Background: Metabolic phenotypes are the result of an intricate interplay between multiple factors, including diet, genotype, and the gut microbiome. Per-Arnt-Sim (
PAS) kinase is a nutrient-sensing
serine/threonine kinase, whose absence (PASK-/-) protects against
triglyceride accumulation,
insulin resistance, and
weight gain on a high-fat diet; conditions that are associated with
dysbiosis of the gut microbiome. Methods: Herein, we report the metabolic effects of the interplay of diet (high fat high
sugar, HFHS), genotype (PASK-/-), and microbiome (16S sequencing). Results: Microbiome analysis identified a diet-induced, genotype-independent forked shift, with two discrete clusters of HFHS mice having increased beta and decreased alpha diversity. A "lower" cluster contained elevated levels of Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria and Defferibacteres, and was associated with increased
weight gain,
glucose intolerance,
triglyceride accumulation, and decreased
claudin-1 expression. Genotypic effects were observed within the clusters, lower cluster PASK-/- mice displayed increased
weight gain and decreased
triglyceride accumulation, whereas upper PASK-/- were resistant to decreased
claudin-1. Conclusions: These results confirm previous reports that
PAS kinase deficiency can protect mice against the deleterious effects of diet, and they suggest that microbiome imbalances can override protection. In addition, these results support a healthy diet for beneficial microbiome maintenance and suggest microbial culprits associated with
metabolic disease.