The ARMOR Study of Fecal Microbiota Transplantation to Treat Aging
The composition of the gut microbiome, the relative sizes of the various microbial populations, changes with age in ways that promote chronic inflammation and dysfunction throughout the body. The production of beneficial metabolites decreases, while microbes capable of provoking a constant inflammatory reaction increase in number. Studies of fecal microbiota transplantation have demonstrated that the unfavorable composition of the gut microbiome in old animals can be rejuvenated via the introduction of donor material from young animals. One treatment produces lasting rejuvenation, though presumably the processes of aging will slowly degrade the gut microbiome over time, just as they did before. Health is improved and life span increased.
Fecal microbiota transplantation sees enough use in medicine for researchers and clinicians to broadly understand the safety profile of the treatment, and for a body of work to have evolved regarding best practices for sourcing, screening, storing, and using donor material. But the most common use case, to treat C. difficile infections in which hostile bacteria have overrun the intestine, is not focused on older people, and donors do not necessarily tend to be younger people. Clinical trials that do provide evidence specifically for the use of young donor material to treat old patients are thin on the ground. So it is good to see that at least one group is making the effort to run such a trial; we might expect to see results in a few years.
Aging Resilience Through Microbiota Optimization and Regulation (ARMOR)
It has been proposed that changes in the gut microbiota in aging individuals, known as gut dysbiosis, contribute to sarcopenia. Species diversity decreases, and bacterial representation is altered, which could impair muscle function through various pathways, such as mitochondrial dysfunction, chronic inflammation, and disruption of protein synthesis. Muscle function loss is strongly associated with cognitive and metabolic impairment in older adults.
Recently, it has been demonstrated that fecal microbiota transplantation (FMT) is an effective procedure for modulating gut microbiota and has proven highly effective in managing cases of Clostridium difficile-associated chronic diarrhea. The main objective of this project is to carry out FMT from young, physically active donors to a cohort of older adults to evaluate its effect on muscle, cognitive, and metabolic function.
Why donors who exercise? There is growing evidence that gut microbiota diversity is increased in young, physically active individuals. The FMT is planned to be administered through lyophilized microbiota capsules. By restoring microbial diversity, it is expected to improve the quality and function of skeletal muscles, leading to greater cognitive and metabolic resilience.
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.
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 biomarkers, gut microbiota composition (shotgun metagenomics), cognitive performance, and psychological well-being.
By restoring microbial diversity and function, FMT from young, active donors may enhance muscle quality, cognitive resilience, and metabolic health in older adults. This study introduces a novel, non-invasive therapeutic approach based on lyophilized and encapsulated microbiota, offering a feasible and scalable strategy to promote healthy aging.