Abstract 4141398: Relationship between Gut Microbial Butyrate and Hypertension

Background: Hypertension is the most common cardiovascular disease risk factor of which African Americans have a greater burden. Gut microbial production of short chain fatty acids (SCFA) has been associated with blood pressure status in animals, with limited evidence in humans. The complex and diverse gut microbial ecosystem contributes to synthesizing the SCFA butyrate. Aim: The goal of the study is to determine if butyrate production in the gut is associated with hypertension and how the microbial composition differs in normal and hypertensive participants. Methods: Fecal samples from 20 participants diagnosed with normal (n = 10) or high (n = 10) blood pressure were sequenced via the 16S rRNA gene. Inference-based modeling generated functional (PICRUSt2) and metabolic (MICOM) models of microbial communities focusing on carbohydrate fermentation pathways. Supervised learning was conducted to identify significant (p < 0.05) differences in predicted functional genes and microbial communities. Results: Microbial dominance was inversely correlated with increasing systolic blood pressure (Pearson, p < 0.05, R = -0.44); however, no significant correlation was measured for beta diversity between the two groups. More importantly, inference modeling showed differences in microbial function and metabolism between groups. Functional pathways associated with carbohydrate fermentation were significantly (ANOVA, p < 0.05) lower for hypertensive compared to normal participants. Carbohydrate fermentation accounted for only 8.05% of the predicted functions of the identified pathways. Within this subset, pyruvate fermentation to isobutanol was the most abundant pathway (12.6%), followed by starch degradation (9.6%) and glycolysis III (9.34%). Additionally, metabolic flux models revealed Catenibacterium, Subdoligranulum , and Roseburia were predicted as butyrate producers. Catenibacterium and Subdoligranulum produced 51% and 44% butyrate, respectively, in the normal group. In contrast, a different distribution was observed in the hypertensive group, with Catenibacterium accounting for 97% and Roseburia contributing 3% of the butyrate production. Conclusion: Our preliminary investigation elucidates the potential relationship between SCFA producers (as well as butyrate producers) and blood pressure status among minority participants, providing insights into how gut microbiota may influence or be influenced by blood pressure.