Characterization of milk fat globule membrane interaction with the gut microbiota

Abstract

Lipids' unique composition and arrangement in the human milk fat globule membrane (hMFGM) provides infants versatile benefits, including interaction with the gut and gut microbiota. Probiotics, such as Lactobacillus, associated with breastfed infants' gut microbiota have been proven effective in regulating intestinal health. Our study is designed to assess the probiotic potential of Lactiplantibacillus plantarum (MRK3), Limosilactobacillus ferementum (MK1) isolated from infant feces, and its interaction with globule membrane during conditions mimicking infant digestive tract, which is not well elucidated. The finding reveals that both strains (MK1, MRK3) had a high tolerance to gastrointestinal conditions (87-96%) with remarkable cell surface hydrophobic properties (>90%) and significantly strong anti-pathogen activity against S. aureus with an inhibition zone of 12 mm. Notably, significant difference in membrane-bound xanthine oxidase activity, membrane roughness, and surface topography was observed along the infant digestion tract. In the presence of hMFGM, survival of MRK3 was higher than MK1 throughout in vitro digestion. Scanning Transmission Electron Microscopy (STEM) and Scanning Electron Microscopy (SEM) results revealed structural integrity, interaction and successful entrapment of MRK3 in the membrane matrix throughout digestion. Interestingly, probiotic-membrane matrix interaction showed significant synergy to alleviate oxidative stress and damage induced by cell free supernatant (CFS) of E.coli infected Caco-2 cells. In addition, pre-incubation with hMFGM before adding CFS of E. coli and P. aeruginosa significantly reduces the deleterious effect of pathogens. Our results show that a probiotic encapsulated membrane matrix could protect against oxidative stress and disruption induced by pathogens in an infant's gut, thereby opening the route for developing functional infant formula.