Gut Bacteria Alterations Are Dependent on Offspring’s Sex
To prevent newborn sepsis caused by maternal Group B Streptococcus exposure, antibiotic use was promoted during labor and delivery starting in the 1990s. Since then, the use of prophylactic antibiotics given to laboring mothers has increased to more than 30% of all deliveries in the United States. However, this practice was implemented before our present-day and still emerging understanding of the microbiota’s important role in many aspects of health. Recently, researchers at the MIND Institute published a study investigating the effect of antibiotics administered to pregnant mice on offspring gut microbiome composition and metabolic capabilities. The researchers also investigated how these microbiota changes can influence the offspring’s immune responses. The study’s design involved administering a broad-spectrum antibiotic orally to pregnant mice during late gestation through birth. Post-birth, bacterial DNA was taken from offspring fecal samples and was then sequenced and analyzed. The offspring’s serum and brain tissue cytokine levels were also analyzed. The results showed that the antibiotic cocktail given to the pregnant mice produced significant diversity and taxonomic changes in their offspring’s microbiome. Also altered in the offspring were genomic and metabolic pathways. Interestingly, an increased Firmicutes/Bacteroidetes (F/B) ratio was found in female offspring but not males. An increased F/B ratio is associated with dysbiosis and metabolic disorders. The MIND Institute researchers concluded that maternal antibiotic exposure could produce long-lasting effects on the offspring’s gut microbiome and neuroimmune responses. They believe their findings demonstrate how important the role of the early microbiome is in the development of gastrointestinal and immune systems.
