Four bacterial strains isolated from the gastrointestinal tract of adult shrimp Litopenaeus vannamei, Vibrio alginolyticus UTM 102,
Bacillus subtilis UTM 126, Roseobacter gallaeciensis SLV03, and Pseudomonas aestumarina SLV22, were evaluated for potential use
as probiotics for shrimp. In vitro studies demonstrated antagonism against the shrimp-pathogenic bacterium, Vibrio parahaemolyticus
PS-017. Feeding shrimp with diets containing the potential probiotics showed the best feed conversion ratio in comparison with the control
groups. After feeding with the potential probiotics for 28 days, challenge by immersion indicated effectiveness at reducing disease
caused by V. parahaemolyticus in shrimp.