[The concepts and research progress: from heritability to microbiability]

Heritability, one of the central quantitative genetic parameters, is critically important to measure the genetic variation of traits, especially in the studies of the response to selection in evolutionary biology and agriculture, and the prediction of disease risks in medicine. The statistical model and method for estimating heritability have been continually developed and improved, since the genetic variance components was first proposed by Fisher in 1918. Recently, the term "microbiability" (m ²), an analogous concept and estimated method to heritability, was introduced in gut microbiome research for evaluating the effect of entire microbiota on a host phenotype. In this review, we summarize the progress of statistical methods in the heritability estimation, as well as the current state of gut microbiome associations with the host genome, with a particular focus on the concept and estimated methods of microbiability. Our review will provide a reference for the future study of host phenotypic variation that can be inferred by the gut microbiota.