Intestinal microbiota in coeliac disease pathogenesis

SANZ YOLANDA; GIADA DE PALMA; MEDINA MARCELA; INMACULADA NADAL; DONAT ESTER; CARMEN RIBES-KONINCKX; MIGUEL CALABUIG

Budapest-Hungría

Congreso; 42th ESPGHAN Annual; 2009

European Society for Paediatric Gastroenterology Hepatology and Nutrition (ESPGHAN)

Intestinal microbiota in coeliac disease pathogenesis (PRESENTACION ORAL) Yolanda Sanz1*, Giada De Palma1, Marcela Medina1, Inmaculada Nadal1, Ester Donat2, Carmen Ribes-Koninckx2 and Miguel Calabuig3 *E-mail: yolsanz@iata.csic.es 1Microbial Ecophysiology and Nutrition Group. Institute of Agrochemistry and Food Technology (IATA), Spanish National Research Council (CSIC), Valencia, Spain; 2Hospital Universitario La Fe, Avenida Campanar 21, 40009 Valencia, Spain.3Hospital General Universitario, Avenida Tres Cruces s/n 46014 Valencia, Spain.  AIM: To evaluate the possible associations between intestinal dysbiosis and the presentation and evolution of coeliac disease (CD), and the potential role of specific bacteria in the inflammatory process associated with this disorder. METHODS: Altogether 64 children were included in the study: 26 untreated CD patients (mean age 5.5 years, range 2.1-12.0 years) on a normal gluten-containing diet, 18 symptom-free coeliac disease (SFCD) patients (mean age 5.5 years, range 1.0-12.3 years) treated with a gluten-free diet for at lest 2 years, and 20 healthy children (mean age 5.3 years, range 1.8-10.8 years) without known food intolerance. Microbiological analyses of faecal samples were carried out by using fluorescent in situ hybridization and flow cytometry techniques. Immunoglobulin-coated bacteria were detected using fluorescent-labelled antibodies by flow cytometry (FCM). The contribution of the faecal microbiota of CD patients to the pro-inflammatory milieu characteristic of CD and the possible benefits of Bifidobacterium strains were evaluated by analysing cytokine production and cell surface antigen expression in peripheral blood mononuclear cells (PBMCs) after stimulation with faecal samples and selected Bifidobacterium strains. Cytokines were analysed by ELISA and cell surface antigen expression by using fluorescent-conjugated antibodies and flow cytometry. RESULTS: IgA-coated faecal bacterial levels were significantly lower in both untreated and treated SFCD patients than in healthy controls. IgG and IgM-coated bacterial levels were also significantly lower in treated CD patients than in untreated CD patients and controls. Gram-positive to Gram-negative bacteria ratio was significantly reduced in untreated CD patients and in treated SFCD patients compared to controls. Bifidobacterium and Faecalibacterium prausnitzii groups were less abundant (P<0.050) in untreated CD patients than in healthy controls. In contrast, Bacteroides-Prevotella group was more abundant (P<0.050) in untreated CD patients than in controls. Faeces of both active CD and SFCD patients, representing an imbalanced microbiota, significantly increased TNF-a production and CD86 expression in PBMCs, while decreased IL-10 cytokine production and CD4 expression compared with control samples. Active CD-patient samples also induced significantly higher IFN-g production compared with controls. However, Bifidobacterium strains suppressed the pro-inflammatory cytokine pattern induced by the large intestinal content of CD patients and increased IL-10 production. CONCLUSION: CD is associated with intestinal dysbiosis and reductions in IgA-coated bacterial levels. Moreover, the intestinal microbiota of CD patients could contribute to the Th1 pro-inflammatory milieu characteristic of the disease, while B. longum ES1 and B. bifidum ES2 could reverse these deleterious effects. These findings provide new insights into the possible role of the intestinal microbiota in CD pathogenesis and hold future perspectives of interest in the disease therapy.