Lactic acid bacteria as probiotics*

Lactic acid bacteria (LAB) are commonly found on human and animal mucous membranes in dairy products and naturally on some plant surfaces. They are normal residents of the gastrointestinal tract of human beings. Several species are commercially used in production of fermented milks, yoghurt, other dairy and meat products, as well as other foods. The antimicrobial activities of LAB have been known long ago and recognised as important in food fermentations, food preservation and intestinal ecology. The general nutritious effect is scientifically well established and documented but a considerable amount of doubt or scepti­ cism exists in relation to various prophylactic and therapeutic claims attributed to probiotic preparations. This article represents the species of LAB that have been used as human probiotics or in fermented dairy products claimed to promote health. Additional index words: Lactic acid bacteria, species used in fermented milks production. Antimicrobial activities, Fermentations, Food preservation. Intestinal ecology.