Characterization and stability assessment of polyphenols bound to Lycium barbarum polysaccharide: Insights from gastrointestinal digestion and colon fermentation.

Polysaccharides and polyphenols are biologically active components that coexist in Lycium barbarum fruit, and there may be interactions between them that affect the release of each other. In this study, polyphenols bound to L. barbarum polysaccharide (LBP) were characterized, and the stability of bound phenolics (BP) was assessed by gastrointestinal digestion and colon fermentation. The results showed that a total of 65 phytochemicals such as flavonoids, phenolic acids, and coumarins were identified by UPLC-MS/MS. Quantitative analysis revealed that the major phenolic constituents were rutin, p-coumaric acid, catechin, ferulic acid, protocatechuic acid, and gallic acid, and their contents were 58.72, 24.03, 14.24, 13.28, 10.39, and 6.7 mg GAE/100 g DW, respectively. The release of BP by gastric digestion and gastrointestinal digestion was 9.67 % and 19.39 %, respectively. Most polyphenols were greatly affected by gastric digestion, while rutin was released in small intestine. The BP were fully released (49.77 %) and metabolized by gut microorganisms, and a considerable number of intermediates and end-products were detected, such as phloroglucinol, phenylacetic acid, and phenyllactic acid. Microbiomics data emphasized the positive impact of LBP on gut bacteria of Bacteroides, Parabacteroides, and Clostridioides. These findings could deepen our understanding of the bioavailability and biological fate of BP and also provide reference data for nutrient release and utilization of L. barbarum as a whole.

Serum metabolomics combined with 16S rRNA sequencing to reveal the effects of Lycium barbarum polysaccharide on host metabolism and gut microbiota.

Gut microbes and microbial metabolites derived from polysaccharides mediate beneficial effects related to polysaccharides consumption. Lycium barbarum polysaccharide (LBP) is the main bioactive components in L. barbarum fruits and possesses considerable health-promoting effects. In the present study, we aimed to investigate whether LBP supplementation influenced host metabolic responses and gut microbiota in healthy mice, and to identify bacterial taxa associated with the observed beneficial effects. Our results indicated that mice supplied with LBP at 200 mg/kg BW showed lower serum total cholesterol (TC), triglyceride (TG), and liver TG levels. LBP supplementation strengthened the antioxidant capacity of liver, supported the growth of Lactobacillus and Lactococcus, and stimulated short-chain fatty acids (SCFAs) production. Serum metabolomic analysis revealed that fatty acid degradation pathways were enriched, and RT-PCR further confirmed that LBP up-regulated the expression of liver genes involved in fatty acid oxidation. The Spearman's correlation analysis indicated that some serum and liver lipid profiles and hepatic SOD activity were associated with Lactobacillus, Lactococcus, Ruminococcus, Allobaculum and AF12. Collectively, these findings provide new evidence for the potential preventive effect of LBP consumption on hyperlipidemia and nonalcoholic fatty liver disease.

Preparation of edible starch nanomaterials for the separation of polyphenols from fruit pomace extract and determination of their adsorption properties.

Apple polyphenols are abundantly present in apple pomace, and their applications are limited by the low efficiency of traditional extraction methods and the tendency to pollute the environment. Starch nanoparticles (SNPs) have received much attention due to their renewable, low cost and biocompatibility. The aim of this study was to prepare SNPs of different sizes from corn starch using ultrasonic-assisted chemical precipitation with adsorption of apple polyphenols, investigate the relationship between particle size and adsorption, while experiments were performed to assess antioxidant activity, simulate in vivo digestion and polyphenol release. The results showed that the smaller the particle size of SNPs the higher the adsorption of polyphenols, and the combination of characterization and adsorption kinetics showed that this adsorption was a physicochemical binding process. DPPH radical scavenging activity showed that polyphenols bound to SNPs were more stable than free polyphenols. In vitro simulation of digestion and release processes, SNPs loaded with polyphenols showed better anti-digestive properties, polyphenols are released in small amounts in gastric juices and continuously in intestinal juices. Our results provide a theoretical basis for the direct separation of polyphenols from fruit pomace polyphenol extracts using nanomaterials and the industrial utilization of polyphenol products.