Human milk oligosaccharides as a factor in the formation of differentiated microbiological profiles of the gut microbiota in infants during the first months of life

Abstract

Introduction . During the early postnanal life, gut microbiota establishment is an important stage of ontogenesis, which plays a key role in the development and maturation of the child's metabolic and immune systems. Oligosaccharides, which reach a child’s body with the breast milk and have prebiotic and immunomodulatory properties, are critical regulators in the formation of the microbial community. Aim . To assess taxonomic development of the gut microbiota in breastfed and formula-fed infants in the first months of life and interpret the characteristics of its metabolic potential from the perspective of the biological role of breast milk oligosaccharides. Materials and methods. We conducted a prospective, longitudinal, non-interventional, parallel-group cohort study. The study included 90 infants: 45 were breastfed, 45 were formula-fed, receiving a probiotic-containing infant formula supplemented with galactooligosaccharides, and 2'-fucosyllactose. The infants were observed on 30 ± 2, 60 ± 2, and 120 ± 2 days of age. Microbiological tests of stool samples were performed at Visits 1 and 3. After quality control, 126 samples from 64 infants were included in the final test, of which 34 were from breastfed infants and 30 from formula-fed infants. The LEfSe method was employed to identify significantly discriminative taxa between groups. Results. It was found that some statistically significant differences in the composition of the intestinal microbiota were stable between the groups both at 30 days and 4 months of age. These findings confirm that breastfeeding is a key factor for the early establishment of the intestinal microbiota. In its absence, the microbial colonization trajectories, the taxonomic structure, and the nature of interspecies interactions in microbial communities undergo changes. However, the inclusion of prebiotic components in infant formula is a key growth factor for Bifidobacterium. This helps to adjust the trend of development of the gut microbiota, bringing it closer to the breastfed infants’ indicators. Conclusions. As can be seen from the above, feeding type has a marked impact on the early development of the gut microbiota. A formula enriched with 2'-fucosyllactose promotes intestinal colonization by the bacterial genus Bifidobacterium. The increased proportion of these bacteria in formula-fed infants may be considered as an adaptive protective mechanism of the development of microbiota in the absence of breast milk.