The results of the study of the effects of glyphosate and antibiotics on the composition and functions of the intestinal microbiome of broilers

Background.The combined effect of residual amounts of pesticides and antibiotics in poultry feed can lead to a negative effect on the composition of the intestinal microbiome of livestock. Purpose. To analyze changes in the composition of broilers intestinal cecum microbiome under the influence of glyphosate in an amount of 1 MPC for food products in isolation and with a combination of glyphosate with antibiotics and an anticoccidial drug. Materials and methods.The experimental birds were divided into 4 groups: Group I - control, which received the basic diet (BD), experimental group II - BD with the addition of glyphosate; III experimental - BD with the addition of glyphosate and veterinary antibiotics; IV experimental - BD with the addition of glyphosate and anticoccidial drug. The composition of bacteria was determined by NGS sequencing on a MiSeq automatic sequencer (Illumina, Inc., USA). PICRUSt2 (v.2.3.0) software (https://github.com/picrust/picrust2) was used to perform functional activity prediction of the metagenome, gene families, and proteins. Results.The results showed that under the influence of glyphosate (experimental group II), on the 7th and 40th days of life of broilers, microorganisms of the phylum Proteobacteria were completely eliminated from the community of microorganisms in the chyme of the intestinal cecum; on the 14th day, their content decreased by 3 .7 times compared to control group I (P≤0.05). In groups III and IV, their number increased compared to group II to 3.1 and 7.9 times, respectively (P≤0.05). At 7 days of age in experimental group II, as well as at 7-40 days of age in experimental group III, the number of Ruminococcaceae and Oscillospiraceae bacteria decreased to 10.3 and 11.8%, respectively, compared to control group I (P≤0. 05). Changes in the composition of microbial taxa under the influence of pesticides and medicinal substances introduced into feed led to changes in 185 potential functional pathways (P≤0.05). Thus, the activity of the pathways of energy, carbohydrate, protein metabolism, fat metabolism, biosynthesis of coenzymes and cofactors, vitamins decreased in experimental groups II-IV compared to control group I (P≤0.05). Conclusion.Our data indicate that during the experimental contamination of feed with the herbicide glyphosate, the introduction of veterinary antibiotics and anticoccidial drug into the feed in the caeca of the intestines of broiler chickens, changes in the structure of the microbiome occurred already at high taxonomic levels, and critical inhibition was also observed important potentially underlying functional pathways. This can negatively affect the host's body.