Fighting Immunosenescence and Promoting Immunity by a Fasting-mimicking Diet Elderly.

Plain-language summary

Background: Immunosenescence is an aging-dependent phenomenon underlying age dependent deterioration in the function of the immune system, characterized by a decline in B and T cells with a relative increase in natural killer (NK) cells. Aging also promotes chronic inflammation accompanied by increased levels of pro-inflammatory cytokines. Both immunosenescence and inflammation contribute to frailty, which is a geriatric syndrome characterized by age-related deterioration in multiple physiological systems resulting in greater vulnerability to stressors and increased risk of poor outcomes including longer hospital stays, postoperative complications, poor responses to vaccination, functional decline, and death. Although pharmacological interventions could be developed to address immunosenescence, inflammation and frailty, a dietary intervention that does not cause weight or muscle loss may be a preferable option, particularly if it is periodic in nature and it only needs to be adopted for a few weeks per year. Hypothesis: We will test the hypothesis that a newly formulated and relatively high calorie fasting mimicking diet (FMD) to be administered to subjects age 65-80 once a month for 5 days for two to six cycles can partially reverse immunosenescence and inflammation, thus contributing to the reduction of frailty. Aims: This proposal is divided into 2 main tasks: Task 1: We will determine whether FMD cycles in mice: a) prevent frailty syndrome onset and symptoms B) delay or reverse age-related immunosenescence and inflammaging, C) improve the functionality of bone marrow cells, D) enhances the response to flu vaccination. Task 2: A )We will develop a special relatively high calorie FMD medical food for testing in humans, B) We will test the safety and efficacy of the FMD medical food in an aged and frail individuals (65-80 yr) for 2-5 day cycles preceding their annual influenza vaccination. Expected results: In mice, we expect that the FMD diet will reduce the clinical signs of frailty during aging, and in particular increase immune system influenza vaccine response by preventing immunesenescence. We expect that the FMD will reduce phosphorylation of mTOR and of its downstream targets, and induce autophagy and apoptosis in WBCs. These effects are anticipated to remove damaged cells and promote the activation of hematopoietic stem cells and the generation of new WBCs. We also expect that the transient increase in corticosteroids and removal of damage immune cells will be accompanied by a decrease in systemic inflammation. Increased performance on rotarod and other measures of frailty is also anticipated. In humans, we expect that the FMD will be well tolerated by the pre-frail elderly without major adverse events and that it will be possible to achieve high compliance to this diet. We also anticipate that elderly undergoing the FMD protocol followed by 30 days of a normal diet plus supplements will exhibit better functional status and better response to the flu vaccine as compared to patients from the control arm. An improvement in handgrip strength and in lean body mass, as detected by BIA, is also expected, at least in a fraction of the patients from the intervention arm. Impact: Frailty is a geriatric syndrome characterized by age-related deterioration in multiple physiological systems and homeostatic mechanisms, resulting in greater vulnerability to stressors and increased risk of poor outcomes including longer hospital stays, postoperative complications, poor responses to vaccination, functional decline, and death. Thus, the identification of a dietary strategy, potentially to be applied for only 10 days a year but able to rejuvenate the immune profile and function while reducing systemic inflammation could have a major impact on both healthspan and health-related expenses. Because older individuals are often taking multiple drugs, the dietary intervention being investigated here would also reduce the potential toxicity of an additional pharmacological intervention.

Who can participate

What they're measuring

Trial details