Evidence Hub

Randomized, double-blind, placebo-controlled trial of fecal microbiota transplantation from young physically active donors to promote resilient aging: clinical trial protocol (ARMOR study)

Astudillo-Guerrero C, Garrido Á, Masferrer D, Sepúlveda C, Olavarría L, Del Campo R, Bravo-Sagua R, Cubero FJ et al.

BMC geriatrics, 2026

1 citation

Abstract

BACKGROUND: Sarcopenia, characterized by the progressive loss of skeletal muscle mass and strength in older adults, is a key determinant of frailty and functional decline. Affecting up to 15% of individuals aged 65–80 years and more than 50% of those over 80, sarcopenia not only compromises physical autonomy but also increases the risk of metabolic dysfunction and cognitive decline. Emerging evidence suggests that age-related gut microbiota dysbiosis contributes to these impairments by reducing microbial diversity and altering host metabolic signaling, leading to chronic inflammation and mitochondrial dysfunction. The present study aims to evaluate the safety, tolerability, and preliminary efficacy of oral fecal microbiota transplantation derived from young, physically active donors administered to older adults, focusing on outcomes related to functional autonomy, muscle performance, metabolism and cognition. METHODS: This is a double-blind, randomized, placebo-controlled clinical trial involving community-dwelling adults aged 65–84 years. Participants will be randomized 1:1 to receive either FMT capsules or placebo following a short course of oral rifaximin (or placebo). Assessments will be performed at baseline and at 4, 8, and 20 weeks post-intervention. The primary outcomes are safety and tolerability, as well as changes in the Global Index of Functional Autonomy (GDLAM battery) and muscle strength. Secondary outcomes include gait speed, body composition (DXA), metabolic…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

Read the paper

Related studies

Go deeper in Evidence Hub

Evidence Hub adds a study data sheet (design, sample size, evidence level, key numbers), an AI summary and a chat grounded in the paper's text.

Open this study Sign up free