergies and bowel disease start.
"There is substantial evidence that intestinal bacteria interact with stress hormones- the same hormones that have been implicated in chronic illnesses like obesity and asthma," said Lisa Christian, PhD, a researcher with Ohio State's Institute for Behavioral Medicine Research. "A toddler's temperament gives us a good idea of how they react to stress. This information combined with an analysis of their gut microbiome could ultimately help us identify opportunities to prevent chronic health issues earlier."
Christian and study co-author, microbiologist Michael Bailey, PhD, studied stool samples from 77 girls and boys, and found that children with the most genetically diverse types of gut bacteria more frequently exhibited behaviors related with positive mood, curiosity, sociability and impulsivity. In boys only, researchers reported that extroverted personality traits were associated with the abundances of microbes from the Rikenellaceae and Ruminococcaceaefamilies and Dialister and Parabacteroides genera.
"There is definitely communication between bacteria in the gut and the brain, but we don't know which one starts the conversation," said Dr. Bailey, who is currently a researcher with Nationwide Children's Hospital and a member of Ohio State's Institute for Behavioral Medicine Research. "Maybe kids who are more outgoing have fewer stress hormones impacting their gut than shy kids. Or maybe the bacteria are helping mitigate the production of stress hormones when the child encounters something new. It could be a combination of both."
Overall, associations of temperament with the gut microbiome in girls were fewer and less consistent than boys. However, in girls, behaviors like self-restraint, cuddliness and focused attention were associated with a lower diversity of gut bacteria, while girls with an abundance of Rikenellaceae appeared to experience more fear than girls with a more balanced diversity of microbes.
To identify correlations between gut bacteria and temperament, researchers asked mothers to assess kid's behavior using a questionnaire which measures 18 different traits that feed into three composite scales of emotional reactivity: Negative Affect, Surgency/Extraversion and Effortful Control. Scientists looked at the different genetic types and relative quantity of bacteria found in the toddler's stool samples along with their diets.
The average gastrointestinal tract contains 400-500 different species of bacteria, and most of them belong to one of ten phyla of bacteria. Advancements in DNA-based methods have allowed scientists to identify bacteria in stool, along with the relative concentration of those bacteria -- giving them a much more accurate look at the diversity and composition of the microbial community.
"In the past, bacteria were cultured from samples in the lab, and scientists assumed that what grew was an accurate reflection of what was in the gut," said Dr. Bailey. "Now we can see that's not the case. All of the predominant bacteria that we found in our study have been previously linked to either changes in behavior or immune response, so I think we are definitely on the right track."
Similar to other child behavior studies, researchers separated their findings by gender to analyze temperament. Overall, the study found few differences in the abundance and types of gut microbiota between girls and boys.
While scientists believe that the microbiome is generally set by the age of two, there are dramatic changes in gut microbes that take place during and after birth, as babies pick up bacteria from their mothers during labor and through breastfeeding. Babies born via C-section will have different microbes than babies delivered vaginally.
However, the researchers found that gut bacterial composition wasn't impacted by delivery method, diet or length of breast feeding. The authors acknowledge that their study didn't delve deeply into individual diets, but looked generally at when food types were introduced and the types and frequency of food consumed daily.
"In this study, the associations between temperament and the gut microbiome that we saw weren't due to differences in the diets of children. However, it is possible that effects of diet would emerge if we used a more detailed assessment. It is certainly possible that the types or quantities of food that children with different temperaments choose to eat affect their microbiome. " said Dr. Christian, who also holds appointments in the departments of psychiatry, psychology and obstetrics/gynecology at Ohio State's College of Medicine.
Both researchers say that parents shouldn't try to change their child's gut microbiome just yet. Scientists still don't know what a healthy combination looks like, or what might influence its development.
"The bacterial community in my gut is going to look different than yours -- but we are both healthy. The perfect microbiome will probably vary from person to person," said Dr. Bailey.
Drs. Christian and Bailey are continuing to study how the gut microbiome impacts human health and behavior, recently publishing evidence that the babies of obese mothers have a different gut microbiome than babies of normal weight mothers. They are currently applying for an R01 grant to determine how this difference may predispose babies for developing obesity later in childhood.
Story Source:
The above post is reprinted from materials provided by Ohio State University Center for Clinical and Translational Science. Note: Materials may be edited for content and length.
Journal Reference:
- Lisa M. Christian, Jeffrey D. Galley, Erinn M. Hade, Sarah Schoppe-Sullivan, Claire Kamp Dush, Michael T. Bailey. Gut microbiome composition is associated with temperament during early childhood. Brain, Behavior, and Immunity, 2015; 45: 118 DOI: 10.1016/j.bbi.2014.10.018
Cite This Page:
Ohio State University Center for Clinical and Translational Science. "Toddler temperament could be influenced by different types of gut bacteria." ScienceDaily. ScienceDaily, 27 May 2015. <www.sciencedaily.com/releases/2015/05/150527091438.htm>.
