Changes to the bacteria that live inside all of us are responsible for increasing the number of people with allergies, suggests new research. The programme investigates this claim by conducting a unique experiment with two allergic families in order to find out just what it is in the modern world that is to blame.
In the opening episode, they explore how this chemistry fuels and builds our bodies. Michael begins by trying the first meal most of us enjoyed, human breast milk, which contains everything a baby needs - fats, carbs, vitamins and minerals. As we grow, we continue to seek the same chemistry in our diet but from a wide variety of scrumptious fare as Michael and James discover. In San Francisco, they unravel why sourdough bread is so good for us, in the Philippines, they learn how a river weed - rice - has become a comforting staple food, and in Bulgaria, they discover why letting your mushrooms sunbathe may help you get a calcium boost from your dairy food.
This week, we meet a girl whose heart has formed outside her ribcage, a man who can spend nine minutes underwater without taking a breath, a woman who is growing a second skeleton and a paralysed man who is regaining movement thanks to a chip implanted into his brain that can 'read' his brain signals.
With a family history of heart problems, presenter Michael Mosley takes a personal interest in these pioneers, who teetered on the scalpel-edge between saviour and executioner. Michael has a go at heart surgery, meets a man with no heartbeat and witnesses an operation where the patient is cooled until their brain stops and has all of their blood sucked out.
We all know that mankind can't live without air, food and water...the same is true of salt. The salt on your table is a key to unlocking the story of our planet and the cosmos. Big History reveals how this simple molecule underpins our civilization