Gut microbiome composition in the Hispanic Community Health Study/Study of Latinos is shaped by geographic relocation, environmental factors, and obesityOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study examined how the gut microbiome of Hispanic adults living in the USA is shaped by birthplace, migration history, and lifestyle factors. Researchers used 16S rRNA gene V4 amplicon sequencing to profile bacteria and ITS1 fragment sequencing to profile fungi in self-collected stool samples. The analysis was cross-sectional, looking at sociodemographic and migration-related variables alongside obesity status to explain differences in microbiome composition.
Who was studied?
The study drew on 1,674 participants from four centers of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL), aged 18 to 74 years old at recruitment. Participants included people born in the USA as well as those who relocated from Latin America at different points in life, including early childhood and adulthood over age 45. This design allowed comparison across USA-born individuals, childhood arrivals, and adult migrants.
What were the most important findings?
Those who relocated to the USA early in life showed reduced Prevotella to Bacteroides ratios that persisted throughout their lives, along with low Shannon diversity for both bacteria and fungi. In contrast, adults who relocated after age 45 had high bacterial and fungal diversity and high Prevotella to Bacteroides ratios compared to USA-born individuals and childhood arrivals. Low bacterial diversity was associated with obesity, and unlike prior studies in other populations, this Latino cohort showed an increasing Prevotella to Bacteroides ratio with greater obesity. Several taxa, including Acidaminococcus, Megasphaera, Ruminococcaceae, Coriobacteriaceae, and Clostridiales, were also implicated in these patterns.
What are the greatest implications of this study?
The findings suggest that age at migration is a durable determinant of gut microbiome composition, with effects that persist across the life course rather than fading with time in a new country. Because the Prevotella to Bacteroides and obesity relationship ran counter to patterns seen in other populations, the results caution against generalizing microbiome-obesity associations across ethnic and migration backgrounds. This points to a need for population-specific reference ranges when interpreting gut microbiome signatures tied to metabolic health.