Kavli Affiliate: Robert Edwards
| Authors: Craig Liddicoat, Bart A Eijkelkamp, Timothy R Cavagnaro, Jake M Robinson, Kiri Joy Wallace, Andrew D Barnes, Garth Harmsworth, Damien J Keating, Robert A Edwards and Martin F Breed
| Summary:
The global rise in human allergic and autoimmune diseases is linked to altered environmental microbiome exposures from increasing land use change, ecosystem degradation and biodiversity loss. Yet, microbiome-mediated impacts of global change on metabolic health have received little attention. Type 2 diabetes (T2D) is a complex metabolic disease with rapidly increasing global prevalence, uncertain pathogenesis and influences from gut microbiome-host interactions and environmental factors. Soil microbiomes shift in composition and functional capacity with ecosystem condition and are an important source for priming and resupplying the human gut microbiome, which is critical in metabolism. Here, we sought to examine overlapping functional capacities in model case study microbiome datasets from (1) soils from a gradient of ecosystem quality (from highly disturbed to mature/natural sites under forest ecosystem restoration) and (2) gut microbiomes in T2D versus normal health to investigate plausible links between ecosystem degradation and metabolic anomalies encoded in T2D gut microbiomes. We developed a novel method to translate microbiome functional capacities (i.e., functional gene-associated biochemical pathway relative abundances) to ‘compound processing potential’ (CPP, %), reflecting the potential metabolism of individual compounds. Examining selected compounds relevant to soil and gut health, and via exhaustive compound-wide trend analyses, we identified compounds that shared potential metabolism trends. We found increased potential metabolism for sugars and decreased potential metabolism for lignin and monomethyl branched-chain fatty acids, in both T2D and degraded ecosystems. These trends were confirmed in two separate T2D case study cohorts from Sweden and China, suggesting a generalizable pattern. Our findings support a consequential new hypothesis that excessive exposures to degraded ecosystem soil microbiomes may distort gut microbiome functional capacities and metabolism and thereby contribute to type 2 diabetes.