The effects of AG1® supplementation on the gut microbiome of healthy adults: a randomized, double-blind, placebo-controlled clinical trial

Background This study aimed to examine the effect of a commercially available multi-ingredient powder (AG1 (R)) on the gut microbiome and assess the impact of AG1 (R) on GI tolerability and other clinical safety markers in healthy men and women. Methods Using a double-blind, randomized, two-arm, placebo-controlled, parallel design, we examined a 4-week daily supplementation regimen of AG1 (R) vs. placebo (PL). Fifteen men and 15 women provided stool samples for microbiome analysis, questionnaires for digestive quality of life (DQLQ), and completed visual analog scales (VAS) and Bristol stool charts to assess stool consistency and bowel frequency before and after the 4-week intervention. Participant's blood work (CBC, CMP, and lipid panel) was also assessed before and after the 4-week intervention. Alpha diversity was determined by Shannon and Chao1 index scores and evaluated by a two-way ANOVA, beta diversity in taxonomic abundances and functional pathways was visualized using partial least squares-discriminant analyses and statistically evaluated by PERMANOVA. To identify key biomarkers, specific feature differences in taxonomic relative abundance and normalized functional pathway counts were analyzed by linear discriminant analysis (LDA) effect size (LEfSe). Questionnaires, clinical safety markers, and hemodynamics were evaluated by mixed factorial ANOVAs with repeated measures. This study was registered on clinicaltrials.gov (NCT06181214). ResultsAG1 (R) supplementation enriched two probiotic taxa (Lactobacillus acidophilus and Bifidobacterium bifidum) that likely stem from the probiotics species that exist in the product, as well as L. lactis CH_LC01 and Acetatifactor sp900066565 ASM1486575v1 while reducing Clostridium sp000435835. Regarding community function, AG1 (R) showed an enrichment of two functional pathways while diminishing none. Alternatively, the PL enriched six, but diminished five functional pathways. Neither treatment negatively impacted the digestive quality of life via DQLQ, bowel frequency via VAS, or stool consistency via VAS and Bristol. However, there may have been a greater improvement in the DQLQ score (+62.5%, p = 0.058, d = 0.73) after four weeks of AG1 (R) supplementation compared to a reduction (-50%) in PL. Furthermore, AG1 (R) did not significantly alter clinical safety markers following supplementation providing evidence for its safety profile. Conclusions: AG1 (R) can be consumed safely by healthy adults over four weeks with a potential beneficial impact in their digestive symptom quality of life.