Billionaire Bill Gates has put his body (read: mind) on the line to trial a machine that turns sewage to drinking water in the matter of minutes.

Footage released by the Gates Foundation shows the computer programmer-turned-philanthropist take a tentative sip of water from the machine, coined the Janicki OmniProcessor, knowing that just five minutes earlier that liquid was human waste.

He purses his lips for a moment before cracking a smile of relief.

"It's water," he confirms.

The machine works by boiling and separating sewage sludge over a number of stages to create water, electricity and sterile ash that can be used as fertilizer.

The foundation believes it could help deliver clean drinking water to more than 2.5 billion people who go without using the funds generated by selling electricity back to the grid.