Figure 2.

An illustration of microbiome impact on host gene expression for a hypothetical gene, and the effect of an eQTL, which is designated with a star with two variants (red and green). (A) microbiome does not alter gene expression; (B) Microbiome regulates the gene and causes an increase in gene expression in a consistent manner, regardless of genetic variation; (C) Microbiome regulates the gene and causes an increase in gene expression only if the eQTL has the red variant.