Probiotics in aging skin

Health benefits of probiotics have been established by several studies in animals and humans and the scientific literature shows that the clinical uses of probiotics are broad and are open to continuing evaluation. The most common microorganisms used as probiotics are strains of lactic acid bacteria (LAB), which are gram-positive, nonsporing, catalase-negative organisms that are devoid of cytochromes and of nonaerobic habit, but are aerotolerant, acid-tolerant, and strictly fermentative; lactic acid is the major end product of sugar fermentation. Particular attention is paid to specific species of lactic acid bacteria (LAB), including Lactobacilli and Bifidobacteria, that are part of the intestinal microbiota. Most probiotics are included in foods or dietary supplements and are aimed at functioning in the intestine. However, even if gastrointestinal tract has been the primary target, it is becoming evident that other conditions not initially associated with the gut microbiota might also be affected by probiotics. © Springer-Verlag Berlin Heidelberg 2010.