Fusobacterium nucleatum: an emerging gut pathogen?

The Gram-negative, non-sporulating, obligately anaerobic species, Fusobacterium nucleatum, is rapidly gaining notoriety as a pathogen with a surprising number of associated diseases. Recently, we have found that F. nucleatum is a more common resident of the GI tract than originally thought, and thus, through several studies, we have attempted to determine its gut-relevant potential for virulence. We have found that F. nucleatum possesses a number of pathogenic traits with relevance to gut diseases such as inflammatory bowel disease (IBD), however, we have also documented strain-associated differences in virulence. An intriguing picture emerges that paints F. nucleatum as both conferring beneficial as well as detrimental effects on host cells; and we suggest that the ultimate effects of F. nucleatum infection in the gut are a consequence of the microbes with which this species aggregates.