LCT and lactose intolerance: Diminished or too low lactase expression causes lactose intolerance (hypolactasia) and might lead to GI problems when lactose is ingested: the incompletely digested lactose might enter the colon and be fermented by the residing colonic microbiota, yielding excessive gas formation (mainly short-chain fatty acids (SCFA) are formed), leading to symptoms like abdominal distension, bloating, flatulence and/or colic.