ELISA SALVETTI
University of Verona, Department of Biotechnology, Verona, Italy

Abstract

Probiotics are a heterogeneous group of nonpathogenic bacteria that are functionally defined by their ability to produce a health benefit to the host when provided in adequate amounts. A conspicuous number of rigorous researches based on double blind randomized placebo-controlled human intervention trials have been carried out, which give evidence that human health is positively affected by the regular administration of a specific probiotic for a wide range of clinical applications, either inside or outside the gastrointestinal tract. Advances in the research of human microbiota and its impact on the host gene expression will allow in the near future the choice of a specific/next-generation probiotic strain suitable for a particular human genotype within personalized medicine efforts.

The definition of probiotics (the Latin word “pro,” means “for” and the Greek word βιωτικός (biÞtikos) means “bios” or “life”) states that “probiotics are live microorganisms that confer a health benefit on the host when administered in adequate amounts (1, 2). 

This definition implies that a probiotic must be safe for the intended use and must be a defined entity. In the global marketplace, probiotics are found primarily in foods (dairy products, juices, nutrition bars, infant formulas), dietary supplements and pharmaceuticals. 

Probiotics include several species of microorganisms: species of genera Lactobacillus and Bifidobacterium are the most commonly used, together with some Bacillus, Clostridium (C. butyricum strains, recently approved as a novel food in the European Union), Streptococcus and Escherichia species and the yeast Saccharomyces boulardii. 

Research on probiotics is a mainstream scientific area: over 1500 trials have bee ...