How Gut Bacteria Influence Intestinal Peristalsis

According to a study published today in Nature, gut microorganisms support healthy digestion by helping intestinal nerve cells regulate peristalsis in the colon. However, this relationship can also be disrupted in cases of intestinal disorders, like irritable bowel syndrome (IBS).

“While it’s been well-documented that the microorganisms in our gut influence the function of many organs in our body, including the brain, there’s less understanding about the role they play in maintaining the healthy functioning of the millions of nerve cells within digestive system itself,” says senior author Vassilis Pachnis of the Francis Crick Institute. “The work we describe here shows that AhR, a molecule which is very important for the function of immune and epithelial cells in the gut, is also used by intestinal nerve cells to sense the presence of microbes and regulate peristalsis, and in doing so, promote healthy digestion.”

A healthy gut contains trillions of microorganisms, which help the digestion of food and promote the fitness of gut tissues such as the epithelial lining of the lumen and the vast collection of immune and nerve cells within the gut wall. The levels and types of microorganisms in the gut vary from person to person and are affected by diet and commonly used drugs, such as antibiotics, which often result in abnormal gut contractions. The work described in this paper helps us understand how nerve cells sense the microbes in the gut and how they could coordinate their function with other gut tissues.

“Disturbances of intestinal motility are extremely common and cause a lot of suffering in patients after surgical operations or in conditions such as irritable bowel syndrome,” says coauthor Andrew Macpherson of the University of Bern. “This work provides a foundation to unravel why patients that are colonized with different groups of microbes are susceptible to these intestinal problems.”

According to Vassilis, it could also be possible in the future to develop microbial products that would change AhR activity in nerve cells, which could alleviate the consequences of abnormal gut peristalsis.