The metabolic flexibility of the gut. There's been a lot of focus on fiber because carbohydrate-rich diets are the natural diets of mice and those are the animals typically used for microbiome research to study physiology.
Her name is Dr. Lucy Mailing.
Hunter-gatherer tribes eat a lot of fruit and really fibrous starchy tubers when there isn't meat or honey or fruit available. It's more of a fallback food for them. The research also didn't figure in all the soil microbes when they're eating. The research got really zeroed in on the fiber and followed that. That's not to say that adding fiber . . . does help with their symptoms. Let's not assume that adding fiber is right for everyone. Sonbergs did a really great study where they had people increase their fiber consumption or increase their fermented foods and fiber did nothing for gut diversity, but increasing their fermented DID INCREASE their gut diversity. Even more so, fermented food consumption had universal anti-inflammatory factors across all the subjects. Those were healthy individuals, so it's not to say that everyone with a gut issue is going to respond well to fermented foods. Yeah, so I think the hype around fiber needs to be tempered a little bit.