Candida, the Gut Microbiome, and the Epidemic Levels of Cancer and Autoimmune Disease in Young Women, Dementia, and Obesity

Candida has traditionally only been framed as an opportunistic infection. Unfortunately this rather limited view has impeded appreciation for this pathobiont and its growing role as a facilitator of gut dysbiosis and limited gut biodiversity. Candida overgrowth (CO) is linked to a gut microbiome that lacks biodiversity and sufficient butyrogenic bacteria. CO promotes intestinal permeability (leaky gut) and upregulates the estrobolome. The former is associated with dementia and autoimmune disease (AID) and the latter with many hormone driven cancers. Most appear to be estrogen receptor positive. Obesity predisposes to CO and to hormone driven cancers, dementia, AID, dementia, cardiovascular disease (CVD), and infectious disease. All report altered tryptophan metabolism (ATM). Candida can create its own indoleamine dioxygenase (IDO) to manipulate levels of this essential amino acid that otherwise inhibits hyphal morphogenesis. Candida releases numerous proteases and induces release of bacterial proteases as well. These proteases activate protease activated receptor (PAR2), linked to IBS (irritable bowel syndrome), IBD (inflammatory bowel disease), progression of estrogen receptor (ER) positive cancers, and AID. To quell proteolytic hyperactivity, gut microbiota produce an inhibitor - β-glucuronidase. This deconjugates estrogen in bilirubin otherwise destined for excretion, enabling its reabsorption. This Candida enabled increase in circulating estrogen may be the facilitator of this epidemic of cancer and AID in young women. Although the connection between CO and this unforgiving epidemic is provocative and supported by the pathophysiology, definitive clinical confirmation is required.