Identification of intestinal microbial population structure of Penaeus vannamei supplemented with chitosan oligosaccharide using 2bRAD-M

Abstract

ABSTRACT The intestinal microbiota of Penaeus vannamei is critical for its health and disease resistance, but imbalances can increase the risk of infections, especially by pathogenic Vibrio species. This study used the 2bRAD-M method to analyze the effects of dietary chitosan oligosaccharide (COS) supplementation on the gut microbiota of P. vannamei. Shrimp were fed diets with COS at 5‰ and 10‰ levels. Results showed that as COS concentration increased, beneficial microbial taxa (e.g., Bacteroidetes, Actinobacteria, and Campylobacter) significantly increased, while harmful bacteria decreased. For example, Vibrio parahemolyticus abundance dropped from 0.084 in controls to 0.033 in the 5‰ group, and Vibrio rotiforianus decreased from 0.216 in controls to 0.121 and 0.021 in the 5‰ and 10‰ groups, respectively. Photobacterium damselae also declined from 0.244 in controls to 0.049 and 0.094 in the 5‰ and 10‰ groups. These findings indicate that COS supplementation can enhance beneficial microbes and reduce harmful bacteria in P. vannamei intestines. This study highlights COS as a sustainable dietary intervention to improve shrimp health and reduce antibiotic use in aquaculture.IMPORTANCEThis study demonstrates that dietary chitosan oligosaccharide (COS) supplementation can effectively modulate the intestinal microbiota of Penaeus vannamei. At 5‰ and 10‰ levels, COS increased beneficial bacteria (e.g., Bacteroidetes and Actinobacteria) while reducing harmful pathogens like Vibrio parahaemolyticus and Vibrio rotiferianus. This shift enhances nutrient absorption, immune function, and disease resistance in shrimp. COS thus offers a sustainable alternative to antibiotics in aquaculture, promoting healthy growth and reducing environmental impact.

Keywords

• 2bRAD-M sequencing
• intestinal microbiome
• chitosan oligosaccharide
• intestinal health