Lactose ingestion in the adult golden hamster (Mesocricetus auratus)

Adult mammals generally demonstrate a lower preference for the disaccharide sugar lactose than for any other common sugar, and because adults typically have low levels of the intestinal enzyme lactase, lactose ingestion may cause gastrointestinal distress. The lactose intake of adult golden hamsters was examined in three experiments; the main findings were: (a) hamsters allowed to choose between tap water and lactose solutions (maximum concentration = 32% weight/volume) over a 20-day period showed a clear preference for lactose solutions and ingested substantial quantities of lactose (up to 3 g/100 g body weight/day) without noticeable adverse effects; (b) hamsters consuming a single diet with lactose added (maximum concentration = 50%) over a period of days ingested up to 3.42 g/100 g body weight/day of lactose without noticeable adverse effects; (c) both hamsters with prior exposure to lactose solutions and those without such exposure consumed similar amounts of 32% lactose solution over an 8-day period, suggesting that hamsters' lactose intake does not depend on the occurrence of adaptation. It is suggested that the fermentative capacity of the hamster's pregastric pouch may underlie this animal's unusual tolerance for lactose.