Fig 1.
The laboratory mouse model is widely used to demonstrate causality of correlations between the microbiome and human disease.
(A) Analysis of many humans reveals a negative association between the severity of disease symptoms and an index of the microbiome, e.g., abundance of a specific taxon or functional trait. (B) “Humanized” mice (i.e., mice colonized with microbiome samples from humans) are used to infer a causal role of the microbiome in the human disease: mice display disease symptoms when colonized with microbiome samples from diseased, but not healthy, humans. This figure is a generalized illustration and is not intended to be representative of any specific disease or microbiome dataset.
Fig 2.
The traditional animal models are amenable to microbiome research.
(A) The advantages and limitations of traditional models for microbiome research. *Zebrafish older than 6–8 days require feeding, which is technically demanding under strictly sterile conditions [27]. (B) The key microbiological manipulations required for experimental investigation of microbiome function.