Prebiotic supplementation in frail older people affects specific gut microbiota taxa but not global diversity

There are complex interactions between ageing, frailty, diet and the gut microbiota; modulation of the gut microbiota by diet could lead to healthier ageing. The purpose of this study was to test the effect of diets differing in sugar, fat and fibre content upon the gut microbiota of mice humanized with microbiota from healthy or frail older people. We also performed a 6-month dietary fibre supplementation in three human cohorts representing three distinct life-stages.