Irritable Bowel Syndrome, or IBS, is a common stomach problem. It hurts the belly and can cause constipation or diarrhea. Women get it more often than men. Doctors still don’t know exactly why it happens.
One clue is a chemical called serotonin. Most people think serotonin only lives in the brain, but more than 90 % of it is made in the gut. There it helps move food through the intestines.
Scientists also know that tiny bugs called gut microbes can change how much serotonin the body makes. A new study showed that two specific microbes can actually produce serotonin themselves.
Two Bacteria That Create Serotonin
The researchers found that Limosilactobacillus mucosae and Ligilactobacillus ruminis work together to make serotonin. They gave these bacteria to mice that had no normal gut microbes and very low serotonin levels.
After the bacteria were added, the mice’s intestines had more serotonin. The mice also grew more nerve cells in the colon, and food moved through their gut at a normal speed again.
What This Means for IBS
When the scientists looked at stool samples from people with IBS, they saw less of L. mucosae compared to healthy volunteers. This bacterium carries the enzyme needed to build serotonin.
Experts say the discovery opens a new path for IBS treatment. If we can boost these helpful bacteria, we might raise serotonin levels in the gut and ease IBS symptoms.
"Our results show that some gut bacteria can make real, active serotonin and that this could be important for keeping the intestine healthy," said a professor of medical gastroenterology.
Another researcher added, "Understanding how gut microbes make signaling chemicals like serotonin may help explain the link between our gut and our brain."