Influences of Intestinal Bacteria in Human Inflammatory Bowel Disease

The Gut Microbiota and IBD

“…Another consistent fi nding seen in multiple studies in patients with CD is that the phylum Firmicutes has been shown to be reduced [ 52,[55][56][57][58][59] . Speci fi cally, Faecalibacterium prausnitzii , a Firmicute , has been found to be decreased in IBD [60][61][62] .…”

“…In CD, there have been consistent fi ndings of increase in mucosa-associated E. coli in both the ileum and colon. The E. coli isolated in CD is often adherent and invasive (AIEC) phenotype, which is characterized by the invasion of epithelial cells and replication within macrophages [ 51 ] without causing cell death and induction of the secretion of the tumor necrosis factor (TNF)-a [ 51,52 ] . CD-associated AIEC strains are also capable of adhering to ileal enterocytes in patients with CD, however not from control enterocytes [ 53 ] .…”

Colorectal Adenocarcinoma and Inflammatory Bowel Disease: An Update and Review

“…Although these types dominate, there are over 1500 genera and thousands of different species present [45]. IBD patients exhibit a "dysbiosis" in their gut microbiota but whether these changes are causative or associative remains to be shown [46,47]. A number of difference have been described in the literature, with studies having found changes in the number of microbes present, alterations in community composition, increased adherence to mucosa, invasiveness or virulence of select species, and alterations in functional and metabolic characteristics [46,47].…”

“…IBD patients exhibit a "dysbiosis" in their gut microbiota but whether these changes are causative or associative remains to be shown [46,47]. A number of difference have been described in the literature, with studies having found changes in the number of microbes present, alterations in community composition, increased adherence to mucosa, invasiveness or virulence of select species, and alterations in functional and metabolic characteristics [46,47]. Germ-free mice, those with no intestinal bacteria, are less likely to develop oncogenetic mutations or tumor formation [48,49].…”

Manipulation of Microbiome, a Promising Therapy for Inflammatory Bowel Diseases

“…Endeavors on deciphering this complication wind up in 3 hypotheses: i) there is a subset of gut flora that not only triggers, but also persists after the onset of IBD, however, the identification exceeds the capacity of current methodology; ii) the causative agent has been wiped out by the time of disease occurrence; iii) the microbiome is influenced by underlying defects in the mucosal immune system and does not directly cause the inflammation [107].…”