Effect of green propolis crude extract on the modulation of intestinal microbiota and on the productive performance of juvenile Nile tilapia.

The study aimed to investigate the impact of dietary supplementation with green propolis crude extract on juvenile tilapia's growth and intestinal microbiota. The experiment was conducted in raceway tanks with a volume of 19m, comprising two treatments with three replicates each. Fish were assigned to either a control diet or a diet supplemented with 0.67% green propolis crude extract. Each experimental unit consisted of 30 fish, initially averaging 22.38 g ± 0.32 in weight, and which were fed ad libitum for 60 days. Results demonstrated that dietary supplementation with green propolis crude extract significantly improved the growth of juvenile tilapia compared to the control group. Firmicutes, Proteobacteria, Verrucomicrobia, Bacteroidetes, and Cyanobacteria were identified as the predominant bacterial phyla in the intestinal microbiota of both groups. The genera Candidatus xiphinematobacter (Verrucomicrobia) and Somerae (Firmicutes) were consistently abundant across treatments, with Somerae and Dispar as the most prevalent species. Significant differences in alpha diversity were observed between treatments at the genus and species levels according to the Chao 1 index. However, no significant differences were detected in Shannon index diversity between the control and green propolis crude extract groups. Beta diversity analysis revealed distinct clustering between treatments. Linear discriminant analysis Effect Size (LEfSe) highlighted significant differences in bacterial abundance between the control and green propolis crude extract groups. In conclusion, dietary supplementation with green propolis crude extract improved growth. It also modulated the intestinal microbiota of juvenile Thai tilapia.