Vetri Science® Laboratories Fast Balance G.I. Paste contains a specialized yeast extract, rich in mannan oligosaccharide (MOS), derived from the cell wall of yeast. It also includes probiotics in several strains, fungal-derived enzymes, and B vitamins, which work together to help normalize the G.I. tract. Fast Balance is recommended for garbage gut, nervous gut, and food sensitivities, as well as stress, quick normalization of digestion, and older pets in need of digestive support. Fast Balance G.I. Paste is available in a convenient dial-a-serving tube.