Study links Parkinson's disease to gut bacteria Published: Friday 12 December 2014 at 3am
PST Parkinson's Disease Infectious Diseases / Bacteria / Viruses GastroIntestinal / Gastroenterology MNT featured Academic journal A new study finds that compared to healthy controls, people with Parkinson's disease appear to have distinctly different gut bacteria. They have hardly any bacteria from one family and the amount present from another family seems to increase with disease severity.
The gut bacteria of people with Parkinson's disease is different to that of healthy people. The study, led by the University of Helsinki Institute of Biotechnology in Finland, is published in the journal Movement Disorders.
It involved 72 patients with Parkinson's disease and an equal number of matched, healthy controls.
More and more studies are discovering the huge influence that our gut bacteria - which vastly outnumber the cells of our body - have on our health: when they get sick, we get sick.
Parkinson's disease is a progressive motor disorder that develops when the brain loses cells that produce dopamine - a chemical that controls reward and pleasure and also regulates movement and emotional responses.
Parkinson's symptoms include trembling, stiffness, slowness of movement and problems with balance and coordination.
The disease rarely strikes before the age of 50 and gradually gets worse - to the point where everyday life and self-care becomes very difficult.
According to the National Parkinson's Foundation, up to 60,000 new cases of Parkinson's are diagnosed each year in the US, adding to the 1 million Americans who currently live with the condition.
Some clues already exist about the links between Parkinson's and gut problems. For example, as the study authors say in their paper, "gastrointestinal dysfunction, in particular constipation, is an important non-motor symptom" in Parkinson's disease, and "often precedes the onset of motor symptoms by years."
They also mention that recent research shows gut bacteria interact with parts of the nervous system via various pathways, including the enteric nervous system - the so-called "brain in the gut" - and the vagal nerve.
Highlighting their findings, lead author of the new study, Dr. Filip Scheperjans, a neurologist in the Neurology Clinic of Helsinki University Hospital, says:
"Our most important observation was that patients with Parkinson's have much less bacteria from the Prevotellaceae family; unlike the control group, practically no one in the patient group had a large quantity of bacteria from this family."
The team did not find out what an absence of Prevotellaceae might mean in Parkinson's disease. But they have many questions. For example, does this family of bacteria protect against the disease? Or does the disease wipe them out?
"It's an interesting question which we are trying to answer," says Dr. Sheperjans.
Knowing about gut bacteria could help improve prognosis and treatment in Parkinson's The team also found that levels of another family of bacteria called Enterobacteriaceae appear to be linked to severity of Parkinson's symptoms. They observed patients who had more difficulty with balance and walking tended to have higher levels of these bacteria.
Dr. Sheperjans and his colleagues are already planning further research to explore the connection between Parkinson's disease and gut bacteria.
They have begun to re-examine the same group of patients to find out if the differences in gut bacteria are permanent or whether they change as the disease progresses. If they do change with disease progression, this could help doctors give more accurate prognoses.
"In addition," Dr. Sheperjans says, "we will have to see if these changes in the bacterial ecosystem are apparent before the onset of motor symptoms."
And, he adds, they also want to discover the underlying biological mechanism between gut bacteria and Parkinson's disease.
They hope eventually that their findings will lead to new tests for Parkinson's and perhaps even new treatments to stop, slow or even prevent the disease by focusing on gut bacteria.
Funds from the Michael J. Fox Foundation for Parkinson's Research and the Finnish Parkinson Foundation helped finance the study.
In November 2014, Medical News Today learned of a stem cell treatment breakthrough for Parkinson's disease. A study involving laboratory rats suggests it may be possible to replace dopamine cells lost to Parkinson's disease by making them from embryonic stem cells and then transplanting them into the brain.
Written by Catharine Paddock PhD
Copyright: Medical News Today
PST Parkinson's Disease Infectious Diseases / Bacteria / Viruses GastroIntestinal / Gastroenterology MNT featured Academic journal A new study finds that compared to healthy controls, people with Parkinson's disease appear to have distinctly different gut bacteria. They have hardly any bacteria from one family and the amount present from another family seems to increase with disease severity.
The gut bacteria of people with Parkinson's disease is different to that of healthy people. The study, led by the University of Helsinki Institute of Biotechnology in Finland, is published in the journal Movement Disorders.
It involved 72 patients with Parkinson's disease and an equal number of matched, healthy controls.
More and more studies are discovering the huge influence that our gut bacteria - which vastly outnumber the cells of our body - have on our health: when they get sick, we get sick.
Parkinson's disease is a progressive motor disorder that develops when the brain loses cells that produce dopamine - a chemical that controls reward and pleasure and also regulates movement and emotional responses.
Parkinson's symptoms include trembling, stiffness, slowness of movement and problems with balance and coordination.
The disease rarely strikes before the age of 50 and gradually gets worse - to the point where everyday life and self-care becomes very difficult.
According to the National Parkinson's Foundation, up to 60,000 new cases of Parkinson's are diagnosed each year in the US, adding to the 1 million Americans who currently live with the condition.
