Non–digestible oligosaccharides and defense functions: lessons learned from animal models

Abstract

Animals are constantly exposed to a diversity of health challenges and the gastrointestinal tract (GIT) is a major, if not the principal, site of exposure. Animal models and a limited number of human clinical studies have shown that the assemblages and metabolic activities of the resident bacteria are important determinants of the effectiveness of the various host defense mechanisms and thereby influence the ability of animals to respond to health challenges. The assemblages of bacteria resident in the GIT provide a first line of defense that can exclude invading pathogens, reduce the proliferation of opportunistic pathogens already resident in the GIT, and reduce the availability, carcinogenicity, or toxicity of noxious chemicals. The mucosa of the GIT is a second, multilayered line of defense that includes the mucous and other secretions, the epithelial cells, and immune-associated cells scattered within and under the epithelium. The final line of defense contends with pathogens or noxious chemicals that transcend the mucosal barrier and enter the host and consists of the innate and acquired components of the systemic immune system and the xenobiotic metabolizing enzymes. The lactic acid producing bacteria (LAB) are considered to be immunomodulatory and directly or indirectly influence the GIT and systemic defense functions. Corresponding with this, supplementing the diet with inulin, oligofructose, or other nondigestible oligosaccharides that increase the densities and metabolic capacities of the LAB enhances defense mechanisms of the host, increases resistance to various health challenges, and accelerates recovery of the GIT after disturbances. b-fructans: Inulin: Oligofructose: Oligosaccharides: Immune: Lactic acid bacteria:Gastrointestinal tract

Proportion of Murine Cytotoxic T Cells is Increased by High Molecular-Weight Fucoidan Extracted from Okinawa mozuku (Cladosiphon okamuranus)

“…In addition, the oral administration of easily fermented oligosaccharides such as short-chain fructooligosaccharide and oligofructose affects T cell status and tumor induction. 11,12) Those results suggest that the molecular weight of indigestible saccharides administered by orally can influence immune function.…”

Specific Response of a Novel and Abundant Lactobacillus amylovorus -Like Phylotype to Dietary Prebiotics in the Guts of Weaning Piglets

“…Nowadays, the emergence of antibiotic resistance in the human commensal bacteria has raised concerns about the impact of anitimicrobial compounds for agricultural use (53) and has accelerated the search for alternative nutritional strategies, such as the addition of probiotics and prebiotics. These approaches have become an increasingly important consideration in swine nutrition because of accumulating evidence of their potential benefits in animals and humans and the possibility that they could replace antibiotics in feed (5,21,61,64). The development of such dietary strategies requires a combination of in vitro, in vivo, and challenge studies involving both expertise in animal nutrition and an evaluation of the composition and activity of the indigenous microbiota throughout the GI tract.…”

The Impact of the Use of Symbiotics in the Progression of Nonalcoholic Fatty Liver Disease in a Rat Model

“…The results may also be related to the intestinal microbiota, since the metabolic profile and bacterial composition of the microbiota determine a greater or lesser inflammatory response, depending on the predominant host strains 19 . Symbiotics may also alter the synthesis of short chain fatty acids (SCFA) due to the presence of Bifidobacterium , Lactobacillus and oligosaccharides 6 , 26 . SCFA can alter the expression of genes involved in neoglycogenesis or beta-oxidation, thereby increasing the energy extraction from diet and intrahepatic fat.…”