(P03-014-23) Differences in Gut Microbiome Composition by Bowel Movement Frequency and Proton Pump Inhibitor Use: The Boston Puerto Rican Health Study

Objectives: Factors that influence bowel health including daily bowel movement (DBM) frequency, and changes associated with proton pump inhibitor (PPI) use, such as increased gastric pH and enteric infections, are associated with gut microbiome changes. However, no studies to date have focused on Puerto Ricans, who have unique lifestyle characteristics impacting bowel health. We sought to examine the association between gut microbiome and DBM and PPI use in Boston Puerto Rican Health Study (BPRHS), where we observe increasing utilization of PPIs.

Methods: BPRHS is an ongoing longitudinal cohort that enrolled Boston-area Puerto Rican adults at baseline (n=1502) through wave 4 (~12.7y from baseline). Our study was comprised of 309 wave 4 participants with metagenomic profiling of self-collected stool samples. We examined cross-sectional associations between DBM and PPI use and alpha (Shannon) diversity and Bray-Curtis dissimilarity. Differentially abundant gut microbial taxa in the DBM and PPI groups were identified using Microbiome Multivariable Associations with Linear Models (MaAsLin2).

Results: Among 309 participants with stool metagenomic profiles (mean age 68.8 y±7.3 y; female 74.6%), 91 (29.4%), 121 (39.1%) and 97 (31.4%) self-reported DBM of < 1X, 1X and ≥ 2X per day, respectively. 112 (36.2%) self-reported PPI use (yes/no). Shannon alpha diversity was similar across DBM and PPI groups. In univariate PERMANOVA of Bray-Curtis dissimilarities, DBM and PPI use explained a small, but significant variation in taxonomic composition (DBM: P = 0.004; PPI: P = 0.01), but was attenuated after adjusting for relevant covariates. After adjusting for age, sex, BMI, alcohol use, smoking, comorbidities, medications (incl. laxatives & antibiotics), Bristol stool scale, fiber intake and Mediterranean diet, we observed higher abundance of Bifidobacterium adolescentis (b= 4.66, P < 0.01, q = 0.18) with DBM < 1X/day, and higher abundance of Streptococcus anginosus group (b= 2.02, P < 0.01, q = 0.16) and Streptococcus vestibularis (b= 2.18, P < 0.01, q = 0.17) among PPI users.

Conclusions: In this study of older Boston-area Puerto Rican adults, we observed higher abundance of Bifidobacterium adolescentis in the DBM < 1X/day group and Streptococcus species, implicated in small intestinal bacterial overgrowth, among PPI users.

Funding Sources: National Institutes of Health