Some clues already exist about the links between Parkinson's and gut problems. For example, as the study authors say in their paper, "gastrointestinal dysfunction, in particular constipation, is an important non-motor symptom" in Parkinson's disease, and "often precedes the onset of motor symptoms by years."
They also mention that recent research shows gut bacteria interact with parts of the nervous system via various pathways, including the enteric nervous system - the so-called "brain in the gut" - and the vagal nerve.
Highlighting their findings, lead author of the new study, Dr. Filip Scheperjans, a neurologist in the Neurology Clinic of Helsinki University Hospital, says:
"Our most important observation was that patients with Parkinson's have much less bacteria from the Prevotellaceae family; unlike the control group, practically no one in the patient group had a large quantity of bacteria from this family."
The team did not find out what an absence of Prevotellaceae might mean in Parkinson's disease. But they have many questions. For example, does this family of bacteria protect against the disease? Or does the disease wipe them out?
"It's an interesting question which we are trying to answer," says Dr. Sheperjans.
Knowing about gut bacteria could help improve prognosis and treatment in Parkinson's The team also found that levels of another family of bacteria called Enterobacteriaceae appear to be linked to severity of Parkinson's symptoms. They observed patients who had more difficulty with balance and walking tended to have higher levels of these bacteria.
Dr. Sheperjans and his colleagues are already planning further research to explore the connection between Parkinson's disease and gut bacteria.
They have begun to re-examine the same group of patients to find out if the differences in gut bacteria are permanent or whether they change as the disease progresses. If they do change with disease progression, this could help doctors give more accurate prognoses.
"In addition," Dr. Sheperjans says, "we will have to see if these changes in the bacterial ecosystem are apparent before the onset of motor symptoms."
And, he adds, they also want to discover the underlying biological mechanism between gut bacteria and Parkinson's disease.
They hope eventually that their findings will lead to new tests for Parkinson's and perhaps even new treatments to stop, slow or even prevent the disease by focusing on gut bacteria.
Funds from the Michael J. Fox Foundation for Parkinson's Research and the Finnish Parkinson Foundation helped finance the study.
In November 2014, Medical News Today learned of a stem cell treatment breakthrough for Parkinson's disease. A study involving laboratory rats suggests it may be possible to replace dopamine cells lost to Parkinson's disease by making them from embryonic stem cells and then transplanting them into the brain.
Written by Catharine Paddock PhD
Copyright: Medical News Today
Gut microbiota are related to Parkinson's disease and clinical phenotype, Filip Scheperjans, et al., Movement Disorders, doi:10.1002/mds.26069, published online 5 December 2014, abstract.
University of Helsinki news release accessed 11 December 2014 via AlphaGalileo.
Science News from research organizations Decreased social anxiety among young adults who eat fermented foods
Date:June 9, 2015
Source: University of Maryland, Baltimore Summary:
A possible connection between fermented foods, which contain probiotics, and social anxiety symptoms, is the focus of recent study. The study is just the first in a series that the researchers have planned to continue exploring the mind-gut connection, including another examination of the data to see whether a correlation exists between fermented food intake and autism symptoms.
Psychologists have traditionally looked to the mind to help people living with mental health issues. But a recent study led by William & Mary researchers shows that the stomach may also play a key role, suggesting that the old adage "you are what you eat" is more than a cliché.
W&M Psychology Professors Matthew Hilimire and Catherine Forestell recently joined with University of Maryland School of Social Work Assistant Professor Jordan DeVylder to investigate a possible connection between fermented foods, which contain probiotics, and social anxiety. The researchers found that young adults who eat more fermented foods have fewer social anxiety symptoms, with the effect being greatest among those at genetic risk for social anxiety disorder as measured by neuroticism.
The journal Psychiatry Research accepted the study in April for publication in August.
"It is likely that the probiotics in the fermented foods are favorably changing the environment in the gut, and changes in the gut in turn influence social anxiety," said Hilimire. "I think that it is absolutely fascinating that the microorganisms in your gut can influence your mind."
The researchers designed a questionnaire that was included in a mass testing tool administered in the university's Introduction to Psychology courses during the fall 2014 semester; about 700 students participated. The questionnaire asked students about the fermented foods over the previous 30 days; it also asked about exercise frequency and the average consumption of fruits and vegetables so that the researchers could control for healthy habits outside of fermented food intake, said Hilimire.
"The main finding was that individuals who had consumed more fermented foods had reduced social anxiety but that was qualified by an interaction by neuroticism. What that means is that that relationship was strongest amongst people that were high in neuroticism," Hilimire said.
The secondary finding was that more exercise was related to reduced social anxiety. Although the researchers were pleased to see the findings so clearly support their hypothesis, the study is just the first in a series they have planned to continue exploring the mind-gut connection, including another examination of the data to see whether a correlation exists between fermented food intake and autism symptoms, said Hilimire.
The researchers will also soon create an experimental version of the study. Without that experimental phase, the researches can't make a causative connection between eating fermented foods and reduced social anxiety.
