Enzymatic modification of pomelo pectins for shaping the gut microbiota to a healthy pattern

This study investigated the impact of enzymatic hydrolyzation on the characteristics, composition, and in vitro fermentation patterns of pectins extracted from pomelo (Citrus maxima) by thermal treatments. Pectins were obtained using subcritical water extraction (SWE) and hot water extraction with chelator assistance, and subsequently, enzymatically modified using pectinase. The investigation covered constituent monosaccharide composition, molecular weight (Mw) distribution, and other structural parameters of the pectins. The primary monosaccharide present in the extracted pomelo pectins was uronic acid (UA), accompanied by relatively low levels of other neutral monosaccharides. The findings indicate that chelating agents coupled with thermal treatment allowed for the successful extraction of low degree of methylation (DM) pectins from pomelo peel. Enzymatic hydrolyzation reduced the DM and Mw of pectin, while maintaining a nearly unchanged monosaccharide mole ratio compared to the parental pectins. In vitro fermentation models were employed to compare the fermentation patterns of pectin before and after enzymatic modification. Enzymatic modification not only heightened the fermentability of pectins but also altered UA utilization patterns, expediting the production of short-chain fatty acids (SCFAs) during in vitro fermentation. Moreover, enzymatic hydrolyzation induced changes in microbial composition, elevating the relative abundance of potential probiotics such as Bacteroides while suppressing potential pathogens like Escherichia-Shigella. In conclusion, the study posits that enzymatic modification of pectins into low Mw and low DM fragments enhances fermentability and beneficially modifies the microbiota of fermented digesta into a potentially healthy pattern.