IBD—what role do Proteobacteria play?

The gastrointestinal microbiota has come to the fore in the search for the causes of IBD. Microbial diversity studies have continually demonstrated an expansion of the Proteobacteria phylum in patients with IBD. In this Review, the authors comprehensively describe the various associations of Proteobacteria and IBD. They postulate that Proteobacteria with adherent and invasive properties might exploit host defenses, drive proinflammatory change, alter the intestinal microbiota in favor of dysbiosis and ultimately lead to the development of IBD.