In vitro fecal fermentation of propionylated high-amylose maize starch and its impact on gut microbiota.

Resistant starch (RS) acylated with propionate groups is of particular interest in terms of their capacity to deliver specific short-chain fatty acids (SCFAs) to the colon with health benefits. In the present study, we fabricated propionylated high-amylose maize starches with different degrees of substitution (DS), and monitored the in vitro human fecal fermentation profiles. Propionylated modification did not change the slow gas production properties of high-amylose maize starch throughout the whole fermentation period. The final concentration of propionate (13.68-21.10 mM) produced by propionylated starch fermentation enhanced gradually with increase of DS value, resulting from the release of introduced propionyl groups. Certain beneficial gut microbiota such as Roseburia, and Blautia were obviously promoted, suggesting that propionylated starch could regulate the composition of gut microbiota. The results may facilitate the design and manufacture of functional food products with the aim of improving colonic health.