Toxicological and Biochemical Parameters of the Influence of the New Probiotic for Pigs Based on Bacillus Bacteria on Laboratory and Target Species of Animals

Abstract

The development of new domestic probiotics targeted at immunomodulatory effects is both timely and holds scientific and practical value. To carry out preclinical studies of the 'Combio' probiotic, which is a mixture of probiotic bacteria Bacillus subtilis, Bacillus licheniformis, Bacillus amyloliquefaciens, Enterococcus faecium and other substances developed by the team of authors of SSRILDVSE, under the conditions of several toxicological experiments on laboratory (white rats, rabbits) and target animals toxico-biochemical parameters were identified. The findings of the trial of the acute toxicity of the 'Combio' probiotic showed that the LD50 value could not be calculated, since the death of laboratory animals was not registered within 14 days after administration; the maximum administered dose of the preparation (by absolute weight) was 30,000.0 mg/kg of body weight, which allows it to be assigned to toxicity class VI – relatively harmless substances (LD50>15,000.0 mg/kg of body weight), and according to the degree of danger to IV class – low-risk substances (LD50>5000.0 mg/kg body weight). When applied to the skin (acute dermal toxicity) and the mucous membrane of the eye of rabbits in doses from 750.0 to 3000.0 mg/kg of body weight, the 'Combio' probiotic did not have an irritating effect, and according to the degree of danger, it can be classified as IV class – low- hazardous substances (LD50>2500.0 mg/kg of body weight). According to the results of extended oral feeding of the probiotic in doses of 1500.0; 7500.0 and 15000.0 mg/kg of feed it showed no evidence of hematological, hepatic, or nephrotoxic effects on the laboratory animals under subacute toxicological conditions. On the contrary, it showed the ability to induce metabolic responses in the bodies of white rats (according to dynamics of hematopoiesis and liver protein-synthesizing functions, especially at therapeutic doses). The dynamics of changes in metabolic indicators during extended 60-day oral feeding of probiotics to target animals and poultry in the dose range showed no evidence of hematological, immunological, or hepatoxic effects and correlated with the hematological indicators, which indicated the restoration of nonspecific resistance and the protein profile in the bodies of experimental animals and a sign of increased metabolic respond and immune responsiveness in pigs organisms. The findings regarding the effect of the new 'Combio' probiotic based on the bacteria Bacillus spp. in several experiments on laboratory and target (pigs) animals give grounds to assert that it is ecologically safe and promising for the result – improving the survival rate of target animals and poultry, increasing their body weight gain, optimizing feed conversion, and enhancing the overall quality of production.