title: Low-methoxyl pectin stimulates small intestinal mucin secretion irrespective of goblet cell proliferation and is characterized by jejunum Muc2 upregulation in rats.
abstract: Generally, soluble fibers increase small intestinal mucin secretion by increasing the number of goblet cells in a viscosity-dependent manner. The present study aimed to examine the mechanism by which low-methoxyl pectin (LPC) affects mucin secretion in the small intestine. First, diets containing 50 g/kg of low-viscosity fiber (LPC, gum arabic, guar gum, low-molecular konjac mannan, arabinogalactan, sodium alginate) or high-molecular konjac mannan (KMH) were fed to Wistar rats for 10 d. Luminal mucin was greater in the LPC and KMH groups than in the fiber-free control group, but only the KMH group had more goblet cells in the ileum compared with the other groups. Next, Sprague-Dawley rats were fed LPC, KMH, or high-methoxyl pectin (HPC) diets (50 g/kg) for 10 d. The KMH and LPC groups, but not the HPC group, had greater luminal mucin than the control group, whereas jejunum Muc2 expression was higher only in the LPC group. Sprague-Dawley rats fed the LPC diet for 1 or 3 d had greater luminal mucin and jejunum Muc2 expression than those fed the control diet. In vitro studies using HT-29MTX cells showed that, of the various fibers studied, only LPC and HPC affected mucin secretion. Finally, Wistar rats were fed the LPC diet with or without neomycin in drinking water for 10 d; neomycin treatment did not compromise the effect of LPC on mucin secretion. We conclude that LPC does not affect the number of goblet cells but can interact directly with the epithelium and stimulate small intestinal mucin secretion.
authors.affiliation: Department of Applied Biological Chemistry, Faculty of Agriculture, Shizuoka University, Shizuoka, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Hino
authors.forename: Kei
authors.initials: K
authors.lastname: Sonoyama
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Bito
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Kawagishi
authors.forename: Seiichiro
authors.initials: S
authors.lastname: Aoe
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Morita
mesh_terms: D000818:Animals; D002460:Cell Line; D049109:Cell Proliferation; D004043:Dietary Fiber / Q000378:metabolism; D019587:Dietary Supplements; D005638:Fruit / Q000737:chemistry; D020397:Goblet Cells / Q000166:cytology / Q000378:metabolism; D006801:Humans; D007082:Ileum / Q000166:cytology / Q000378:metabolism*; D007413:Intestinal Mucosa / Q000166:cytology / Q000378:metabolism*; D007583:Jejunum / Q000166:cytology / Q000378:metabolism*; D008297:Male; D027845:Malus / Q000737:chemistry; D008745:Methylation; D055262:Mucin-2 / Q000378:metabolism*; D009077:Mucins / Q000378:metabolism*; D010368:Pectins / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D015854:Up-Regulation; D014783:Viscosity
chemical_list: D004043:Dietary Fiber; C524628:Muc2 protein, rat; D055262:Mucin-2; D009077:Mucins; D010368:Pectins