Anorexia, a case of microbes and gut feelings?

In our anthropocentric arrogance, humans typically draw a sharp line between Self and Other. But the more we learn, the fuzzier the boundaries get. Each self contains a great deal of other, from the viral genetic invaders in our very DNA to the vast population of microbes inhabiting our digestive tracts.

And now we are discovering that our own mental states may be directly impacted by the nature of the population of all those intestinal flora.

From the University of North Carolina School of Medicine via Newswise:

Researchers at the UNC School of Medicine found that people with anorexia nervosa have very different microbial communities residing inside their guts compared to healthy individuals and that this bacterial imbalance is associated with some of the psychological symptoms related to the eating disorder.

The findings, published today in the journal Psychosomatic Medicine, provide more evidence that the abundance and diversity of the gut microbiota – the trillions of bacteria that affect digestive health and immunity – could also affect the so-called “gut-brain axis.” This research suggests that gut bacteria could play a prominent role in the debilitating symptoms of anorexia nervosa, a serious eating disorder that affects more than 3 million Americans and has the highest mortality rate of any psychological disorder.

“Other studies have linked gut bacteria to weight regulation and behavior,” said Ian Carroll, PhD, senior author of the paper and assistant professor of medicine in the UNC Center for Gastrointestinal Biology and Disease. “Since people with anorexia nervosa exhibit extreme weight dysregulation, we decided to study this relationship further.”

Carroll added, “We’re not able to say a gut bacterial imbalance causes the symptoms of anorexia nervosa, including associated symptoms, such as anxiety and depression. But the severe limitation of nutritional intake at the center of anorexia nervosa could change the composition of the gut microbial community. These changes could contribute to the anxiety, depression, and further weight loss of people with the disorder. It’s a vicious cycle, and we want to see if we can help patients avoid or reverse that phenomenon. We want to know if altering their gut microbiota could help them with weight maintenance and mood stabilization over time.”