Lactobacillus acidophilus is a beneficial bacteria that primarily resides in the small intestine. Researchers think that maintaining a healthy “colony” of acidophilus is crucial for maintaining overall health.

Small amounts of L. acidophilus occur in cultured food products such as yogurt and acidophilus milk. However, in order to be effective, many doctors suggest that larger quantities need to be consumed in the form of supplements.

Dosage Info

Dosage Range

From 1-2 billion cfu (colony forming units) daily for maintenance. Doses up to 10 billion cfu daily for approximately two weeks are recommended to recolonize the intestinal microflora following antibiotic therapy.

Most Common Dosage

10 billion cfu daily.

Dosage Forms

Capsules, tablets, and bulk powder.

Interactions and Depletions


Reported Uses

Lactobacillus acidophilus may provide a number of benefits including prevention of infections, enhancement of digestion, metabolism of cholesterol and overall strengthening of the immune system.

L. acidophilus supplementation may be especially useful for helping patients restore beneficial bacteria to the intestines after treatment with antibiotics. (1) Doctors say that doses up to 10 billion cfu daily may be required for individuals with diarrhea following a regime of antibiotics.

Because of L. acidophilus’ ability to reduce cholesterol levels, it can potentially reduce the risk of coronary heart disease by 6 to 10 percent. (2) Meanwhile, infants treated with L. acidophilus may recover from bouts with diarrhea more quickly. (3)

Studies suggest that acidophilus may also spell relief for people who are lactose intolerant. (4) It has also been studied for use in preventing vaginal yeast infections. (5) Lactobacillus acidophilus may also reduce the risk of colon cancer. (6)

Toxicities & Precautions


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This dietary supplement is considered safe when used in accordance with proper dosing guidelines.

Pregnancy / Breast Feeding

To date, the medical literature has not reported any adverse effects related to fetal development during pregnancy or to infants who are breast-fed. Yet little is known about the use of this dietary supplement while pregnant or breast-feeding. Therefore, it is recommended that you inform your healthcare practitioner of any dietary supplements you are using while pregnant or breast-feeding.

Age Limitations

To date, the medical literature has not reported any adverse effects specifically related to the use of this dietary supplement in children. Since young children may have undiagnosed allergies or medical conditions, this dietary supplement should not be used in children under 10 years of age unless recommended by a physician.


  1. View Abstract: Cremonini F, Di Caro S, Santarelli L, et al. Probiotics in antibiotic-associated diarrhoea. Dig Liver Dis. Sep2002;34 Suppl(2):S78-80.
  2. View Abstract: Anderson JW, et al. Effect of Fermented Milk (yogurt) Containing Lactobacillus Acidophilus L1 on Serum Cholesterol in Hypercholesterolemic Humans. J Am Coll Nutr. Feb1999;18(1):43-50.
  3. View Abstract: Michielutti F, et al. Clinical Assessment of a New Oral Bacterial Treatment for Children with Acute Diarrhea. Minerva Med. Nov1996;87(11):545-50.
  4. View Abstract: Kim HS, et al. Lactobacillus Acidophilus as a Dietary Adjunct for Milk to Aid Lactose Digestion in Humans. J Dairy Sci. May1983;66(5):959-66.
  5. View Abstract: Elmer GW, et al. Biotherapeutic Agents. A Neglected Modality for the Treatment and Prevention of Selected Intestinal and Vaginal Infections. JAMA. Mar1996;275(11):870-76.
  6. View Abstract: Oberreuther-Moschner DL, Jahreis G, Rechkemmer G, Pool-Zobel BL. Dietary intervention with the probiotics Lactobacillus acidophilus 145 and Bifidobacterium longum 913 modulates the potential of human faecal water to induce damage in HT29clone19A cells. Br J Nutr. Jun2004;91(6):925-32.