Lactobacillus acidophilus

ACIDOPHILUS

SCIENTIFIC NAME: Lactobacillus acidophilus

RELATED TERMS: Acidophilus, Acidophilus Extra Strength®, acidophilus milk, Actimel®, Bacid®, DDS-Acidophilus, Enpac®, Fermalac® (Canadian), Florajen®, Gynoflor®, Kala®, Kyo-Dophilus®, L. acidophilus milk, L. acidophilus yogurt, Lactinex®, Lactobacillaceae (family), lactobacillus, Lacto Bacillus, lactobacilli, Lacteol Fort®, MoreDophilus®, Narine®, Probiata®, Pro-Bionate®, probiotic, Superdophilus®, yogurt.

HISTORY

 For several decades, health and nutritional benefits have been claimed for products containing Lactobacillus cultures.

The topical or intravaginal application of yogurt products has been reported to control yeast and bacterial infections, and

the ingestion of these preparations has been recommended to reduce the symptoms of antibiotic-induced diarrhea or sore

mouth caused by Candida infections. Other reports have indicated that the ingestion of acidophilus-containing products

can reduce serum cholesterol levels, improve lactose intolerance, and slow the growth of experimental tumors. L.

acidophilus has been referred to as a probiotic, defined as microorganisms that have a beneficial effect on the host by

improving the properties of the indigenous microflora. The term "probiotic" is used to describe organisms that are used medicinally, including bacteria such as L. acidophilus and yeast such as Saccharomyces Boulardii.


PHARMACOLOGY

Replenishment of normal bacterial flora: Products containing live cultures have been investigated for their ability to

compete with pathogens in the microenvironment, thereby permitting the reestablishment of normal bacterial flora.

Lactobacilli have been shown to inhibit the growth of other vaginal microorganisms including Escherichia coli, Candida

albicans, and Gardnerella vaginalis. Several factors may contribute to the possible activity of Lactobacillus, including

the ability to generate lactic acid, hydrogen peroxide, and exogenous antibacterial compounds, to influence the

production of interferon by target cells, and to alter the adherence of bacteria. Lactacin F, an antibacterial compound

produced by L. acidophilus, has been isolated and partially characterized as a heat-stable protein with at least 56 amino

acid residues.

Lactobacillus has long been considered to be a component of the protective flora in the vagina. Recently, Lactobacillus

species that produce hydrogen peroxide have been found in normal vaginal flora. Consequently, the therapeutic benefits

of Lactobacillus products have been investigated in women with vaginal and urinary tract infections. Women who used

acetic acid jelly, an estrogen cream, a fermented lactobacillus-containing milk product, or metronidazole (eg, Flagyl)

were evaluated to determine the effects of intravaginal therapy on bacterial vaginosis.  The American Medical

Association proposed guidelines for manufacturers to state on yogurt containers the number of viable L. acidophilus

organisms contained therein.9 Vaginal tablets containing L. acidophilus and estriol were shown to cure bacterial

vaginosis. A study showed decreased candidal vaginitis after ingestion of yogurt containing L. acidophilus.

Lactobacillusspecies that are strong producers of hydrogen peroxide and are highly adherent to vaginal epithelial cells

effectively treat bacterial vaginosis. Specific isolates of Lactobacillus with these characteristics are potential probiotics

for vaginal recolonization. The weekly instillation of Lactobacillus has been shown to reduce the recurrence rate of

uncomplicated lower urinary tract infections in women, and the use of a strain that is resistant to nonoxynol-9, a

spermicide that kills protective vaginal flora, may have potential for use in women with recurrent cystitis using this

contraceptive agent.

L. acidophilus is normally found in the human alimentary tract. Because of its acid-resistance, it persists in the stomach

much longer than other bacteria do. Consequently, the oral administration of products containing L. acidophilusmay be

useful in the management of a variety of conditions associated with altered GI flora. Their beneficial effects may be

related to the ability to suppress the growth of pathogens. In vitro, L. acidophilus has been shown to suppress the growth

of Campylobacter pylori, a pathogen implicated as a causative factor in acid-peptic disease.

No consensus has been reached regarding the effectiveness of Lactobacillus-containing products in ameliorating

antibiotic-induced diarrhea. However, L. acidophilusdid not prevent traveler's diarrhea.

Effect on cholesterol levels: It has been suggested that appropriately selected strains of Lactobacillus may be useful

adjuncts for the control of hypercholesterolemia in humans, by virtue of the bacteria's ability to assimilate cholesterol

and to grow well in the presence of bile.

Consumption of yogurt containing L. acidophilusin asthmatic patients showed trends in decreased eosinophilia and

increased interferon gamma, however, without improving clinical parameters. Viability might be a prerequisite for

effects on the immune system.

Effect on lactose intolerance: Acidophilus milk containing L. acidophilushas been used in hospitals to treat patients

with lactose intolerance, although controversy remains regarding effectiveness on lactose digestion. In a randomized

trial of 18 patients, symptoms were not significantly improved after ingestion of L. acidophilus.

USES

Uses based on scientific evidence

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.

Bacterial vaginosis

Vaginal candidiasis (yeast infection)

Diarrhea treatment (children)

Diarrhea prevention

Hepatic encephalopathy (confused thinking due to liver disorders)

Asthma

High cholesterol

Lactose intolerance

Necrotizing enterocolitis prevention in infants

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. 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.




TOXICOLOGY

     Endocarditis caused by Lactobacillusspecies, including L. acidophilus has been reported. This is a rare

infection seen in patients with abnormal heart valves who have recently experienced dental manipulation. Neurological

sequelae from D-lactic acidosis, caused by consumption of acidophilus tablets and yogurt containing L. acidophilus,

was observed in a child with short-bowel syndrome. Complete avoidance of L. acidophilus in children with short-bowel

syndrome may help prevent episodes of D-lactic acidosis.

SUMMARY

    Preparations containing L. acidophilusinclude yogurt, milk, tablets, capsules, and granules. They are used

most frequently to restore normal flora to the GI tract and vagina. However, the data supporting the efficacy of these

products for these uses are conflicting. Use of L. acidophilus is generally considered safe. Rare adverse events include

endocarditis in susceptible patients and lactic acidosis in children with short-bowel syndrome.

PATIENT INFORMATION — Acidophilus

    Uses: L. acidophilus has been used to restore normal oral, GI, and vaginal flora in those affected by

antibiotics or by Candida and bacterial infections. Its value in treating these infections, lower urinary tract infections,

and lactose intolerance remains unclear. In vitro, it suppresses growth of C. pylori, implicated in acid-peptic disease. In

vivo, it suppresses growth of H. pylori, also implicated in upper GI diseases.

    Side Effects: L. acidophilus is generally considered safe, as it is normally found in the human alimentary

tract. However, in patients with abnormal heart valves who have recently experienced dental manipulation, endocarditis

caused by Lactobacillus species has been reported. Complete avoidance of L. acidophilusin children with short-bowel

syndrome may help prevent episodes of D-lactic acidosis.