La Monica · Journal of the International Society of Sports Nutrition 2024 · randomized double-blind placebo-controlled trial · n=30

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

Cited 5 times in the scientific literature.

Level 2 - randomized trial

Individual randomized double-blind placebo-controlled trial

PubMed 39352252 · doi:10.1080/15502783.2024.2409682 · record verified 2026-08-26

What was done

A double-blind, randomized, two-arm, placebo-controlled parallel trial investigated the effects of 4 weeks of daily supplementation with AG1 (a commercial multi-ingredient powder) versus placebo in 30 healthy adults (15 men, 15 women). Stool samples were collected before and after the 4-week period to evaluate microbiome alpha and beta diversity, taxonomic relative abundance, and functional pathways. Secondary outcomes included digestive quality of life (DQLQ), visual analog scale (VAS) assessments of bowel frequency and stool consistency (Bristol stool chart), and safety blood work (CBC, CMP, lipid panel).

What was found

AG1 enriched taxa including *Lactobacillus acidophilus*, *Bifidobacterium bifidum*, *L. lactis* CH_LC01, and *Acetatifactor* sp900066565 ASM1486575v1, while reducing *Clostridium* sp000435835. AG1 enriched two functional pathways and diminished none, whereas placebo enriched six and diminished five. DQLQ showed a trend toward greater improvement with AG1 compared to placebo (+62.5% vs. -50%, p = 0.058, d = 0.73). Neither treatment altered bowel frequency or stool consistency, and AG1 did not significantly change clinical safety markers.

Why it matters

This study provides initial controlled clinical data regarding the short-term safety and gut microbiome shifts associated with a widely marketed commercial dietary supplement.

Limits

The sample size was very small (n = 30 total). The primary digestive quality of life improvement did not reach standard statistical significance (p = 0.058). The 4-week intervention cannot establish long-term safety or efficacy, and studying a multi-ingredient blend precludes attributing observed effects to any individual ingredient.

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