2013/03/29 by Benjamin Misselwitz, Daniel Pohl, Heiko Frühauf +3 · 2 citations
Biochemistry, Genetics and Molecular Biology · Medicine · #Abdominal pain #Biology #Bloating #Congenital gastrointestinal and neural anomalies #Diet and metabolism studies #Digestive system and related health #Food intolerance #Food science #Gastroenterology #Immunology #Ingestion #Internal medicine #Lactase #Lactose #Lactose intolerance #Malabsorption #Medicine #Pathology #Placebo
paper · pdf · doi:10.1177/2050640613484463
openalex publication_date 2013/03/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Lactose malabsorption is a common condition caused by reduced expression or activity of lactase in the small intestine. In such patients, lactose intolerance is characterized by abdominal symptoms (e.g. nausea, bloating, and pain) after ingestion of dairy products. The genetic basis of lactose malabsorption is established and several tests for this condition are available, including genetic, endoscopic, and H2-breath tests. In contrast, lactose intolerance is less well understood. Recent studies show that the risk of symptoms after lactose ingestion depends on the dose of lactose, lactase expression, intestinal flora, and sensitivity of the gastrointestinal tract. Lactose intolerance has recently been defined as symptoms developing after ingestion of lactose which do not develop after placebo challenge in a person with lactose maldigestion. Such blinded testing might be especially important in those with functional gastrointestinal diseases in whom self-reported lactose intolerance is common. However, placebo-controlled testing is not part of current clinical practice. Updated protocols and high-quality outcome studies are needed. Treatment options of lactose intolerance include lactose-reduced diet and enzyme replacement. Documenting the response to multiple doses can guide rational dietary management; however, the clinical utility of this strategy has not been tested. This review summarizes the genetic basis, diagnosis, and treatment of lactose malabsorption and intolerance.