"However, if we rely on the animal models that have come before us and the human experimental work that has come before us in other anxiety and depression studies, it does seem that there is a causative mechanism," said Hilimire. "Assuming similar findings in the experimental follow-up, what it would suggest is that you could augment more traditional therapies (like medications, psychotherapy or a combination of the two) with fermented foods -- dietary changes -- and exercise, as well."
DeVylder noted that research over the past several years has increasingly supported a close relationship between nutrition and mental health. "This study shows that young adults who are prone towards anxiety report less social anxiety if they frequently consume fermented foods with probiotics. These initial results highlight the possibility that social anxiety may be alleviated through low-risk nutritional interventions, although further research is needed to determine whether increasing probiotic consumption directly causes a reduction in social anxiety," he said.
Story Source:
The above post is reprinted from materials provided by University of Maryland, Baltimore. Note: Materials may be edited for content and length.
Journal Reference:
Cite This Page:
University of Maryland, Baltimore. "Decreased social anxiety among young adults who eat fermented foods." ScienceDaily. ScienceDaily, 9 June 2015. <www.sciencedaily.com/releases/2015/06/150609092803.htm>.
Date:June 9, 2015
Source: University of Maryland, Baltimore Summary:
A possible connection between fermented foods, which contain probiotics, and social anxiety symptoms, is the focus of recent study. The study is just the first in a series that the researchers have planned to continue exploring the mind-gut connection, including another examination of the data to see whether a correlation exists between fermented food intake and autism symptoms.
Psychologists have traditionally looked to the mind to help people living with mental health issues. But a recent study led by William & Mary researchers shows that the stomach may also play a key role, suggesting that the old adage "you are what you eat" is more than a cliché.
W&M Psychology Professors Matthew Hilimire and Catherine Forestell recently joined with University of Maryland School of Social Work Assistant Professor Jordan DeVylder to investigate a possible connection between fermented foods, which contain probiotics, and social anxiety. The researchers found that young adults who eat more fermented foods have fewer social anxiety symptoms, with the effect being greatest among those at genetic risk for social anxiety disorder as measured by neuroticism.
The journal Psychiatry Research accepted the study in April for publication in August.
"It is likely that the probiotics in the fermented foods are favorably changing the environment in the gut, and changes in the gut in turn influence social anxiety," said Hilimire. "I think that it is absolutely fascinating that the microorganisms in your gut can influence your mind."
The researchers designed a questionnaire that was included in a mass testing tool administered in the university's Introduction to Psychology courses during the fall 2014 semester; about 700 students participated. The questionnaire asked students about the fermented foods over the previous 30 days; it also asked about exercise frequency and the average consumption of fruits and vegetables so that the researchers could control for healthy habits outside of fermented food intake, said Hilimire.
"The main finding was that individuals who had consumed more fermented foods had reduced social anxiety but that was qualified by an interaction by neuroticism. What that means is that that relationship was strongest amongst people that were high in neuroticism," Hilimire said.
The secondary finding was that more exercise was related to reduced social anxiety. Although the researchers were pleased to see the findings so clearly support their hypothesis, the study is just the first in a series they have planned to continue exploring the mind-gut connection, including another examination of the data to see whether a correlation exists between fermented food intake and autism symptoms, said Hilimire.
The researchers will also soon create an experimental version of the study. Without that experimental phase, the researches can't make a causative connection between eating fermented foods and reduced social anxiety.
"However, if we rely on the animal models that have come before us and the human experimental work that has come before us in other anxiety and depression studies, it does seem that there is a causative mechanism," said Hilimire. "Assuming similar findings in the experimental follow-up, what it would suggest is that you could augment more traditional therapies (like medications, psychotherapy or a combination of the two) with fermented foods -- dietary changes -- and exercise, as well."
DeVylder noted that research over the past several years has increasingly supported a close relationship between nutrition and mental health. "This study shows that young adults who are prone towards anxiety report less social anxiety if they frequently consume fermented foods with probiotics. These initial results highlight the possibility that social anxiety may be alleviated through low-risk nutritional interventions, although further research is needed to determine whether increasing probiotic consumption directly causes a reduction in social anxiety," he said.
Story Source:
The above post is reprinted from materials provided by University of Maryland, Baltimore. Note: Materials may be edited for content and length.
Journal Reference:
- Matthew R. Hilimire, Jordan E. DeVylder, Catherine A. Forestell. Fermented foods, neuroticism, and social anxiety: An interaction model. Psychiatry Research, 2015; 228 (2): 203 DOI: 10.1016/j.psychres.2015.04.023
Cite This Page:
University of Maryland, Baltimore. "Decreased social anxiety among young adults who eat fermented foods." ScienceDaily. ScienceDaily, 9 June 2015. <www.sciencedaily.com/releases/2015/06/150609092803.htm>.
Autism’s Gut-Brain Connection
The different gut bacteria in autistic individuals may be contributing to the disorder.
By Melissa Pandika, for OZY
PUBLISHED NOVEMBER 14, 2014
Stress can send your stomach into a painful tailspin, causing cramps, spasms and grumbling. But trouble in the gut can also affect the brain.
