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Browsing by Author "Weir, Tiffany L., advisor"

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    Exploring microbiome-targeted interventions in the mitigation of endothelial dysfunction
    (Colorado State University. Libraries, 2024) Risk, Briana D., author; Weir, Tiffany L., advisor; Gentile, Christopher L., advisor; Chicco, Adam J., committee member; Foster, Michelle T., committee member
    Cardiovascular disease (CVD) has been the leading cause of mortality in the United States for more than seventy years eclipsing cancer and respiratory disease by more than 13%. Despite sincere efforts to decrease the incidence of CVD, various environmental and intrinsic factors contribute to CVD progression, making it challenging to mitigate this complex condition. However, the past decade has shown tremendous growth in understanding the connection between the gut microbiome in its protective, or pathogenic progression of CVD. The gut microbiome, or the consortia of microbial species, genes, and metabolites, that shapes the gastrointestinal environment has a profound impact on the vascular endothelium through mechanisms not yet entirely understood. Therefore, the purpose of the research in this dissertation was to: 1) Utilize next-generation sequencing and metabolomics to characterize microbial contribution to varied endothelial response after a dietary blueberry intervention in post-menopausal females; 2) Determine if a hypertensive microbiome after blueberry treatment confers gastrointestinal and endothelial phenotype in a humanized mouse model; 3) Evaluate the efficacy of a probiotic in reversing endothelial dysfunction in dietarily obese mice, while exploring the contribution to gut barrier integrity and vasoactive metabolite proliferation in a novel cell co-culture.
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    The effect of hop extract supplementation on gut microbiota and metabolic function in ovariectomized mice
    (Colorado State University. Libraries, 2017) Hamm, Alison Kay, author; Weir, Tiffany L., advisor; Cox-York, Kimberly A., committee member; Broeckling, Corey D., committee member; Avens, John S., committee member; Bunning, Marisa L., committee member
    Estrogen decline with aging, or menopause, is associated with increased risk for cardiometabolic diseases primarily due to altered metabolism and weight gain. Standard treatment has traditionally been with 17β-estradiol (E2) prescription, although its use has declined over the last decade due to associated increase in breast and ovarian cancer risk. As a result, use of phytoestrogenic herbal supplements has increased, due to their perceived safety and effectiveness in treatment of menopausal side effects. The gut microbiota may also be important in terms of mitigating disease risk and hormone exposure during the menopause transition, as our gut microbiota are important modulators of local and systemic inflammation. Gut microbes also can metabolize hormones and dietary flavonoids, altering their bioactivity and bioavailability. In this study, we supplemented ovariectomized (OVX) or control sham-operated C57BL/6 mice, with oral E2, a flavonoid-rich extract from hops (Humulus lupulus), or placebo carrier oil, and observed differences in adiposity, inflammation, and gut bacteria composition. Hops extract (HE) did not protect against ovariectomy-associated weight gain or increased visceral adiposity, while E2-treated animals had similar body weights and fat depot sizes as Sham-operated animals. However, HE was protective against liver triglyceride accumulation, to levels similar to Sham control and OVX E2 groups. We found no evidence of OVX having a significant impact on the overall gut bacterial community structure in any of our treatment groups. We did find differences in abundance of two bacteria; Akkermansia muciniphila was lower with HE treatment in the Sham group, and Ruminococcus gnavus was higher with OVX compared to Sham control. Possible mechanisms of the interplay between gut bacteria, loss of estrogen, and hormone replacement will be discussed.