Novel Acylated Naringin Enhances Propionate Release and Stimulates the Growth of Flavanone-Metabolizing Bacteria in an In Vitro Batch Fermentation Model

The increasing prevalence of non-communicable diseases (NCDs) is strongly associated with gut microbiota (GM) imbalances and reduced short-chain fatty acid (SCFA) production, primarily driven by poor diet and microbial dysbiosis. Since SCFAs are crucial for gut health, immune regulation, and inflammation control, restoring their levels is a key therapeutic target. SCFA-acylated naringin derivatives offer a novel approach by enhancing SCFA delivery and modulating GM composition. In this study, we investigated the effects of naringin acetate and naringin propionate on SCFA production using a 24 h short-term in vitro batch fecal fermentation model with microbiota from two donors. Naringin propionate and naringin plus free propionate significantly increased propionate levels by 0.74 mM and 0.75 mM, respectively (<i>p</i> < 0.0001), while naringin acetate induced a smaller increase of 0.26 mM. Donor-specific reflected differences in microbial communities, yet SCFA enhancement was observed across samples. Additionally, naringin treatments stimulated the growth of beneficial polyphenol-metabolizing bacteria, including <i>Bacteroides</i>, <i>Streptococcus</i>, and <i>Eubacterium siraeum</i>. The strong effect of naringin propionate suggests a sustained SCFA release mediated by microbial enzymes. These preliminary results highlight the potential of SCFA-acylated flavonoids as functional dietary components to increase SCFA bioavailability and support gut health, particularly from citrus-derived co-products.