This two-way relationship may be an unlikely key to solving one of medicine's most pressing—and perplexing—mysteries: autism. Nearly 60 years after the disorder was first identified, the number of cases has surged, and the United Nations estimates that up to 70 million people worldwide fall on the autism spectrum. Yet there is no known cause or cure.
But scientists have found promising clues in the gut. Research has revealed striking differences in the trillions of bacteria - collectively known as the microbiome—in the intestines of autistic and healthy children. But the gut bacteria in autistic individuals aren't just different. Researchers at the California Institute of Technology have shown for the first time that they may actually contribute to the disorder. Last month, they reported in the journal Cell that an experimental probiotic therapy alleviated autism-like behaviors in mice and are already planning a clinical trial.
Today autism is treated primarily through behavioral therapy. But the new study suggests that treatment may one day come in the form of a probiotic—live, "friendly" bacteria like those found in yogurt. "If you block the gastrointestinal problem, you can treat the behavioral symptoms," Paul Patterson, a professor of biology at Caltech who co-authored the study, toldSFARI.org. University of Colorado Boulder professor Rob Knight hailed the finding as "groundbreaking" in a commentary in Cell.
Autism is a complex spectrum of disorders that share three classic features - impaired communication, poor social engagement and repetitive behaviors. On one end of the spectrum are people who are socially awkward but, in many cases, incredibly bright. At the other extreme are individuals with severe mental disabilities and behavioral problems.
Among autistic children's most common health complaints? Gastrointestinal problems. Although estimates vary widely, some studies have concluded that up to 90 percent of autistic children suffer from tummy troubles. According to the CDC, they're more than 3.5 times more likely to experience chronic diarrhea and constipation than their normally developing peers.
Following these hints, Arizona State University researchers analyzed the gut bacteria in fecal samples obtained from autistic and normally developing children. They found that autistic participants had many fewer types of bacteria, probably making the gut more susceptible to attack from disease-causing pathogens. Other studies have also found striking differences in the types and abundance of gut bacteria in autistic versus healthy patients.
But is the gut microbiome in autistic individuals responsible for the disorder? To find out, Caltech postdoctoral researcher Elaine Hsiao engineered mice based on earlier studies showing that women who get the flu during pregnancy double their risk of giving birth to an autistic child. In the mouse model, pregnant females injected with a mock virus gave birth to pups with autism-like symptoms, such as obsessive grooming, anxiety and aloofness.
The mouse pups went on to develop so-called "leaky gut," in which molecules produced by the gut bacteria trickle into the bloodstream, possibly reaching the brain—a condition also seen in autistic children.
But how did these bacteria influence behavior? To find out, Hsiao analyzed the mice's blood. The blood of "autistic" mice contained a whopping 46 times more 4EPS, a molecule produced by gut bacteria, thought to have seeped from their intestines. What's more, injecting healthy mice with 4EPS made them more anxious. A similar molecule has been detected at elevated levels in autistic patients.
Hsiao then laced the animals' food with B. fragilis, a priobiotic that's been shown to treat GI problems in mice—and the results were jaw-dropping.
Five weeks later, the leaky gut in "autistic" mice had sealed up, and the levels of 4EPS in their blood had plummeted. Their gut microbiomes had come to more closely resemble those of healthy mice—and so did their behavior. They were less anxious and more vocal, and stopped obsessively burying marbles in their cages.
But the treated mice remained aloof when a new mouse was placed in their cage. "This is a real limitation in the conclusions from this study as, in many ways, social interaction deficits are at the core ... of autism," Ted Abel, a professor of biology at the University of Pennsylvania, told SFARI.org.
What's more, a probiotic may only help the subset of autistic patients who experience GI problems, Hsiao said. And only a clinical trial will reveal whether the results also apply to humans.
Still, autism researchers shouldn't underestimate the importance of gut bacteria, said John Cryan, a professor of anatomy and neuroscience at University Cork College. In 2011, his group reported in the Proceedings of the National Academy of Sciences that probiotic-fed mice were less anxious and produced fewer stress hormones."You have this kilo of microbes in your gut that's as important as the kilo of nerve cells in your brain," he said. "We need to do much more studies on autistic biota."
For autistic patients and their families, however, even a supplemental therapy for a subset of sufferers is a huge step forward. "It's really impactful, this notion that by changing the bacteria, you could ameliorate what's often considered an intractable disorder," Hsiao said. "It's a really crazy notion and a big advance."
This piece comes from our partner OZY. Melissa Pandika is a lab rat-turned-journalist with eye to all things science, medicine and more.
*With some reporting from SFARI.org. Updated August 12, 2014.
Science News
from research organizations
A single species of gut bacteria can reverse autism-related social behavior in mice
Date:
June 16, 2016
Source:
Cell Press
Summary:
The absence of a one specific species of gut bacteria causes social deficits in mice, researchers report. By adding this bacteria species back to the guts of affected mice, the researchers were able to reverse some of their behavioral deficits, which are reminiscent of symptoms of autism spectrum disorders (ASDs) in humans. The investigators are now looking to explore the effects of probiotics on neurodevelopmental disorders in future work.
