Taking good care of your teeth can prevent tooth decay and boost your oral health - but, surprisingly, the benefits extend well beyond your mouth. Keeping your teeth and gums clean can help your heart and your brain, reducing the risk of diseases from diabetes to dementia. To find out why, Michael Mosley speaks to Dr. Sim Singhrao from the University of Central Lancashire School of Dentistry. She reveals bacteria in your mouth can travel from your gums into your blood causing problems in other organs, including your brain. Meanwhile, our volunteer Lowri has a go at brushing and using interdental brushes every day to see if it’s something she’d like to fit into her lifestyle.