Stamen Grigorov (1878<unk>1945), ɗalibin likitanci na Bulgarian a Geneva, ya fara nazarin microflora na yogurt na Bulgarian. A cikin 1905, ya bayyana shi a matsayin wanda ya kunshi ƙwayoyin cuta masu ƙwayoyin cuta masu ƙwayoyin cuta. A cikin 1907, an kira kwayar cuta mai kama da ƙwayoyin cuta Bacillus bulgari (yanzu Lactobacillus delbrueckii subsp. bulgaricus). Gwarzon Nobel na Rasha da masanin ilimin halitta Ilya Mechnikov, daga Institut Pasteur a Paris, aikin Grigorov ya rinjayi shi kuma ya yi zaton cewa cin abinci na yau da kullum na yogurt yana da alhakin lafiyar Bulgarian.
Kwayar cuta