This Mayo Clinic article is talking about intestinal candidiasis and diet. This Mayo Clinic article is talking about Candida albican in oral thrust. These are two different conditions. The first condition is not official recognized and diet has no effect. In the second instance the condition is well recognized and diet makes a difference.
I believe the article you quoted "...increasing evidence for yeasts being able to cause IBS symptoms in sensitized patients via Candida products" comes from a 2005 article in the European Journal of Gastroenterology & Hepatology. The complete quote is "Even if the involvement of yeasts in the aetiology of IBS still remains unclear, there is increasing evidence for yeasts being able to cause IBS-symptoms in sensitized patients via Candida products, antigens and cross-antigens. But more research is needed before antifungal treatment can be recommended as a first line treatment for IBS." Furthermore the article acknowledges that "There are no satisfactory studies addressing intestinal colonization of Candida in IBS patients that support, or refute a causative effect." The rest of article reviews previous research findings based on the unproven assumption that a causal relationship might exist.
Careful attention has to paid to the wording of research articles in order to tease out the limitations of a study and the claims its authors are making
Reference Santelmann, H. and J. M. Howard: Yeast metabolic products, yeast antigens and yeasts as possible triggers for irritable bowel syndrome. [Review]. European Journal of Gastroenterology & Hepatology January 2005;17(1):21-26.
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