Responses of the intestinal microbiota to exposure of okadaic acid in marine medaka Oryzias melastigma

• Published in: Journal of hazardous materials 2024-03, Vol.465, p.133087-133087, Article 133087
• Main Authors: Yang, Yongmeng, Li, Aifeng, Qiu, Jiangbing, Gao, Dongmei, Yin, Chao, Li, Dongyue, Yan, Wenhui, Dang, Hui, Li, Peiyao, Wu, Ruolin, Han, Lilin, Wang, Xiaoyun
• Format: Article
• Language: English
• Subjects: Functional prediction analysis; Inflammation; Intestinal microbiota; Okadaic acid; Oryzias melastigma
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2023.133087

It is still limited that how the microalgal toxin okadaic acid (OA) affects the intestinal microbiota in marine fishes. In the present study, adult marine medaka Oryzias melastigma was exposed to the environmentally relevant concentration of OA (5 μg/L) for 10 days, and then recovered in fresh seawater for 10-days depuration. Analysis of taxonomic composition and diversity of the intestinal microbiota, as well as function prediction analysis and histology observation were carried out in this study. Functional prediction analysis indicated that OA potentially affected the development of colorectal cancer, protein and carbohydrate digestion and absorption functions, and development of neurodegenerative diseases like Parkinson’s disease, which may be associated with changes in Proteobacteria and Firmicutes in marine medaka. Significant increases of C-reactive protein (CRP) and inducible nitric oxide synthase (iNOS) levels, as well as the changes of histology of intestinal tissue demonstrated that an intestinal inflammation was induced by OA exposure in marine medaka. This study showed that the environmental concentrations of OA could harm to the intestinal microbiota thus threatening the health of marine medaka, which hints that the chemical ecology of microalgal toxins should be paid attention to in future studies. [Display omitted] •Marine medaka was exposed to the environmentally relevant concentration of OA.•Dysbiosis of the intestinal microbiota in marine medaka was caused by OA exposure.•Functional prediction analysis hinted that OA possibly induced colorectal cancer.•Parkinson’s disease was potentially caused by OA via altered metabolism pathways.•Intestinal inflammation was caused by OA exposure in marine medaka.