Fusobacterium varium in Ulcerative Colitis: Is It Population-Based?

摘要: Certain members of the Fusobacterium genus, notably F. nucleatum, necrophorum, and varium have recently gained notoriety as gastrointestinal pathogens; nucleatum in particular has been associated with appendicitis, Crohn’s disease, colorectal cancer [2]. was first ulcerative colitis (UC) by Ohkusa et al. [3], who subsequently characterized bacteria isolated from inflamed mucosal biopsies ten patients active UC. Remarkably, half tested samples contained varium, which, when cultured, produced a butyrate-rich supernatant that induced experimental UC mice [3]. The same group demonstrated can invade colonic epithelial cells initiate proinflammatory response [4]. Moreover, combination antibiotic therapy proven vitro effectiveness against reduced counts while improving clinical activity endoscopic histological scores, compared to non-treated control [5], inducing long-term remission-typical alteration intestinal microflora [6]. These preliminary data support an association between infection disease activity. In this issue Digestive Diseases Sciences, Tahara colleagues use quantitative real-time polymerase chain reaction (qPCR) report prevalence spp. biopsy tissues obtained 152 screen [1], building on reported Okhusa group. qPCR rather than culture terminal restriction fragment length polymorphism (T-RFLP) much larger cohort stratified according severity is technically methodologically superior procedures used prior studies. Building findings demonstrating emerging importance gut pathogen, PCR primers specific for species addition designed amplify diverse species, termed ‘‘pan-Fusobacterium signatures’’ which were present 54.6 % specimens tested, although only 6.3 positives suggesting population at least, not significantly disease. Although primer sets study searching organism future likely yield important data. number recent studies, high-throughput sequencing methods probe microbial composition gut-derived inflammatory bowel including [7–9]. Intriguingly, none work indicates are particularly prevalent, or even present, studied. How these be reconciled discussed above? First, potential pathogenic role has, date, examined Japanese patients, whereas most sequence-based analyses performed cohorts other parts Asia, well North America Europe. Because its unique history, Japan mostly countries until * 150 years ago, explained observed differences microbiota populations comparison [10, 11]. It possible, then, dysbiosis triggered Westernization Japan, widely thought responsible increasing rates IBD there, could manifest variations taxa among world’s peoples? Thus, involvement (in varium) E. Allen-Vercoe (&) Molecular Cellular Biology, University Guelph, Canada e-mail: eav@uoguelph.ca