Sea cucumber body vesicular syndrome is driven by pond water microbiome via altered gut microbiota

Sea cucumber (Apostichopus japonicus) is one of the most valuable aquaculture species in China and diseases limit the development of its culture industry. Recently, a novel disease, named body vesicular syndrome (BVS), has been frequently observed during the aquaculture of A. japonicus. Due to it can only found after boiling at the post-harvest process, BVS could result in more severe economic losses than other diseases. In the present study, a multi-mics method covering gut microbiota, pond environmental microbiome, and A. japonicus itself was establish for investigating the BVS. Detailed analyses of differentially expressed proteins and metabolites revealed that the changes of cell adhesion structure caused by disorder of fatty acid beta oxidation mediated by vitamin B5 deficiency might be the main mechanism of BVS occurrence. Furthermore, intestinal dysbacteriosis due to the variation of microbiome in pond water was considered to be the potential reason for vitamin B5 deficiency. A BVS index based on the biomarkers recognized from gut microbiota of A. japonicus was proven to be used for BVS diagnosis. Finally, vitamin B5 supplementation verified the deduced mechanism of BVS and proved that it can be used to treat BVS.

刺参（Apostichopus japonicus）是中国极具经济价值的水产养殖物种之一，病害制约了其养殖产业的发展。近年来，仿刺参养殖过程中频繁暴发一种新型病害——体腔囊泡综合征（Body Vesicular Syndrome，BVS）。由于该病害仅在采收后蒸煮环节才可被检出，因此BVS造成的经济损失较其他病害更为严重。本研究建立了一套涵盖仿刺参肠道菌群、养殖池塘环境微生物组以及仿刺参自身的多组学（multi-omics）研究方法，用于解析BVS的致病机制。通过对差异表达蛋白与代谢物的深入分析，研究发现：由维生素B5缺乏介导的脂肪酸β-氧化紊乱所引发的细胞黏附结构异常，可能是BVS发生的核心机制。此外，养殖池塘水体微生物组群落结构失衡引发的肠道菌群失调，被认为是导致维生素B5缺乏的潜在诱因。基于仿刺参肠道菌群筛选得到的生物标志物构建的BVS诊断指数，已被证实可用于BVS的临床诊断。最终，通过维生素B5补充实验验证了本研究推导的BVS致病机制，并证实其可用于BVS的治疗。