Lactose is a carbohydrate and like other carbohydrates, is broken down in the body to give us energy. While there is limited research into its health benefits, it is thought lactose may have a prebiotic effect.

Lactose is a naturally occurring carbohydrate found in mammalian milk, including cow's milk and other dairy foods. It is normally broken down or digested by an enzyme in our body called lactase and ends up in the bloodstream as glucose (a simple sugar). Lactose is essentially an energy source - like other carbohydrates, it's broken down in the body to give us energy.

While there is limited research into its health benefits, some studies suggest lactose may have a prebiotic effect in some people - which means it may stimulate the growth and/or activity of certain 'good' bacteria in the gut.¹

The amount of lactose in dairy foods varies. For example, most hard cheeses have virtually no lactose because of the way they're made.

References

1. Szilagyi, Andrew. “Adaptation to Lactose in Lactase Non Persistent People: Effects on Intolerance and the Relationship between Dairy Food Consumption and Evaluation of Diseases.” Nutrients 7 8 (2015): 6751-79 .