Tuberculosis is a serious infectious disease caused by Mycobacterium tuberculosis. You most often hear about pulmonary tuberculosis, but the bacteria may infect any organ in human body. The disease is still very frequent in developing countries. In the United States, affected patients often belong to risk groups whose immune system does not work well (for example alcoholics, homeless people or those infected with human immunodeficiency virus) or people who had traveled to endemic areas.
Current Treatment of Tuberculosis
If you are diagnosed with tuberculosis, you have to be treated for over half a year with a combination of several anti-tuberculosis drugs (isoniazid, rifampin, pyrazinamide and ethambutol or streptomycin). These drugs were discovered in the mid-20th century, and they need to be given in combination to prevent developing resistance of the microorganisms against these drugs.
Traditional Role of Garlic in the Treatment of Tuberculosis
Since ancient times, doctors knew that garlic is beneficial in treatment of various infectious diseases, including tuberculosis. During the 20th century, researchers isolated active ingredients of garlic (such as thiosulfinate allicin, as well as tri- and tetra sulfides and determined effects on various bacteria were determined.
In 1946, around the same time as the discovery of the first anti-tuberculosis drugs ethambutol and isoniazid, the research group of Raghunandana Rao in India asked whether garlic extract affects the growth of mycobacteria. They tested the question both in cell culture in vitro, as well as in infected guinea pig in vivo. Results indicated that garlic stops growth of mycobacteria in both -- the dish and the animals. Not many researchers then followed this line of investigation, but in 1985, the anti-tuberculosis effects of garlic were confirmed and expanded by Gelaha nd Garagusi. However, because we have available specific anti-tuberculosis drugs, no clinical trials tested the effect of garlic on tuberculosis in patients.
Co-Administration of Existing Anti-Tuberculosis Drugs and Garlic
You may wonder whether garlic could enhance the effects of the existing anti-tuberculosis drugs. Abbruzzese’s team addressed this question by testing whether mycobacteria in culture grow less when one of the anti-tuberculosis drugs is added to the culture alone or together with garlic extract. The researchers did not find any synergistic effect, which suggests that the role of garlic in treatment of tuberculosis was replaced by the currently used drugs. However, to firmly establish whether garlic improves the course of tuberculosis, clinical studies would need to compare whether addition of garlic vs. placebo is beneficial to the existing therapy.