Alterations of immune function and gut microbiota with ageing. Can probiotic supplementation counteract these changes

Abstract

There has been increasing attention recently in the amelioration of health conditions of elderly people. Ageing is associated with several alterations of immune function, a process known as immunosenescence. This is characterised by profound changes of both adaptive and innate immunity, leading to increased susceptibility to infections and development of chronic inflammatory status. Ageing also affects the intestinal microflora composition, with a reduction in the numbers and diversity of many protective commensal anaerobes, such as bifidobacteria and, to a lesser extent, lactobacilli. Several bifidobacteria and lactobacilli strains are common probiotics that exert beneficial effects for human health. The mechanisms underlying their benefits include the improvement of microbiota composition and modulation of the host immune response. On the basis of these properties, probiotics have been suggested as a possible therapeutic intervention to improve the health status of the elderly, and recent studies on animal and human trials have provided encouraging results supporting this type of supplementation.