title: Oat β-glucan depresses SGLT1- and GLUT2-mediated glucose transport in intestinal epithelial cells (IEC-6).
abstract: Oat β-glucan consumption is linked to reduced risk factors associated with diabetes and obesity by lowering glycemic response and serum level of low-density lipoproteins. The purpose of this study was to identify the mechanism of action of oat β-glucan at the interface between the gut wall and the lumen responsible for attenuating glucose levels. We proposed that viscous oat β-glucan acts as a physical barrier to glucose uptake in normally absorptive gut epithelial cells IEC-6 by affecting the expression of intestinal glucose transporters. Concentration and time-dependent changes in glucose uptake were established by using a nonmetabolizable glucose analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino]-2-deoxy-d-glucose. The effectiveness of nutrient transport in IEC-6 cells was shown by significant differences in glucose uptake and corresponding transporter expression. The expressions of glucose transporters sodium-glucose-linked transport protein 1 (SGLT1) and glucose transporter 2 (GLUT2) increased with time (0-60 minutes) and glucose levels (5-25 mmol/L). The suppression of glucose uptake and SGLT1 and GLUT2 expression by increasing concentrations (4-8 mg/mL) of oat β-glucan demonstrated a direct effect of the physical properties of oat β-glucan on glucose transport. These results affirmed oat β-glucan as a dietary agent for minimizing postprandial glucose and showed that modulating the activity of the key intestinal glucose transporters with oat β-glucan could be an effective way of lowering blood glucose levels in patients with diabetes.
authors.affiliation: Department of Food Science, University of Guelph, Guelph, ON, Canada N1G 2W1.
authors.forename: Nazanin N
authors.initials: NN
authors.lastname: Abbasi
authors.affiliation: Departamento de Technología y Calidad de los Alimentos, Universidad Nacional del Centro de la Provincia de Buenos Aires, Buenos Aires, Argentina.
authors.forename: Peter P
authors.initials: PP
authors.lastname: Purslow
authors.affiliation: Food Research Centre, Agriculture and Agri-Food, Guelph, ON, Canada N1G 5C9.
authors.forename: Susan M
authors.initials: SM
authors.lastname: Tosh
authors.affiliation: Department Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada N1G 2W1. Electronic address: mbakovic@uoguelph.ca.
authors.forename: Marica
authors.initials: M
authors.lastname: Bakovic
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004847:Epithelial Cells / Q000187:drug effects* / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D051273:Glucose Transporter Type 2 / Q000235:genetics / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000378:metabolism; D007422:Intestines / Q000166:cytology / Q000187:drug effects*; D019518:Postprandial Period / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D051269:Sodium-Glucose Transporter 1 / Q000235:genetics / Q000378:metabolism*; D047071:beta-Glucans / Q000032:analysis / Q000494:pharmacology*
chemical_list: D000199:Actins; D051273:Glucose Transporter Type 2; D012333:RNA, Messenger; C495683:Slc2a2 protein, rat; C495676:Slc5a1 protein, rat; D051269:Sodium-Glucose Transporter 1; D047071:beta-Glucans; C067858:beta-glucan, (1-3)(1-4)-; D005947:Glucose
keywords: Diabetes; Glucose absorption; IEC-6 cells; Oat β-glucan; Soluble fiber; Viscosity