Lactose Intolerant
Do Probiotics Help

Will yogurt or perhaps a probiotic supplement help if you're lactose intolerant? Find out which probiotics should be part of a lactose intolerance diet.

Some probiotics, including many of the Lactobacillus family either contain ß-galactosidase or lactase within their cell.

The theory is that by eating probiotic food or taking a supplement, the probiotic will adhere to the intestinal lining and digest the lactose, thereby easing the symptoms for lactose intolerant people.

Not all fermented dairy foods have this ability to autodigest lactose - it depends on which bacteria is present. Some probiotic bacteria, because they are resistant to acid and bile, do not release their enzymes in the small intestine. And some probiotics have a low ß-galactosidase activity.probiotic bacteria

The two best bacteria for this are two that many people overlook because they're not regarded as true "probiotics" (because they are unable to proliferate in the intestine.) Don't let that put you off them. These two are the goods! But we'll get to them in a minute.

There have been trials done on fermented dairy foods to gauge their benefit on lactose intolerance. Unfortunately, many of these trials have not said which strain was used which makes the information of less practical use. Many simply refer to "Lactobacillus acidophilus milk" or "sweet acidophilus milk". Many of the trial were carried out through the 1990's when we didn't understand quite how important it was to specify a strain.

In one study1, comparing Lactobacillus acidophilus B and Lactobacillus bulgaricus 449, the latter proved much better for lactose intolerant people.

Lactose maldigestion was measured by breath hydrogen (the standard test for this) after people had eaten 400ml of the non-fermented milk (2% low fat) containing one of those two bacteria.

The results were:

  • non-fermented milk containing L acidophilus B at 108 cfu/ml did NOT reduce breath hydrogen OR symptoms

  • non-fermented milk containing L acidophilus B at 109 cfu/ml slightly decreased breath hydrogen but SIGNIFICANTLY REDUCED symptoms

  • non-fermented milks containing L bulgaricus 449 at both 108 and 109 cfu/ml SIGNIFICANTLY REDUCED both breath hydrogen and symptoms

Lactobacillus delbrueckii subsp bulgaricus (frequently abbreviated to simply L bulgaricus) is a standard "starter" bacteria in yogurt and it is this bacteria rather than acidophilus that explains why many people who are lactose intolerant can eat yogurt.

In 2002, when the WHO and the FAO were working on the Guidelines For The Evaluation Of Probiotics in Food they stated;

"The current state of evidence suggests that probiotic effects are strain specific. Strain identity is important to link a strain to a specific health effect as well as to enable accurate surveillance and epidemiological studies. A possible exception is the ability in general of S. themophilus and L. delbrueckii ssp. bulgaricus to enhance lactose digestion in lactose intolerant individuals. In this case, or in other cases where there is suitable scientific substantiation of health benefits that are not strain specific, individual strain identity is not critical."

So if you're buying yogurt to reduce symptoms of lactose intolerance, it is these two classic "starters" - Streptococcus themophilus and Lactobacillus bulgaricus - that you're looking for rather than all the fancy bacteria with their trademarked names. You'll find these two in many yogurts - just ensure that it is live and active.


Is kefir better

Another study2 compared milk, plain and flavored yogurt, and plain and flavored kefir in reducing breath hydrogen and symptoms. Plain kefir, plain yogurt, and flavored yogurt reduced breath hydrogen levels most effectively.

The most common symptom reported of lactose intolerance is gas and the milk increased both the severity and and frequency of that compared against the other four. The symptoms of abdominal pain and diarrhea were not very pronounced in any of the five dairy products (including milk!) in this particular study.

So from that result kefir seems equally as good for helping helping lactose intolerant people as yogurt although anecdotally many people believe it is superior.


What is lactose intolerance

People who are lactose intolerant are unable to digest the sugar (lactose) that is found in milk and products made from milk. This is not the same as being allergic to milk.

Adults of any species do not normally consume milk and especially milk from another species. However, many people can "get away" with it - lactose intolerant folk can't. They experience symptoms such as diarrhea, abdominal cramping and bloating after they eat lactose containing foods.

