Lactose Intolerance Flashcards
1
Q
What is lactose?
A
A sugar that’s found in milk and several other dairy products
2
Q
Why does lactose intolerance occur?
A
They lack the enzyme lactase which hydrolyses lactose into glucose and galactose
3
Q
What are the symptoms of lactose intolerance?
A
- bloating
- wind
- diarrhoea
4
Q
Why does diarrhoea occur?
A
- lactose is soluble, but cannot be digested due to lactase absence
- lactose remains in gut lumen
- water potential of gut lowers to below that of epithelial cells
- therefore water leaves cells due to osmosis down a water potential gradient
- colon cannot absorb the extra water, which results in diarrhoea
5
Q
Why does bloating and wind occur?
A
- lactose in the gut acts as extra food for bacteria
- bacteria respire and ferment lactose, which produces gas
- this causes bloating and wind
