Gut Microbiota and Nutrition in Nursing Homes: Challenges and Translational Approaches for Healthy Aging.

The growing aging population is leading to an increase in demand for long-term care. This is particularly true in nursing homes, where residents are exposed to various challenges such as immunosenescence, frailty, multimorbidity, and dietary and environmental constraints. These interrelated factors contribute to gut microbiota alterations, underscoring the need for tailored strategies to preserve health and resilience in a long-term care setting. Despite its recognized relevance in healthy aging, the gut microbiome of institutionalized older adults remains markedly understudied. This review provides a comprehensive report of the current evidence on the interplay between diet, gut microbiota, and aging among nursing-home residents. The available literature suggests that both aging and institutional living contribute to a less favorable microbiome profile, and several contributing factors, many of them dietary, have been identified. Altered gastrointestinal physiology, malnutrition, and other common conditions in residential care, such as functional or cognitive impairments, frequently lead to changes in food intake that affect the gut ecosystem. Decline in immune system, increased infection risk, sarcopenia, cognitive deterioration, and high medication burden have also been linked to microbiota disruptions in this population. Importantly, adjusting several modifiable features of institutional care, particularly those related to diet and lifestyle, may help counteract these effects by supporting gut health. We further examine how appropriate nutritional strategies can positively influence gut microbiota composition and function, offering a pathway to promote resilience and functionality even in the presence of geriatric syndromes. In addition to identifying these challenges, this review outlines feasible, microbiota-informed strategies to improve quality of life and health outcomes. These include individualized dietary adaptations, targeted supplementation, physical activity interventions, and the integration of digital and artificial intelligence tools to support personalized nutrition. Finally, we highlight the need for standardized protocols and implementation science frameworks to enhance clinical translation, thereby advancing an integrative and as yet underrepresented perspective on microbiota-based strategies to promote healthier aging trajectories in institutionalized older adults.