E-Mail IMAGE: Lead author Bridget McGivern in June 2018, shortly after setup of the soil experiment. view more Credit: Provided/Bridget McGivern Fruits, vegetables, red wine and chocolate are all rich in polyphenols, natural plant compounds that double as cancer-fighting antioxidants. We can access these foods' health benefits because the microbes in our guts happily feast on them, breaking them down into smaller chemical components. Microbiome scientists at Colorado State University wanted to know if microbes can also break down those same polyphenols in systems outside the human body, including the microbial wild west of soils. A research team led by Kelly Wrighton, associate professor in the College of Agricultural Sciences' Department of Soil and Crop Sciences, has uncovered new insights into the role of polyphenols in the soil microbiome, known as a black box for its complexity. They proffer an updated theory that soils - much like the human gut - can be food sources for the microbes that live there. Their results could upend a long-held theory that, under certain conditions, soil microbes can't access polyphenols and could thus be used as carbon traps to reduce greenhouse gases in the atmosphere.