Gut bacteria that synthesize serotonin may help understand the mechanisms of irritable bowel syndrome

Irritable bowel syndrome remains one of the most common digestive system disorders and predominantly affects women, writes xrust. The main manifestations include pain and discomfort in the abdomen, as well as stool disorders in the form of constipation, diarrhea, or alternation of both. Despite the significant incidence, the exact cause of the disease is still unclear. The attention of researchers is increasingly being drawn to internal factors of the intestine, in particular the composition of its microbiota and the role of serotonin as a key chemical regulator.

The role of serotonin and microbiota in intestinal function

class=»notranslate»>__GTAG7__Serotonin is known primarily as a neurotransmitter of the central nervous system, affecting the emotional state, writes sciencedaily. Meanwhile, more than 90% of all serotonin in the body is synthesized in the intestinal wall. Here it regulates motility, secretion and sensitivity through the enteric nervous system — the so-called “second brain” of humans. Previous studies have already pointed to a connection between the microbiota and serotonin levels, but the ability of the bacteria themselves to produce its active form has long remained in question.

Main fact: two types of producing bacteria have been identified

class=»notranslate»>__GTAG5__In a paper published in the journal Cell Reports, scientists at the University of Gothenburg described two strains of bacteria that co-synthesize serotonin: Limosilactobacillus mucosae and Ligilactobacillus ruminis. In the experiment, these microorganisms were introduced into germ-free mice with artificially reduced levels of serotonin. After colonization, the concentration of serotonin in the intestine increased, the number of nerve cells in the colon increased, and the rate of movement of contents through the digestive tract normalized.

“It is amazing how gut bacteria are able to produce bioactive signaling molecules that affect health,” says Fredrik Bäckhed, professor of molecular medicine at the Sahlgrenska Academy at the University of Gothenburg and one of the lead authors of the paper.

Observations in patients with IBS

When comparing stool samples from patients with irritable bowel syndrome and healthy people, a significantly lower level of the bacterium L. mucosae was recorded in the first group. It is this species that possesses the enzyme necessary for the biosynthesis of serotonin.

Prospects opening up after opening

Magnus Simren, Professor of Medical Gastroenterology at the Sahlgrens Academy of the University of Gothenburg, emphasized: “Our results show that some gut bacteria can produce bioactive serotonin and thus play an important role in gut health, opening new possibilities for the treatment of functional gastrointestinal disorders such as irritable bowel syndrome.”

Fredrik Backhead added: “Our findings suggest that gut bacteria can produce signaling substances such as serotonin, which may be key to understanding how the gut and its inhabitants may influence our brains and behavior.”

Xrust Gut bacteria that synthesize serotonin may help understand the mechanisms of irritable bowel syndrome