Table 1.

PICOS elements

Population	Mean age ≥ 65 years
Intervention	Single intervention of probiotic, prebiotic or synbiotic
Comparison	Placobo or no intervention
Outcome	1. Physical function 2. Frailty 3. Mood and cognition 4. Mortality 5. Receipt of care- hospital admissions or length of stay
Study design	Any design or setting