Compositions and methods for treatment or prophylaxis of a bipolar disorder disease state, in which the compositions include the bacilli (1) Bacillus subtilis, (2) Bacillus coagulans, and (3) Enterococcus faecium. The compositions may be embodied in suitable dose forms such as capsules containing the microbial species in combination with a substrate for the microbial species, e.g., fructo-oligosaccharides, for oral administration according to a predetermined dosage schedule.
