anti-seizure effect of keto diet mediated by gut bacteria

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Gut bacteria play key role in anti-seizure effects of ketogenic diet
May 24, 2018 , University of California, Los Angeles

Quote:

UCLA scientists have identified specific gut bacteria that play an essential role in the anti-seizure effects of the high-fat, low-carbohydrate ketogenic diet. The study, published today in the journal Cell, is the first to establish a causal link between seizure susceptibility and the gut microbiota—the 100 trillion or so bacteria and other microbes that reside in the human body's intestines.
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In a study of mice as a model to more thoroughly understand epilepsy, the researchers found that the diet substantially altered the gut microbiota in fewer than four days, and mice on the diet had significantly fewer seizures.

To test whether the microbiota is important for protection against seizures, the researchers analyzed the effects of the ketogenic diet on two types of mice: those reared as germ-free in a sterile laboratory environment and mice treated with antibiotics to deplete gut microbes.

"In both cases, we found the ketogenic diet was no longer effective in protecting against seizures," said lead author Christine Olson, a UCLA graduate student in Hsiao's laboratory. "This suggests that the gut microbiota is required for the diet to effectively reduce seizures."

The biologists identified the precise order of organic molecules known as nucleotides from the DNA of gut microbiota to determine which bacteria were present and at what levels after the diet was administered. They identified two types of bacteria that were elevated by the diet and play a key role in providing this protection: Akkermansia muciniphila and Parabacteroides species.

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How do the bacteria do this? "The bacteria increased brain levels of GABA—a neurotransmitter that silences neurons—relative to brain levels of glutamate, a neurotransmitter that activates neurons to fire," said co-author Helen Vuong, a postdoctoral scholar in Hsiao's laboratory.

"This study inspires us to study whether similar roles for gut microbes are seen in people that are on the ketogenic diet," Vuong said.

Reference:


"The Gut Microbiota Mediates the Anti-Seizure Effects of the Ketogenic Diet", Christine A. Olson, Helen E. Vuong, Jessica M. Yano, Qingxing Y. Liang, David J. Nusbaum, and Elaine Y. Hsiao; 2018, Cell 173, 1728–1741