The immune-enhancing effects of dietary fibres and prebiotics

Abstract

The gastrointestinal tract is subjected to enormous and continual foreign antigenic stimuli from food and microbes. This organ must integrate complex interactions among diet, external pathogens, and local immunological and non-immunological processes. It is critical that protective immune responses are made to potential pathogens, while hypersensitivity reactions to dietary antigens are minimised. There is increasing evidence that fermentable dietary fibres and the newly described prebiotics can modulate various properties of the immune system, including those of the gut-associated lymphoid tissues (GALT). This paper reviews evidence for the immune-enhancing effects of dietary fibres. Changes in the intestinal microflora that occur with the consumption of prebiotic fibres may potentially mediate immune changes via: the direct contact of lactic acid bacteria or bacterial products (cell wall or cytoplasmic components) with immune cells in the intestine; the production of short-chain fatty acids from fibre fermentation; or by changes in mucin production. Although further work is needed to better define the changes, mechanisms for immunomodulation, and the ultimate impact on immune health, there is convincing preliminary data to suggest that the consumption of prebiotics can modulate immune parameters in GALT, secondary lymphoid tissues and peripheral circulation. Future protocols on the physiological impact of consuming prebiotics should be designed to include assessments of the gut microflora, gut physiology and the function and composition of the various regions of GALT.

Effects of the prebiotics inulin and lactulose on intestinal immunology and hematology of preruminant calves

“…Field et al, 1999;Schley and Field, 2002;Hosono et al, 2003). In this study, leukocyte counts in peripheral blood were decreased in lactulosetreated calves and monocyte numbers were decreased in both treatment groups.…”

“…It has been shown to lead to a shift in the intestinal bacterial flora toward more beneficial bifidobacteria , to impede carcinogenesis (Femia et al, 2002) or to stimulate the immune system (Schley and Field, 2002). In addition, it was shown to enhance growth performance of livestock (Van Loo, 2007).…”

Effects of inulin supplementation on selected faecal characteristics and health of neonatal Saanen kids sucking milk from their dams

“…Studies in humans and animals have shown that fructans can alter intestinal microbial populations, pH and SCFA concentrations and have the potential to positively affect host health, immune function and animal performance (digestion, BW gain, feed efficiency; Buddington et al, 2002;Saavedra and Tschernia, 2002;Schley and Field, 2002;Masanetz et al, 2011). However, data on the efficacy of fructans are variable owing to the type of fructans and basal diet used and animal characteristics (species, age, stage of production, health status) and are not yet fully conclusive (Schley and Field, 2002;De Vrese and Marteau, 2007).…”

“…However, data on the efficacy of fructans are variable owing to the type of fructans and basal diet used and animal characteristics (species, age, stage of production, health status) and are not yet fully conclusive (Schley and Field, 2002;De Vrese and Marteau, 2007).…”

Prebiotics: An Emerging Nutritional Approach for Improving Gut Health of Livestock and Poultry

“…Possible mechanisms underlying the immune-modulating effects may include: (a) Direct contact of lactic acid bacteria or bacterial products with immune cells in the intestine, (b) Production of SCFA from fermentation which increase T-cell numbers in the gastro-intestinal system and (c) Modulation of mucin production through increase in the number of goblet cells (Schley and Field, 2002). Prebiotics can modulate the type and function of cells from Gut Associated Lymphoid Tissue (GALT) especially payer's patches, secondary lymphoid tissues and peripheral circulation.…”