Mouse study: direct link detected between gut microbiome, brain function

While increasing evidence points to a link between the gut microbiome and neurological conditions such as autism, researchers have had difficulty finding evidence of a direct connection between gut microbes and the brain. Now, however, researchers report that they have detected two microbial molecules present in both the gut and the brain in mice. 

Heather Hulme and colleagues used a technique called mass spectrometry imaging to map the two molecules produced by gut bacteria as they traveled to distinct parts of the brain. The molecules have a structure similar to carnitine, which is used to help burn fatty acids for energy, and they localize with and antagonize the function of carnitine in the brain. 

The researchers say, “This is the first mechanistic description of a microbial molecule inhibiting the function of the mitochondria in cells of the central nervous system…. Given their potency at the physiological concentrations found in the [mouse] brain, our findings indicate that neurological conditions where mitochondrial dysfunction has been described and where disturbances in the gut microbiome are noted should be looked at with increased emphasis on potential for microbiome input.” 

Citations

“Microbiome-derived carnitine mimics as previously unknown mediators of gut-brain axis communication,” Heather Hulme, Lynsey M. Meikle, Nicole Strittmatter, Justin J. J. van der Hooft, John Swales, Ryan A. Bragg, Victor H. Villar, Michael J. Ormsby, Stephanie Barnes, Sheila L. Brown, Alex Dexter, Maya T. Kamat, Jasper C. Komen, Daniel Walker, Simon Milling, Emily K. Osterweil, Andrew S. MacDonald, Chris J. Schofield, Saverio Tardito, Josephine Bunch, Gillian Douce, Julia M. Edgar, RuAngelie Edrada-Ebel, Richard J. A. Goodwin, Richard Burchmore, and Daniel M. Wall, Science Advances, March 11, 2020 (free online). Address: Daniel (Dónal) Wall, [email protected]. 

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“Scientists describe new molecules that form direct link between gut microbiome and brain function,” news release, University of Glasgow, March 12, 2020.