Effects of galacto-oligosaccharide and bacterial status on mucin distribution in mucosa and on large intestine fermentation in rats

Abstract

The purpose of the present paper was to study the effects of a dietary undigestible carbohydrate and intestinal microflora on mucin distribution (neutral, acid, sulphonated), glycolytic activities: beta-D-galactosidase (EC 3.2.1.23), N-acetyl-beta-D-galactosaminidase (EC 3.2.1.43), N-acetyl-beta-D-glucosaminidase (EC 3.2.1.30), alpha-L-fucosidase (EC 3.2.1.51) and bacterial metabolism (gas production, short-chain fatty acids (SCFA) and lactic acid caecal concentration) in germ-free (GF), conventional (CV) and heteroxenic (HE) rats (GF rats associated with a human flora). Rats were fed on either a control diet or a diet containing 40 g trans-galactosylated oligosaccharide (TOS)/kg. In GF rats fed on the control diet caecal pH was almost neutral and glycolytic activities negligible. The number of mucus-containing cells increased from the caecum to the colon for the three types of mucin. TOS had no effect in the caecum but it modified mucin cell repartition in the colon. In CV and HE rats fed on the control diet caecal pH was similar (6.8), but caecal SCFA and lactic acid concentrations (mumol/g) and gas production (ml/24 h) were higher in CV (70, 5.9 and 2.3 respectively) than in HE rats (32, 4.6 and 0.4 respectively). In CV, as in HE rats, acid-mucin-containing cells increased from the caecum to the colon and glycolytic activities were similar. TOS reduced acid-mucin-containing cells in the caecum of CV rats by twofold but had no effect in either the caecum or the colon of HE rats. TOS strongly increased beta-galactosidase activity and slightly modified the other glycolytic activities. Its effect on bacterial metabolites depended on bacterial status. However, comparison between CV and HE rats showed no evident relationship between the number of mucus-containing cells and measured bacterial metabolites. Differences between CV and HE rats might be due to bacterial microflora specificity. TOS had an intrinsic effect on mucus cell distribution in the colon of GF rats. In CV and HE rats the presence of the flora abolished this effect.

Influences of probiotic bacteria on organic acid production by pig caecal bacteriain vitro

“…All correlation coefficients shown were significant (P < 0·05 constitutes the major part of the mucin in the bulk-phase contents (Meslin et al 1993), from which the inoculum was taken.…”

Galacto-oligosaccharides and colorectal cancer: Feeding our intestinal probiome

“…A study by Zhong et al (2009) showed that GOS feeding significantly improved intestinal barrier function in rats with severe acute pancreatitis [170] . An earlier study by Meslin et al [88] showed that consumption of β (1–4) GOS [(referred as trans galacto-oligosaccharides (TOS) in the study] modified the mucin cell distribution in the colon of germ-free rats. The authors hypothesized that the lower number of mucus cells observed for the three types of mucins (neutral, acid, and sulphonated) in the proximal colon and the greater number in the distal colon was related to changes in osmolality produced by β (1–4) GOS.…”

Mise au point d'un dosage sélectif des différents types de mucines gastro-intestinales : utilisation de réactifs histochimiques

“…Nos observations en histologie (Meslin et al, 1993) (Bara et al, 1990;Yamori et al, 1989). Perumal et ai (1966) (Filipe, 1979;Mian et al, 1979).…”