Jeffrey Gordon of the Washington University School of Medicine in St. Louis studies the gut response to what we eat, which involves trillions of microbes:
Gordon has been working with colleagues to take gut microbes from human feces and transplant them into the intestinal tracts of previously germ-free mice.Using powerful DNA sequencing tools that allow them to take a “census” of the gut bugs without having to culture them, Gordon’s team then showed that this kind of microbe transplant is successful. The mice end up with a collection of gut microbes that mimic the populations found in the original human sample.
Then the team explored what would happen to these microbes if mice were switched from their standard low-fat, plant-rich mouse chow to a diet that was high in fat and sugar.
They found that in less than 24 hours the gut’s microbial populations changed abruptly, according to a study in the journal Science Translational Medicine.
“We were quite amazed that the community really restructured itself in terms of the proportional representation of different bacterial species, the proportional representation of genes with different functions, in a very short period of time,” says Gordon. “Certain members of that society of microbes became very dominant, and certain members became more diminutive.”
And when this new collection of human microbes was transplanted into germ-free mice, the mice gained an increased amount of fat tissue even when fed low-fat diets, compared to mice that got human microbes from mice fed low-fat diets.