Lactose

Milk sugar

What does Lactose do in your body?

The sugar in milk. Digesting it needs lactase — an enzyme many adults produce less of.

What does Lactose do?

Broken into glucose and galactose by lactase in the small intestine.

Can you get too much Lactose?

With low lactase, undigested lactose reaches the colon and causes gas, bloating and diarrhea. Not dangerous, and not an allergy.

What does Lactose interact with?

Most people with lactose malabsorption tolerate small amounts, yogurt and hard cheeses.

Evidence & sources

• Most people with lactose intolerance can consume some lactose without symptoms. Evidence: strong. Known: Clinical guidance. Unknown: Tolerance varies. Source: NIH NIDDK, Lactose Intolerance — Eating, Diet & Nutrition (Current revision).

Connected topics

• Milk
• Yogurt
• Cheese
• Small Intestine
• Gut Microbiome
• Sugars

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General education only, not medical advice. Drafted Oct 2026 · pending qualified expert review.