Investigating the effects of synbiotics, postbiotics and bacilli in the modulation of gut microbiota and the survival of Litopenaeus vannamei challenged with Vibrio parahaemolyticus.

The effect of feed and water additives was evaluated on the gut microbiota and survival of white shrimp challenged with V. parahaemolyticus. Bacillus licheniformis BCR 4 − 3 and vibrio cultures were spray dried. Inulin, probiotics, and postbiotics of bacilli (SPB) and postbiotics of vibrios (PVp) were added to commercial feed. Viable bacilli cells were added to water. An experiment with four treatments in triplicate was performed to determine the effect of diet on survival and the intestinal microbiota by sequencing the V3 region of the bacterial 16S ribosomal gene. Metagenomic analysis was performed on the Shaman, MicrobiomeAnalyst, and Ivikodak platforms. The growth was not affected by the additives but survival of animals in treatments was significantly higher as compared to control group. The phyla and genera that predominated in the white shrimp intestine were Proteobacteria, Bacteroidetes, Firmicutes, Vibrio, Agarivorans, Tropicibacter, and Roseovarius. The Vibrio genus increased in treatments with bacilli in feed and water and decreased in PVp in feed. The control and treatments shared 219 Operational Taxonomic Units. No changes were observed in the bacterial diversity (richness and relative abundance of species). In the bacterial community of the shrimp intestine (species replacement) changes were observed. Bacterial functional profile (Lipid, amino acid, and energy metabolism and digestive and immune systems) was modulated in treatments. Synbiotics, postbiotics, and bacilli in water enhance survival rates and modulated the gut microbiota of L. vannamei.