NEONATAL EXPOSURE TO ANTIBIOTICS: WHAT IS HAPPENING TO THE MICROBIOME?

The microbiota is influenced by several factors such as age, stress, disease, diet, antibiotics, etc. Antibiotics (Abx) are the most commonly used drugs in pediatrics in western countries. Early life antibiotic exposure causes alterations in the gut microbiota and associated with increased risk for inflammatory bowel disease (IBD), overweight, and asthma. The aim of the current study was to examine the impact of neonatal antibiotic administration on weight, metabolic changes and gut microbiota up to 6 months from the exposure time compared to control (CT) neonates. We perform fecal transplants to GF mice from all experimental and control infants in order to further test the microbial effects on the different pathways presented. The identification of the microbiota from neonates and mice stool samples was performed using 16S rRNA gene sequences. We monitor changes in the immune system by comparing levels of pro-inflammatory cytokines as well a metabolic hormones in the serum of Abx- treated vs. control subjects. Our results show that penicillin had major effects on infants and mice microbiota as long as 6 months after treatment with significance reduction in Bifidobacterium spp. In addition, mice after FMT from Abx neonates gain less weight compared to CT fecal transplants mice and had significant reduction in mucin degrading and SCFA producer’s bacteria. To date, there is no conclusive opinion regarding the impact of neonatal antibiotic exposure and these results raise concern about the use of AB early in life.