Two Weeks of AG1 Supplementation Alters Fecal Metabolites in Highly Active Adults

Objective: The objective of our study was to explore how two weeks of AG1® supplementation influences the production of fecal metabolites in highly active men and women. Methods: A double-blind, randomized, placebo-controlled crossover designed study was conducted in 20 highly active male (n =10; 26.4 y; 85.6 kg) and female (n=10; 26.9 y; 70.0 kg ) adults with an average of 9.7 years of resistance training experience. Each participant maintained their normal diet and supplemented with AG1® (13g/day) and placebo (maltodextrin matched for color and taste; 13g/day) in a randomized, counterbalanced order for 14 days with a 2-week washout period in-between treatments. Stool was collected and placed in tubes for preservation (OMNImet GUT ME-200; DNA Genotek, CAN) from each participant before and after each trial period to assess changes in the fecal metabolome. Stool samples were methanol-extracted and analyzed using UPLC-HRMS (ACQUITY UPLC + Q Exactive Orbitrap, ESI±, m/z 70–1050). Chromatographic separation used a HSS T3 column and gradient of 0.05% formic acid and acetonitrile. Multivariate modeling (PCA, PLS-DA) and biomarker selection (VIP > 1, p < 0.05) were performed using SIMCA and Compound Discoverer. QC samples confirmed analytical stability (%RSD < 30%). Comparisons included within- and between-arm pre/post analyses to assess AG1 effects on the fecal metabolome. All significantly altered stool metabolites were annotated using metabolomics databases and literature to assess their clinical relevance and underlying pathways (e.g., bile acid metabolism, inflammation, etc). Results: A total of 19 metabolites were identified as significantly increased and 18 metabolites were significantly decreased (p < 0.05) following the AG1 treatment compared to placebo. Overall, AG1 supplementation led to changes in metabolites typically associated with improved host and microbiome function. Increases in genistein and mevalonic acid suggest enhanced antioxidant capacity, isoprenoid synthesis, and cardiometabolic support. Decreases in xenobiotic compounds such as N, N-dimethyl-p-phenylenediamine, and markers of microbial proteolysis (e.g., piperidine, 4-aminophenol) imply reduced toxicant burden and proteolytic fermentation. A shift in tryptophan metabolism, marked by decreased xanthurenic acid, may reflect lower neuroinflammatory potential. Enrichment of beneficial taxa (Bifidobacterium, Lactobacillus; reported elsewhere) likely mediated observed alterations in bile acid metabolism, including reduced 12-ketodeoxycholic acid, indicating improved microbial-host crosstalk within the gut-liver axis. Conclusion: AG1 supplementation in highly active adults resulted in favorable shifts in the fecal metabolome, with reduced markers of proteolytic fermentation. These changes may suggest AG1 promotes a healthier gut metabolic profile and future work should investigate how these specific microbiome-mediated metabolic shifts translate to systemic physiological outcomes. This abstract was presented at the American Physiology Summit 2026 and is only available in HTML format. There is no downloadable file or PDF version. The Physiology editorial board was not involved in the peer review process.