Partial restoration of the microbiota of cesarean-born infants via vaginal microbial transfer

Exposure of newborns to the maternal vaginal microbiota is interrupted with cesarean birthing. Babies delivered by Cesarean section (C-section) acquire a microbiota that differs from that of vaginally delivered infants, and C-section delivery has been associated with increased risk for immune and metabolic disorders. Here we conducted a pilot study in which infants delivered by C-section are exposed to maternal vaginal fluids at birth. Similar to vaginally delivered babies, the gut, oral, and skin microbiome of these newborns during the first 30 days of life was enriched in vaginal bacteria underrepresented in unexposed C-section infants, albeit similarity to vaginally-delivered infants was higher in oral and skin than in anal samples. Although the long-term health consequences of restoring the microbiota of C-section born infants remain unclear, our results demonstrate that vaginal microbes can be partially restored at birth in C-section delivered babies

The composition of the zebrafish intestinal microbial community varies across development

The assembly of resident microbial communities is an important event in animal development; however, the extent to which this process mirrors the developmental programs of host tissues is unknown. Here we surveyed the intestinal bacteria at key developmental time points in a sibling group of 135 individuals of a model vertebrate, the zebrafish (Danio rerio). Our survey revealed stage-specific signatures in the intestinal microbiota and extensive interindividual variation, even within the same developmental stage. Microbial community shifts were apparent during periods of constant diet and environmental conditions, as well as in concert with dietary and environmental change. Interindividual variation in the intestinal microbiota increased with age, as did the difference between the intestinal microbiota and microbes in the surrounding environment. Our results indicate that zebrafish intestinal microbiota assemble into distinct communities throughout development, and that these communities are increasingly different from the surrounding environment and from one another