Methods for assessing the immunostimulating properties of dietary lactobacilli - A critical appraisal

Several species of lactic acid bacteria are known as therapeutic agents since long. Consumption of fermented milks, containing dietary lactobacilli, confer positive influences on the gastro-intestinal microecology and hence they have been used in the treatment of a variety of GI-tract disorders. Dietary lactobacilli have also been found to have hypocholesterolemic and antitumour properties. in the last couple of decades, interesting observations on their immunomodulatory influences in several types of hosts have been reported. Selected species of lactobacilli play positively with host's defence mechanisms, which may involve checking the translocation of invading bacteria and development of specific and non-specific immune responses. Several in vitro and in vivo studies are conducted on experimental animals, but very limited work involving in vivo human studies have been done on this very interesting aspect of lactobacilli. This review critically analyses the work done so far in the area and will help in planning the future strategies for commercially and technologically exploiting this very important beneficial activity of lactobacilli.