Every one of us teems with trillions of microorganisms: Streptococcus, Flavobacterium, and thousands of other kinds of bacteria and fungi. Some of these microbes are what we call "germs," but many more of them are actually good for us. Discover the health benefits of having aliens inside us, and see how those benefits are being threatened by our modern, sterile lifestyles. Then follow Dr. Dominguez-Bello on her expedition to the Amazon, where DNA samples of a remote group show how drastic the microbial imbalance in the Western world has become.

Aliens Inside Us

National Geographic: Incredible Human Machine takes viewers on a two-hour journey through an ordinary, and extraordinary, day-in-the-life of the human machine. With stunning high-definition footage, radical scientific advances and powerful firsthand accounts, Incredible Human Machine plunges deep into the routine marvels of the human body. Through 10,000 blinks of an eye, 20,000 breaths of air and 100,000 beats of the heart, see the amazing and surprising, even phenomenal inner workings of our bodies on a typical day. And explore striking feats of medical advancement, from glimpses of an open-brain surgery to real-time measurement of rocker Steven Tyler's vocal chords.

National Geographic: Incredible Human Machine

Dr Spencer Wells retraces the footsteps of 200 random New Yorkers and proves they are all cousins.  On the most diverse street in the most diverse city in the most diverse country in the world, a team of National Geographic scientists swab the cheeks of some 200 random New Yorkers. The goal: to retrace our ancestral footprints and prove we are all cousins in the “family of man.”  Cutting edge science, coupled with a cast of New Yorkers – each with their own unique genetic history - will help paint a picture of these amazing journeys. Ultimately, Man’s First Migrations answers some of humanity’s most burning questions, such as who we are and where we come from, and forces us to change how we think not only about our relationships with our neighbours, but ourselves.