Maillard conjugates of whey protein isolate and gum Arabic: Enhanced functional properties and unique gut microbiota regulation

Interactions between proteins and polysaccharides can be used to design food ingredients with potential functional properties. However, the effects of the products formed through different interactions on the gut microbiota remain unclear. In this study, the functional properties and gut microbiota regulation of whey protein isolate (WPI), gum Arabic (GA), their physical mixture (WPI-GA-M) and Maillard conjugates (WPI-GA-C) were investigated in vitro, aiming to understand the effects of protein-polysaccharide conjugation on gut microbiota and to promote the potential applications of conjugates in the food industry. The results showed that WPI-GA-C prepared by Maillard reaction showed improved antioxidant, emulsifying, and anti-inflammatory properties than WPI, GA and WPI-GA-M. Moreover, WPI-GA-C showed unique effects in regulating the gut microbiota by significantly increasing the relative abundances of Bacteroides eggerthii and B. ovatus and enriching the pathways of carbohydrate metabolism and other amino acids metabolism. In brief, the conjugates showed better functional properties with the potential to improve human health by promoting the growth of beneficial bacteria.