Acute hepatopancreatic necrosis disease (AHPND) reasoned by Vibrio parahaemolyticus has
caused severe damage to the shrimp farming industry of Vietnam. Probiotics are chosen as a
prophylactic method to mitigate the outbreak of diseases. We reported in this article the isolation and
evaluation the effect of a potential probiotic, Bacillus subtilis BLD01, which enhanced the survival
rates and changed gut microbiota of whiteleg shrimp (Penaeus vannamei) after challenge with
AHPND V. parahaemolyticus. After seven days of the challenge, the treatment where shrimps were
fed with B. subtilis BLD01 strain (106 CFU/g) and challenge with AHPND V. parahaemolyticus (106
CFU/mL) showed high survival rates of 71% as compared to 33% in the treatment where shrimp were
given standard feed without probiotics supplementation and challenged with AHPND V.
parahaemolyticus. 16S rRNA amplicon data of the shrimp gut microbiome in four treatments were
carried out using Illumina sequencing. A total of 231 436 reads were obtained, and a total of 14 phyla,
28 classes, 142 genera were revealed. The most abundant phyla in all subjects were Proteobacteria
and Bacteroidetes. The sequence number of the Vibrio genus was the highest with 28% in treatment
without B. subtillis BLD01 in-feed addition and shrimps challenged with AHPND V.
parahaemolyticus. The sequence number of Bacillus genus was the highest with 3% in the treatment
with B. subtillis BLD01 addition and without AHPND V. parahaemolyticus challenge. These results
contribute to confirm the mechanism of action of B. subtilis against V. parahaemolyticus in the
experimental model, creating a scientific basis for the development and use of probiotic products
applied in shrimp farming in Vietnam.