Success in the culture of intraintestinal lactic acid bacteria for the first time in the world by Minoru Shirota

In 1930 (Showa 5), Shirota discovered lactobacillus casei strain shirota (Yakult bacteria). At the time, he thought about bacteria as an epidemic, and that prevention was important as to not suffer, and a person can become healthy if the bowels are healthy.

Shirota discovered a type of lactobacillus bacteria and succeeded in repeated culturing and refinement ofit, producing a strengthened strain. As this was the first of its kind in the world, the bacterium was named “L. casei strain Shirota“. It was used, and still is being used, in the lactic acid bacteria drink”Yakult“.

Most lactic acid bacteria died before reaching the bowels, but the strengthened bacteria that Shirota cultured reached the bowels.

In his childhood, Shirota came upon the idea of “preventive medicine”.
Shirota was from Inadani, enclosed by high mountains. The land was steep, crops did not grow well, and families lived in destitute. Children were dying one after another because of infectious diseases such as dysenteries.
To save children, Shirota made the decision to become a doctor.

After Shirota’s success with intraintestinal lactic acid bacteria, he established Yakult Ltd. “People are able to buy Yakult by spending the cost of just one postcard or cigarette,” became the company slogan, meaning that a person with little money can also maintain his or her health. “A healthy intestinal tract leads to long life,” was the idea of the company.