Lactose ni disaccharide iboneka mu mata y’inyamabere, agizwe na molekile imwe ya glucose na molekile imwe ya galaktose. Nibintu nyamukuru bigize lactose, isoko nyamukuru yibiribwa kubantu nandi matungo y’inyamabere mugihe cyo kuvuka. Lactose igira uruhare rukomeye mumubiri wumuntu. Nisoko yingufu.