Midlife is often seen as a point of no return for health, but it could be the perfect moment to make a radical change. New research suggests that your gut microbiome holds the key to aging well, protecting you from chronic disease, and even reversing some of the damage from years of poor diet and stress.

Few people understand this better than Rich Roll, who went from an overweight, junk-food-addicted workaholic to one of the world’s fittest men - all after the age of 40. Now a plant-fuelled ultramarathoner and bestselling author, Rich shares the wake-up call that forced him to transform his life.

He’s joined by Professor Tim Spector, one of the world’s top 100 most cited scientists and professor of epidemiology at King’s College London, who explains why gut health becomes even more important as we age - and how small changes to diet, movement, and daily habits can have an outsized impact later in life.