The absence of a one specific species of gut bacteria causes social deficits in mice, researchers at Baylor College of Medicine report June 16, 2016 in Cell. By adding this bacteria species back to the guts of affected mice, the researchers were able to reverse some of their behavioral deficits, which are reminiscent of symptoms of autism spectrum disorders (ASDs) in humans. The investigators are now looking to explore the effects of probiotics on neurodevelopmental disorders in future work.
"Other research groups are trying to use drugs or electrical brain stimulation as a way to reverse some of the behavioral symptoms associated with neurodevelopmental disorders -- but here we have, perhaps, a new approach," says senior author Mauro Costa-Mattioli, a neuroscientist at Baylor College of Medicine. "Whether it would be effective in humans, we don't know yet, but it is an extremely exciting way of affecting the brain from the gut."
The inspiration for the paper came from human epidemiological studies that have found that maternal obesity during pregnancy could increase children's risk of developing neurodevelopmental disorders, including ASDs. In addition, some individuals with ASD also report recurring gastrointestinal problems. With emerging research showing how diet can change the gut microbiome and how gut microbes can influence the brain, Costa-Mattioli and his co-authors suspected there could be a connection.
To begin, the researchers fed approximately 60 female mice a high-fat diet that was the rough equivalent of consistently eating fast food multiple times a day. They bred the mice daily and waited for them to bear young. The offspring stayed with their mother for three weeks and then were weaned onto a normal diet. After a month, these offspring showed behavioral deficits, such as spending less time in contact with their peers and not initiating interactions.
"First we wanted to see if there was a difference in the microbiome between the offspring of mouse mothers fed a normal diet versus those of mothers fed a high-fat diet. So, we used 16S ribosomal RNA gene sequencing to determine the bacterial composition of their gut. We found a clear difference in the microbiota of the two maternal diet groups," says first author Shelly Buffington, a postdoctoral fellow in Costa-Mattioli's lab. "The sequencing data was so consistent that by looking at the microbiome of an individual mouse we could predict whether its behavior would be impaired."
Buffington next tested whether the specific differences in the microbiome were causative factors underlying the social impairments in offspring of mothers fed a high-fat diet. Because mice eat each other's excrement, the researchers housed the animals together so that they would acquire microbiota from their cagemates. When socially impaired three-week-old mice born to mothers on a high-fat diet were paired with normal mice, a full restoration of the gut microbiome and a concurrent improvement in behavior was observed within four weeks. The investigators concluded that one or more beneficial bacterial species might be important for normal social behavior. Fecal-transplant experiments in mice without microbiota (germ-free mice) provided causal evidence that an imbalanced microbial ecology in the mice born to mothers on a high-fat diet is responsible for their social deficits.
The investigators next wanted to know the specific bacterial species that could be affecting the social behavior of the mice. Whole-genome shotgun sequencing revealed one type of bacteria, Lactobacillus reuteri, which was reduced more than nine-fold in the microbiome of mice born to mothers on the high-fat diet.
"We cultured a strain of Lactobacillus (L.) reuteri originally isolated from human breast milk and introduced it into the water of the high-fat-diet offspring. We found that treatment with this single bacterial strain was able to rescue their social behavior," Buffington says. Other ASD-related behaviors, such as anxiety, were not restored by the reconstitution of the bacteria. Interestingly, the authors found that L. reuteri also promoted the production of the "bonding hormone" oxytocin, which is known to play a crucial role in social behavior and has been associated with autism in humans.
The authors wondered whether the reward circuitry in the socially impaired mice was dysfunctional. "We found that in response to social interaction there was a lack of synaptic potentiation in a key reward area of the brain that could be seen in the normal control mice," Costa-Mattiol says. "When we put the bacteria back in the maternal-high-fat-diet offspring, we could also restore the changes in synaptic function in the reward circuitry."
The researchers believe that their work, which uses a human bacteria species to promote oxytocin levels and improve social behavioral deficits in deficient mice, could be explored as a probiotic intervention for the treatment of neurodevelopmental disorders in humans. "This is where the science is unexpectedly leading us. We could potentially see this type of approach developing quite quickly not only for the treatment of ASD but also for other neurodevelopmental disorders; anyway, this is my gut feeling," Costa-Mattioli says.
Story Source:
The above post is reprinted from materials provided by Cell Press. Note: Materials may be edited for content and length.
Journal Reference:
1. Buffington et al. Microbial reconstitution reverses maternal diet-induced social and synaptic deficits in offspring. Cell, 2016 DOI:10.1016/j.cell.2016.06.001
Cite This Page:
Cell Press. "A single species of gut bacteria can reverse autism-related social behavior in mice." ScienceDaily. ScienceDaily, 16 June 2016. <www.sciencedaily.com/releases/2016/06/160616140723.htm>.
The different gut bacteria in autistic individuals may be contributing to the disorder.
