ABSTRACT

How changes in the human intestinal microbiota are associated to the human health status is not yet fully understood. However, it is widely accepted that bacterial species in the normal gut microflora of a healthy individual, amongst which there are several microorganisms that are considered as probiotic, do influence human health status. It is accepted that the supplementation of human diet with selected probiotic microorganisms could be beneficial for human health (Lee 2014). In fact, more than a hundred years ago Elie Metchnikoff, Nobel Laureate in Medicine and one of the pioneers of the study of immunology, linked human health and longevity to the consumption of bacteria present in fermented dairy products (Metchnikoff 1908, Shah 2007). Since then, several studies have demonstrated a strong association between various aspects of human health and the direct consumption of bacterial or yeast strains or food products that contain them or their exopolysaccharides (Rodríguez et al. 2010).