While growing up, I got tired of hearing how a bit of dust and grime is good for my health, and how important it is to build up that fort called immunity. And I remember those sour vegetables, bland yogurts, and other, very awful nameless edible things I had to eat, forced upon me by my folks, which I am trying to force upon my 9-year-old now. You and I and millions after us, will have to endure all of these distastes for a greater purpose - to keep our stomach/gut/intestines balanced and happy. Which is the focus of this month’s cover story. Nicola Davis writes about how new research is suggesting that our gut and the bacteria it decides to play host to dictate not just the distribution of nutrients in the body but also affects our demeanour, stress levels and disposition. And that communication between the brain and the gut can go both ways. Do read on page 34. In other pages, we cover history’s two most powerful personalities - Caeser and Hitler - both dictators. Of course we all know who killed Caeser. It was Brutus and Cassius but what we don’t know is that the brains behind the deceit were someone else’s. Find out the plot and who the bigger villain was on page 30. In another must–read essay, the famous biographer Ian Kershaw explores the enduring enigma of Hitler and the devastating but unique impact he had on his people, and the world. On page 62. The rest of the issue has got the good stuff too. Enjoy NASA’s new mission, experience the animals of the Namib Desert, and explore newer technologies that seem set to address the issue of climate change. When you are done reading, we would love to hear your worldview and your feedback. Write in your letters to edit.bbcknowledge@wwm.co.in. Cheers