In which food would you find lactic acid bacteria? Mention some of their useful applications.

(N/A) Lactic acid bacteria $(LAB)$ are commonly found in curd.
These bacteria grow in milk and convert it into curd by producing acids that coagulate and partially digest the milk proteins.
During this process,they significantly increase the nutritional quality of curd by increasing the content of vitamin $B_{12}$.
In our stomach,$LAB$ play a beneficial role by checking disease-causing micro-organisms and maintaining gut health.