The Grapevine

Moving To The US? Here's How Your Gut Health Could Change

Immigrating to a different country is a lot of change to get used to. While you adapt to a new place and culture, your gut also has to deal with changes in bacteria due to diet, lifestyle and other environmental factors.

To gain a better understanding of these changes, researchers at the University of Minnesota (UMN) conducted a study to examine Chinese and Thai immigrants who moved to the United States. The paper titled "US Immigration Westernizes the Human Gut Microbiome" was published in the journal Cell on Nov. 1.

More than 500 female participants were recruited — while one group moved to the U.S. after growing up in Southeast Asia, the others were born and raised in the U.S. by parents who emigrated from Southeast Asia.

"We found that when people come to the U.S.A., they almost immediately begin losing some of their native microbes," said senior author Dan Knights, a quantitative biologist at UMN.

The researchers looked at the eating habits, gut microbes, and body mass index of the immigrants before and after they made their move to the west. Post-immigration, one of the notable changes was the loss of diversity in their gut bacteria.

Furthermore, this loss occurred just six to nine months after they moved to the U.S. The study refers to it as the "westernization" of microbiome since the gut bacteria of the immigrants began to closely resemble that of Caucasian Americans.

"In speaking with community members, we also realized that for them, the biggest concern was obesity," explained Pajau Vangay, a co-author of the paper and a researcher at UMN.

It is not too surprising since past research has also shown people who move to America become prone to unhealthy weight gain. Yet, it remains unclear whether changes in gut bacteria lead to obesity or vice versa.  

Since these microbiomes live in our digestive systems, it is a strong possibility that changes in dietary patterns are influencing this. By taking a look at eating habits, the researchers found instances of reduced fiber intake and increased consumption of processed sugars.

It is known processed foods are quite prevalent in the American diet. However, the researchers suggest that other aspects could also play a role such as the quality of drinking water or the type of medications available in the country.

"Because they had observed in themselves and their relatives and friends that when they moved to the U.S., they gained a lot of weight. And in some cases, they hadn't really changed too much about their diet," Vangay noted.

Given the rise in immigration today, further studies must be done to understand how we can combat these gut health changes and associated health conditions.