By Melissa Pandika, for OZY
PUBLISHED NOVEMBER 14, 2014
Stress can send your stomach into a painful tailspin, causing cramps, spasms and grumbling. But trouble in the gut can also affect the brain.
This two-way relationship may be an unlikely key to solving one of medicine's most pressing—and perplexing—mysteries: autism. Nearly 60 years after the disorder was first identified, the number of cases has surged, and the United Nations estimates that up to 70 million people worldwide fall on the autism spectrum. Yet there is no known cause or cure.
But scientists have found promising clues in the gut. Research has revealed striking differences in the trillions of bacteria - collectively known as the microbiome—in the intestines of autistic and healthy children. But the gut bacteria in autistic individuals aren't just different. Researchers at the California Institute of Technology have shown for the first time that they may actually contribute to the disorder. Last month, they reported in the journal Cell that an experimental probiotic therapy alleviated autism-like behaviors in mice and are already planning a clinical trial.
Today autism is treated primarily through behavioral therapy. But the new study suggests that treatment may one day come in the form of a probiotic—live, "friendly" bacteria like those found in yogurt. "If you block the gastrointestinal problem, you can treat the behavioral symptoms," Paul Patterson, a professor of biology at Caltech who co-authored the study, toldSFARI.org. University of Colorado Boulder professor Rob Knight hailed the finding as "groundbreaking" in a commentary in Cell.
Autism is a complex spectrum of disorders that share three classic features - impaired communication, poor social engagement and repetitive behaviors. On one end of the spectrum are people who are socially awkward but, in many cases, incredibly bright. At the other extreme are individuals with severe mental disabilities and behavioral problems.
Among autistic children's most common health complaints? Gastrointestinal problems. Although estimates vary widely, some studies have concluded that up to 90 percent of autistic children suffer from tummy troubles. According to the CDC, they're more than 3.5 times more likely to experience chronic diarrhea and constipation than their normally developing peers.
Following these hints, Arizona State University researchers analyzed the gut bacteria in fecal samples obtained from autistic and normally developing children. They found that autistic participants had many fewer types of bacteria, probably making the gut more susceptible to attack from disease-causing pathogens. Other studies have also found striking differences in the types and abundance of gut bacteria in autistic versus healthy patients.
But is the gut microbiome in autistic individuals responsible for the disorder? To find out, Caltech postdoctoral researcher Elaine Hsiao engineered mice based on earlier studies showing that women who get the flu during pregnancy double their risk of giving birth to an autistic child. In the mouse model, pregnant females injected with a mock virus gave birth to pups with autism-like symptoms, such as obsessive grooming, anxiety and aloofness.
The mouse pups went on to develop so-called "leaky gut," in which molecules produced by the gut bacteria trickle into the bloodstream, possibly reaching the brain—a condition also seen in autistic children.
But how did these bacteria influence behavior? To find out, Hsiao analyzed the mice's blood. The blood of "autistic" mice contained a whopping 46 times more 4EPS, a molecule produced by gut bacteria, thought to have seeped from their intestines. What's more, injecting healthy mice with 4EPS made them more anxious. A similar molecule has been detected at elevated levels in autistic patients.
Hsiao then laced the animals' food with B. fragilis, a priobiotic that's been shown to treat GI problems in mice—and the results were jaw-dropping.
Five weeks later, the leaky gut in "autistic" mice had sealed up, and the levels of 4EPS in their blood had plummeted. Their gut microbiomes had come to more closely resemble those of healthy mice—and so did their behavior. They were less anxious and more vocal, and stopped obsessively burying marbles in their cages.
But the treated mice remained aloof when a new mouse was placed in their cage. "This is a real limitation in the conclusions from this study as, in many ways, social interaction deficits are at the core ... of autism," Ted Abel, a professor of biology at the University of Pennsylvania, told SFARI.org.
What's more, a probiotic may only help the subset of autistic patients who experience GI problems, Hsiao said. And only a clinical trial will reveal whether the results also apply to humans.
Still, autism researchers shouldn't underestimate the importance of gut bacteria, said John Cryan, a professor of anatomy and neuroscience at University Cork College. In 2011, his group reported in the Proceedings of the National Academy of Sciences that probiotic-fed mice were less anxious and produced fewer stress hormones."You have this kilo of microbes in your gut that's as important as the kilo of nerve cells in your brain," he said. "We need to do much more studies on autistic biota."
For autistic patients and their families, however, even a supplemental therapy for a subset of sufferers is a huge step forward. "It's really impactful, this notion that by changing the bacteria, you could ameliorate what's often considered an intractable disorder," Hsiao said. "It's a really crazy notion and a big advance."
This piece comes from our partner OZY. Melissa Pandika is a lab rat-turned-journalist with eye to all things science, medicine and more.
*With some reporting from SFARI.org. Updated August 12, 2014.
Science News
from research organizations
A single species of gut bacteria can reverse autism-related social behavior in mice
Date:
June 16, 2016
Source:
Cell Press
Summary:
The absence of a one specific species of gut bacteria causes social deficits in mice, researchers report. By adding this bacteria species back to the guts of affected mice, the researchers were able to reverse some of their behavioral deficits, which are reminiscent of symptoms of autism spectrum disorders (ASDs) in humans. The investigators are now looking to explore the effects of probiotics on neurodevelopmental disorders in future work.
