Life Sciences Commons^™

Understanding Neonicotinoid Related Immunosuppression: A Potential For Beneficial Bacterial Intervention, John A. Chmiel

Electronic Thesis and Dissertation Repository

The use of neonicotinoid pesticides has been implicated in the recent decrease of honey bee (Apis mellifera) populations. In this thesis, a Drosophila melanogaster model was used to characterize immune impairment associated with imidacloprid (neonicotinoid) exposure and test the ability of beneficial bacteria (lactobacilli) to alleviate these harmful effects. The experiments outlined in chapters 2 and 3 demonstrate that imidacloprid alters the gut microbiota by exploiting the cooperation between gut immune pathways. The pesticide reduces expression of Duox via dysregulation of the immune deficiency pathway resulting in decreased hydrogen peroxide production. This contributes to the microbiota changes but …

Mitigation Of Pesticide Toxicity By Food-Grade Lactobacilli, Mark E. Trinder

Electronic Thesis and Dissertation Repository

Lactobacilli are Gram-positive bacteria used in fermented foods. Many species are commensal microbiota members that confer host benefits. This thesis investigated lactobacilli mitigation of organophosphate and neonicotinoid pesticide toxicity in mammals and insects, respectively. Lactobacillus rhamnosus GG (LGG) and GR-1 (LGR-1) were found to sequester, but not metabolize, organophosphate pesticides (parathion and chlorpyrifos) in solution. For LGG, this sequestration reduced organophosphate pesticide absorption in a Caco-2 intestinal Transwell model and promoted survival of Drosophila melanogaster lethally exposed to chlorpyrifos. Supplementation of mice with LGR-1 was found to alter host xenobiotic metabolism in the liver, and consequently chlorpyrifos metabolism following acute …

Clinical And Mechanistic Insights Into Novel Probiotic Functions And Formulations, Jordan Bisanz

Electronic Thesis and Dissertation Repository

Using a combination of hypothesis and discovery based approaches, the goal of this thesis was to better describe novel probiotic functions and their mechanisms while striving to better understand the effect of formulation on Bifidobacterium animalis subsp. lactis, Lactobacillus paracasei and L. rhamnosus.

Using RNA-Seq, a bacterial metatranscriptome analysis of a commonly consumed probiotic yogurt showed that the organisms adapted to storage time and flavor additions. This led to the discovery that in addition to the probiotic health benefits, members of the L. casei group (L. rhamnosus and L. paracasei) produce volatile sulfur compounds mediated by a novel …