That yeast possesses curative properties was appreciated in the olden times. Hippocrates recommended its use in leukorrhea, and the monks used it for the treatment of plague. Not until the middle of the nineteenth century, however, did the medical profession look favorably on its use. About that time, it was used successfully in furunculosis, anthrax and diabetes.
Later it was shown to be effective in diseases of the skin, suppurative processes, diseases of the respiratory passages, gastro-intestinal diseases, vaginitis, general infectious diseases, etc. In fact, for an interval of many years yeast was used as a curative agent in a long list of widely differing disorders. Then came a reaction, and yeast was used comparatively little by the medical profession during the latter part of the nineteenth century.
In 1899 the researches of Brocq1 emphasized anew the therapeutic importance of yeast, and from 1900 to 1907 many important contributions
HAWK PB, KNOWLES FC, REHFUSS ME, CLARKE JA, Bergeim O, Fishback HR, Smith CA, Lichtenthaeler RA. THE USE OF BAKERS' YEAST IN DISEASES OF THE SKIN AND OF THE GASTRO-INTESTINAL TRACT. JAMA. 1917;LXIX(15):1243-1247. doi:10.1001/jama.1917.02590420035009