ABSTRACT
Gut microbiota is a complex bacterial community present in the human intestinal tract. It aids digestion of dietary compounds, recovery of energy and supply of vitamins and micronutrients. A balanced intestinal microbiome confers benefi ts to the host, while microbial imbalances are associated with metabolic and immune-mediated disorders (Laparra and Sanz 2010). The composition of the gut microbiome is infl uenced by several endogenous and environmental factors (hormones, stressing events, immune-depression, antibiotic treatments) and diet is considered a major driver for changes in gut bacterial diversity. The primary role of diet is to provide suffi cient nutrients to meet the basic nutritional requirements; but from the 1980’s, the emergence of dietary compounds with health benefi ts offered the opportunity to enhance public health (Chen et al. 2006) and so the word “nutraceutical” was coined. Nutraceuticals are defi ned as a ‘food, or parts of a food, that provide medical or health benefi ts, including the prevention and treatment of disease to humans’ (Lockwood 2010). Examples
Email: erika.mangiapane@unito.it
of nutraceuticals are carnitine, creatine, coenzyme Q10, vitamins in general, bioactive peptides, probiotics and antioxidants. In this area, the combination of probiotics and compounds with a well documented antioxidant activity, such as selenium, could be very promising. The fi rst supplement forms of selenium were food-grade yeasts since they could be rapidly produced in high quantity and were known to contain and metabolize bioactive organic forms of selenium (Schrauzer 2001). A more innovative option consists in the combination of probiotic lactobacilli with selenium: this fi eld has begun to be explored in recent years, but a lot of work must be done in order to shed light on the mechanisms involved in selenium metabolism in lactobacilli.