The absence of a one specific species of gut bacteria causes social deficits in mice, researchers at Baylor College of Medicine report June 16, 2016 in Cell. By adding this bacteria species back to the guts of affected mice, the researchers were able to reverse some of their behavioral deficits, which are reminiscent of symptoms of autism spectrum disorders (ASDs) in humans. The investigators are now looking to explore the effects of probiotics on neurodevelopmental disorders in future work.
"Other research groups are trying to use drugs or electrical brain stimulation as a way to reverse some of the behavioral symptoms associated with neurodevelopmental disorders -- but here we have, perhaps, a new approach," says senior author Mauro Costa-Mattioli, a neuroscientist at Baylor College of Medicine. "Whether it would be effective in humans, we don't know yet, but it is an extremely exciting way of affecting the brain from the gut."
The inspiration for the paper came from human epidemiological studies that have found that maternal obesity during pregnancy could increase children's risk of developing neurodevelopmental disorders, including ASDs. In addition, some individuals with ASD also report recurring gastrointestinal problems. With emerging research showing how diet can change the gut microbiome and how gut microbes can influence the brain, Costa-Mattioli and his co-authors suspected there could be a connection.
To begin, the researchers fed approximately 60 female mice a high-fat diet that was the rough equivalent of consistently eating fast food multiple times a day. They bred the mice daily and waited for them to bear young. The offspring stayed with their mother for three weeks and then were weaned onto a normal diet. After a month, these offspring showed behavioral deficits, such as spending less time in contact with their peers and not initiating interactions.
"First we wanted to see if there was a difference in the microbiome between the offspring of mouse mothers fed a normal diet versus those of mothers fed a high-fat diet. So, we used 16S ribosomal RNA gene sequencing to determine the bacterial composition of their gut. We found a clear difference in the microbiota of the two maternal diet groups," says first author Shelly Buffington, a postdoctoral fellow in Costa-Mattioli's lab. "The sequencing data was so consistent that by looking at the microbiome of an individual mouse we could predict whether its behavior would be impaired."
Buffington next tested whether the specific differences in the microbiome were causative factors underlying the social impairments in offspring of mothers fed a high-fat diet. Because mice eat each other's excrement, the researchers housed the animals together so that they would acquire microbiota from their cagemates. When socially impaired three-week-old mice born to mothers on a high-fat diet were paired with normal mice, a full restoration of the gut microbiome and a concurrent improvement in behavior was observed within four weeks. The investigators concluded that one or more beneficial bacterial species might be important for normal social behavior. Fecal-transplant experiments in mice without microbiota (germ-free mice) provided causal evidence that an imbalanced microbial ecology in the mice born to mothers on a high-fat diet is responsible for their social deficits.
The investigators next wanted to know the specific bacterial species that could be affecting the social behavior of the mice. Whole-genome shotgun sequencing revealed one type of bacteria, Lactobacillus reuteri, which was reduced more than nine-fold in the microbiome of mice born to mothers on the high-fat diet.
"We cultured a strain of Lactobacillus (L.) reuteri originally isolated from human breast milk and introduced it into the water of the high-fat-diet offspring. We found that treatment with this single bacterial strain was able to rescue their social behavior," Buffington says. Other ASD-related behaviors, such as anxiety, were not restored by the reconstitution of the bacteria. Interestingly, the authors found that L. reuteri also promoted the production of the "bonding hormone" oxytocin, which is known to play a crucial role in social behavior and has been associated with autism in humans.
The authors wondered whether the reward circuitry in the socially impaired mice was dysfunctional. "We found that in response to social interaction there was a lack of synaptic potentiation in a key reward area of the brain that could be seen in the normal control mice," Costa-Mattiol says. "When we put the bacteria back in the maternal-high-fat-diet offspring, we could also restore the changes in synaptic function in the reward circuitry."
The researchers believe that their work, which uses a human bacteria species to promote oxytocin levels and improve social behavioral deficits in deficient mice, could be explored as a probiotic intervention for the treatment of neurodevelopmental disorders in humans. "This is where the science is unexpectedly leading us. We could potentially see this type of approach developing quite quickly not only for the treatment of ASD but also for other neurodevelopmental disorders; anyway, this is my gut feeling," Costa-Mattioli says.
Story Source:
The above post is reprinted from materials provided by Cell Press. Note: Materials may be edited for content and length.
Journal Reference:
1. Buffington et al. Microbial reconstitution reverses maternal diet-induced social and synaptic deficits in offspring. Cell, 2016 DOI:10.1016/j.cell.2016.06.001
Cite This Page:
Cell Press. "A single species of gut bacteria can reverse autism-related social behavior in mice." ScienceDaily. ScienceDaily, 16 June 2016. <www.sciencedaily.com/releases/2016/06/160616140723.htm>.
