Research Article Association of Levels of Antibodies from Patients with Inflammatory Bowel Disease with Extracellular Proteins of Food and Probiotic Bacteria Arancha Hevia, 1 Patricia López, 2 Ana Suárez, 2 Claudine Jacquot, 3 María C. Urdaci, 3 Abelardo Margolles, 1 and Borja Sánchez 4 1 Instituto de Productos L´ acteos de Asturias, Consejo Superior de Investigaciones Cient´ ıficas (IPLA-CSIC), Paseo R´ ıo Linares s/n, Villaviciosa, 33300 Asturias, Spain 2 Department of Functional Biology, Immunology Area, University of Oviedo, C/Juli´ an Claver´ ıa s/n, Oviedo, 33006 Asturias, Spain 3 UMR 5248 CBMN CNRS-Universit´ e Bordeaux 1-ENITAB, Laboratoire de Microbiologie et Biochimie Appliqu´ ee, 1 Cours du G´ en´ eral de Gaulle, 33175 Gradignan Cedex, France 4 Nutrition and Bromatology Group, Department of Analytical and Food Chemistry, Food Science and Technology Faculty, University of Vigo, Ourense Campus, 32004 Ourense, Spain Correspondence should be addressed to Borja S´ anchez; borja.sanchez@uvigo.es Received 27 February 2014; Revised 18 May 2014; Accepted 19 May 2014; Published 4 June 2014 Academic Editor: Julio Villena Copyright © 2014 Arancha Hevia et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Inlammatory bowel disease (IBD) is an autoimmune disease characterized by a chronic inlammation of the gastrointestinal tract mucosa and is related to an abnormal immune response to commensal bacteria. Our aim of the present work has been to explore the levels of antibodies (IgG and IgA) raised against extracellular proteins produced by LAB and its association with IBD. We analyzed, by Western-blot and ELISA, the presence of serum antibodies (IgA and IgG) developed against extracellular protein fractions produced by diferent food bacteria from the genera Bifidobacterium and Lactobacillus. We used a sera collection consisting of healthy individuals (HC,  = 50), Crohn’s disease patients (CD,  = 37), and ulcerative colitis patients (UC,  = 15). Levels of IgA antibodies developed against a cell-wall hydrolase from Lactobacillus casei subsp. rhamnosus GG (CWH) were signiicantly higher in the IBD group ( < 0.002;  = 52). he speciicity of our measurements was conirmed by measuring IgA antibodies developed against the CWH peptide 365-VNTSNQTAAVSAS-377. IBD patients appeared to have diferent immune response to food bacteria. his paper sets the basis for developing systems for early detection of IBD, based on the association of high levels of antibodies developed against extracellular proteins from food and probiotic bacteria. 1. Introduction Inlammatory bowel disease (IBD) is an autoimmune disease characterized by a chronic inlammation of the gastroin- testinal tract (GIT) mucosa. Depending on the severity and location of the injuries, two main forms are distinguished, Crohn’s disease (CD) and ulcerative colitis (UC). Both are chronic disorders of unexplained origin, in which persistent ulcerations appear in the small or large bowel mucosa. Interestingly, genetic susceptibility only explains up to 23% of the disease, in the case of CD (16% for UC), with the rest being attributed to environmental factors, such as an exacerbated response of the innate immune system to the commensal microbiota [1]. Experiments in germ-free animals have shown that microbial colonization is crucial in the instruction, matura- tion, and regulation of the immune system. For instance, the presence of Bacteroides fragilis ofers protection from experi- mental colitis, induced by Helicobacter hepaticus, in an animal model, with this beneicial activity being dependent on the presence of an exopolysaccharide [2]. In addition, recent metagenomic studies with human samples have revealed that lifestyle in developing countries is associated with an altered microbial colonization of the human gut [3]. Indeed, Hindawi Publishing Corporation BioMed Research International Volume 2014, Article ID 351204, 8 pages http://dx.doi.org/10.1155/2014/351204