Background

Levilactobacillus brevis (L. brevis) is a type of probiotic ("good" bacteria) found naturally in the human body. It's also found in fermented foods.

"Good" bacteria such as L. brevis might help the body break down food, absorb nutrients, and fight off "bad" organisms that might cause diseases. These bacteria are sometimes added to fermented foods like yogurt and also found in dietary supplements.

People use L. brevis for alcohol-related liver disease, overgrowth of bacteria in the vagina (bacterial vaginosis), common cold, dry skin, gum disease, insomnia, and many other conditions, but there is no good scientific evidence to support these uses.

Don't confuse L. brevis with other probiotics, or with fermented food products such as fermented milk, kefir, or yogurt. These are not the same. Also note that L. brevis used to be classified under the Lactobacillus genus. But Lactobacillus was split up into 25 different genera in April 2020. Some product labels might still list this species as Lactobacillus brevis rather than its new name, Levilactobacillus brevis.

Safety Safety definitions

When taken by mouth: L. brevis is possibly safe for most people. L. brevis has been used safely in doses of up to 12 billion colony-forming units (CFUs) daily for up to 3 months. It seems to be well-tolerated. But there isn't enough reliable information to know if heat-killed L. brevis is safe or what the side effects might be.

When applied to the vagina: L. brevis is possibly safe. It's been used safely in doses of up to 2 billion CFUs twice daily for 6 months.

Special Precautions & Warnings:

Pregnancy and breast-feeding: There isn't enough reliable information to know if L. brevis is safe to use when pregnant or breast-feeding. But there are no reasons to expect safety concerns when used appropriately.

Children: L. brevis is possibly safe in most children when taken by mouth appropriately. It's been used safely in children 4-14 years-old in doses of up to 4 billion colony-forming units (CFUs) daily for up to 2 months or 10 billion CFUs for 4 weeks. There isn't enough reliable information to know if L. brevis is safe for very small premature infants. Also, there isn't enough reliable information to know if heat-killed L. brevis is safe or what the side effects might be.

Weakened immune system: Probiotics have caused blood infections in a small number of people with weakened immune systems. If you have a weakened immune system, talk with your healthcare provider before taking probiotics, including L. brevis.

Damaged heart valves: Probiotic preparations can cause an infection in the inner lining of the heart chambers and heart valve. This is extremely rare, but people with damaged heart valves should stop taking probiotics, including L. brevis, before dental procedures or surgical procedures.

Effectiveness

Dosing & administration

In adults, L. brevis has most often been taken by mouth alone or together with other probiotics in doses of 1-10 billion colony-forming units (CFUs) daily for 1-4 months. It's most often been applied to the vagina in doses of 4 billion CFUs daily for 6 months. It's also been used in gels and creams. Speak with a healthcare provider to find out what type of product and dose might be best for a specific condition.

Interactions with pharmaceuticals

Antibiotic drugs

Interaction Rating=Moderate Be cautious with this combination.

L. brevis is a type of friendly bacteria. Antibiotics are used to reduce harmful bacteria in the body. Taking antibiotics along with L. brevis can reduce the effects of L. brevis. To avoid this interaction, take L. brevis products at least 2 hours before or after antibiotics.

Interactions with herbs & supplements

There are no known interactions with herbs and supplements.

Interactions with foods

There are no known interactions with foods.