Analysis of bacterial community shifts in the gastrointestinal tract of pigs fed diets supplemented with β-glucan from Laminaria digitata, Laminaria hyperborea and Saccharomyces cerevisiae

Abstract

This study was designed to evaluate the effects of algal and yeast b-glucans on the porcine gastrointestinal microbiota, specifically the community of Lactobacillus, Bifidobacterium and coliforms. A total of 48 pigs were fed four diets over a 28-day period to determine the effect that each had on these communities. The control diet consisted of wheat and soya bean meal. The remaining three diets contained wheat and soya bean meal supplemented with b-glucan at 250 g/tonne from Laminaria digitata, Laminaria hyperborea or Saccharomyces cerevisiae. Faecal samples were collected from animals before feeding each diet and after the feeding period. The animals were slaughtered the following day and samples were collected from the stomach, ileum, caecum, proximal colon and distal colon. Alterations in Lactobacillus in the gastrointestinal tract (GIT) were analysed using denaturing gradient gel electrophoresis (DGGE) profiles generated by group-specific 16S rRNA gene PCR amplicons. Plate count analysis was also performed to quantify total coliforms. DGGE profiles indicated that all b-glucan diets provoked the emergence of a richer community of Lactobacillus. The richest community of lactobacilli emerged after feeding L. digitata (LD b-glucan). Plate count analysis revealed that the L. hyperborea (LH b-glucan) diet had a statistically significant effect on the coliform counts in the proximal colon in comparison with the control diet. b-glucan from L. digitata and S. cerevisiae also generally reduced coliforms but to a lesser extent. Nevertheless, the b-glucan diets did not significantly reduce levels of Lactobacillus or Bifidobacterium. DGGE analysis of GIT samples indicated that the three b-glucan diets generally promoted the establishment of a more varied range of Lactobacillus species in the caecum, proximal and distal colon. The LH b-glucan had the most profound reducing effect on coliform counts when compared with the control diet and diets supplemented with L. digitata and S. cerevisiae b-glucans.Keywords: b-glucans, pigs, algae, yeast, denaturing gradient gel electrophoresis ImplicationsAdministration of antibiotics to animals has come under intense scrutiny because of their contribution to the dissemination of antibiotic-resistant bacteria into the food chain. Algal and yeast b-glucans are biologically active resources from nature. With respect to animal production, an important goal is to determine the optimal microbiota for the animal and then be able to manipulate the microbiota through the diet, supplements, etc. to obtain the desired microbiota. b-glucans derived from macroalgae and yeast aid in gut health during periods of intestinal imbalance, leading to the alteration in the microbial community composition and hence offering an easily accessible alternative to antibiotics. This paper focuses on the use of a molecular and a cultivation-based method to monitor fluctuations in the gastrointestinal microbiota caused by algal and yeast b-glucan supplementation of the pig diet. Molecular analysis of the Lactobaci...

Effect of Whole-Grain Barley on the Human Fecal Microbiota and Metabolome

“…According to this study, cultivable Bacteroides was negatively affected in polypectomized patients after intake of barley ␤-glucans (27). In vitro and animal trials support that Enterobacteriaceae could not utilize ␤-glucans (20,25,50). According to in vitro and animal trials, this study showed a significant reduction in cultivable Enterobacteriaceae and total coliforms.…”

“…An increased level of lactobacilli was found in animal models after a barley-or oat-containing diet, especially using high-viscosity ␤-glucans (22,23,24). At the same time, an oat product-based diet or ␤-glucans from Laminaria digitata, Laminaria hyperborea, and Saccharomyces cerevisiae did not increase the levels of lactobacilli in pigs and rats (25,50). Taken together, these results suggested that the prebiotic potential of whole-grain barley/␤-glucan was not always reproducible in vivo.…”

“…In particular, the positive effects of ␤-glucans on the growth of beneficial intestinal lactobacilli and bifidobacteria were shown in in vitro studies (20,21) and animal experiments (22,23). Nevertheless, other studies that also used animal models did not show significant effects of ␤-glucans on lactobacilli and/or bifidobacteria (24,25). Unfortunately, human clinical challenges that have dealt with the prebiotic effect of ␤-glucans are rather scarce.…”

Influence of different prebiotics and mode of their administration on broiler chicken performance

“…(Jaskari et al, 1998). More recently, Laminaria spp.-derived laminarin has been shown to increase intestinal Lactobacilli numbers in weaned pigs and also reduce coliforms (Murphy et al, 2013). Fucoidan has also been shown to have prebiotic effects in the porcine monogastric model (Lynch et al, 2010;Sweeney et al, 2011).…”

Intestinal microbiota and immune related genes in sea cucumber (Apostichopus japonicus) response to dietary β-glucan supplementation

“…b-glucan can benefit host, including mirror carp (Cyprinus carpio L.) [19], pig [20], juvenile beluga (Huso huso) [21] and broilers [22], by selectively stimulating the growth and/or activity of one or certain microbial genera/species. This study evaluated the intestinal microbiota in sea cucumber response to dietary b-glucan supplementation.…”