<p class="first" id="d26012482e77">Inflammatory bowel disease (IBD) is a chronic immune-mediated
disease affecting the
gastrointestinal tract. IBD consists of 2 subtypes: ulcerative colitis and Crohn disease.
IBD is thought to develop as a result of interactions between environmental, microbial,
and immune-mediated factors in a genetically susceptible host. Of late, the potential
role of the microbiome in the development, progression, and treatment of IBD has been
a subject of considerable interest and enquiry. Indeed, studies in human subjects
have shown that the gut microbiome is different in patients with IBD compared with
that in healthy control subjects. Other evidence in support of a fundamental role
for the microbiome in patients with IBD includes identification of mutations in genes
involved in microbiome-immune interactions among patients with IBD and epidemiologic
observations implicating such microbiota-modulating risk factors as antibiotic use,
cigarette smoking, levels of sanitation, and diet in the pathogenesis of IBD. Consequently,
there has been much interest in the possible benefits of microbiome-modulating interventions,
such as probiotics, prebiotics, antibiotics, fecal microbiota transplantation, and
gene manipulation in the treatment of IBD. In this review we will discuss the role
of the gut microbiome in patients with IBD; our focus will be on human studies.
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