Lactobacillus Acidophilus

by MedlinePlus

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.

Uses based on scientific evidence

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.

Asthma

There is limited research in this area, with unclear results.

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.

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.

Hepatic encephalopathy (confused thinking due to liver disorders)

There is limited study in this area, with mixed results.

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").

Irritable bowel syndrome

Human studies report mixed results in the improvement of bowel symptoms after taking Lactobacillus acidophilus by mouth.

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.

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.

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.

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, allergies, cancer, canker sores, colitis, colon cancer prevention, constipation, diaper rash, Crohn's disease, diverticulitis,E. coliinfection 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.

Dosing

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.

Standardization

Standardization involves measuring the amount of certain chemicals in products to try to make different preparations similar to each other. It is not always known if the chemicals being measured are the "active" ingredients. L. acidophilus is commercially prepared as a concentrate, in a freeze-dried form, or as viable cultures. For all formulations, the dose is based on the number of living organisms. Standardization of L. acidophilus has been a challenge, because it is difficult to assess which products have live bacteria and are free from contaminants. Significant variations in effectiveness and shelf life have been observed. Storage conditions and the length of time the product is stored can alter the effectiveness, and refrigeration is recommended for L. acidophilus products. Pasteurization kills L. acidophilus.

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 (108CFU) 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.

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