Alpha-galactosidase is a digestive enzyme that breaks down complex, gas-producing carbohydrates called oligosaccharides (specifically raffinose, stachyose, and verbascose) found in beans, legumes, and cruciferous vegetables. Because the human body lacks this enzyme in the small intestine, these complex sugars travel undigested to the large intestine, where gut bacteria ferment them—causing significant gas and bloating. Alpha-galactosidase cuts these sugars into easily absorbable glucose and galactose before they reach the colon.