The disclosure provides compositions and dosage forms for promoting healthy microbial flora in a mammal, for example, a human. The disclosure further provides compositions and dosage forms for disrupting biofilm or preventing formation of biofilm containing pathogenic bacteria and/or pathogenic fungi in a particular region of a subject. The dosage forms contain (i) an isolated non-pathogenic fungal strain that is viable in the region of the subject, (ii) an isolated non-pathogenic bacterial strain that is viable in the region of the subject, and optionally (iii) an enzyme capable of disrupting the biofilm. The present disclosure also provides methods of disrupting a biofilm or preventing formation of a biofilm with such a composition or dosage form, methods of identifying a subject suitable for treatment with such a composition or dosage form, and methods of improving nutrient absorption using such a composition or dosage form.