Human milk oligosaccharides and lactose differentially affect infant gut microbiota and intestinal barrier in vitro. Simulated gut microbiota

This project assessed the effect of lactose, 2-FL, 2-FL+LNnT and a mixture of six HMOs (HMO6: consisting of 2-FL, LNnT, difucosyllactose, lacto-N-tetraose, 3- and 6-sialyllactose) on infant gut microbiota and intestinal barrier integrity using a combination of in vitro models to mimic the microbial ecosystem (baby M-SHIME) and the intestinal epithelium (Caco-2/HT29-MTX co-culture).The results showed that HMOs, especially HMO6, had a microbiota modulatory capacity and generated a significantly different fermentation profile compared to lactose. These results suggest that increased complexity in HMOs mixture composition may benefit the infant gut ecosystem, promoting different bifidobacterial communities and protecting the gut barrier against pro-inflammatory imbalances. These findings reinforce the relevance of breastfeeding practices for optimal infant nutrition.