Immigrant Microbiome Project
Results from a research study on the human gut microbiome and obesity in Hmong and Karen women in the U.S.
The human microbiome
The microbiome is defined as the community of all microbes (bacteria, viruses, parasites, fungi) that live in and on the human body. Our study focuses on the gut microbiome, which are the microbes resident in the human gastrointestinal tract.
The gut microbiome is essential for:
immune system development
metabolism (e.g. break down of dietary fibers)
protection against pathogens
and many other functions
We know that people who move to the U.S. are more likely to gain weight than if they were to stay in their native country. We wondered if perhaps the gut microbiome had a role.
Your immune system and microbiome form a special relationship immediately after birth, and develop together.
External factors (diet, antibiotics, the environment, etc.) are important in shaping your gut microbiome.
Every person has a unique gut microbiome, but people from different parts of the world have very different gut microbiomes.
A diverse gut microbiome is a healthy gut microbiome. Obese people have lower gut diversity than lean people.
Our Research Study
The Immigrant Microbiome Project was an academic-community partnership
built upon equity, inclusiveness, and shared values.
This research project collaboration included the University of Minnesota, the Somali, Latino, and Hmong Partnership for Health and Wellness at West Side Community Health Services in Minnesota, and Chiang Mai University and the Shoklo Malaria Research Unit in Thailand.
We conducted the research with 519 Hmong and Karen individuals living in Thailand and the United States, including first- and second-generation immigrants and 19 Karen individuals sampled longitudinally, and 36 US-born European American individuals.
For every participant, we:
Collected stool sample(s), dietary intake information, migration history, and demographic data
Measured waist circumference, weight, height
Collected information on breastfeeding as a child, tobacco or alcohol usage, and medications
Excluded them from participation if they consumed antibiotics within the last 6 months, were regular users of probiotics, were pregnant, or were immunosuppressed
Community was central to our project, from its inception to the end.
Community Advisory Boards
Members of the Hmong and Karen communities served on our boards as voices for their communities. They consulted on our study design, troubleshooted recruitment challenges, and helped us find ways to interpret our scientific findings into meaningful results.
Our Hmong and Karen community researchers were members of our research team from Day 1. As trusted leaders in their communities, our researchers were critical for the successful recruitment of all of our study participants. Learn more about our team here.
We found that Hmong and Karen in Thailand were leaner and also had the highest gut biodiversity, compared to those in the U.S.
Hmong and Karen gut microbiome changes within months of arriving in the U.S. and continue becoming more "Americanized" for decades
Changes in diet explains some, but not all, changes in the gut microbiomes
Gut biodiversity decreases with time in the U.S. and increasing Body Mass Index (BMI)
Hmong immigrants have gut microbiomes that can no longer degrade certain fibers that they used to
Second-generation Hmong American gut microbiomes look fully Americanized, but they still eat Hmong foods
Non-Western gut microbiomes look more Western in composition after about a decade in the U.S.
Consumption of sugars, fats, and proteins increases with longer residency in the U.S.
Diet & Microbes
Diet is important but does not explain all of the variation in Hmong and Karen gut microbiomes
There are many complex factors that contribute to obesity, and we still have many important questions to answer. We know that Hmong and Karen obesity risk increases after moving to the U.S., and now know that their gut microbiomes change as well.
Our results underscore the importance of preserving traditions not only for Hmong and Karen culture, but also with potential to preserve Hmong and Karen microbiomes and health.
Meet Our Team
This research was funded by grants from the UMN Clinical and Translational Science Institute, UMN Institute on Diversity, Equity and Advocacy, UMN Healthy Foods Healthy Lives Institute, and the UMN Graduate School. Outreach activities were funded by Allina Health.
Images were designed by Annie Au and Jennifer Moss.
Icons used throughout this website were designed by Freepik.