The role of bound polyphenols in the anti-obesity effects of defatted rice bran insoluble dietary fiber: An insight from multi-omics.

Considering the high abundance of bound polyphenols (BP) in whole grain dietary fiber (DF), this study utilized multi-omics approach to evaluate the impact of BP of defatted rice bran insoluble DF (RIDF) in modulating obesity. Mice on high-fat diet were gavage-administered RIDF, BP-removed or formulated RIDF. The results indicated that DF significantly reduced serum total cholesterol, triglycerides, high-density and low-density lipoprotein cholesterol levels. Moreover, hepatic lipid accumulation and damage induced by high-fat diet were significantly ameliorated with DF intervention. The presence of BP increased the abundance of beneficial bacteria g_Akkermansia and g_Butyricicocus, as well as the expression of butyric acid/propionic acid. Furthermore, the expression of hepatic lipids and lipid-like molecules was significantly decreased under the combined intervention of BP and DF, and this was accompanied by alterations in genes related to lipid, sterol, and cholesterol metabolic biological processes. These findings suggest that BP contribute to the anti-obesity effects of DF.

Ameliorative effect of bound polyphenols in mung bean coat dietary fiber on DSS-induced ulcerative colitis in mice: the intestinal barrier and intestinal flora.

The consumption of dietary fiber is beneficial for gut health, but the role of bound polyphenols in dietary fiber has lacked systematic study. The aim of this study is to evaluate the ameliorative effect of mung bean coat dietary fiber (MDF) on DSS-induced ulcerative colitis in mice in the presence and absence of bound polyphenols. Compared to polyphenol-removed MDF (PR-MDF), MDF and formulated-MDF (F-MDF,backfilling polyphenols by the amount of extracted from MDF into PR-MDF) alleviated symptoms such as weight loss and colonic injury in mice with colitis, effectively reduced excessive inflammatory responses, and the bound polyphenols restored the integrity of the intestinal barrier by promoting the expression of tight junction proteins. Additionally, bound polyphenols restored the expression of autophagy-related proteins (mTOR, beclin-1, Atg5 and Atg7) and inhibited the excessive expression of apoptotic-related proteins (Bax, caspase-9, and caspase-3). Furthermore, bound polyphenols could ameliorate the dysregulation of the intestinal microbiota by increasing the abundance of beneficial bacteria and inhibiting the abundance of harmful bacteria. Thus, it can be concluded that the presence of bound polyphenols in MDF plays a key role in the alleviation of DSS-induced ulcerative colitis.

Exploration of the role of bound polyphenols on tea residues dietary fiber improving diabetic hepatorenal injury and metabolic disorders.

Consumption of tea residues dietary fiber (TRDF) contributed to the relief of hyperglycemia symptoms in type 2 diabetes (T2D). Given the properties of TRDF abundant in bound polyphenols, the research intended to evaluate the effect of the presence or absence of bound polyphenols in TRDF on the improvement of diabetic complications (liver and kidney injury, metabolic disorders) in T2D rats induced by high-fat diet and streptozocin injection. Our results revealed that the presence of bound polyphenols in TRDF was remarkably beneficial for the amelioration of liver and kidney damage caused by T2D, which was supported by significant differences in activities of serum glutamic oxaloacetic transaminase (AST) and glutamic-pyruvic transaminase (ALT), contents of inflammatory factors in liver and kidney, the levels of kidney oxidative stress, as well as histopathological status between TRDF and bound polyphenols removed-TRDF (TRDF-DF) groups. In addition, metabolomic analysis revealed that TRDF interventions could increase the levels of metabolites such as S-Adenosylmethionine, L-Homophenylalanine and Riboflavin, as well as differ in the regulation of the metabolic pathways including arachidonic acid metabolism and cysteine and methionine metabolism as compared to TRDF-DF without bound polyphenols. These results suggested that bound polyphenols ensured the health-promoting effects for T2D complications of TRDF.

Elucidation of the interaction effect between dietary fiber and bound polyphenol components on the anti-hyperglycemic activity of tea residue dietary fiber.

Dietary fiber intake is beneficial for the prevention of some chronic metabolic diseases. Considering the characteristic that dietary fiber from tea residues (TRDF) is rich in bound polyphenols, the study aimed to elucidate the interaction effect between dietary fiber components (TRDF-DF) and bound polyphenol components (TRDF-BP) on the anti-hyperglycemic activity of TRDF. A type 2 diabetes (T2D) rat model induced by high-fat diet and streptozotocin injection was applied in this study. The results showed that bound polyphenol components rather than dietary fiber components were essential for the anti-hyperglycemic activity of TRDF, as evidenced by remarkable differences in fasting blood glucose (FBG), the insulin resistance index (HOMA-IR) and the levels of serum oxidative stress between the TRDF and TRDF-DF groups, as well as the up-regulation of the expression of insulin signaling pathway-related proteins in the liver after TRDF and TRDF-BP administration. In addition, the synergistic effect between TRDF-BP and TRDF-DF components modulated gut microbiota dysbiosis and increased the content of short chain fatty acids (SCFAs) via enriching beneficial bacteria and inhibiting harmful bacteria. The role of TRDF-BP and TRDF-DF as well as their interaction effect on the anti-hyperglycemic activity of TRDF are elucidated, which can provide theoretical basis for TRDF as a dietary supplement to manage T2D.