(OR12-06-26) Intake of Spices Enhances Relative Abundance of Short Chain Fatty Acid-Producing Bacteria and Influences Metabolic Health

Objectives: Dietary polyphenols are emerging as modulators of gut microbial proliferation and cardiometabolic health. As such, it was hypothesized that metabolism of spice polyphenols by intrinsic microflora in the colon may elicit metabolic effects resulting from the stimulated release of gut-derived metabolites, specifically short-chain fatty acids (SCFA) and peptide YY (PYY).

Methods: In a single-blind, crossover design clinical trial, women (n=25, 58.4±3.9 y) were randomized to twice daily yogurt consumption with or without a culinary dose of cinnamon (3g) and ginger (1g) for four weeks with a two-week washout period (ClinicalTrials.gov #NCT06313580). Yogurt was selected as the delivery vehicle for spices, as it is a standard of care for gut health. Pre- and post-study arms, stool samples were analyzed for gut microbial communities and SCFA.  Serum PYY and metabolic biomarkers were assessed from the fasted state. To limit confounding, participants maintained regular diets while limiting polyphenol-rich foods to ≤ 3 per day.

Results: Intervention compliance was 93%.  Principal Coordinate Analysis plots of beta-diversity reflect 34% similarity in taxa across experimental conditions.  Thus, the microbial population did not change significantly, yet an increase in relative abundance was observed in SCFA-producing bacteria in the intervention arm.  Enrichment in Alistipes, Roseburia, and Ruminococcaceae was significantly associated with increases in PYY production (p=0.018, p=0.02, p=0.03, respectively).  In addition to significant increases in PYY post-intervention (p=0.025), serum glucose was inversely associated with PYY, albeit non-significantly (p=0.06).  Acknowledging the direct and indirect role of SCFA in glucose metabolism, butyrate was significantly inversely associated with serum glucose (p=0.04).

Conclusions: Results suggest that polyphenol-rich spices added to yogurt enhance the proliferation of SCFA-producing bacteria, thus enhancing the benefit of yogurt.  Further, this synbiotic intervention contributed to increases in gut-derived metabolites influencing glucose metabolism.  Taken collectively, spice consumption represents a palatable, cost-effective approach to enhance gut-mediated production of bioactive compounds eliciting systemic therapeutic effects.

Funding Sources: McCormick Science Institute