Microbial Modulation of Host Intestinal Glycosylation Patterns

Abstract

The host and its intestinal microora function together as a complex ecologic system in which there is a significant impact of the intestinal flora on the host. The structure and functioning of the gastrointestinal tract are dependent upon the presence of the resident and transient flora. The inuence of the microflora on the secretory pattern of the intestinal glycoconjugates is an emerging field of research. This review summarizes and examines the evidence that commensal intestinal bacteria can modulate the host intestinal glycosylation patterns. Changes in the glycosylation patterns might be associated with the induction and/or degradation of glycans, and are usually studied using either in vitro or in vivo models. In vitro microbial modulation of the intestinal glycosylation remains largely related to the degradation of glycoconjugates. On the other hand, most of the in vivo studies are associated with the induction of particular glycan structures. These two processes are associated but often analysed independently. Likewise, there are few studies involving the same bacterial species and for which both in vitro and in vivo approaches are used. On-going research should focus both the induction and degradation of glycoconjugates and the use of in vitro and in vivo models in a combined manner. The biological role of alteration in complex carbohydrate expression has yet to be determined. Due to their localisation at the cell surface in the gastrointestinal tract, glycans act as mediators of many host-microbial interactions, providing a wide range of binding sites for bacteria, pathogens and toxins. The knowledge of host receptors and their possible microbial modulation may lead to improved means of control and treatment of bacterial infections. Keywords: host-microbial interactions, intestinal glycosylation, in vivo , in vitro , commensal microflora.