Comparative study of thermal processing on the physicochemical properties and prebiotic effects of the oat β-glucan by in vitro human fecal microbiota fermentation

This study aimed to compare the prebiotic effects of oat beta-glucan between steaming and microwave processing by high-throughput sequencing. The results showed that microwave-processed oat beta-glucan with lower average molecular weight (M-w) exhibited a more significant effect in promoting Lactobacillus and Bifidobacterium compared with steaming processed oat beta-glucan with higher M-w at the genus level. The overall microbial composition structure results indicated that the relative abundance of Escherichia-Shigella, Lactobacillus, Enterococcus, and Dialister exhibited significant differences between the samples (p < 0.05). Additionally, the shortchain fatty acid in microwave-processed oat beta-glucan fermentation slurries significantly increased (p < 0.05), and more butyrate was produced from microwave-processed oat beta-glucan, which may be attributed to the higher levels of Blautia and Dialister as butyrate-producers. These results suggest that microwave processing contributed to the degradation of oat beta-glucan and enhanced its prebiotic function.