Lactobacillus acidophilus: MedlinePlus Supplements

Skip navigation

Search Terms


Other herb and supplement names:	A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Lactobacillus acidophilus

Contents of this page:
Background Synonyms Evidence Dosing	Safety Interactions Methodology Selected references

Lactobacillus acidophilus

BackgroundReturn to top

Lactobacilli are bacteria that normally live in the human small intestine and vagina. Lactobacillus acidophilus is generally considered to be beneficial because it produces vitamin K, lactase, and anti-microbial substances such as acidolin, acidolphilin, lactocidin, and bacteriocin. Multiple human trials report benefits of L. acidophilus for bacterial vaginosis. Other medicinal uses of L. acidophilus are not sufficiently studied to form clear conclusions.

The term "probiotic" is used to describe organisms that are used medicinally, including bacteria such as L. acidophilus and yeast such as Saccharomyces boulardii .

Although generally believed to be safe with few side effects, oral L. acidophilus should be avoided in people with intestinal damage, a weakened immune system, or with overgrowth of intestinal bacteria.

SynonymsReturn to top

Acidophilus, Acidophilus Extra Strength®, acidophilus milk, Actimel®, Bacid®, Cultura®, DDS-Acidophilus, Endolac®, Enpac®, Fermalac® (Canadian), Florajen®, fresh poi, Gynoflor®, Infloran®, Kala®, Kyo-Dophilus®, L-92, L. acidophilus, L. acidophilus OLL2769, L. acidophilus milk, L. acidophilus yogurt, Lacteol Fort®, lactic acid-producing bacteria (LAB), Lactinex®, Lactobacillaceae (family), lactobacilli, lactobacillus, Lactobacillus acidophilus 145 , Lactobacillus acidophilus DDS-1, Lactobacillus acidophilus LA 02, Lactobacillus acidophilus La5, Lactobacillus acidophilus L-92, Lactobacillus acidophilus NCFM, Lactobacillus acidophilus NCK56, Lactobacillus acidophilus strain 27L, Lactobacillus acidophilus strain LB (LaLB), Lacto Bacillus, MoreDophilus®, Narine®, poi, Probiata®, Pro-Bionate®, probiotic, sour poi, Superdophilus®, yogurt.

EvidenceReturn to top

These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Uses based on scientific evidence	Grade^*
Bacterial vaginosis Multiple human studies report that Lactobacillus acidophilus vaginal suppositories are effective in the treatment of bacterial vaginosis. A small number of studies suggest that eating yogurt enriched with Lactobacillus acidophilus may be similarly beneficial. Additional research is necessary before a firm conclusion can be reached. Patients with persistent vaginal discomfort are advised to seek medical attention.	B
Allergy treatment (Japanese cedar pollen) A small study was conducted to evaluate the effects of Lactobacillus acidophilus strain L-92 (L-92) on the symptoms of Japanese cedar-pollen allergy with positive results. Further research is needed before a decision can be made.	C
Asthma There is limited research in this area, with unclear results.	C
Diarrhea prevention A small amount of human research suggests that Lactobacillus acidophilus may not be effective when used to prevent diarrhea in travelers or in people taking antibiotics. Several studies report that the related species Lactobacillus GG may be helpful for the prevention of diarrhea in children and travelers. Additional study is needed in these areas before a firm conclusion can be drawn.	C
Diarrhea treatment (children) A small amount of research in children, using different forms of acidophilus, reports no improvement in diarrhea. Future studies should use a viable Lactobacillus acidophilus culture to assess effects on diarrhea. Lactobacillus GG, a different species, is suggested by multiple human studies to be a safe and effective treatment for diarrhea in otherwise healthy infants and children. Lactobacillus acidophilus may aid in the management of chronic or persistent diarrhea and bacterial-overgrowth related diarrhea. Further research is needed to determine what dose may be safe and effective.	C
Hepatic encephalopathy (confused thinking due to liver disorders) There is limited study in this area, with mixed results.	C
High cholesterol There is conflicting information from several human studies regarding the effects of Lactobacillus acidophilus- enriched dairy products on lowering blood levels of total cholesterol or low-density lipoprotein ("bad cholesterol").	C
Irritable bowel syndrome Human studies report mixed results in the improvement of bowel symptoms after taking Lactobacillus acidophilus by mouth.	C
Lactose intolerance There is conflicting information from several human studies as to whether using Lactobacillus acidophilus by mouth improves digestion of lactose. More research is needed in this area a before a conclusion can be drawn.	C
Necrotizing enterocolitis prevention in infants One human study using L. acidophilus in combination with another bacterium ( B. infantis ) in infants reported fewer cases of necrotizing enterocolitis (severe inflammation of the gut), and no complications related to treatment. Additional research is necessary in this area before a conclusion can be drawn.	C
Vaginal candidiasis (yeast infection) Lactobacillus acidophilus taken by mouth or as a vaginal suppository has not been adequately assessed for the prevention or treatment of vaginal yeast infections. More research is needed in this area a before a conclusion can be drawn.	C

