Efeitos do consumo de kefir de leite na lactação por ratas Wistar sobre a microbiota do leite materno, microbiota e saúde intestinal da prole superalimentada no período neonatal

Abstract

Environmental factors, when present during critical periods of development, such as lactation, can play a fundamental role in health during childhood and/or adulthood, a phenomenon known as "metabolic programming." In this context, the intake of probiotics like milk kefir during this period may result in beneficial effects on the intestinal microbiota of newborns. Thus, the objective of this study was to evaluate the effects of milk kefir consumption by lactating Wistar rats during lactation on the microbiota of maternal milk and the gut microbiota and health of the overfed offspring during the neonatal period. In this study, lactating Wistar rats and their offspring were divided into four groups: normal litter (NL), kefir normal litter (KNL), small litter (SL), and kefir small litter (KSL), based on litter size (NL: 10 or SL: 3) and probiotic consumption. The rats were daily fed via gavage with commercial feed + water (NL and SL) or commercial feed + probiotics (1.0 x 108 CFU/mL). The body weight of the offspring was assessed daily, with the overfed groups gaining more weight over 21 days. Sequencing of the 16S rRNA gene in maternal milk revealed the predominance of the phyla Proteobacteria, Firmicutes, and Actinobacteriota, with some differences in the abundances of bacterial genera observed between groups. Sequencing of the offspring's intestinal microbiota showed variation in beta diversity, and the phyla Bacteroidota, Firmicutes, Proteobacteria, and Campylobacterota were the most abundant. Some differences in the abundances of bacterial genera in the intestinal microbiota were also observed between groups. No statistically significant differences were found in the morphometric analysis of intestinal crypts between groups, as well as in the analysis of short-chain fatty acid concentration in the offspring's feces. Thus, maternal milk kefir consumption during lactation had positive effects on the intestinal microbiota of the offspring, particularly at the phylum level, and a possible influence of litter size on the maternal milk microbiota was observed. However, one aspect to be considered is the short period of 21 days, which indicates the need for further research to fully understand the potential benets of milk ker on the microbiota and intestinal health.