Proton pump inhibitors (PPI), used to treat gastrointestinal disorders, are associated with alterations in the gut microbiome. However, this is understudied in Hispanics and Latinos, including Puerto Ricans, who have unique dietary and lifestyle characteristics. Further, we observed high PPI use among Puerto Rican adults in the Boston-Puerto Rican Health Study (BPRHS). Therefore, we examined gut microbial variations associated with PPI use in the BPRHS.

The BPRHS is a prospective cohort that enrolled 1500 participants at baseline. Data was collected across four waves, over thirteen years of follow-up. Data from the fourth wave was used in the present study. At wave 4, 309 BPRHS participants self-reported PPI use and self-collected, metagenomically profiled, stool samples. PPI use was classified as any past use. Cross-sectional associations between gut microbial taxa, functional pathways, and PPI use were analyzed using omnibus tests, multivariate linear modeling in MaAsLin2, and random forest classifier in feature-wise analyses. We further compared our results with the non-Hispanic Health Professionals Follow-Up Study to validate key findings and examine ethnicity-related differences.

Among 309 participants (mean age 68.8 years; female 74.6%), 112 (36%) self-reported PPI use. After adjusting for relevant covariates, we observed an enrichment of Streptococcus parasanguinis (=3.16, FDR P=0.01), S. anginosus (=2.89, FDR P<0.01), S. salivarius (=2.56, FDR P=0.01), S. gordonii (=1.98, FDR P=0.15), and Rothia mucilaginosa (=1.54, FDR P=0.06), among PPI users compared to non-users. Streptococci and Lactobacilli predominantly contributed to the functional pathways associated with PPI use. The observed enrichment of oral-typical taxa, such as Streptococci, among PPI users in the BPRHS, suggests the potential of PPIs to alter gut microbial composition. More studies are needed to understand the impact of PPI use on the gut microbiome in different ethnicities.