pro ‧ bi ‧ ot ‧ ic /ˌprəʊbaɪˈɒtɪk◂ $ ˌproʊbaɪˈɑː-/ BrE AmE noun [uncountable and countable]
a food or other substance that contains ↑ bacteria and is used in a positive way to improve health, or the use of this type of food to improve health:
Probiotics have been reported to enhance digestion.
probiotic yoghurt