In mice, a low-fiber, high-fat diet for multiple generations caused a stable, severe loss of gut microbiome species that did not recover even when returned to a high-fiber diet.

“The difference is that when we put the mice on the low fiber, high fat diet, and then kept them on that for multiple generations, we saw this progressive deterioration over the course of generations whereby the fourth generation, the gut microbiome was a fraction of what it originally was. Let's say 30% of the species only remained something like 70% of the species had gone extinct, or appeared to have gone extinct.”

“And we switched those mice, half the mice, to a low fiber diet. And we were basically asking the question that if you switch to kind of a Western-like diet, a low fiber, higher fat diet, what happens to the gut microbiota? And we saw the microbiota change, it lost diversity. It was very similar to what we see in the difference between industrialized and traditional populations.”

“The difference is that when we put the mice on a low-fiber, high-fat diet and then kept them on that for multiple generations, um, we saw this progressive deterioration over the course of generations where by the fourth generation, the gut microbiome was a, you know, a fraction of what it originally was. Let's say 30% of the species only remained um, something like 70% of the species had gone extinct or appeared to have gone extinct.”