A research team at the University of Melbourne has documented changes in intestinal function and in the microbiome as a result of administration of vancomycin for the first 10-days after birth.  Effects persisted through to six weeks of age corresponding to young adulthood in humans.  Antibiotic-treated male mouse pups had significantly lower fecal weight compared to controls and antibiotic-treated females had longer whole gut transit times.  Fecal water content was increased in both male and female mouse pups.

Vancomycin affected myenteric and submucosal neurons with males more affected than females.  Antibiotic administration induced chronic changes in the microbiome of the colon with reduced serotonin levels in the mucosa.

Additional studies will have to be conducted since mice are not small humans, despite similarities in gastrointestinal function.  The study did, however, demonstrate that vancomycin had a prolonged effect on the enteric nervous system with possible parallels in human development.

*Poon, S. et al, Neonatal antibiotics have long-term sex-dependent effects on the enteric nervous system. Journal of Physiology. doi.org/10.1113/jp282939. September 2022