The present invention provides method for treating a metabolic disorder, dietary intolerance, or malabsorption in a subject that causes an excess of a metabolite or a dietary substance, particularly a carbohydrate such as galactose or fructose, that the subject does not tolerate by administering an effective amount of an adaptively evolved yeast strain to the subject or to food that reduces the excess of the metabolite or dietary substance. Specifically, the invention is directed to methods for treating the metabolic disorder, such as galactosemia or fructosemia, in which an excess of the carbohydrate is present. The invention also provides isolated, adaptively evolved yeast strains that degrades a metabolite or dietary ingredient, such as galactose or fructose, and methods for preparing such isolated, adaptively evolved yeast strains.