*Key to grades
A: Strong scientific evidence for this use;
B: Good scientific evidence for this use;
C: Unclear scientific evidence for this use;
D: Fair scientific evidence against this use;
F: Strong scientific evidence against this use.

Grading rationale

Uses based on tradition or theory

The below uses are based on tradition or scientific theories. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.

Acne, AIDS, cancer, canker sores, colitis, colon cancer prevention, constipation, diaper rash, Crohn's disease, diverticulitis, E. coli infection in cancer patients, fever blisters, heart disease, heartburn, hives, immune enhancer, indigestion, infection, overgrowth of bacteria in the small bowel, preoperative prevention of infections or gut bacteria loss, stomach ulcer, thrush, ulcerative colitis, urinary tract infection.

DosingReturn to top

The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.

Adults (18 years and older)

Tablets/capsules/liquid/yogurt: Expert opinion suggests that a dose between 1 and 10 billion viable (live) L. acidophilus bacteria taken daily in divided doses is sufficient for most people. Higher doses may cause mild abdominal discomfort, and smaller doses may not be able to establish a stable population in the gut. For vaginal bacterial infections, a dose that has been used is 8 ounces of yogurt containing L. acidophilus in a concentration of 100 million colony-forming units (108 CFU) in each milliliter. Capsules containing 1.5 grams of Lactobacillus acidophilus were used in one study.

Vaginal suppository: Doses that have been used for vaginal infections include 1 to 2 tablets (containing 10 million to 1 billion CFU in each tablet), inserted into the vagina once or twice daily.

Anal suppository: Capsules containing 1.5 grams of Lactobacillus acidophilus have been used to treat diarrhea.

Children (younger than 18 years)

Tablets/capsules/liquid: Some natural medicine textbooks and experts suggest that one-quarter teaspoon or one-quarter capsule of commercially available L. acidophilus may be safe for use in children for the replacement of gut bacteria destroyed by antibiotics. Up to 12 billion lyophilized heat-killed L. acidophilus has been given every 12 hours for up to five days. It is often recommended that L. acidophilus supplements be taken two hours after antibiotic doses, because antibiotics may kill L. acidophilus if taken at the same time. Consult a qualified healthcare practitioner prior to using L. acidophilus in children, and use cautiously in those under three years of age.

Applied to the skin: Liquid preparations have been used on the diaper area to treat yeast infections, although safety and effectiveness are not well studied. Consult a qualified healthcare practitioner prior to using L. acidophilus in children, and use cautiously in those under three years of age.

SafetyReturn to top

The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.

Allergies

Lactose sensitive people may develop abdominal discomfort from dairy products containing L. acidophilus.

Side Effects and Warnings

Studies report few side effects from L. acidophilus when used at recommended doses. The most common complaint is abdominal discomfort or gas, which usually resolves with continued use. Some experts recommend limiting the daily dose of living L. acidophilus organisms to reduce the risk of abdominal discomfort. Some women have reported burning of the vagina after using L. acidophilus vaginal tablets.

There are rare reports of infections of heart valves with L. acidophilus , and the risk may be greater in people with artificial heart valves. People with severely weakened immune systems (due to disease or drugs like cancer chemotherapy and organ transplant immunosuppressants) may develop serious infections or bacteria in the blood from taking L. acidophilus . Therefore, L. acidophilus should be avoided in such individuals. People with intestinal damage or recent bowel surgery should avoid taking lactobacilli.

Pregnancy and Breastfeeding

There is not enough scientific study available to establish safety during pregnancy. Therefore, pregnant women should use L. acidophilus cautiously and under medical supervision, if at all. A small number of pregnant women have taken part in studies investigating L. acidophilus vaginal tablets and a culture of L. acidophilus with no negative effects reported. Further research is necessary.

InteractionsReturn to top

Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.

Interactions with Drugs

Some experts believe that L. acidophilus taken by mouth should be used two to three hours after antibiotic doses, to prevent killing the L. acidophilus . It has also been suggested that lactobacilli are damaged by alcohol, and should not be taken at the same time. Scientific research is limited in these areas.

