Effect of AG1 ® supplementation on nutritional adequacy and gut microbial composition in trained adults.
Level 2 - randomized trial
Individual randomized, double-blind, placebo-controlled crossover trial
PubMed 41988471 · doi:10.3389/fnut.2026.1783951
What was done
Twenty healthy resistance-trained adults (10 men, age 26.4 ± 6.5 years; 10 women, age 26.9 ± 5.3 years) participated in a randomized, double-blind, placebo-controlled crossover trial. Participants consumed either the multinutrient supplement AG1 or a placebo daily for 14 days, followed by a 2-week washout before crossing over to the alternate condition. Gut microbial composition was evaluated via stool samples, digestive tolerance was measured using the Digestion-associated Quality of Life Questionnaire (DQLQ), and dietary intake was assessed using 24-hour dietary recalls at baseline and after each 14-day period.
What was found
AG1 supplementation did not produce large shifts in microbial alpha or beta diversity, but was associated with selective enrichment of specific bacterial taxa: Lactiplantibacillus plantarum, Lacticaseibacillus rhamnosus, and Bifidobacterium animalis. AG1 significantly increased the total number of micronutrient Estimated Average Requirements (EARs) met compared to placebo (2.8; p = 0.0011), with vitamins A, C, and E being the most common gaps filled. Digestive quality-of-life scores did not differ significantly between groups (p = 0.777).
Why it matters
This study provides randomized controlled trial evidence on a widely used commercial multinutrient supplement, showing short-term increases in self-reported micronutrient adequacy and delivery of specific probiotic taxa without adverse digestive symptoms in trained adults.
Limits
The study is constrained by a small sample size (n = 20) and a short 14-day duration. The cohort was restricted to young, resistance-trained individuals. Micronutrient adequacy was assessed via dietary recall rather than blood biomarkers, and long-term functional or clinical outcomes were not measured.
Cited by
- partial AG1 NextGen was tested in four clinical trials, showing it improved key nutrient levels in 3 months and increased healthy gut bacteria tenfold.