Impact of probiotics and prebiotics in the modulation of the major events of the aging process: A systematic review of randomized controlled trials

Background: The increase in life expectancy has led to profound changes in disease prevention and health maintenance. Because of the impact of dysbiosis on the host's health, it is worth considering microbiome-targeted therapies to attenuate or delay age-related perturbations.Aim: The aim of the present review was to systematically evaluate the impact of probiotics, prebiotics, and synbiotics on the major events that affect individuals aged 65 or older.Methods: We performed a literature search in MEDLINE and the Cochrane Central Register of Controlled Trials. Randomized Clinical Trials (RCTs) performed on old people and published between 2009 and 2019 were included.Results: Nine RCTs and 1 secondary analysis (n = 475, 55.8% female) were eligible for inclusion and retrieved in this systematic review. Overall, most interventions resulted in improvements in certain parameters when compared to control (glucose homeostasis, cognitive function, frailty phenotype, gut microbiota profile, immune parameters), while others remained unvariable. Conclusions: The use of probiotics and prebiotics raises a great opportunity to modulate the process of aging and looks promising for health prevention in old adults. However, more RCTs in subjects older than 65 years are needed to elucidate the suitability of these supplementations and establish the underlying potential mechanisms.