Xanthohumol microbiome and signature in healthy adults (the XMaS trial): a phase I triple-masked, placebo-controlled clinical trial

Phase I, randomized, triple-masked, placebo-controlled clinical trial in healthy adults without chronic disease. For the xanthohumol arm, 12 participants were randomized in a 1:1 allocation trial; the protocol planned up to 16 adults per arm to allow for attrition. Eligibility included ages 21-50 years, BMI 20-30, and non-smoker status.

Xanthohumol was given orally as a 99+% pure 24 mg/day dose in an orange capsule for 8 weeks. The capsule also contained rice protein, microcrystalline cellulose, Aerosil® 200 fumed silica, and magnesium stearate; the rice protein carrier was included to improve bioavailability. The regimen was compared with placebo in a triple-masked design.

This packet does not report numerical outcome results, p-values, or a completed efficacy conclusion for xanthohumol. The trial was designed to evaluate safety, tolerability, inflammation-related biomarkers, gut permeability, bile acid metabolism, xanthohumol metabolism, gut microbiota, and health-related quality of life over 8 weeks, with laboratory safety tests repeated every 2 weeks and adverse events monitored throughout. Baseline values and effect estimates for the key outcomes are not provided here, so no interpretable efficacy signal can be extracted from the source packet.

Phase I study in a small sample of healthy adults, limiting power and generalizability. The intervention period was short at 8 weeks, and the extracted packet does not provide numerical outcome results, baseline values, or effect sizes. Customary dietary intake data were not collected, and physical activity information was limited, which reduces interpretability for microbiome and biomarker outcomes.