In the US, 15% of Caucasians, over 50% of Mexican Americans, and over 80% of African Americans have lactose intolerance.3If this interests you, there is a fascinating table at Wiki showing the levels of lactose intolerance of various ethnic groups. We difer widely in our tolerance of milk. Just scroll down the Wiki page and you'll find it.


Hidden sources of lactose

  • Bread and other baked goods
  • Processed breakfast cereals
  • Mixes for pancakes, biscuits, and cookies
  • Instant potatoes, soups, and breakfast drinks
  • Margarine
  • Nonkosher lunchmeats
  • Salad dressings
  • Candies and other snacks


What causes lactose intolerance

People who are lactose intolerant do not have enough of the lactose-cleaving enzyme ß-galactosidase in their small intestine. This is actually a normal thing in adults.

Fermented milk products such as yogurt contain live bacteria that have this ß-galactosidase enzyme and also help it to survive the journey through the stomach. Once it gets to the small intestine it supports lactose hydrolysis there to improve our ability to digest lactose and so avoid the bloating and gas of lactose intolerance.4


Yogurt or supplement?

The findings of a recent study into the whether a supplement was of more benefit than yogurt concluded that "probiotics promote lactose digestion in lactose malabsorbers no better than conventional yogurt."

So there you have it. Yogurt is just as good as a supplement and a plain yogurt - so long as it has plenty of the two "starter" bacteria, Streptococcus themophilus and Lactobacillus bulgaricus - is just as good as all your fancy types!

Reader's Question - Lactose Intolerant With Bacterial Vaginosis

This question came in from Tammy of Kentucky.

Q. Can I take Fem-dophilus (which has dextrose in it) for a bacterial vaginal infection if I can't have dairy?

A. Probably!

Now I know that isn't much of an answer but you are the only person who knows just how sensitive you are to dextrose.

I have been in correspondence with Dr Gregor Reid who discovered the probiotics in Fem Dophilus and he said this about the dextrose in it; "with such low amounts in the capsules, I find it hard to imagine a reaction."

If you haven't seen this page on adding Fem Dophilus to yogurt it might help you. That lady also was concerned about the dextrose in the capsules.

I do know that they have used the Fem Dophilus capsule vaginally for bacterial vaginosis and got a good cure rate that way. Maybe that would be helpful in your situation.


7 Symptoms of Lactose Intolerance

The following are the most common 7 symptoms of lactose intolerance but do remember that each person may experience their symptoms differently.

The severity will vary according to the amount of lactase a person can tolerate and the amount you have eaten.

  • nausea
  • cramps
  • bloating
  • gas
  • diarrhea
  • floating stools - usually a sign that you are not absorbing nutrients or producing too much gas
  • foul smelling stools

These symptoms of being lactose intolerant will begin usually between 30 minutes to two hours after eating food or drinking something that contains lactose.

In children they may include:

  • malnutrition
  • slow growth
  • weight loss


1. Lin MY, Yen CL, Chen SH. Management of lactose maldigestion by consuming milk containing lactobacilli. Dig Dis Sci. 1998 Jan;43(1):133-7.

2. Steven R. Hertzler, Shannon M. Clancy MS. Kefir improves lactose digestion and tolerance in adults with lactose maldigestion. Journal of the American Dietetic Association, Volume 103, Issue 5, May 2003, Pages 582-587.

3. Vesa TH, Marteau P, Korpeia R. Lactose intolerance. J Am Col Nutr 2000;19:165S?175S

4. de Vrese M, Stegelmann A, Richter B, Fenselau S, Laue C, Schrezenmeir J. Probiotics?compensation for lactase insufficiency. Am J Clin Nutr. 2001;73:421S?9S.

5. Michael de Vrese3, Philippe R. Marteau. Probiotics and Prebiotics: Effects on Diarrhea. The American Society for Nutrition J. Nutr. 137:803S-811S, March 2007