Lactose malabsorption and intolerance: What should be the best clinical management?

Abstract

Lactose malabsorption (LM) is the incomplete hydrolysis of lactose due to lactase deficiency, which may occur as a primary disorder or secondary to other intestinal diseases. Primary adult-type hypolactasia is an autosomal recessive condition resulting from the physiological decline of lactase activity. Different methods have been used to diagnose LM. Lactose breath test represents the most reliable technique. A recent consensus conference has proposed the more physiological dosage of 25 g of lactose and a standardized procedure for breath testing. Recently a new genetic test, based on C/T13910 polymorphism, has been proposed for the diagnosis of adult-type hypolactasia, complementing the role of breath testing. LM represents a well-known cause of abdominal symptoms although only some lactose malabsorbers are also intolerants. Diagnosing lactose intolerance is not straightforward. Many non-malabsorber subjects diagnose themselves as being lactose intolerant. Blind lactose challenge studies should be recommended to obtain objective results. Besides several studies indicate that subjects with lactose intolerance can ingest up to 15 g of lactose with no or minor symptoms. Therefore a therapeutic strategy consists of a lactose restricted diet avoiding the nutritional disadvantages of reduced calcium and vitamin intake.Various pharmacological options are also available. Unfortunately there is insufficient evidence that these therapies are effective. Further double-blind studies are needed to demonstrate treatment effectiveness in lactose intolerance.

Lactose Intolerance: Common Misunderstandings

“…In the AFRs induced by CMA, also small protein doses can cause symptoms, so the management is based on the strict avoidance of the cow’s milk-derived allergenic peptides in the diet. On the contrary, a reduction of lactose intake rather than full exclusion is recommended in lactose intolerance, because available data suggest that adolescents and adults can usually ingest up to 12 g of lactose in a single dose (equivalent to 1 cup of milk, corresponding to 240 mL) with no or minimal symptoms [35]. So, in these patients dietary treatment consists only in a low-lactose diet (Tables 2, 3) [2, 35].…”

“…In secondary hypolactasia, a restricted diet is necessary only for a limited time [35]. Concern about lactose intolerance and osmotic diarrhea in the treatment of undernourished children has led to a restricted use of lactose in these patients.…”

“…On the contrary, a reduction of lactose intake rather than full exclusion is recommended in lactose intolerance, because available data suggest that adolescents and adults can usually ingest up to 12 g of lactose in a single dose (equivalent to 1 cup of milk, corresponding to 240 mL) with no or minimal symptoms [35]. So, in these patients dietary treatment consists only in a low-lactose diet (Tables 2, 3) [2, 35]. There is no scientific evidence to identify the tolerable dose of lactose for children with lactose intolerance.…”

Molecular Genetic Markers as a Basis for Personalized Medicine / MOLEKULARNO-GENETIČKI MARKERI KAO OSNOV ZA PERSONALIZOVANU MEDICINU

“…Predictive genetic tests can indicate that a person needs to modify the diet, to avoid the harmful effects of nutrients, for example gluten (for celiac disease) (74), lactose (for adult hypolactasia) (75), caffeine (for hypersensitivity) (76,77) or fat (for obesity) (78)(79)(80)(81)(82). Nutrigenomics, based on the individual's genetic background, provides the ability to correct a congenital metabolic imbalance with proper diet or certain food supplements.…”

Carbohydrate Malabsorption and Putative Carbohydrate-Specific Small Intestinal Bacterial Overgrowth: Prevalence and Diagnostic Overlap Observed in an Austrian Outpatient Center

“…In the small intestine, the non-absorbable disaccharide lactose is hydrolyzed into the absorbable monosaccharides glucose and galactose by the lactase enzyme [4] . Primary lactose malabsorption is an inherited autosomal recessive condition, tightly linked to a single nucleotide polymorphism (SNP) (C/T -13910 ) 14 kb upstream of the lactase gene ( LCT ) locus.…”