Restoration of host–microbiota homeostasis for attaining healthy aging: the role of milk and fermented milk

Intestinal microbiota and gut-associated lymphoreticular tissue are in a dynamic equilibrium, the rupture of which causes a condition of dysbiosis in the host. Among many natural foods, milk, because of its composition, is able to influence the host–microbiota relationship. Donkey’s and goat’s milk represents a good alternative to human milk. Healthy effects of both kinds of milk have been reported in either in vitro or in vivo experiments. When administered to elderly subjects, donkey’s milk increased the release of interleukins 6 and 8, while goat’s milk exerted opposite effects. With special reference to fermented cow’s milk, a symbiotic (Gorbach and Goldin) when administered to another group of elderly people, behaved as donkey’s milk upregulating interleukins 6, 8 and also 1. In conclusion, the ability of milk and fermented milk to modulate the altered immune response in senescence needs to be exploited more for maintaining healthy aging.