Probiotics discussed in the product industry are defined as living microorganisms, which play a healthy role in the host when ingested in sufficient quantities. Three conditions that probiotics must meet:

1) living microorganisms;

2) take enough;

3) It is beneficial to the health of the host.

Probiotics are defined from the perspective of being beneficial to the health of the host. At present, the most popular probiotics are Bifidobacterium, Lactobacillus, Bacillus, Clostridium butyricum and so on. Among them, Bifidobacterium, Lactobacillus and Bacillus belong to lactic acid bacteria, so some lactic acid bacteria are included in probiotics, but not all lactic acid bacteria are probiotics.

Lactic acid bacteria is not a strict microbial classification standard, and its definition is not rigorous, but it has been recognized by the public at present. Therefore, the definition of lactic acid bacteria in the food industry is:

Lactic acid bacteria generally refer to bacteria that can ferment sugar and mainly produce lactic acid.