Persimmon Powder from Discarded Fruits as a Potential Prebiotic to Modulate Gut Microbiota in Postmenopausal Women

Faced with the challenge of reducing food waste, transforming discarded fruit into functional ingredients useful for the food industry is a valuable solution. Ingredients from fruit such as persimmons, which are rich in indigestible carbohydrates and bioactive compounds with antiradical capacity, could positively impact on the health of certain population groups due to their potential prebiotic effect. This study aimed to select the most suitable drying conditions and milling intensity for obtaining powdered persimmon ingredients with a prebiotic-like effects observed in vitro for postmenopausal women, and to evaluate this effect by considering the stimulation of health-promoting bacterial growth and short-chain fatty acids (SCFAs) production. First, the effect of the drying method (hot air drying at 60 and 70 °C, and freeze-drying) and grinding intensity on antiradical capacity, particle size, and the release of bioactive antiradical components into the intestinal lumen after an in vitro gastrointestinal digestion was determined. Next, the effect of these conditions on the microbiota composition of postmenopausal women was preliminary assessed in a batch colonic fermentation experiment for 24 h. The results showed that the ingredient dried with air at 70 °C had the highest phenol and flavonoid content, suffered the least degradation during in vitro gastrointestinal digestion and promoted the differential growth of fiber-degrader genera. Consequently, this was the ingredient selected as the most suitable. Lastly, the impact of this ingredient on the microbiota composition of 4 postmenopausal women has been evaluated in a long-term study using the Simulator of the Human Intestinal Microbial Ecosystem (SHIME^®) coupled to high throughput sequencing. The growth stimulation of health-associated bacteria, such as Akkermansia muciniphila, Faecalibacterium prausnitzii or Phascolarctobacterium faecium, and the promotion of beneficial metabolic pathways, such as the sugar uptake-specific phosphotransferase system, sugar metabolism and propionate and isobutyrate production, were detected along 14 days of persimmon powder supplementation. A holistic framework for promoting human health while advancing environmental sustainability is represented by the combination of sustainable by-product valorization and microbiota-targeted functional food development.