Other underlying contributors include exposure to pesticides and herbicides, which kill friendly flora, encourage pathogenic microbes, impair immune function, and increase blood glucose levels. Chronic stress or sympathetic dominance, which weakens immunity, increases glucose levels and destroys healthy gut flora. A gut that is too alkaline, as this is the environment that yeast needs for growth. Heavy metal toxicity which degrades the integrity of the gut and impairs immunity. Hormonal imbalances which create an environment that encourages yeast overgrowth. Nicotine use strengthens proliferation, morphogenesis and Candida's ability to adhere, as well as weakening immunity and elevating blood glucose levels and disrupting neurotransmitters needed for gut function.