Tailoring senior diets: using an in vitro fecal fermentation model for an adapted instant soup/purée design – the diet65+ project

Objective: Changes in gastrointestinal function and gut microbiota dysbiosis are frequent among the elderly. The Diet65+ project intends to develop food products fully adapted and tailored towards a nutritional pattern fulfilling 65+ years nutritional requirements. This work also aims to specifically explore its potential influence on gut microbiota modulation. Methods: An instant soup/purée using different vegetable protein sources was developed to fulfill the distinct protein needs of the elderly population. The soup/purée formulations were subjected to an in vitro gastrointestinal digestion model (INFOGEST). Afterward, their prebiotic effect on gut microbiota will be assessed by in vitro fermentations using human donors’ fecal samples as inoculum. By using both young adult and elderly donors, the impact of these products, measured by short-chain fatty acids, amino acid quantification, and bacterial population analysis, in different populational groups is accomplished. Results: Considering the presence of different fermentable plant-based dietary fiber and vegetable proteins in the formulations, it is expected a prebiotic effect in the human gut microbiota. We believe that this foreseen positive impact will be translated into an enhanced relative abundance of different species of Bacteroides, Bifidobacterium, and Lactobacillus and of short-chain fatty acids levels (e.g. propionate and butyrate). Conclusions: The use of in vitro gastrointestinal tract and fermentation models is of extreme relevance in adapting and tailoring foods to a specific population’s nutritional requirements. A first screening, using in vitro models will allow the understanding of the feasibility of the food formulations and their improvement for future clinical studies application. Acknowledgments This work is part of Diet65+ project from Agenda VIIAFOOD – Plataforma de Valorização, Industrialização e Inovação Comercial para o AgroAlimentar (nºC644929456-00000040), which was a project supported by Plano de Recuperação e Resiliência (PRR, www.recuperarportugal.gov.pt).