Influence of high-protein diet on the functional ability of the liver in rats and correction possibilities

Aim. To study the changes of biochemical parameters of blood serum, the qualitative and quantitative composition of the large intestinal microbiota, the feces of prepubertal rats with a high-protein type of nutrition and following correction with the probiotic «Normobakt». Methods. To create a model, Wistar rats were used, who received a high-protein diet (35% of the total diet) for 7 weeks (group 1). The second group of laboratory animals received «Normobakt» preparation for 2 weeks. The control group was on a balanced diet. Biochemical parameters of blood serum were evaluated using an automatic biochemical analyzer СА-400 (Japan) with liquid stable diagnostic kits (Diasys, Germany). For bacteriological study, samples of feces and large intestine tissues of the laboratory animals were obtained. Results. In animals receiving a high protein diet, the biochemical parameters of blood serum were characterized by high levels of aspartate aminotransferase, alanine aminotransferase, total protein, triglycerides compared to the control group, and by contrast, concentration of cholesterol and Apo-A1-protein was decreased. In the microflora of the large intestine and feces, the level of opportunistic microflora remained unchanged, levels of Bifidobacterium spp. and Lactobacillus spp. were significantly lower than those of the control group. Correction with the «Normobakt» preparation led to a significant decrease of the levels of aspartate aminotransferase, total protein and glucose in the blood serum. Moreover, in microbiota of the large intestine and feces, the level of opportunistic microflora reduced to zero, but the concentration of Lactobacillus spp. and Bifidobacterium spp. significantly increased in comparison with the rat group without biotic correction. Conclusion. High-protein diet has a negative effect on the functional ability of the liver, causing an increase of aminotransferase activity, changes in cholesterol and protein metabolism, accompanied by changes of the intestine and feces microbiota; use of the drug «Normobakt» promotes normalization of the parameters; on the background of increasing levels of Lactobacillus spp. and Bifidobacterium spp. quantitative parameters of opportunistic microflora decrease.