Natural Health Products

Natural solutions to help manage your health and wellness.


General Information

Acidophilus is a type of bacteria belonging to the Lactobacilli family. Lactobacilli bacteria are found throughout the human body, mainly in the digestive and genitourinary tracts. They can also be found in fermented foods such as yogurt and milk.

Common Name(s)
acidophilus, acidophilus lactobacillus, L. acidophilus
Scientific Name(s)
Lactobacillus acidophilus
How is this product usually used?

Lactobacillus acidophilus can be taken orallyorallyto be taken by mouth (swallowed) (by mouth) as tablets, capsules, powders, or liquids. It is also available as suppositories. It can also be found in foods such as yogurt that contain this specific type of Lactobacillus.

For oral formulations, a dose between 1 billion and 10 billion live lactobacillus acidophilus bacteria taken daily in divided doses is sufficient for most people.

What is this product used for?

Acidophilus is considered a probiotic, a word used to describe live bacteria that have health benefits for people who take them in adequate amounts. Probiotics help form part of the healthy, "good" digestive bacteria found naturally in the body. When taken orallyorallyto be taken by mouth (swallowed), acidophilus may help with digestion and protect against some harmful bacteria that can cause diarrhea.

Acidophilus has been used for a variety of digestive tract problems, including:

  • abdominalabdominalrelating to the stomach and intestines pain
  • constipation
  • lactose intolerance
  • inflammatory bowel disease (Crohn’s disease, ulcerative colitis)
  • infant colic
  • irritable bowel syndrome
  • diarrhea prevention and treatment of infectious or antibiotic origin
  • diarrhea in children caused by rotavirus

Acidophilus has also been used for bacterial vaginosis and vaginal infections caused by bacteria or yeast.

Other uses include prevention and treatment of common colds and other respiratory infections and childhood eczema.

Your health care provider may have recommended this product for other conditions. Contact a health care provider if you have questions.

What else should I be aware of?

Numerous studies have shown that acidophilus can be effective in the treatment of vaginal infections caused by bacteria. More research is needed to determine its effectiveness in treating vaginal infections caused by yeast.

Some studies have shown that children in daycare who are given milk containing acidophilus are less likely to experience influenza-like symptoms (fever, cough, and runny nose), and if they do experience them they will tend to be of milder intensity and shorter duration. Children were also less likely to use antibiotics for the symptoms. More studies are needed to determine its effectiveness in adults.

Lactobacillus acidophilus has not been shown to be effective in the prevention or treatment of diarrhea in travelers or in people taking antibiotics, and more research still needs to be done before a firm conclusion can be made. However, Lactobacillus GG, a different type of lactobacillus, may be useful in reducing the number of days with severe diarrhea in a person who has infectious diarrhea, traveler’s diarrhea, diarrhea, and diarrhea associated with antibiotic use.

Acidophilus has not been shown to improve symptoms related to lactose intolerance, inflammatory bowel disease, or irritable bowel syndrome. People with intestinal damage or who recently had bowel surgery should also avoid taking lactobacilli.

Acidophilus is usually well tolerated in adults and children. The most common side effects of oral supplements are intestinal gas and bloating. People who are lactose sensitive or intolerant may develop abdominalabdominalrelating to the stomach and intestines discomfort when taking dairy sources of acidophilus.

Lactobacilli are bacteria that can cause an infection in people with a weak immune system, such as people with HIV/AIDS or cancer, as well as people who are taking medications that suppress the immune system (for example, those who have had a transplant) or who are receiving chemotherapy. If any of these apply to you, talk to your health care professional first before taking any type of acidophilus supplements.

If symptoms of digestive upset occur, worsen, or persist for more than 3 days, or if you notice blood in your stool, you should discontinue the use of acidophilus and consult a health care practitioner.

Acidophilus should not be taken at the same time as antibiotics – they should be taken at least 2 hours apart.

There may be an interaction between lactobacillus acidophilus and any of the following. If you are taking any of these, talk to your doctor before taking any acidophilus supplements.

Before taking any new medications, including natural health products, speak to your physician, pharmacist, or other health care provider. Tell your health care provider about any natural health product you may be taking.

  1. Lactobacillus Monograph. Natural Medicines Comprehensive Database. Available online by subscription:, accessed 29 June 2012.
  2. Acidophilus. Ulbricht C, Basch EM. Natural Standard Herb & Supplement Reference: Evidence-based Clinical Reviews. Massachusetts: Elsevier Mosby, 2005.
  3. Health Canada. Drugs and Health Products. Acidophilus product information., accessed 14 april 2009.
  4. Health Canada. Natural Health Products Compendium of Drug Monographs. Probiotics., accessed 29 June 2012.
  5. Natural Standard.Lactobacillus acidophilus. Available online via subscription. Accessed 29 June 2012.