Abstract
Organophosphate pesticides used in agriculture can pose health risks to humans and wildlife. We hypothesized that dietary supplementation with Lactobacillus, a genus of commensal bacteria, would reduce absorption and toxicity of consumed organophosphate pesticides (parathion and chlorpyrifos). Several Lactobacillus species were screened for tolerability of 100 ppm of chlorpyrifos (CP) or parathion in MRS broth using 24 h growth curves. Certain Lactobacillus strains were unable to reach stationary phase culture maxima and displayed abnormal culture morphology in response to pesticide. Further characterization of commonly used, pesticide-tolerant and pesticide-susceptible, probiotic L. rhamnosus GG (LGG) and L. rhamnosus GR-1 (LGR-1) revealed that both strains could significantly sequester organophosphate pesticides from solution after 24 h co-incubations, respectively. This effect was independent of metabolic activity, as LGG did not hydrolyze CP and no difference in organophosphate sequestration was observed between live and heat-killed strains. Furthermore, LGR-1 and LGG, reduced the absorption of 100 μM parathion or CP in a Caco-2 Transwell model of the small intestinal epithelium. To determine the effect of sequestration on acute toxicity, newly eclosed Drosophila melanogaster were exposed to food containing 10 μM CP with or without supplementation of live LGG. Drosophila supplemented with LGG simultaneously, but not 3 d prophylactically, mitigated CP-induced mortality. In summary, the results suggest that L. rhamnosus may be useful for reducing toxic organophosphate pesticide exposure via passive binding. These findings could be transferable to clinical and livestock applications due to the affordable and practical ability to supplement products with food grade bacteria.
