In vitro fermentation of pretreated oat bran by human fecal inoculum and impact on microbiota

Owing to its potential role in improving intestinal health, oat bran has received a lot of attention. In vitro digestion and fermentation were performed on oat brans that had been pretreated with steaming, microwave, and hot-air drying. The results showed that the dietary fiber after in vitro digestion and beta-glucan content of pretreated oat brans changed insignificantly (p > 0.05). The abundance of Firmicutes and Proteobacteria varied significantly between samples (p < 0.05). The steaming oat bran was utilized by gut microbiota to produce acetate, propionate, and butyrate, the relative abundance of Faecalibacterium prausnitzii significantly increased, and Escherichia-Shigella significantly decreased. Furthermore, the genus level flora differed significantly between steaming, microwave, and hot-air drying oat bran. Overall, steaming improved oat bran fermentability, pro-moting increased SCFA production and bacterial shifts associated with health benefits. Our findings provide a solid foundation for further research into the role of oat bran and gut microbiota in host health.