Recently, a study published in the journal Cell pointed out that changes in the intestinal flora caused by immigration play an important role in the process of obesity. For example, after the residents of Southeast Asia migrate to the United States, the intestinal flora will be “Westernized”, which may cause metabolic health problems.
The researchers found that Prevotella strains in the intestines of “newcomers” were replaced by Bacteroides, which lost bacterial enzymes involved in plant fiber degradation. The study's lead author, Dan Knihgts, a biologist at the University of Minnesota, said that when immigrants first arrived in the United States, they began to lose the "indigenous" flora in the intestines and gradually acquired the same "foreign" flora as Europeans and Americans. . The problem is that the newly acquired flora cannot replenish the lost flora, which reduces the diversity of the intestinal flora of immigrants.
Refugees are more susceptible to weight gain. According to the survey data, the body mass index (BMI) of the Southeast Asian refugees who have flowed to the United States is the fastest growing, second only to immigrants. The subjects also included second-generation immigrants (born in the US), and the researchers wanted to confirm whether changes in the gut flora of the first-generation US immigrants would be passed on to the next generation. The study tracked 19 South Korean refugees who were in the United States. They spent six to nine months in the United States. Researchers began tracking the refugees when they first arrived in the United States. The purpose of this move is to assess the impact of short-term immigration to the US on intestinal flora. The results show that the longer the migrants live in the United States, the lower the diversity of the intestinal flora.