In just 12 weeks, a daily fibre supplement improved brain function in twins over the age of 65. Could the microbes in our gut hold the key to preventing cognitive decline in our ageing population? The study my colleagues and I conducted showed that this simple and cheap food supplement can improve performance in memory tests – tests that are used to spot early signs of Alzheimer’s disease. As populations age globally, the prevalence of age-related conditions such as declining brain and muscle function is on the rise, so we need innovative ways to slow and prevent this. The number of gut microb…