Research and development on probiotics

Abstract

It has long been thought that microorganisms, particularly lactic acid bacteria (LAB) could provide benefits for human health. In the early 20th century, Elie MetchniNoff advocated the theory of longevity by yogurt that LAB in yoghurt improve microbiota and contribute to health maintenance and longevity. The term “probiotics” was first used by Lilly and Stillwell in 1965. Thereafter, several definitions of probiotics have been proposed. Among them, the definition proposed by Fuller in 1989 that probiotics are “a live microbial feed supplement which beneficially affects the host animal by improving its intestinal microbial balance” is well known. The health effects of probiotics have been reported in a wide range of research fields. Among others, many studies of the regulation of intestinal function for disorders associated with the gastrointestinal tract and allergic rhinitis have been performed in humans. Several systematic reviews and meta-analyses have verified the efficacy of probiotics in irritable bowel syndrome and have concluded that probiotics have beneficial effects on the improvement of irritable bowel syndrome. In addition, meta- analysis on the treatment of allergic rhinitis has provided evidence of beneficial clinical effects of probiotics. In this review, we have focused on the intestine-regulating function of probiotics and the effect of probiotics on brain function, which is the current topics, as their health effects.