GüT F33_LinGs: 3DS aNd The Mi-Kro:Bi.Om3

E. coli bacteria

www.edbites.com/2013/01/gut-feelings-eds-and-the-microbiome/

 

Consider this thought experiment:

Drop a person in a blender (since it’s all hypothetical, go ahead and make it someone you don’t like. Feel better? I bet you do!). Then, count all the total number of cells that are produced. Only one in ten of these cells will be human. The other 90%? Those are all microbes. If you look at the total number of genes in your human smoothie (NOT coming soon to a Jamba Juice near you), the numbers are even more skewed: only one in 100 genes are human. The rest are, again, bacterial. The total collection of all of these bacteria living in and on our bodies is known as the microbiome.

The idea isn’t to gross out the card-carrying germophobes among us. But let’s face it: we’re just as much bacterial as we are human. Plenty of these microbes live on our skin, in our lungs and genital tracts. The mother lode of microbes, however, live in our gut. They are crucial to extracting energy from food, and these microbes are extremely sensitive to what we eat. Starving mice for just one day dramatically alters the composition of their gut microbes. Specifically, it decreases a type of bacteria known as Firmicutes. When researchers transplanted Firmicutes into the guts of lean mice, they rapidly gained weight (Crawford et al., 2009)

When it comes to eating disorders, there isn’t much talk of microbes. There are the occasional papers from researchers like Sergei Fetissov about potential auto-immune responses in people with eating disorders, and some work on PANS (pediatric auto-immune neuropsychiatric syndrome) and anorexia, but generally, researchers haven’t looked at the role of the microbiome in triggering or perpetuating an eating disorder.

Much work has been done in obesity research. Scientists have consistently found that people with a BMI >30 have different gut microbes than people with BMIs in the “normal” range. As well, bariatric surgery also significantly changes gut microbes as people lose weight, making them look more similar to the bacterial profiles seen in “normal weight” individuals. A more recent study in The ISME Journal proposed a microbiome diet: eating foods that would eliminate a type of bacteria called Enterobacter helped a person lose drastic amounts of weight in a short period of time (Fei & Zhao, 2012).

So how are microbes involved in eating disorders? No one really knows. Cindy Bulik has begun a study looking at this relationship, but the results still aren’t in. Based on the studies above, it’s reasonable to assume that ED behaviors (starving, binge eating, and/or purging) will have a significant effect on a person’s microbiota. It still has to be measured, but I would bet a lot of money on it. The question is what do these microbial changes have to do with ED symptoms?

Imbalances in gut microbes in mice and rats have been found to alter patterns of risk-taking and anxious behaviors–something that also happens in people with EDs. They could also, perhaps, explain weight loss seen in anorexia and EDNOS. Maybe the initial restricting triggered a significant change in gut microbes that amplified the effects of malnutrition. Maybe they lacked a group of microbes that produced an important hormone regulating hunger and satiety. No one really knows.

One hint to the potential role of microbes in EDs comes from a study published today in the journal Science (Smith et al., 2013). The scientists studied the relationship between gut microbes and kwashiorkor, a form of severe malnutrition that occurs when a person doesn’t eat enough protein. Of the 317 twin pairs from Malawi that the researchers followed for three years, half became significantly malnourished and 7% developed signs of kwashiorkor. Obviously, a lack of protein is crucial to the development of this disease but it’s not the only factor as not everyone with a severely protein-deficient diet will develop kwashiorkor. Something else had to be going on.

First, the researchers treated twin pairs discordant for kwashiorkor (that is, one twin had it, whereas the other didn’t) with “ready-to-use therapeutic food”- basically peanut butter on steroids. Twins with kwashiorkor had significantly different from nearby twins who (presumably) at pretty close to the same diet. The researchers found significant changes to the gut microbes in the ill children with the use therapeutic food. Discontinuing the therapeutic food caused a regression in the functioning of the gut microbes.

The kicker is this: when the researchers fed mice a standard Malawian diet and inoculated them with microbes from the guts of malnourished children, they rapidly lost weight and also developed kwashiorkor. This happened despite the fact that their diets contained adequate calories. One of the reasons that the researchers believed the therapeutic food is so effective at treating kwashiorkor is that it helped restore normal gut microbes.

To say what effect restoring normal gut flora will have on ED symptoms remains to be seen. Probiotics are a hot item, but much of the research is fairly overblown. There’s definitely still potential there, and we need to know more about which populations of people are likely to benefit and which aren’t. But it’s an interesting idea, and I think we need to know a lot more about the role of the microbiome in the development and perpetuation of EDs.

