The 'gut health' response to dietary Bio-Mos: effects on gut microbiology, intestinal morphology and immune response
Health and development of livestock, companion animals and humans depends greatly on a stable and healthy gastrointestinal microbial population. Rapid changes in the microflora and/or the proliferation of intestinal pathogens can lead to gastrointestinal diseases or even death.
The gut microflora depends on nutrient availability in both the small and large intestine. Processing techniques that overheat feed, or poor diet formulation, can reduce enzymatic digestion in the intestine, leading to increased flow of substrate available for microbial fermentation in the large intestine. This may lead to bacterial overgrowth and consequently digestive problems such as gastroenteritis or bloat.
Studies in food animals have shown that dietary inclusion of a type of oligosaccharide, mannan oligosaccharide (Bio-Mos, Alltech Inc.), derived from the outer cell wall of a specific strain of Saccharomyces cerevisiae, has been associated with reductions in Salmonella and E. coli (Spring, 2002).
Mannan-based oligosaccharides can have a direct impact on pathogenic enteric bacteria colonisation. Mannose residues essentially block the type-1 fimbriae by which many bacteria including many pathogenic coliforms attach to the intestinal wall (Spring et al., 2000).
Colostrum quality is also improved when Bio-Mos is included in gestation diets of mares, sows and cows.
Specific immunity was enhanced by Bio-Mos supplementation of dry cow diets as evidenced by greater serum rotavirus neutralisation titers at calving (Franklin et al., 2005).
A wide range of techniques has been employed to investigate the effects of Bio-Mos on immune function. Responses in innate and cellmediated immunity include increased activity/effectiveness of phagocytic cells (Sisak, 1995; Zennoh, 1995), reduced incidence of vaccine failure in broilers (KÃµrÃ¶si and KÃµrÃ¶si-MolnÂ¡Â¡ï¿½ï¿½Â¢r, 2003), reduced inflammatory (fever) response in poults injected with LPS from S. typhimurium strain SL 684 (Ferket, 2002), and changes in lymphocyte proliferative response to mitogens (PHA) in broilers (Cotter and Weinner, 1997).
In studies with food animals, the indirect (and welcome) responses to enhanced immunity are improved weight gain and efficiency, which are assumed to reflect a reduced need to divert nutrients to immune function. Importantly, this implies an overall lower, not 'stimulated', immune response.
Bio-Mos supplementation affects intestinal morphology, which has an important role in enteric disease resistance. Ferket (2002) examined jejunum villi morphology in 14-day old poults given diets supplemented with no additive, Bio-Mos or virginiamycin. Bio-Mos had a greater effect on gut morphology.
Weight gain and efficiency of Bio-Mos-supplemented poults were also significantly improved, which may have been due at least in part to more surface area available for nutrient absorption.
Gut health involves maintenance of a robust gut microbial population and a chemical environment conducive to enzymatic digestion along with the normal morphology of the intestinal epithelium.
When a balanced and adequately high population of bacteria is in place, intestinal pH is maintained in the range optimum for digestive enzyme activity, which prevents shifting site of digestion to the hindgut, and opportunistic pathogens are rapidly excluded. Bio-Mos affects microbial populations with a resulting increase in desirable versus undesirable species.
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Article made possible through the contribution of Alltech.