The new study published in Cell (covered here in NMJ) by UCLA researchers who report a possible mechanism for the ketogenic diet’s benefit in reducing seizures may suggest some new ways to think about a number of things. The researchers, led by Elaine Hsiao, suggest that following the ketogenic diet quickly shifts populations of bacteria that comprise the gut biome in favor of Akkermansia and Parabacteroides. These bacteria create a reaction that increases GABA levels in the brain. The increased GABA suppresses seizures.
No wonder people report how ‘good they feel’ when following a ketogenic diet; they are increasing GABA levels, something that is rather hard to do. Sure people take supplements containing GABA but the research has long questioned if any of this crosses the blood brain barrier to actually reach the brain. Following this diet may do what supplementation can’t.
Think of GABA as the opposite of caffeine; it is calming, inhibits unwanted excitement, the mellowing neurotransmitter. The more anxious and frenetic the individual, probably the more they will cherish how they feel eating a ketogenic diet.
Just because people ‘feel good’ does not tell us whether this is a healthful practice in the long run. The actions of the human biome are complicated. The general rule is that diversity is good and anything that simplifies the ecosystem less good. It may be that increasing these two populations of bacteria using the ketogenic diet is helpful, but let’s not be surprised when we eventually discover the downside.