Modulation of the Intestinal Microbiota Alters Colitis-Associated Colorectal Cancer Susceptibility

It is well established that the intestinal microbiota plays a key role in the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC) collectively referred to as inflammatory bowel disease (IBD). Epidemiological studies have provided strong evidence that IBD patients bear increased risk for the development of colorectal cancer (CRC). However, the impact of the microbiota on the development of colitis-associated cancer (CAC) remains largely unknown. In this study, we established a new model of CAC using azoxymethane (AOM)-exposed, conventionalized-Il10−/− mice and have explored the contribution of the host intestinal microbiota and MyD88 signaling to the development of CAC. We show that 8/13 (62%) of AOM-Il10−/− mice developed colon tumors compared to only 3/15 (20%) of AOM- wild-type (WT) mice. Conventionalized AOM-Il10−/− mice developed spontaneous colitis and colorectal carcinomas while AOM-WT mice were colitis-free and developed only rare adenomas. Importantly, tumor multiplicity directly correlated with the presence of colitis. Il10−/− mice mono-associated with the mildly colitogenic bacterium Bacteroides vulgatus displayed significantly reduced colitis and colorectal tumor multiplicity compared to Il10−/− mice. Germ-free AOM-treated Il10−/− mice showed normal colon histology and were devoid of tumors. Il10−/−; Myd88−/− mice treated with AOM displayed reduced expression of Il12p40 and Tnfα mRNA and showed no signs of tumor development. We present the first direct demonstration that manipulation of the intestinal microbiota alters the development of CAC. The TLR/MyD88 pathway is essential for microbiota-induced development of CAC. Unlike findings obtained using the AOM/DSS model, we demonstrate that the severity of chronic colitis directly correlates to colorectal tumor development and that bacterial-induced inflammation drives progression from adenoma to invasive carcinoma

Evaluation of a Non-invasive Method to Detect Cytomegalovirus (CMV)-DNA in Stool Samples of Patients with Inflammatory Bowel Disease (IBD): A Pilot Study

A severe flare of colitis in patients with IBD treated with immunosuppressive therapy may be complicated by an underlying CMV infection. The aim of this pilot study was to investigate the diagnostic efficacy of quantitative polymerase chain reaction (PCR) to detect CMV DNA in stool samples of IBD patients

Inter- and Intraobserver Reliability and Validation of a New Method for Determination of Eosinophil Counts in Patients with Esophageal Eosinophilia

Diagnosis of eosinophilic esophagitis (EoE) requires quantification of esophageal eosinophilia

Modulation of the Intestinal Microbiota Alters Colitis-Associated Colorectal Cancer Susceptibility

It is well established that the intestinal microbiota plays a key role in the pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC) collectively referred to as inflammatory bowel disease (IBD). Epidemiological studies have provided strong evidence that IBD patients bear increased risk for the development of colorectal cancer (CRC). However, the impact of the microbiota on the development of colitis-associated cancer (CAC) remains largely unknown. In this study, we established a new model of CAC using azoxymethane (AOM)-exposed, conventionalized-Il10−/− mice and have explored the contribution of the host intestinal microbiota and MyD88 signaling to the development of CAC. We show that 8/13 (62%) of AOM-Il10−/− mice developed colon tumors compared to only 3/15 (20%) of AOM- wild-type (WT) mice. Conventionalized AOM-Il10−/− mice developed spontaneous colitis and colorectal carcinomas while AOM-WT mice were colitis-free and developed only rare adenomas. Importantly, tumor multiplicity directly correlated with the presence of colitis. Il10−/− mice mono-associated with the mildly colitogenic bacterium Bacteroides vulgatus displayed significantly reduced colitis and colorectal tumor multiplicity compared to Il10−/− mice. Germ-free AOM-treated Il10−/− mice showed normal colon histology and were devoid of tumors. Il10−/−; Myd88−/− mice treated with AOM displayed reduced expression of Il12p40 and Tnfα mRNA and showed no signs of tumor development. We present the first direct demonstration that manipulation of the intestinal microbiota alters the development of CAC. The TLR/MyD88 pathway is essential for microbiota-induced development of CAC. Unlike findings obtained using the AOM/DSS model, we demonstrate that the severity of chronic colitis directly correlates to colorectal tumor development and that bacterial-induced inflammation drives progression from adenoma to invasive carcinoma

Tryptase Staining of Mast Cells May Differentiate Eosinophilic Esophagitis from Gastroesophageal Reflux Disease

Mast cells may contribute to the pathogenesis of eosinophilic esophagitis (EoE), but their role in diagnosis is unknown. Our aim was to determine whether tryptase staining of esophageal mast cells differentiates EoE from GERD and has utility for diagnosis of EoE

Clinical, Endoscopic, and Histologic Findings Distinguish Eosinophilic Esophagitis From Gastroesophageal Reflux Disease

Features of eosinophilic esophagitis (EoE) and gastroesophageal reflux disease (GERD) overlap; because they cannot be differentiated based on eosinophil counts alone, it can be a challenge to distinguish between these disorders. We aimed to characterize the clinical, endoscopic, and histologic features of EoE and GERD and identify factors that might be used to differentiate them