Selection of signal-bearing subcompositions with application to human microbiome studies
摘要
A common peculiarity of large-scale applied studies is that the relevant features (signals) are sparse and it is of interests to shrink down the focus toward a much smaller subset in a systematic way. This line of inquiry is of special interest for parsimonious modeling in high-dimensional settings where the goal is to balance model complexity, interpretability, and predictive accuracy. Motivated by microbiome and metagenomic research where high dimensionality is combined with an inherently compositional nature of the data, we formulate an innovative, data-driven framework for selection of sparse, signal-bearing segments (subcompositions) hidden in a long sequence of compositional data. Operating with subcompositions as analysis units, the proposed framework is furnished with a broad class of integral probability metrics (IPMs) to quantify a subcomposition’s signal strength, which in turn reflects its influence on the association between the subcomposition’s microbial community and a host phenotype, or any other health/disease-related factor of interest. This class of IPMs is general enough to allow for the incorporation of structural information underlying the data, such as phylogenetic relationships among microbial communities. At the heart of our framework is a threshold-based Selector of Influential Subcompositions (