Dietary supplementation of galactooligosaccharides (GOS) in Pacific white shrimp, Litopenaeus vannamei, cultured in a recirculating system and its effects on gut microflora, growth, stress, and immune response

This study was designed to examine the effects of a prebiotic compound on the immune system, digestive tract histology, and stress physiology of shrimp. The specific effects of dietary supplementation of the prebiotic galactooligosaccharide (GOS or GTGOS) on shrimp health are scarce. This experiment, therefore attempted to evaluate the effects of GOS on growth, survival, intestinal microbiota, stress resistance and immune responses of Pacific white shrimp, Litopaneous vannamei. Over a 35-day trial, shrimps were fed diets, 15 times a day using automated feeder, supplemented with GOS at 0%, 0.25%, and 0.40% by weight. Shrimp survival and weight gain among the treatment groups were good but not significantly different (P >.05). Shrimp fed GOS-supplemented diets had reduced stress (glucose, P <.05) and increased immune responses (total hemocyte counts and phagocytic capacity, P <.05) compared to shrimps fed only basal diet with no supplementation. These results suggest that GOS not only changed the populations of gut microbiota but also reduced stress levels and enhanced immune response in shrimp.