Support WBURImmigrating To The U.S.? Get Ready For A New Gut Microbiome (And Maybe More Pounds)Maanvi SinghNovember 01, 2018 ShareA McDonald's billboard in St. Paul, Minn., advertises in the Hmong language. A new study of first- and second-generation Hmong and Karen immigrants finds their gut microbiomes changed soon after moving to the U.S. (UIG via Getty Images)