One of the most productive areas of disease-related microbiome research has been in gastrointestinal conditions, since an estimated 80% of gut microbes cannot be cultured using routine methods.52 This has limited the study of a variety of pediatric conditions in which disruption of gut microbial balance is suspected as a key component of pathogenesis, like necrotizing enterocolitis (NEC), obesity, and inflammatory bowel disease. 53, 54 With genomic tools, conditions like NEC are yielding to study; rationally selected treatments including probiotics, although still controversial, may eventually provide real benefits. In inflammatory bowel disease, marked progress in understanding the complex interplay of microbial and host genomic factors that results in aberrant inflammation has helped pave the way for a diversity of new targeted treatment approaches.55
