Western diet reduces diversity of gut microbiome

Researchers at the University of Minnesota and the Somali, Latino, and Hmong Partnership for Health and Wellness have new evidence that the gut microbiota of immigrants and refugees rapidly Westernize after a person’s arrival in the United States.

The study of communities migrating from Southeast Asia to the U.S., published in the journal Cell, could provide insight into some of the metabolic health issues, including obesity and diabetes, affecting immigrants to the U.S.

“We found that immigrants begin losing their native microbes almost immediately after arriving in the U.S. and then acquire alien microbes that are more common in European-American people,” says senior author Dan Knights, a computer scientist and quantitative biologist at the University of Minnesota. “But the new microbes aren't enough to compensate for the loss of the native microbes, so we see a big overall loss of diversity.”

The study findings demonstrate that immigration to the U.S. is associated with profound perturbations to the gut microbiome, including loss of diversity, loss of native strains, loss of fiber degradation capability, and shifts from Prevotella dominance to Bacteroides dominance. These changes begin immediately upon arrival, continue over decades of U.S. residence, and are compounded in obese individuals and in second-generation immigrants born in the U.S.

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