New evidence of ‘gut brain’ controlling balance between ‘good’ and ‘bad’ bacteria

New research from the University of Oregon suggests the enteric nervous system regulates gut microbes important for digestive health. It could give researchers a therapeutic target for people with Hirschsprung’s disease who have issues with their “gut brain.”

Believe it or not, our bodies essentially have two brains. One is the obvious pink lump in our heads. The second, however, is hidden away in the intestines with its own network of neurons and cells to regulate various functions ranging from motor control to the immune response. The recent study adds to the enteric nervous system’s growing list of responsibilities showing regulation of gut microbes.

The researchers studied zebrafish lacking the sox10 gene, which causes the enteric nervous system not to form. The mutation is most associated with Hirschsprung’s disease, which also causes immature gut nervous system development and severe intestinal inflammation. With zebrafish, the inflammation and type of bacteria present in the intestines at birth can be controlled.

The team hypothesized that the lack of the sox10 gene might cause issues with gut pH which in turn increases inflammation. When zebrafish were given larvae acid-sensing dyes, the ones with missing gut nerves had more acidic guts. Having a large amount of acidic guts led to the growth of harmful gut bacteria.

A heartburn drug called omeprazole decreased acidity levels and restored the balance between ‘good’ and ‘bad’ gut bacteria. However, when zebrafish were given acetazolamide — used for altitude sickness, epilepsy, etc) to increase acidity, it caused the number of ‘bad’ bacteria to soar.

“We found an unexpected connection between the nervous system of the intestine and the community of gut microbes,” said Karen Guillemin, a University of Oregon microbiologist in a press release. “The nervous system is regulating the microbes.”

The study was recently published in the journal PLOS Pathogens.

Leave a Comment