Yakult (ヤクルト, Yakuruto) is a Japanese sweetened probiotic milk beverage fermented with the bacteria strain Lacticaseibacillus casei Shirota. It is sold by Yakult Honsha, based in Tokyo. It is distributed through convenience stores and supermarkets in single-serving containers of (depending on the manufacturer) 65 mL (2.3 imp fl oz; 2.2 US fl oz) or 100 mL (3.5 imp fl oz; 3.4 US fl oz), often in single-row packs of five or ten. The name "Yakult" was coined from jahurto, an Esperanto word meaning "yogurt".
Yakult's ingredients are water, skimmed milk, glucose-fructose syrup, sucrose, natural flavors (citrus), and live Lacticaseibacillus casei Shirota bacteria.The strain was originally classified as being Lactobacillus casei.
Yakult is prepared by adding glucose to skimmed milk and heating the mixture at 90 to 95 °C for about 30 minutes. After letting it cool down to 45 °C, the mixture is inoculated with the lactobacillus and incubated for 6 to 7 days at 37 to 38 °C. After fermentation, water, sugar, gums and lactic acid are added.