Lactobacillus acidophilus is a species of friendly bacteria that is an integral part of normal vaginal flora. Lactobacilli help to maintain the vaginal ecosystem by preventing the overgrowth of unfriendly bacteria and Candida. Lactobacilli produce lactic acid, which acts like a natural antibiotic.

Lactobacillus acidophilus can be taken orally in the form of acidophilus yogurt, or in capsules or powder. It can also be administered vaginally. In a controlled trial, women who consumed 8 ounces of Lactobacillus acidophilus-containing yogurt per day had a threefold decrease in the incidence of vaginal yeast infections and a reduction in the frequency of Candida colonization in the vagina.¹ In another trial, women who were predisposed to vaginal Candida infection because they were HIV-positive received either Lactobacillus acidophilus vaginal suppositories, the antifungal drug, clotrimazole (e.g., Gyne-Lotrimin®), or placebo weekly for 21 months.² Compared to those receiving placebo, women receiving Lactobacillus acidophilus suppositories had only half the risk of experiencing an episode of Candida vaginitis—a result almost as good as that achieved with clotrimazole.

Many women find relief using an acidophilus-containing yogurt douche daily for a few days or weeks, depending on the severity of the infection.³ Three capsules of acidophilus or one-quarter teaspoon of powder can be taken orally one to three times daily. Acidophilus can also be taken preventively during antibiotic use to reduce the risk of Candida vaginitis.^4,5

Boric acid capsules inserted in the vagina have been used successfully as a treatment for vaginal yeast infections. One study demonstrated that 85% of women who used boric acid vaginal suppositories were cured of chronic recurring yeast vaginitis.⁶ These women had all previously failed to respond to treatment with conventional antifungal medicines. The suppositories, which contained 600 mg of boric acid, were inserted vaginally twice a day for two weeks, then continued for an additional two weeks if necessary. Boric acid should never be swallowed.

In a preliminary study, topical application of an alcohol extract of Brazilian propolis resolved candidiasis in 12 of 12 people who were experiencing oral candidiasis associated with the use of dentures. The extract, which was prepared by mixing 2 grams of dried propolis in 25 ml of an 80:20 alcohol:water solution, was applied to the lesions four times a day for seven days.⁷

A small, preliminary trial found that a mouthwash with diluted tea tree oil was effective in decreasing the growth of Candida albicans and in improving symptoms in AIDS patients with oral Candida infections (thrush) that had not responded to drug therapy.⁸ People in the study took 15 ml of the oral solution (dilution of tea tree oil was not given) four times per day and were instructed to swish it in their mouth for 30 to 60 seconds and then spit it out. For use of tea tree oil as a mouthwash, one should not exceed a 5% dilution and should be extremely careful not to swallow the solution.

The essential oil of cinnamon contains various chemicals that are believed to be responsible for cinnamon’s medicinal effects. Important among these compounds are eugenol and cinnamaldehyde. Cinnamaldehyde and cinnamon oil vapors exhibit extremely potent antifungal properties in test tubes.⁹ In a preliminary study in people with AIDS, topical application of cinnamon oil was effective against oral thrush.¹⁰

Many doctors recommend that people with recurrent yeast infections take measures to support their immune system. Echinacea, which has the capacity to enhance immune function, is often used by people who suffer from recurrent infections. In one study, women who took echinacea experienced a 43% decline in the recurrence rate of yeast infections.¹¹

A test tube study demonstrated that oil of oregano, and an extract in the oil called carvacrol in particular, inhibited the growth of Candida albicans far more effectively than a commonly employed antifungal agent called calcium magnesium caprylate.¹² However, clinical studies are needed to confirm these actions in humans.