The influence of dietary fibers on cell immunity under the adequate nutrition and in the presence of alimentary polyhypovitaminosis in rats
AbstractThe effect of wheat bran on cell immunity in rats adequately provided with vitamins or insufficiently supplied with vitamins has been investigated. 48 male Wistar rats (58,1±0,5 g) were divided into 6 group and fed with complete semi-synthetic diet, containing 100% or 20% of vitamin mixture (Vit) with or without supplement of insoluble dietary fiber (DF) in the dose corresponding to the upper allowable level of its consumption (5% wheat bran of diet mass) for 4 weeks. The animals of the 1 group received 100% of vitamin mixture (100% Vit); 2 group – 100% Vit+DF; 3 group – 20% of vitamin mixture (20% Vit); 4 group – 20% of vitamin mixture and DF (20% Vit+DF). The next 5 days rats from vitamin-deficient groups were fed with diets supplemented with 80% of Vit: (5 group – 20% Vit+ 80% Vit; 6 group – 20% Vit+DF+80% Vit). The contents of lymphocytes, relative quantity of B- (CD45RA+) and T-lymphocytes (CD3+), subpopulations of T-lymphocytes: T-helper (CD3+CD4+) and cytotoxic T-lymphocytes (CD3+CD8+), NK-cells (CD161a+) in the peripheral blood of rats were determined by the method of flow cytometry using Beckman Coulter FC 500 (USA) cytometer. In rats fed complete semi-synthetic diet supplemented with DF (100% Vit+DF) the reduction of relative contents of T-lymphocytes and the increase of the fraction of cytotoxic T-lymphocytes in peripheral blood has been found. The analogous changes and more pronounced degree of immunosupression, that appeared in a lymphocytopenia, much smaller level of T-lymphocytes, T-helper and increase of cytotoxic T-lymphocytes content in rats fed a low vitamins diet (20% Vit) in comparison with these parameters of control group, have been detected. In rats received 20% Vit+DF the suppressed cell immunity was accompanied with decreased level of NK-cells. Normalization of vitamins content in the diets of rat deficient groups led to an almost complete recovery of cell immunity indicators to the level of the animals from the corresponding control groups. Inclusion in the diet of fiber requires its further enrichment with vitamins. Special studies of fiber diet influence on are needed to clarify the upper allowable level of insoluble dietary fiber in human nutrition.
Keywords:cell immunity, subpopulations of lymphocytes, alimentary combined vitamin deficiency, insoluble dietary fibers