Effects of the glutathione administration via dietary on intestinal microbiota of white shrimp, Penaeus vannamei, under cyclic hypoxia conditions

Abstract

Environmental stress can impair the survival, growth performance, and intestinal environment of shrimp. The objective of this study was to investigate the effect of glutathione (GSH) on the survival, growth performance, intestinal oxidation, microbiota, and histology of shrimp under hypoxia. Four treatments were used: (1) normoxia, (2) cyclic serious/medium hypoxia (CSMH), (3) CSMH and 75 mg kg⁻¹ GSH, and (4) CSMH and 150 mg kg⁻¹ GSH. White shrimp (Penaeus vannamei) in groups 3 and 4 were fed a commercial diet supplemented with 75 and 150 mg kg⁻¹ GSH for a 28 day period, respectively, and they were cultured under CSMH (0.8 – 3.5 mg L⁻¹ dissolved oxygen) for the last 14 days of the experiment. P. vannamei supplemented with 75 mg kg⁻¹ GSH showed significantly improved survival and growth performance under CSMH compared with the CSMH condition alone. The dose of 75 mg kg⁻¹ GSH completely eliminated overproduction of reactive oxygen species and malondialdehyde to suppress serious histopathological lesions and improve bacterial diversity and the relative abundance of beneficial bacteria, such as Rhodobacteraceae, thereby preventing pathogen (e.g., Vibrio) invasion in the intestine of shrimp under CSMH. However, the dose of 150 mg kg⁻¹ GSH was excessive, as it led to serious impairment of survival and growth. These results indicate that 75 mg kg⁻¹ GSH has the potential to control shrimp mortality and growth inhibition under CSMH in the shrimp farm setting.