Researchers at the University of Chicago Medicine found that mice genetically susceptible to developing inflammatory bowel disease (IBD) and treated with antibiotics during the final stages of pregnancy and early post-birth period had an increased risk of their offspring developing IBD. The study, “Peripartum Exposure to Antibiotics Promotes Persistent Gut Dysbiosis, Immune Imbalance, and Colitis in Genetically Prone Offspring,” was published in the journal Cell Reports. The antibiotic treatment altered the gut microbiome (the natural community of microbes) of mothers, suggesting that the disturbed maternal microbiome contributed to the offsprings' increased risk for developing IBD. Notably, the adult mothers showed no increase in IBD burden, which suggests that the timing of exposure to antibiotics is crucial and early exposure can result in detrimental impacts to future generations. "The newborn mice inherited a very altered, skewed population of microbes," Eugene B. Chang, MD, the Martin Boyer Professor of Medicine at the University of Chicago, director of the microbiome medicine program of the Microbiome Center, and the study's lead author, said in a press release. These results, however, do not mean that mothers, during pregnancy or with newborn babies, should stop taking antibiotics if they have dangerous bacterial infections. Instead, they highlight the necessity for cautious assessment of antibiotic use, and that taking antibiotics "just to be safe" should be avoided.