Robert Nichols Receives USDA Chlorpyrifos Grant

"The organophosphate (OP) chlorpyrifos" is a commonly used pesticide (7 million pounds annually) for fruits and vegetables (e.g., apples, peaches, bell peppers) despite its potential to cause neurotoxicity in children and neonates. The gut microbiome is a potential contributor to disease pathogenesis and progression and has been reported to interact with numerous OPs. No studies have investigated the effect of chlorpyrifos on the gut microbiome at environmentally relevant dietary doses (EPA reference dose is 0.3 μg/kg/day). This study includes a unique multi-disciplinary approach to mechanistically dissect the impact of chronic environmentally relevant dietary exposure to chlorpyrifos in wild type and germ-free mice at the following doses; the EPA reference dose of 0.3 μg/kg/day, ten times higher (3 μg/kg/day), and ten times lower (0.03 μg/kg/day) in both a normal chow diet and a high-fat diet (60% kcal from fat). This study will test the hypothesis that chronic environmentally relevant dietary exposure of chlorpyrifos will promote impaired gut microbiome metabolism, gut permeability, an increase of circulating LPS in mouse serum and will exacerbate the effects of a high-fat diet. Established microbiome and metabolomic pipelines will delineate how microbiome compositional changes and perturbations influence the host-gut metabolic axis. A bacterial flow cytometry approach will explore structural changes and can differentiate between direct and indirect effects of chlorpyrifos. A newly established metatranscriptomic pipeline will be the first to validate the above data by elucidating bacterial enzymatic gene changes. Together these results will illustrate that chlorpyrifos exposure promotes detrimental modulation of the gut microbiome." Robert will be working with Chris Houser from Penn State Extension in the near future to connect with some local farmers and their work.