What is normal and abnormal in lactose digestion?

In simple terms

This isn't a real study—it's just a short comment with no data or experiments. We can't say anything for sure about lactose digestion because no one actually tested anything.

Analysis score

1/ 5

Maximum 5 for a narrative review.

Where the score came from

Reporting0

Methodology0

Publication100

Statistical0

Study type (basis of the score)

Narrative Review

Level 5 - Expert opinion

What’s the bottom line?

Most adults can't digest milk because their bodies stop making the enzyme lactase — that's normal. A DNA test can tell if you're one of those people, but it won't tell you if your stomach problem is from an infection or inflammation.

Where does this study sit?

Reviews of RCTs (Meta-analyses)

Max 100

Randomized Trials

Max 90

Reviews of Cohort Studies

Max 85

Cohort Studies

Max 72

Reviews of Case-Control Studies

Max 63

Case-Control Studies

Max 58

Cross-Sectional & Case Series

Max 50

Expert Opinion

Max 5

StrongerWeaker

Expert Opinion

Level 5

1 / 100

Quality score

Based on clinical experience or non-systematic literature reviews. The lowest level of evidence as they are most susceptible to bias and personal perspective.

Cannot establish causation

Save studies & get personalized insights

Create a free account to save this study, track new evidence as it comes in, and get breakdowns of studies in the topics you care about.

Key takeaways

Summary

Based on the study abstract and findings.

1This matters because people with temporary gut problems (like after an infection) might be wrongly told they're lactose intolerant for life if only a DNA test is used.
2About two-thirds of adults worldwide can't digest lactose naturally.
3DNA tests can detect this inherited trait but not lactose problems caused by illness.

Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data