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Diabetes mellitus type 2 (DMt2) is an increasing health concern of epidemic proportion in the United States. High fructose corn syrup (HFCS) and artificial sweeteners (AS) have been implicated as contributory factors to DMt2. This project seeks to demonstrate elimination of daily consumption of HFCS and AS in DMt2 patients can contribute to lower hemoglobin A1C (HgbA1C) levels by comparing two groups of patients receiving two differing diabetes education programs. A reduction of HgbA1C levels by 0.2-0.5% is expected in DMt2 patients instructed to eliminate HFCS and AS, and no change is expected in HgbA1C levels in DMt2 patients receiving ADA standards diabetes education alone.

Five strains of German cockroaches, WM, RG386, Ryan, CDR, and SY, were collected from field sites in California. Resistance to five bait insecticides was assessed in laboratory arenas and compared to the UCR susceptible strain, revealing increased survivability towards baits. Contact resistance towards bait active ingredients and deltamethrin was found in all strains from topical applications of the 3 x LD95 and 10 x LD95 of the UCR strain. The physiological resistance mechanisms of deltamethrin and fipronil resistance were assessed. The involvement of metabolic detoxification was evidenced by increases in topical toxicity of deltamethrin or fipronil diagnostic doses with the synergists piperonyl butoxide (PBO), S,S,S-tributyl phosphorotrithioate (DEF), and diethyl maleate (DEM). Elevated general esterase and glutathione-S-transferase activities were detected with biochemical assays of whole-body homogenates. The pyrethroid resistance-conferring L993F kdr mutation and the fipronil resistance-conferring Rdl mutation of the GABA chloride channel was found in all field-collected strains.Sucralose is an artificial sweetener that has garnered attention as a potential safe insecticide. The oral toxicity of sucralose was found to be concentration dependent for the UCR, WM, and RG386 strains through provisions of 5, 10, and 20% solutions in water. Pre-exposure to 20% sucralose solutions for 2 d did not affect the topical toxicity of deltamethrin, fipronil, or hydramethylnon but improved the performance of a hydramethylnon bait. There was no initial preference for contacting or consuming sucralose or water in the UCR and WM strains, but RG386 cockroaches preferred to consume water. Because sucralose cannot be metabolized, it has been hypothesized that mortality is caused by a buildup in the hemolymph, osmotic imbalance in the alimentary system, and subsequent dehydration through water excretion. When provided with 20% sucralose solutions, body water decreased by 23.0–30.29% by 6 d, and sucralose acted ~2–3 d faster against 2 d dehydrated cockroaches. Evidence of alimentary disruption was demonstrated with the significant loss of bacterial diversity in the guts of treated cockroaches.

Use of non-nutritive sweeteners (NNSs) has increased worldwide in recent decades. However, evidence from preclinical studies shows that sweetener consumption may induce glucose intolerance through changes in the gut microbiota, which raises public health concerns. As studies conducted on humans are lacking, the aim of this review was to gather and summarize the current evidence on the effects of NNSs on human gut microbiota. Only clinical trials and cross-sectional studies were included in the review. Regarding NNSs (i.e, saccharin, sucralose, aspartame, and stevia), only two of five clinical trials showed significant changes in gut microbiota composition after the intervention protocol. These studies concluded that saccharin and sucralose impair glycemic tolerance. In three of the four cross-sectional studies an association between NNSs and the microbial composition was observed. All three clinical trials on polyols (i.e, xylitol) showed prebiotic effects on gut microbiota, but these studies had multiple limitations (publication date, dosage, duration) that jeopardize their validity. The microbial response to NNSs consumption could be strongly mediated by the gut microbial composition at baseline. Further studies in which the potential personalized microbial response to NNSs consumption is acknowledged, and that include longer intervention protocols, larger cohorts, and more realistic sweetener dosage are needed to broaden these findings.

Due to their reputation for being a healthier option to traditional table sugar, non-nutritive sweeteners have garnered popularity, particularly with those affected by type II diabetes mellitus (DM2) or obesity. A literature review on the characteristics, metabolism, and optimal cooking guidelines of non-nutritive sweeteners was performed to establish more knowledge about these trending food additives. The literature review indicates that the presence of non-nutritive sweeteners (NNS) may influence glucose metabolism by binding T1R2/T1R3 sweetness receptors present throughout the gastrointestinal tract. However, not all studies showed positive correlations. Though inconclusive, the studies suggest a possible connection between excessive NNS consumption and impaired glucose metabolism, but moderate consumption appears to have no significant effect.

While previous work has demonstrated the effectiveness of nitrogen-doped carbon nanotubes (N-CNTs) as biogenic electrode materials in first- and second-generation biosensors, this thesis primarily explores enzymatic inhibition-based biosensing schemes on N-CNT electrodes. This type of scheme enables the detection of enzymatic inhibitors, as opposed to enzymatic substrates, making these inhibition-based biosensors much more suitable for the monitoring of environmental pollutants. Presented in this thesis is a biosensor which couples N-CNTs with glucose oxidase (GOx) through spontaneous physical adsorption for the highly sensitive detection of aqueous silver ions. Included is a thorough discussion of the parameters that affect response time as well the biosensor’s aptitude for repeated use. A later chapter presents initial work towards the inhibition-based detection of sucralose, a relatively new environmental pollutant. A bi-enzymatic approach is explored, in which both GOx and invertase are immobilized on an N-CNT modified electrode. Finally, shifting focus from inhibition-schemes, the last remaining chapter investigates the coupling of CNTs and N-CNTs with methylene green (MG), a redox mediator used in second-generation biosensors based on NADH oxidation. Common coupling techniques are examined for their effectiveness in decreasing the overpotential required for NADH oxidation.