US Immigration Westernizes the Human Gut Microbiome

Area of Science:

• Human Health
• Microbiome Research
• Immigration Studies

Background:

• Metabolic diseases are prevalent in US immigrant populations, with unclear causes.
• The gut microbiome's role in metabolic disease is established, but immigration's impact is unstudied.

Purpose of the Study:

• To investigate the effects of US immigration on the gut microbiome composition and function.
• To understand how migration influences microbial diversity and metabolic health.

Main Methods:

• Collected stool, dietary, and anthropometric data from Hmong and Karen individuals in Thailand and the US.
• Utilized 16S and deep shotgun metagenomic sequencing for microbiome analysis.
• Included first- and second-generation immigrants, individuals pre- and post-migration, and US-born controls.

Main Results:

• Migration to the US caused immediate loss of gut microbiome diversity and function.
• US-associated microbial strains and functions displaced native ones post-immigration.
• These alterations intensified with duration of US residence, obesity, and across generations.

Conclusions:

• US immigration significantly disrupts the gut microbiome.
• Microbiome changes are linked to duration of residence, obesity, and generational effects.
• Findings highlight the gut microbiome as a factor in immigrant metabolic disease.