ABSTRACT
Introduction: Probiotics are living, non-pathogenic microorganisms (bacteria) that enter through diet in the human body, live during their passage through the gastrointestinal (GI) tract and are beneficial to health. They have become popular in recent years as a way of improving human health through nutrition. This review aims to discuss the efficacy of probiotics for the supportive therapy of certain clinical conditions, especially infectious diseases, as reported in a number of studies, even though some concerns about their safety still remain.
Areas covered: This paper will review the history of probiotics, from ancient ages to date, and the evolution of their use in clinical practice. The study is based on both personal professional experience of the authors and a comprehensive literature analysis, including old documents from libraries, searching the related biological and clinical data on Scopus, Web of Science, PubMed, EMBASE, also using the ‘cited by’ and ‘similar articles’ options available in PubMed.
Expert opinion: Not all researchers agree about the safety and real efficacy of probiotics in common conditions, especially infective diseases. However, the use of probiotics for clinical conditions that may be improved by consumption of these dietary supplements should be considered as a possible supportive therapy in select patients.
Article highlights
Probiotics include a wide range of microorganisms, mainly bacteria and yeasts or fungi
Lactic acid bacteria (or LAB), belong to the class Lactobacillaceae and are the most important probiotics known to have beneficial effects on the human gastrointestinal tract
Over the years, many mechanisms underlying the anti-infective activity of the probiotics have been identified, mostly studying their activity in the gastrointestinal tract
Many probiotics are also able to produce a lot of molecules that may be considered similar to antibiotics: lantibiotics and bacteriocins
The positive potential impact of probiotics on infectious conditions has been demonstrated
However, because some studies report the risk of possible infections due to probiotics consumption, they must belong to a bacterial group considered GRAS/QPS
Declaration of interest
The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.
Reviewer disclosures
Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.
Author contributions
All authors planned the work, participated to data collection and analysis, and approved the manuscript. In addition, I A Charitos was the only author responsible for writing the text.