Fermentable Dietary Fiber Increases GLP-1 Secretion and Improves Glucose Homeostasis Despite Increased Intestinal Glucose Transport Capacity in Healthy Dogs

Abstract

Ileal proglucagon gene expression and postprandial plasma concentrations of proglucagon-derived peptides are reported to change with the type and quantity of dietary fiber ingested by rats. Within the intestine, proglucagon encodes several proglucagon-derived peptides known to modulate intestinal absorption capacity and pancreatic insulin secretion. To determine whether the chronic ingestion of fermentable dietary fiber regulates the expression and synthesis of proglucagon-derived peptides in the distal intestine to modulate glucose homeostasis, the following study was conducted: 16 adult dogs (23 +/- 2 kg) were fed isoenergetic, isonitrogenous diets containing a mixture of high fermentable dietary fibers (HFF) or low fermentable (LFF) wood cellulose for 14 d in a randomized cross-over design. Food was withheld for 16 h before an oral glucose tolerance test was conducted supplying 2 g of glucose/kg body wt, and peripheral blood was collected via a hind-leg catheter at 0, 15, 30, 45, 60, 90 and 120 min for plasma glucose, insulin and glucagon-like peptide-1(7-36)NH2 (GLP-1) analyses. Intestinal samples were collected after the second dietary treatment. Ileal proglucagon mRNA, intestinal (GLP-1) concentrations and the integrated area under the curves (AUC) for plasma GLP-1 and insulin were greater and plasma glucose AUC was reduced when dogs were fed the HFF diet compared to the LFF diet (P < 0.05). Intestinal villi heights, brush border and basolateral glucose transporter protein abundance and jejunal transport capacities were significantly greater when dogs were fed the HFF diet than when fed the LFF diet. In conclusion, improvements in glucose homeostasis are observed in healthy dogs when they ingest fermentable fibers.

Impact of nutrition on canine behaviour: current status and possible mechanisms

“…In dogs fed a diet with a high level of fermentable fibres (sugarbeet pulp, gum arabic and fructo-oligosaccharides), intestinal GLP-1 concentrations were found to be increased compared with dogs fed a diet with low-fermentable fibre (cellulose) levels 168 . GLP-1 slows down gastric emptying 135 and intestinal transit 169 , which may result in prolonged gastric fill and delayed nutrient digestion and absorption.…”

Associations of Dietary Fiber With Glucose Metabolism in Nondiabetic Relatives of Subjects With Type 2 Diabetes

“…Furthermore, fiber regulates several metabolic hormones that affect glucose metabolism (17,33). There is evidence that improvements in glucose homeostasis observed through the long-term high intake of dietary fiber may be explained by increased intestinal proglucagon gene expression (36,37). Proglucagon encodes several proglucagon-derived peptides known to modulate intestinal absorption capacity and pancreatic insulin secretion Ylö nen and Associates (37).…”

“…There is evidence that improvements in glucose homeostasis observed through the long-term high intake of dietary fiber may be explained by increased intestinal proglucagon gene expression (36,37). Proglucagon encodes several proglucagon-derived peptides known to modulate intestinal absorption capacity and pancreatic insulin secretion Ylö nen and Associates (37). Finally, a concomitant intake of other dietary components that affect glucose metabolism and are highly correlated with fiber, e.g., chromium, magnesium, and manganese, may contribute to these beneficial effects.…”

Effect of Dietary Supplementation with Short-Chain Fructooligosaccharides in Lactating Sows and Newly Weaned Piglets on Reproductive Performance of Sows, Immune Response and Growth Performance of Piglets from Birth to Slaughter

“…As a prebiotic ingredient, scFOS modulate intestinal microbiota and increase VFA production in colon of many species, including pigs [21]. They also enhance insulin sensitivity in both healthy and obese animals [8,22]. The relationship between dietary scFOS supplementation, intestinal microbiota modulation and reduction of blood insulinemia has been recently highlighted in humanized gnotobiotic diet-induced obesity mice [23].…”