Effects of phytobiotic feed additives on productivity and gut microbiota of common carp

Background.The use of phytobiotics in feeding may be a promising approach to control animal diseases without antibiotics. The aim of our study was to evaluate the effect of phytobiotic feed additives on the growth performance and on gut microbiome of common carp. Materials and methods.The paper presents the results of a study on the use of phytobiotic feed additives in carp feeding: “Intebio” – an additive based on a mixture of essential oils (garlic, lemon, thyme and eucalyptus) and “Butitan” - a balanced microencapsulated combination of ellagotannins (sweet chestnut wood extract). Results.When the studied additives were included in the diet of fish, a growth-stimulating effect was established: with the inclusion of “Butitan” by 11.7% (P≤0.05), and with “Intebio” by 8.8% (P≤0.05), relative to the control. The introduction of phytobiotic feed additives “Butitan” and “Intebio” into the diet of carp had a significant effect on the gut microbiome of fish. A decrease in the number of bacteria of phylumActinomycetota,BacillotaandBacteroidotaand an increase in the content of microorganisms of taxaPseudomonadotaandFusobacteriota(genus Cetobacterium) were found, which was reflected in the change in the number of microorganisms ofMicrobacteriaceae,Chitinophagaceae, andunclassified_Bacillotafamilies. The analysis of the sequencing results showed that the impact of “Intebio” led to a change in the dominant genera of bacteria in the gut microbiota of fish. Numerous groups were bacteria of the genusAeromonas, the genusVibrioand the genusCetobacterium. Conclusion.The results obtained showed that the inclusion of “Butitan” and “Intebio” in the diet of carp has a positive effect on the indicators of body weight gain and can potentially be used as a basis for drugs to modify the gut microbiota.