Purpose – There is need for exhaustive studies to be undertaken to identify various probiotic strains and to understand the actual mechanism of action by which these probiotics exert their health benefits in order to exploit its fullest health benefits expressed by various kinds of the probiotic strains. The paper aims to discuss these issues. Design/methodology/approach – The health effects of the probiotics can be accessed by in vivo as well as the in vitro studies of live microorganisms and their biological active compounds on various disease-causing organisms and their harmful metabolites. Findings – The paper is a brief review of recent findings about the health benefits of probiotic strains of microorganisms. The health effects of fermented food items were known since the time immemorial, but the actual cause of this was a mystery. Recent discoveries led to the author's knowledge about the mechanism through which they exert these curative effects which is either by competitive inhibition of harmful microbes in gut or by production of biological active compounds against disease-causing organisms and their harmful metabolites. Originality/value – Probiotics are commonly consumed as part of fermented foods which are produced with active live cultures, so various new types of these probiotic cultures can be introduced which can act as food as well as curative agents for treating and preventing various types of diseases at nominal costs.