Immigrants have to deal with more than culture shock when moving to a foreign country. A study found that gut microbiome undergoes changes as well.
Researchers from the University of Minnesota joined forces with the Somali, Latino, and Hmong Partnership for Health and Wellness to find out how the gut microbiota, or the good bacteria that live inside the gut, are affected when immigrants and refugees enter the United States. The study involved individuals from Southeast Asian countries who have immigrated to Minnesota.
The study was published in the journal Cell.
Immigration Affects Gut Microbiome
For the study, the researchers collected stool samples as well as asked for dietary recalls from 514 Hmong and Karen individuals living in Thailand and the United States. The researchers also collected samples from 36 U.S.-born European-Americans.
Previous studies have proven that people from developing countries have a different set of microbiome than those who live in the United States. People from isolated communities, untouched by civilization, have the most diverse microbiome.
The study was inspired by the Hmong and Karen communities in Minnesota. The researchers revealed that one of the most common concerns among members is obesity.
"In other studies, the microbiome had been related to obesity, so we wanted to know if there was potentially a relationship in immigrants and make any findings relevant and available to the communities," explained Pajau Vangay, first author of the study.
In 19 Karen refugees that relocated from Thailand, the researchers were able to observe participants for six months. They found that the change of microbiome took place almost immediately.
Western Bacteria Taking Over
Within a few months, the researchers found that the Western strain of Bacteroides displaced the non-Western strain called Prevotella. Over time, the gut microbiome has become less diverse the longer that immigrants stay longer in the United States.
Unfortunately, the researchers could not say why this is happening. They suspect that diet might have something to do with it.
The study could not also say for sure that changes in the immigrants' gut microbiome are directly causing the obesity epidemic. However, Western microbiome has been linked to obesity.
The researchers concluded that more research is needed into obesity in immigrants and the rest of the population.