The etiology of Crohn's disease (CD) is multifactorial. Bacterial and fungal microbiota are involved in the onset and/or progression of the disease. A bacterial dysbiosis in CD patients is accepted; however, less is known about the mycobiome and the relationships between the two communities.
View Article and Find Full Text PDFMicrobial ecology studies are often performed through extraction of metagenomic DNA followed by amplification and sequencing of a marker. It is known that each step may bias the results. These biases have been explored for the study of bacterial communities, but rarely for fungi.
View Article and Find Full Text PDFBackground And Aims: Mesalazine (5-aminosalicylic acid) is the standard first-line therapy for mild-to-moderate ulcerative colitis. In the PINCE study, remission rates were significantly greater with combined oral/enema vs. oral/placebo treatment at 8 weeks (64% vs.
View Article and Find Full Text PDFBackground: Fibrosis is a serious consequence of Crohn's disease (CD), often necessitating surgical resection. We examined the hypothesis that IL-13 may promote collagen accumulation within the CD muscle microenvironment.
Methods: Factors potentially modulating collagen deposition were examined in intestinal tissue samples from fibrotic (f) CD and compared with cancer control (C), ulcerative colitis (UC) and uninvolved (u) CD.
Background: Iron is an essential cofactor in almost all biological systems. The lactic acid bacteria (LAB), frequently employed as probiotics, are unusual in having little or no requirement for iron. Iron in the human body is sequestered by transferrins and lactoferrin, limiting bacterial growth.
View Article and Find Full Text PDFThe majority of T cells in the human and mouse intestine express the T-cell receptor (TCR) as an alphabeta heterodimer on their cell surface. As the major recognition element of antigens in the context of major histocompatibility complex-derived proteins, an examination of the structure of the alpha beta TCR in intestines has provided significant insights into the potential function of these cells and the major determinants that drive their selection. Studies in the human intestine have shown that the repertoires of intraepithelial lymphocytes (IELs), and likely lamina propria lymphocytes, are polyclonal before and shortly after birth, with the repertoire becoming oligoclonal in adults.
View Article and Find Full Text PDFSimilarities between Johne's disease in ruminants and Crohn's disease in humans have led to speculation that Mycobacterium avium paratuberculosis (MAP) might be a causative agent in Crohn's disease. However, evidence remains inconsistent. In this case-control study (1999-2004), the authors assessed the possible role of drinking water and dairy products potentially contaminated with MAP in the etiology of Crohn's disease.
View Article and Find Full Text PDFIn humans, intestinal antigen exposure during neonatal life influences the T-cell receptor (TCR) repertoire. To define the relative effects of bacteria and food antigens in early life, we examined TCR diversity in the intestine of SPF and GF mice. TCR repertoire was assessed at a single time point pre-, peri- and post-weaning in the small and large intestine of SPF and GF mice using spectratyping and/or TCR-beta-chain sequencing.
View Article and Find Full Text PDFObjectives: We sought to determine whether irritable bowel syndrome (IBS) was associated with attentional bias toward symptom-related cues in IBS patients versus healthy controls, using a modified Stroop task to measure selective processing of gastrointestinal symptom-related cues.
Methods: Fifteen patients with a clinical diagnosis of IBS and 15 healthy controls were recruited into the study. All participants attended a single testing session, during which they completed a modified Stroop task using gastrointestinal symptom-related and neutral control words.
Colonization with commensal flora in very early life may profoundly influence intestinal lymphoid development and bias later immune responses. We defined gut-homing T cell phenotypes and the influence of flora on intestinal immune development in mice. Intestinal T cells were phenotyped and quantified in conventional (CV), germfree (GF) and conventionalized germfree (GF/CV) neonatal mice by immunohistochemistry.
View Article and Find Full Text PDFIntestinal Ag exposure during neonatal life influences appropriate adult immune responses. To define the mechanisms shaping the T cell repertoire during this period, we examined T cell differentiation and receptor diversity in the intestine of human infants. Developmental phenotypes of intraepithelial and lamina propria intestinal T cells from infants aged 1 day to 2 years were assessed ex vivo by flow cytometry and in situ by triple-fluorescent immunohistochemistry.
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