Microecological Koch\u2019s postulates reveal that intestinal microbiota dysbiosis contributes to shrimp white feces syndrome

Zhijian Huang,Satapornvanit Kriengkrai,Jinbo Xiong,Zhixuan Deng,Dongwei Hou,Dongdong Wei,Lingfei Yu,Daliang Ning,Xisha Deng,Jizhong Zhou,Hao Wang,Jianguo He,Renjun Zhou,Shaoping Weng,Chengguang Xing,Shenzheng Zeng

doi:10.1186/s40168-020-00802-3

Abstract

BackgroundRecently, increasing evidence supports that some complex diseases are not attributed to a given pathogen, but dysbiosis in the host intestinal microbiota (IM). The full intestinal ecosystem alterations, rather than a single pathogen, are associated with white feces syndrome (WFS), a globally severe non-infectious shrimp disease, while no experimental evidence to explore the causality. Herein, we conducted comprehensive metagenomic and metabolomic analysis, and intestinal microbiota transplantation (IMT) to investigate the causal relationship between IM dysbiosis and WFS.ResultsCompared to the Control shrimp, we found dramatically decreased microbial richness and diversity in WFS shrimp. Ten genera, such as Vibrio, Candidatus Bacilloplasma, Photobacterium, and Aeromonas, were overrepresented in WFS, whereas 11 genera, including Shewanella, Chitinibacter, and Rhodobacter were enriched in control. The divergent changes in these populations might contribute the observation that a decline of pathways conferring lipoic acid metabolism and mineral absorption in WFS. Meanwhile, some sorts of metabolites, especially lipids and organic acids, were found to be related to the IM alteration in WFS. Integrated with multiomics and IMT, we demonstrated that significant alterations in the community composition, functional potentials, and metabolites of IM were closely linked to shrimp WFS. The distinguished metabolites which were attributed to the IM dysbiosis were validated by feed-supplementary challenge. Both homogenous selection and heterogeneous selection process were less pronounced in WFS microbial community assembly. Notably, IMT shrimp from WFS donors eventually developed WFS clinical signs, while the dysbiotic IM can be recharacterized in recipient shrimp.ConclusionsCollectively, our findings offer solid evidence of the causality between IM dysbiosis and shrimp WFS, which exemplify the ‘microecological Koch’s postulates’ (an intestinal microbiota dysbiosis, a disease) in disease etiology, and inspire our cogitation on etiology from an ecological perspective.FQ9SoidJJGxv1orPr3YvZsVideo abstract

Highlights

Increasing evidence supports that some complex diseases are not attributed to a given pathogen, but dysbiosis in the host intestinal microbiota (IM)
Collectively, our findings offer solid evidence of the causality between IM dysbiosis and shrimp white feces syndrome (WFS), which exemplify the ‘microecological Koch’s postulates’ in disease etiology, and inspire our cogitation on etiology from an ecological perspective
Operational taxonomic units (OTU) were classified into 61 phyla (Additional file 2: Figure S2a) and 1135 genera (Additional file 2: Figure S2b)

Summary

Introduction

Increasing evidence supports that some complex diseases are not attributed to a given pathogen, but dysbiosis in the host intestinal microbiota (IM). For some complex diseases (e.g., aquatic animal diseases) that lack of obvious evidence to be linked to specific mutations or age, but the microbial alterations and the complexity of surrounding environment, neither the Koch’s postulates nor the ecological Koch’s postulates are not sufficiently to interpret. We propose yet another interpretation of Koch’s postulates, which we have termed ‘microecological Koch’s postulates’ (an intestinal microbiota dysbiosis, a disease)

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Results

Conclusion