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Gut Microbes Alter Serotonin Levels, Changing Our Intestinal Physiology

Elizabeth Fox
30th December, 2016

A research team has discovered that gut microbes can affect serotonin regulation, potentially causing changes in physiology and mental states. Gut microbiota are often overlooked in studies but can drastically change how our bodies function. The details are in a paper that was just published in the journal PLOS ONE. Humans have a large number of microbes in their bodies. The largest microbial variety is found in our guts and previous research has linked these microbes to everything from weight gain to Parkinson’s disease. Gut microbes can alter our metabolism and new research suggests that they also affect the availability of neurotransmitters. Scientists from the University of Exeter Medical School and the University of Zaragoza collaborated to study gut microbes and how they might change patients’ intestinal physiology. Specifically, the team studied a receptor called TLR2. The receptor, part of the toll-like receptors class, is activated by molecules produced by microbes. TLR2 aids the body’s immune system and helps with pathogen recognition. Abnormal TLR2 activity had been connected to inflammatory bowel diseases but the exact mechanisms were unknown. The research team investigated a possible connection between TLR2 and intestinal serotonin transporters. The researchers studied how TLR2 activity affected serotonin levels in both human cells and live mice. The team found that TLR2 altered the activity of intestinal serotonin transporters, impacting the availability of serotonin. Abnormal TLR2 activity might lead to inflammatory bowel diseases by increasing or decreasing serotonin levels and changing the body’s intestinal physiology. The team’s findings emphasize the importance of studying gut microbiota. They may affect our physiology more than previously believed. Modern research is continuing to link microbes to certain diseases and mental disorders. TLR2 receptors, which are activated by microbe activity, can control serotonin transporters and affect overall intestinal serotonin levels. This might explain the connection between TLR2 and inflammatory bowel diseases. As scientists continue to learn more about how microbes change our physiology, it may become easier to develop treatments for certain medical problems. REFERENCE Latorre et al. Intestinal Serotonin Transporter Inhibition by Toll-Like Receptor 2 Activation. A Feedback Modulation. PLOS ONE (2016).