A recently-discovered strain of gut bacteria has been found to consume GABA, a neurochemical found in the brain. The neurotransmitter has a calming effect on the brain, and the bacteria’s reliance on GABA could explain how the microbiome has an effect on mood.
The bacterial species found in the gut – called KLE1738 – was found to grow in culture only when supplemented with GABA molecules. “Nothing made it grow, except GABA,” said Philip Strandwitz, a postdoctoral research associate from Northeastern University in Boston. Strandwitz and his colleagues presented their findings at the annual meeting of the American Society for Microbiology, in June.
This is the first time a bacterial species has been found which uses a neurotransmitter as an energy source. As GABA calms down brain activity by inhibiting signals between nerve cells, the researchers were surprised to find that it’s necessary for some microbial life.