chemical compound
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Share
Share to social media
URL
https://64.176.36.150/science/lactose
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

Print
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Share
Share to social media
URL
https://64.176.36.150/science/lactose
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

Also known as: milk sugar

lactose, carbohydrate containing one molecule of glucose and one of galactose linked together. Composing about 2 to 8 percent of the milk of all mammals, lactose is sometimes called milk sugar. It is the only common sugar of animal origin. Lactose can be prepared from whey, a by-product of the cheese-making process. Fermentation of lactose by microorganisms such as Lactobacillus acidophilus is part of the industrial production of lactic acid. Human lactose intolerance is indicated by diarrhea and abdominal bloating and discomfort; lactose intolerance also may be a cause of diarrhea in newborns.

This article was most recently revised and updated by Kara Rogers.