Hacker News Reader

Comment by bentt | Hacker News Reader

IMO ketones are a side effect, not a cause, of any of these improvements. I hypothesize that the actual driver of the improvements is modulation of the microbiome. Keto diets are by definition low in carbs and this starves out certain species in the gut.

"A systematic review of gut microbiota composition in observational studies of major depressive disorder, bipolar disorder and schizophrenia" https://pubmed.ncbi.nlm.nih.gov/35194166/

View on HN

Interesting. The effects of a very-low-carb diet, one such that triggers preponderently-ketone metabolism, are very-rapid-onset (24-48h) and massive. They can also be obiectively measured, by measuring the amount of ketones in urine and in blood. So I really don't see how that is compatible with the ketones being a side effect of gut species in your theory.

Ah maybe this is a case of my misusing the word "side effect". What I might have said instead is that the generation of ketones is coincidental with the effects of the diet. I'm hypothesizing that the microbiome mediates the changes, ketones or not.

(FWIW, I understood what you meant on my first reading; but, in re-reading to try to understand the confusion, I am guessing the issue is you sort of said the keytones were a side effect "of any of these improvements", as opposed to saying they were merely a side effect of the diet.)

Regardless, do you feel the microbiome manages to shift that drastically within 24-48 hours?

Yeah sorry for the confusion. I just meant that ketones are a result of the diet.

>> Regardless, do you feel the microbiome manages to shift that drastically within 24-48 hours?

No, but the population doesn't have to change in order for us to notice the effects of changing our diet. Changing the food we eat and subsequently send to the organisms in the microbiome affects what the various constituent bacteria/fungi metabolize and excrete. These excretions can have rapid effects on us. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9877435/

In the longer run, starving some species out and promoting others to take their place would yield a more permanent effect.

Reply on news.ycombinator.com