title: Starch-enriched diet modulates the glucidic profile in the rat colonic mucosa.
abstract: OBJECTIVE
  The protective function of the intestinal mucosa largely depends on carbohydrate moieties that as a part of glycoproteins and glycolipids form the epithelial glycocalyx or are secreted as mucins. Modifications of their expression can be induced by an altered intestinal microenvironment and have been associated with inflammatory disorders and colorectal cancer. Given the influence of dietary factors on the gut ecosystem, here we have investigated whether a long term feeding on a starch-rich diet can modulate the glucidic profile in the colonic mucosa of rats.
  
  
  METHODS
  Animals were divided into two groups and maintained for 9 months at different diets: one group was fed a standard diet, the second was fed a starch-enriched diet. Samples of colonic mucosa, divided in proximal and distal portions, were processed for microscopic analysis. Conventional stainings and lectin histochemistry were applied to identify acidic glycoconjugates and specific sugar residues in oligosaccharide chains, respectively. Some lectins were applied on adjacent sections after sialidase/fucosidase digestion, deacetylation, and oxidation to characterize either terminal dimers or sialic acid acetylation.
  
  
  RESULTS
  An increase in sulfomucins was found to be associated with the starch-enriched diet that affected also the expression of several sugar residues as well as fucosylated and sialylated sequences in both proximal and distal colon.
  
  
  CONCLUSIONS
  Although the mechanisms leading to such a modulation are at present unknown, either an altered intestinal microbiota or a dysregulation of glycosylation patterns might be responsible for the types and distribution of changes in the glucidic profile here observed.
authors.affiliation: School of Biosciences and Veterinary Medicine, University of Camerino, Via Gentile III da Varano, I, Camerino, 62032, Macerata, Italy. gabriella.gabrielli@unicam.it.
authors.forename: Maria Gabriella
authors.initials: MG
authors.lastname: Gabrielli
authors.affiliation: School of Biosciences and Veterinary Medicine, University of Camerino, Via Gentile III da Varano, I, Camerino, 62032, Macerata, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Tomassoni
mesh_terms: D000818:Animals; D002240:Carbohydrate Sequence; D003106:Colon / Q000166:cytology / Q000378:metabolism*; D000070601:Diet, Carbohydrate Loading / Q000009:adverse effects*; D020895:Enterocytes / Q000166:cytology / Q000378:metabolism; D005260:Female; D005643:Fucose / Q000378:metabolism; D006017:Glycolipids / Q000737:chemistry / Q000378:metabolism*; D006023:Glycoproteins / Q000737:chemistry / Q000378:metabolism*; D006031:Glycosylation; D020397:Goblet Cells / Q000166:cytology / Q000378:metabolism; D007202:Indicators and Reagents / Q000032:analysis / Q000378:metabolism; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism*; D037102:Lectins / Q000032:analysis / Q000378:metabolism; D008871:Microvilli / Q000378:metabolism; D009077:Mucins / Q000737:chemistry / Q000378:metabolism*; D019158:N-Acetylneuraminic Acid / Q000378:metabolism; D017207:Rats, Sprague-Dawley; D013213:Starch / Q000009:adverse effects* / Q000378:metabolism
chemical_list: D006017:Glycolipids; D006023:Glycoproteins; D007202:Indicators and Reagents; D037102:Lectins; D009077:Mucins; C012564:sulfomucin; D005643:Fucose; D013213:Starch; D019158:N-Acetylneuraminic Acid
keywords: Colon; Glycosylation; Lectin histochemistry; Sialic acid; Starch-rich diet