Restoration of gut microbiota with a specific synbiotic-containing infant formula in healthy Chinese infants born by cesarean section
Birth mode and other early life factors can affect the microbial colonization process in neonates with potential long-term health effects. Birth by cesarean section (C-section) is associated with a delayed colonization of bifidobacteria and Bacteroidota species in infancy. Previously, it was shown that an infant formula with a synbiotic mixture of short-chain galacto-oligosaccharides and long-chain fructo-oligosaccharides (scGOS/lcFOS [9:1]) and Bifidobacterium breve M-16V can restore the timely colonization of bifidobacteria in healthy C-section born infants. In this study, we investigated the effects of this synbiotic mixture added to a partially hydrolyzed whey-based protein formula (n=112) on gut microbiota development in healthy Chinese infants participating in a growth equivalence trial (NCT03520764). The trial included a control group (n=112), which received an intact protein formula with the prebiotic scGOS/lcFOS, and a breastfed reference group (n=60). Gut microbiota profiling by 16S rRNA gene sequencing of stools collected at baseline, 17 weeks (end of intervention) and 12 months of age was complemented with analysis of stool pH, short-chain fatty acids, lactic acids, and secretory IgA concentrations. Here, we confirm that both the prebiotic and the synbiotic formula support a dominant and diverse infant-type bifidobacterial community, but with increased abundance of Bifidobacterium breve in the synbiotic group indicating the colonic delivery of the probiotic strain. Additionally, the synbiotic formula restored the bifidobacterial species diversity and the abundance of Parabacteroides and Bacteroides spp. in healthy C-section born infants closer to that of healthy vaginally born infants with effects observed  beyond the intervention period.