Dietary fiber extracted from pomelo fruitlets promotes intestinal functions, both in vitro and in vivo

Pomelo fruitlets contain various active substances that are easily collected and processed. Here, the biological effects of pomelo fruitlet dietary fiber were investigated in vivo and in vitro. Total dietary fiber (TDF), soluble dietary fiber (SDF), and insoluble dietary fiber (IDF) values of pomelo fruitlets were 75.64 ± 3.65 %, 10.10 ± 1.39 %, and 62.48 ± 3.68 %, respectively. The main monosaccharides identified were rhamnose, arabinose, galactose, and glucose. All fibers scavenged free 2,2'-diphenyl-1-picrylhydrazyl radicals and reduced ferric cations. The water-holding, oil-holding, and swelling capacities of the fibers retarded glucose diffusion, inhibited α-amylase, and influenced cholesterol micelle formation. In a mouse model of alloxan-induced diabetes, SDF improved glucose tolerance, controlled blood glucose, and reduced serum insulin better than TDF or IDF. All fiber types decreased the total cholesterol content and the prevalence of Bacteroidetes, Proteobacteria, and Ruminococcaceae, but increased the abundance of Firmicutes, Lactobacillus, and Prevotellaceae in hyperglycemic mice.