Study: Babies’ microbiome may not be from vagina after all

Once we’re born, our fresh, pure body is rapidly colonised by micro-organisms from our mother and the environment. There has been some suggestion that the diseases we might get later in life are affected by this first microbiome.

There is controversy surrounding the differences in a baby’s microbiota depending on whether they were born vaginally or by caesarean.

Researchers have looked into the colonisation of hospital-related pathogens and the disruption to maternal Bacteroides strains such as Enterococcus, Enterobacter and Klebsiella species in babies born by C-section.

The researchers found the colonisation of these pathogens was less in babies delivered vaginally where the mother had antibiotics and in babies who were not breastfed during the first month or so of life.

The study

Over 1600 gut microbiota samples were taken at several points during the neonatal period and in infancy from almost 600 full-term babies. For some of the babies, samples from their mothers were also taken (175 mothers and 178 babies).

The United Kingdom researchers found that the mode of the baby’s delivery was a significant factor affecting the composition of the gut microbiota during the first month of life and into infancy.

After analysis, the 800 bacterial strains found in the babies identified virulence factors and antimicrobial resistance in opportunistic pathogens. This could, the researchers say, predispose the child to opportunistic infections.

The findings, say the researchers, highlight the critical role of the local environment of a baby’s birth in establishing the microbiome of our digestive tracts in these first, early stages of life. The colonisation of these pathogens has been identified as an ‘underappreciated risk factor in hospital births’.

References

Yan Shao et al. (2019) Stunted gut microbiota and increased pathogen colonisation associated with caesarean birth. Nature. DOI: 10.1038/s41586-019-1560-1