MarsNews.com

Manned mission to Mars could threaten life on the Red planet The Economic Times

It could be decades before man steps foot on Mars, but scientists have warned that if he ever does, he’ll bring with him trillions of tiny invaders that pose danger of contaminating the Red planet.
Scientists say a swarming mass of 100 trillion microbes will travel with every astronaut who may land on Mars.
While these microbes have evolved over thousands of years to help humans do everything from digesting their food to keeping bacteria from killing them, there’s no telling how they might interact with the Martian environment, the Daily Mail reported.