In theory, L. acidophilus taken by mouth might not survive the acidic environment of the stomach. Some experts have suggested that antacids should be taken 30 to 60 minutes before taking lactobacilli. However, this has not been well studied in humans.

In theory, L. acidophilus may prolong the effects on some drugs, including birth control pills or benzodiazepines such as diazepam (Valium®). Based on laboratory experiments, L. acidophilus may reduce the effectiveness of sulfasalazine (Azulfidine®), a drug used for inflammatory bowel disease.

Interactions with Herbs and Dietary Supplements

Fructo-oligosaccharides (FOS, also called "prebiotics") are non-digestible sugar chains that are nutrients for lactobacilli. Some experts believe that FOS, taken by mouth, may help the growth of lactobacilli. Natural food sources of FOS include banana, Jerusalem artichoke, onion, asparagus, and garlic.

L. casei , S. boulardi or other probiotics may add to the effects of L. acidophilus .

Methodology Return to top

This information is based on a professional level monograph edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Methodology details

Selected references Return to top

Arvola T, Laiho K, Torkkeli S, et al. Prophylactic Lactobacillus GG reduces antibiotic-associated diarrhea in children with respiratory infections: a randomized study. Pediatrics 1999;104(5):e64.
Bayer AS, Chow AW, Betts D, et al. Lactobacillemia--report of nine cases. Important clinical and therapeutic considerations. Am J Med 1978;64(5):808-813.
dios Pozo-Olano J, Warram JH, Jr., Gomez RG, et al. Effect of a lactobacilli preparation on traveler's diarrhea. A randomized, double blind clinical trial. Gastroenterology 1978;74(5 Pt 1):829-830.
Fedorak RN, Madsen KL. Probiotics and the management of inflammatory bowel disease. Inflamm.Bowel.Dis. 2004;10(3):286-299.
Halpern GM, Prindiville T, Blankenburg M, et al. Treatment of irritable bowel syndrome with Lacteol Fort: a randomized, double-blind, cross-over trial. Am J Gastroenterol 1996;91(8):1579-1585.
Hilton E, Isenberg HD, Alperstein P, et al. Ingestion of yogurt containing Lactobacillus acidophilus as prophylaxis for candidal vaginitis. Ann Intern Med 1992;116(5):353-357.
Ishida Y, Nakamura F, Kanzato H, et al. Clinical effects of Lactobacillus acidophilus strain L-92 on perennial allergic rhinitis: a double-blind, placebo-controlled study. J.Dairy Sci. 2005;88(2):527-533.
Ishida Y, Nakamura F, Kanzato H, et al. Effect of milk fermented with Lactobacillus acidophilus strain L-92 on symptoms of Japanese cedar pollen allergy: a randomized placebo-controlled trial.Biosci Biotechnol Biochem. 2005 Sep;69(9):1652-60.
Kliegman RM, Willoughby RE. Prevention of necrotizing enterocolitis with probiotics. Pediatrics 2005;115(1):171-172.
Pirotta M, Gunn J, Chondros P, et al. Effect of lactobacillus in preventing post-antibiotic vulvovaginal candidiasis: a randomised controlled trial. BMJ 9-4-2004;329(7465):548.
Saggioro, A. Probiotics in the treatment of irritable bowel syndrome. J.Clin.Gastroenterol. 2004;38(6 Suppl):S104-S106.
Saltzman JR, Russell RM, Golner B, et al. A randomized trial of Lactobacillus acidophilus BG2FO4 to treat lactose intolerance. Am J Clin Nutr 1999;69(1):140-146.
Sazawal S, Hiremath G, Dhingra U, et al. Efficacy of probiotics in prevention of acute diarrhoea: a meta-analysis of masked, randomised, placebo-controlled trials. Lancet Infect Dis. 2006 Jun;6(6):374-82.
Tankanow RM, Ross MB, Ertel IJ, et al. A double-blind, placebo-controlled study of the efficacy of Lactinex in the prophylaxis of amoxicillin-induced diarrhea. DICP 1990;24(4):382-384.
Xiao SD, Zhang de Z, Lu H, et al. Multicenter, randomized, controlled trial of heat-killed Lactobacillus acidophilus LB in patients with chronic diarrhea. Adv.Ther. 2003;20(5):253-260.

Natural Standard Logo This evidence-based monograph was prepared by the Natural Standard Research Collaboration. The information provided should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. Talk to your health care provider before taking any prescription or over the counter drugs (including any herbal medicines or supplements) or following any treatment or regimen. Copyright© 2009 Natural Standard (www.naturalstandard.com). All Rights Reserved.