Co-occurrence networks of bacteria associations are a powerful approach to explore ecologically relevant aspects of the gut microbiota structure, beyond community composition alone. Here we exploit the remarkable diversity of cichlid fishes and their multiple lake assemblages to investigate a) network features and patterns of microbial associations that were robust to major phylogeographical variables, and b) community structure changes along cichlid dietary shifts. We tackled these objectives using the large gut microbiota sequencing dataset available (nine lakes from Africa and America), building geographical and diet-specific networks and performing comparative analyses. Major findings indicated that lake and continental networks were highly resembling in global topology and node taxonomic composition, suggesting important constraints in the cichlid gut community assembling. A small fraction of the observed co-occurrence pairwises was conserved across all lake assemblages; while the origin and ecological relevance of these core associations remains unclear, their persistence suggests a potential functional role in the cichlid gut. Comparison of carnivores and herbivores-specific networks as well as mapping of diet-specific values on the African Lake Tanganyika network revealed a clear community shift as a function of diet, with an increase in complexity and node taxonomic diversity from carnivores-omnivores-plantkivores to herbivores. More importantly, diet-associated nodes in herbivores formed complex modules of positive interactions. By intersecting results from association patterns and experimental trials, future studies will be directed to test the strength of these microbial associations and predict the outcome of community alterations driven by diet.

中文翻译：

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丽鱼科鱼类肠道菌群的共现网络比较分析：社区保护和饮食相关变化

细菌协会的共生网络是探索肠道微生物群结构的生态相关方面的强大方法，而不仅仅是社区组成。在这里，我们利用丽鱼科鱼类及其多种湖泊组合的显着多样性来研究a）对主要植物地理学变量具有鲁棒性的微生物群落的网络特征和模式，以及b）丽鱼科鱼类饮食结构变化引起的群落结构变化。我们使用可利用的大型肠道菌群测序数据集（来自非洲和美国的九个湖泊），建立地理和饮食特定网络并进行比较分析来实现这些目标。主要发现表明，湖泊和大陆网络在全球拓扑结构和节点分类学组成上非常相似，这暗示了丽鱼科鱼肠道群落聚集中的重要限制。在所有湖泊群中，观察到的成对成对的一小部分都得到了保留；这些核心协会的起源和生态相关性尚不清楚，但它们的持久性表明在丽鱼科鱼的肠中可能发挥功能作用。肉食动物和草食动物特定网络的比较以及非洲湖坦any尼喀网络上饮食特定价值的映射显示，饮食明显改变了社区，饮食的复杂性和节点分类学多样性从食肉动物-杂食动物-植物食肉动物增加到草食动物。更重要的是，草食动物的饮食相关结节形成了积极互动的复杂模块。通过相交的关联模式和实验结果，