It’s estimated that 75% of the world’s population loses the ability to completely digest lactose after infancy (1). Insufficient levels of lactase are often described as the cause of lactose intolerance, and therefore a common belief is that lactose intolerance is a permanent condition. Research has made it clear that this is not the case, and lactose intolerance can actually be easily treated in most people! Some species of bacteria have lactose digesting enzymes, and when they get a chance to grow in the gut they can transfer their genes to the bacteria on the lining of the gut.
Lactic acid bacteria behave differently depending on the species and have varying effect in people with lactose intolerance (2).
One study showed that symptoms of Lactose Intolerance were alleviated significantly after supplementation with yoghurt and a probiotic capsule containing Bifidobacterium longum (3). Another similar study showed the same results and also concluded that the effect could persist for 3 months after suspension of probiotic consumption (4).
Dairy products act as a “delivery” system and strongly enhance the survival of probiotic bacteria into the gut (6,7). Eating fermented dairy products, such as yoghurt with live cultures, is one of the best strategies to get the needed bacteria. Kefir has shown to improve lactose digestion and tolerance (5).
Prebiotics can be an important part of treatment because it will promote the growth of certain types of bacteria. Prebiotics can be obtained by eating foods such as onions and leeks or through supplementing with oligofructose or inulin. Until the gut adjusts symptoms of lactose intolerance will persist.
Pasteurized, fat-reduced and homogenized milk from sick animals isn’t healthy. Lactose intolerance is for some people a blessing in disguise (like gluten intolerance) if they eat healthier foods instead of milk. However, everyone should be able to choose for themselves and have the knowledge to treat lactose intolerance.
Dairy products should be unprocessed and come from grass-fed cows. Full-fat fermented dairy is the preferred option and will also be a good source of gut bacteria!
1: Pribila BA, Hertzler SR, Martin BR, et al. Improved lactose digestion and intolerance among African-American adolescent girls fed a dairy-rich diet.
J Am Diet Assoc. 2000 May;100(5):524-8; quiz 529-30.
2: Andrew Szilagyi. Prebiotics or probiotics for lactose intolerance: a question of adaptation
Am J Clin Nutr July 1999 vol. 70 no. 1 105-106
3: Zhong Y, Huang CY, He T, et al. Effect of probiotics and yogurt on colonic microflora in subjects with lactose intolerance.
Wei Sheng Yan Jiu. 2006 Sep;35(5):587-91.
4: Almeida CC, Lorena SL, Pavan CR, et al. Beneficial effects of long-term consumption of a probiotic combination of Lactobacillus casei Shirota and Bifidobacterium breve Yakult may persist after suspension of therapy in lactose-intolerant patients.
Nutr Clin Pract. 2012 Apr;27(2):247-51. Epub 2012 Mar 8.
5: Hertzler SR, Clancy SM. Kefir improves lactose digestion and tolerance in adults with lactose maldigestion.
J Am Diet Assoc. 2003 May;103(5):582-7.
6. Wang J, Zhong Z, Zhang W, et al. Comparative analysis of the gene expression profile of probiotic Lactobacillus casei Zhang with and without fermented milk as a vehicle during transit in a simulated gastrointestinal tract.
Res Microbiol. 2012 Apr 20. [Epub ahead of print]
7. Pitino I, Randazzo CL, Cross KL, et al. Survival of Lactobacillus rhamnosus strains inoculated in cheese matrix during simulated human digestion.
Food Microbiol. 2012 Aug;31(1):57-63. Epub 2012 Mar 3.