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.

Goblet cells and mucus layer in the gut of young pigs: Response to dietary contents of threonine and non‐essential amino acids

“…It should be taken also into consideration that Thr‐imbalanced diet may interact directly with epithelium and enhance or impair mucin release from GC without changes in GC number. However, that mechanism of stimulation of mucin secretion was observed only in the jejunum of rats fed diet containing low‐methoxyl pectin (Hino et al, ).…”

Low‐methoxyl lemon pectin attenuates inflammatory responses and improves intestinal barrier integrity in caerulein‐induced experimental acute pancreatitis

“…LMP easily penetrates the mucin layer of the intestine wall [21], which facilitates the interaction of LMP with the intestinal epithelia. It is found that LMP but not HMP stimulate small intestinal mucin secretion by direct interaction with the epithelium [22].…”

Dietary Fibers from Fruits and Vegetables and Their Health Benefits via Modulation of Gut Microbiota

“…Low-methoxylation pectin is typically used for drug delivery, gene delivery, wound healing, tissue reparation, and in edible films (Espitia, Du, Avena-Bustillos, Soares, & McHugh, 2014;Munarin, Tanzi, & Petrini, 2012). Notably, low-methoxylation pectin is fermented more rapidly than highmethoxylation pectin (Dongowski, Lorenz, & Proll, 2002) and protects epithelial cells by stimulating intestinal mucin secretion (Hino et al, 2013).…”