Specific Effects of Guar Gum or Gum Arabic on Adaptation of Cecal Digestion to High Fiber Diets in the Rat

Abstract

The objective of this work was to examine whether the nature of fiber may influence the cecal digestion in the rat fed hydrocolloids such as gums. Adaptation to a high fiber diet containing 15% guar gum (GG) or gum arabic (GA) was thus studied in rats previously adapted to a high starch fiber-free diet. Both gums elicited a marked enlargement of the cecum and a trophic effect on the cecal wall. The cecal pH dropped to 5.8, then plateaued to about 6.1. During the first days of adaptation, a part of GA escaped microbial degradation; thereafter the cecal pool of volatile fatty acids (VFA) was similar with both diets (approximately equal to 1000 mumol). GA promoted propionate-rich fermentations, whereas GG rather enhanced acetic and butyric fermentations. VFA absorption was higher with the gum diets than with the control diet, because blood flow increased in parallel to the weight of cecal wall. K+, Mg2+ and Ca2+ were absorbed in large amounts from the cecum, particularly in rats fed the GA diet. With this diet, high concentrations of nonsoluble Ca2+ and phosphate (but low concentrations of soluble phosphate) were found in the cecum. The study indicates that gums have potent effects on digestion in the large bowel, and that there are specific effects of the different types of gums.

The Role of Viscosity and Fermentability of Dietary Fibers on Satiety- and Adiposity-Related Hormones in Rats

“…Fermentable fibers are well known to induce enlargement of the cecum [14,15,16], as least in part due to the trophic effects of short chain fatty acids, products of fermentation [17,18]. The greater cecum contents weight is likely due to the increased bacterial mass with fermentation and the greater amount of water that would accompany it.…”

“…Additionally, those who have greater intakes of fiber tended to weigh less or experience less weight gain over time [6,7,8,9,10]. However, some have found fiber to have no effect on subjective satiety [11,12,13,14]. The different types and amounts of fibers used in these studies may contribute to the inconsistent results, as different types of dietary fibers may not influence satiety and food intake equally.…”

Toxicity evaluation of a β-galactosidase preparation produced by Penicillium multicolor

“…Examples include wheat bran (Jacobs and Schneeman, 1981), glucomannan (Konishi et al, 1984), guar gum (Tulong et al, 1987), pectin (Zhao et al, 1995), and fructo-and galactooligosaccharides (Sakaguchi et al, 1998). Tilactase, especially at very high doses, is not likely to be completely digested in the upper gastrointestinal tract.…”

Dietary Factors Influencing Magnesium Absorption in Humans

“…Pectin is typically found in the cytosole and the cell membrane of plants, pectin concentration in fruits and vegetables is around 1% [230]. Several rat studies indicated bacterial fermentation of pectin and, similarly, of gums such as gum arab and guar gum [231,232]. Demigné et al [233] found that addition of 10% pectin to the diet over 21 d periods significantly increased Mg flux from the caecum to the blood.…”