Assessment of the health effects of a fruit extract through an in vitro dynamic simulation of the human gastrointestinal system

There are numerous medicinal plants and fruits traditionally used to treat gastrointestinal disorders. However, the effects caused by these vegetal products on the intestinal microbial populations are poorly understood. METHODS: An in vitro gut model (SHIME®) was used in this work to analyze the intestinal effects of two weeks of treatment with three increasing doses of a vegetal extract. Gut microbiota community and metabolites were studied on ascending (AC), transverse (TC), and descending (DC) colon regions using qPCR and chromatographic methods, respectively. The effects of the mixture of metabolites upon the host intestinal cells and the impact of the test products on relevant molecular pathways were evaluated through cell culture assays. RESULTS: A significant increase of acetic acid in TC, and of butyrate in all colons was observed by the end of treatment, while propionate levels remained unchanged. Of 12 targeted microbial populations, some health biomarkers such as Bifidobacterium, Roseburia, and Bacteroides-Prevotella genera significantly increased in at least one of the colon sections due to treatment. The highest dose of the vegetal extract induced an increase of Akkermansia muciniphila in AC and TC as well as an increase of Faecalibacterium prausnitzii in all colon regions. No cytotoxic effects of the plant extract were identified when exposed to human intestinal cell lines. The fermentation-derived metabolic pool activated molecular pathways linked to intestinal health and host immune defense. CONCLUSIONS: Overall, the studied fruit extract induced the growth of health-promoting bacteria and the production of metabolites that potentially contribute to gut barrier integrity and have a beneficial impact on human gastrointestinal health.