Fibre - is it the high carb diet's last straw? Keto bashing in the mainstream. "There goes the keto diet!", predicted the celebrity doctor



Natural selection. The fibre digesting biota becomes extinct.

I’m sure it’s much more nuanced as there would be concurrent evolution and adaptations being made.

My gut feeling is to not create sudden, possibly catastrophic, change to any environment that is outpaces biological adaptation.


I finally got around to listening to this podcast and here’s what I believe is a key point:

Justin’s lab did publish that study that was picked up as kind of the mass extinction inside of our guts that progressively looked at four generations of the high-fiber diet or a low-fiber diet in an animal model. And so they found that by the fourth, at the end of the third generation, even if you switch back to a high-fiber diet, species and strains are gone that are irreversible.

First, this was a study done under lab conditions (mice) where there was no possibility of “contamination” with microbes from an outside source. Even then, it took 3 generations to wipe them out. I’m trying to imagine a scenario where 3 generations of humans are not exposed to common microbes.

Second, I think irreversible was in the context of they won’t reestablish themselves by dietary intervention alone. The whole last part of the podcast was about the company called Seed that produces probiotics reputed to reverse conditions where species are missing.

Third, if looking at microflora on an individual level, lack of diversity isn’t always a Bad Thing IMO. They criticize products that simply throw every species in the mix regardless of whether they are strains proven beneficial or not.

All in all, studying microbiome genetics and what effects various species have in symbiosis with other species and dependant on diet is a science in its infancy. Is it a good idea to be cautious? Sure.