Dietary inulin affects the expression of intestinal enterocyte iron transporters, receptors and storage protein and alters the microbiota in the pig intestine

• Published in: British journal of nutrition Vol. 99; no. 3; pp. 472 - 480
• Main Authors: Tako, E., Glahn, R. P., Welch, R. M., Lei, X., Yasuda, K., Miller, D. D.
• Format: Journal Article
• Language: English
• Published: Cambridge, UK Cambridge University Press 01.03.2008
• Subjects: Animal Nutritional Physiological Phenomena; Animals; Bacteria; Bacteria - isolation & purification; Bifidobacterium; Biological and medical sciences; Cation Transport Proteins - metabolism; Cecum - microbiology; Colon - metabolism; Cytochrome b Group - metabolism; Diet; Dietary Carbohydrates - pharmacology; E coli; Enterocytes - drug effects; Enterocytes - metabolism; Feeding. Feeding behavior; Fundamental and applied biological sciences. Psychology; Gene Expression Regulation - drug effects; Growth - drug effects; Growth - physiology; Hemoglobins - metabolism; Intestinal gene expression; Intestine, Small - metabolism; Inulin; Inulin - pharmacology; Iron; Iron - metabolism; Iron-Binding Proteins - metabolism; Lactobacillus; Microbiota; Mucins - biosynthesis; Mucins - genetics; Nutrition; RNA, Messenger; Sus scrofa; Triticum aestivum; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Intestinal gene expression; Microbiota; Iron; Inulin; Digestive system; Gut; Microflora; Gene expression; Pig; Vertebrata; Mammalia; Storage; Inulin: Iron: Intestinal gene expression: Microbiota; Enterocyte; Artiodactyla; Prebiotic; Ungulata; Carrier protein; Biological receptor
• ISSN: 0007-1145; 1475-2662
• DOI: 10.1017/S0007114507825128

Inulin, a linear β fructan, is present in a variety of plants including chicory root and wheat. It exhibits prebiotic properties and has been shown to enhance mineral absorption and increase beneficial bacteria in the colon. The aim of the present study was to assess the effect of dietary inulin on the gene expression of selected intestinal Fe transporters and binding proteins. Anaemic piglets at age 5 weeks were allocated to a standard maize–soya diet (control) or the same diet supplemented with inulin at a level of 4 %. After 6 weeks, the animals were killed and caecum contents and sections of the duodenum and colon were removed. Segments of the genes encoding for the pig divalent metal transporter 1 (DMT1) and duodenal cytochrome-b reductase (Dcytb) were isolated and sequenced. Semi-quantitative RT-PCR analyses were performed to evaluate the expression of DMT1, Dcytb, ferroportin, ferritin, transferrin receptor (TfR) and mucin genes. DMT1, Dcytb, ferroportin, ferritin and TfR mRNA levels in duodenal samples were significantly higher in the inulin group (P ≤ 0·05) compared with the control. In colon, DMT1, TfR and ferritin mRNA levels significantly increased in the inulin group. Additionally, the caecal content microflora was examined using 16S rDNA targeted probes from bacterial DNA. The Lactobacillus and Bifidobacterium populations were significantly increased in the inulin group (P ≤ 0·05) compared with the control group. These results indicate that dietary inulin might trigger an up regulation of genes encoding for Fe transporters in the enterocyte. The specific mechanism for this effect remains to be elucidated.