Ukungabekezelelani kwe-Lactose yisimo esivamile esidalwa ukwehla kwekhono lokugaya i-lactose, ushukela otholakala emikhiqizweni yobisi. Labo abathintekile bayehluka ebuningini be-lactose abangabubekezelela ngaphambi kokuba izimpawu ziqhamuke Izimpawu zingabandakanya ubuhlungu besisu, ukuqunjelwa, isifo sohudo, igesi kanye nesicanucanu. kuncike enanini umuntu alidlayo noma aliphuzayo.Ukungabekezelelani kwe-lactose akubangeli ukulimala emgodini wamathumbu. Ukungabekezelelani kwe-Lactose kungumphumela wokushoda kwe-lactase, okungaba yizakhi zofuzo (i-hypolactasia eyinhloko kanye ne-alactasia eyinhloko yokuzalwa) noma okubangelwa imvelo (i-hypoalactasia yesibili noma etholakele). Kunoma ikuphi, izimpawu zibangelwa amazinga anganele e-lactase kulwelwesi lwe-duodenum. I-Lactose, i-molecule ye-disaccharide etholakala obisini nasemikhiqizweni yobisi, ayikwazi ukufakwa ngqo odongeni lwamathumbu amancane iye egazini, ngakho-ke, lapho i-lactase ingekho, idlula ihambisane nekholoni [ukucaphuna kuyadingeka]. Amagciwane kukholoni angakwazi ukugaya i-lactose, futhi ukuvutshelwa okuvelayo kuveza inani eliningi legesi (ingxube ye-hydrogen, i-carbon dioxide, ne-methane) edala izimpawu ezahlukahlukene zesisu. Ushukela ongagunyaziwe nemikhiqizo yokuvutshelwa nayo iphakamisa ingcindezi ye-osmotic yekoloni, idala ukugeleza kwamanzi okwenyuka kuya emathunjini (isifo sohudo). Uhlobo lwe-LCT luhlinzeka ngemiyalo yokwenza i-lactase.