In closing, a quote from scientist John Rawls in an interview with Scientific American:

“We are in the midst of a revolution of our ability to describe the composition and physiological potential of these bacterial communities…What we can begin to speculate on, though, are the different types of relationships that might be taking place. We know gut microbiota enhance our ability to extract calories from complex carbohydrates, which is clearly a mutually beneficial relationship. But it’s thought that all vertebrates have the capacity to digest and absorb other types of nutrients, such as lipids, proteins and simple carbohydrates, so it’s not readily clear how we could enter into a mutually beneficial relationship with bacteria with regard to those nutrients.”

ChRon-iK FaTi-Gue SynDro-me is NoT in YouR H34D, is in YoüR GÜT

http://neurosciencenews.com/chronic-fatigue-microbiome-4581/

 

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Chronic Fatigue Syndrome Is Not in Your Head, It’s in Your Gut
Neuroscience NewsNEUROSCIENCE NEWSJUNE 27, 2016
FEATUREDNEUROLOGYOPEN NEUROSCIENCE ARTICLES6 MIN READ

Summary: Researchers have identified biomarkers for chronic fatigue syndrome in gut bacteria and in inflammatory microbial agents in the blood.

Source: Cornell University.

Physicians have been mystified by chronic fatigue syndrome, a condition where normal exertion leads to debilitating fatigue that isn’t alleviated by rest. There are no known triggers, and diagnosis requires lengthy tests administered by an expert.

Now, for the first time, Cornell University researchers report they have identified biological markers of the disease in gut bacteria and inflammatory microbial agents in the blood.

In a study published June 23 in the journal Microbiome, the team describes how they correctly diagnosed myalgic encephalomyeletis/chronic fatigue syndrome (ME/CFS) in 83 percent of patients through stool samples and blood work, offering a noninvasive diagnosis and a step toward understanding the cause of the disease.

“Our work demonstrates that the gut bacterial microbiome in chronic fatigue syndrome patients isn’t normal, perhaps leading to gastrointestinal and inflammatory symptoms in victims of the disease,” said Maureen Hanson, the Liberty Hyde Bailey Professor in the Department of Molecular Biology and Genetics at Cornell and the paper’s senior author. “Furthermore, our detection of a biological abnormality provides further evidence against the ridiculous concept that the disease is psychological in origin.”

“In the future, we could see this technique as a complement to other noninvasive diagnoses, but if we have a better idea of what is going on with these gut microbes and patients, maybe clinicians could consider changing diets, using prebiotics such as dietary fibers or probiotics to help treat the disease,” said Ludovic Giloteaux, a postdoctoral researcher and first author of the study.

In the study, Ithaca campus researchers collaborated with Dr. Susan Levine, an ME/CFS specialist in New York City, who recruited 48 people diagnosed with ME/CFS and 39 healthy controls to provide stool and blood samples.

The researchers sequenced regions of microbial DNA from the stool samples to identify different types of bacteria. Overall, the diversity of types of bacteria was greatly reduced and there were fewer bacterial species known to be anti-inflammatory in ME/CFS patients compared with healthy people, an observation also seen in people with Crohn’s disease and ulcerative colitis.

Image shows gut bacteria.
The researchers sequenced regions of microbial DNA from the stool samples to identify different types of bacteria. Overall, the diversity of types of bacteria was greatly reduced and there were fewer bacterial species known to be anti-inflammatory in ME/CFS patients compared with healthy people, an observation also seen in people with Crohn’s disease and ulcerative colitis. NeuroscienceNews.com image is for illustrative purposes only.
At the same time, the researchers discovered specific markers of inflammation in the blood, likely due to a leaky gut from intestinal problems that allow bacteria to enter the blood, Giloteaux said.

Bacteria in the blood will trigger an immune response, which could worsen symptoms.

The researchers have no evidence to distinguish whether the altered gut microbiome is a cause or a whether it is a consequence of disease, Giloteaux added.

In the future, the research team will look for evidence of viruses and fungi in the gut, to see whether one of these or an association of these along with bacteria may be causing or contributing to the illness.

ABOUT THIS NEUROLOGY RESEARCH ARTICLE
Funding: The study was funded by the National Institutes of Health.

Source: Melissa Osgood – Cornell University
Image Source: This NeuroscienceNews.com image is in the public domain.
Original Research: Full open access research for for “Reduced diversity and altered composition of the gut microbiome in individuals with myalgic encephalomyelitis/chronic fatigue syndrome” by Ludovic Giloteaux, Julia K. Goodrich, William A. Walters, Susan M. Levine, Ruth E. Ley and Maureen R. Hanson in Microbiome. Published online June 23 2016 doi:10.1186/s40168-016-0171-4