The pediatric intestinal mucosal microbiome remains altered after clinical resolution of inflammatory and ischemic disease

Background: The pediatric intestinal microbiome is impacted by many factors including age, diet, antibiotics, and environment. We hypothesized that in surgical patients, changes in antibiotics and mechanoluminal stimulation would demonstrate measurable changes in the intestinal microbiome; and that microbial diversity would be reduced without normal mechanoluminal stimulation and with prolonged antibiotic treatment. Methods: Bacterial 60s16s rRNA was extracted from swabbed samples of 43 intestines from 29 patients, aged 5 days to 13 years old, obtained during initial resection or later stoma closure. Samples were compared using phylogenetic diversity whole tree alpha diversity, unweighted UniFrac distance beta diversity, and by comparing significantly different taxonomic groups. Results: Microbial community structure varied significantly between obstructive and infectiousinflammatory diseases (p=0.001), with an effect size of 0.99 (0.97, 1.00). This difference persisted even six weeks after return to health. Family Enterobacter and Clostridiaceae predominated in patients with necrotizing enterocolitis or focal intestinal perforation; patients with an obstructive pathology had an abundance of Bacteroides. Comparison of UniFrac distance between paired proximal and distal intestines demonstrated that paired samples were significantly closer than any other comparison. Conclusions: In infants, infectiousinflammatory and ischemic intestinal pathologies treated with prolonged courses of antibiotics durably alter the intestinal mucosal microbiome. Diversion of mechanoluminal stimulation, however, does not.