Assessing food digestion in the elderly using in vitro gastrointestinal models

With the global population of individuals aged 65 and older projected to exceed 1.5 billion by 2050, understanding the impact of aging on digestion and nutrient absorption is essential for addressing the nutritional needs of the elderly. This review explores the limitations of traditional in vivo studies and underscores the growing importance of in vitro gastrointestinal models as an ethical and cost-effective alternative for investigating digestion in the elderly. The review provides a comprehensive analysis of age-related physiological changes in the gastrointestinal tract (GIT), and critically evaluates how static and dynamic in vitro models have been adapted to simulate these changes. We also discuss the significant challenges these models face in accurately replicating the complexities of elderly digestion, particularly in mimicking the interactions between digestive processes and the gut microbiome. By addressing these challenges, particularly through the development of more physiologically relevant and personalized in vitro models, this review highlights the potential to enhance our understanding of elderly digestion and improve nutritional strategies, ultimately contributing to better health outcomes for the aging population.