Medically Reviewed by Melinda Ratini, DO, MS on March 03, 2020

Lactobacillus is a type of "friendly" bacteria. It lives in your body but doesn't cause disease. You can also get it in food and supplements.

Lactobacillus may help your body:

  • Break down food
  • Absorb nutrients
  • Resist infections in the gastrointestinal tract

Why do people take lactobacillus?

People take lactobacillus for many reasons.

Digestive system. People take lactobacillus to try to treat or prevent diarrhea. It can help children more quickly get over diarrhea caused by a rotavirus infection.

Lactobacillus may also help prevent diarrhea for:

People also take lactobacillus to try to treat other problems related to the digestive system. Studies show some promise for:

So far, research suggests that lactobacillus does not really help with Crohn's disease. Research has been mixed regarding its prevention of necrotizing enterocolitis (NEC) in premature babies.

Infections. Many studies show that lactobacillus may help prevent infections. For example, it may help prevent lung infections in children in daycare centers. It also may help treat or prevent vaginal infections caused by bacteria.

But there isn't enough known about using lactobacillus for urinary tract infections, flu prevention or weight loss. And it isn't clear if it can boost the immune system or prevent infections in people on ventilators.

Skin problems. People take lactobacillus to try to treat:

  • Acne
  • Eczema, especially in children with eczema in the family

Eczema may benefit from the use of lactobacillus, but there isn't enough evidence to know if it helps with these other skin problems.

As for other uses, it's not clear whether it is effective for lactose intolerance, high cholesterol, or Lyme disease. Promising research suggests that lactobacillus may help lower cholesterol.

Researchers have used many different strains and doses of lactobacillus. The optimal dose is not known. But a typical daily dose ranges from 1 to 10 billion colony-forming units (CFUs) per day. You take this divided into three to four doses each day, ideally before or with meals. It may work better if the product is kept in the refrigerator.

Lactobacillus is called a probiotic when you take it in adequate amounts to help with health. However, supplement ingredients and quality may vary widely from maker to maker. This makes it hard to set a standard dose.

Can you get lactobacillus naturally from foods?

Lactobacillus is present in some fermented foods such as:

  • Yogurt
  • Some Cheese
  • Kefir
  • Sauerkraut
  • Kimchi
  • Olives
  • Pickles

It is also added into some milk, infant foods and juices.

What are the risks of taking lactobacillus?

Lactobacillus is likely safe for adults, children, and babies. Pregnant and breastfeeding women have also used one type of lactobacillus safely. But other types of lactobacillus need more study to be sure they are safe and effective.

Side effects. Lactobacillus may cause mild gas or bloating.

Risks. Do you have a weakened immune system or short bowel syndrome? If so, talk to your doctor before taking lactobacillus. It may raise your risk of infections.

Interactions. Be cautious if you combine lactobacillus with medications that depress the immune system. You may be at higher risk of infection from the lactobacillus. Some examples of these medications are:

Take lactobacillus at least two hours before or after you take any antibiotics.

Supplements are not regulated by the FDA in the same way that food and drugs are.  The FDA does not review these supplements for safety or efficacy before they hit the market.Tell your doctor about any you're taking, even if they're natural. That way, your doctor can check on any potential side effects or interactions with medications or foods. They can let you know if the supplement might raise your risks.

WebMD Medical Reference



Natural Medicines Comprehensive Database: "Lactobacillus."

Taverniti, V. Frontiers in Microbiology, Nov. 19, 2012.

Kumar, M. Experimental Diabetes Research, May 3, 2012.

Walter, J. Applied and Environmental Microbiology, August 2008.

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