First post in the 'In This Future' category where we think up possible scenarios in our tomorrow.
In this future, people only need to exchange their feces, urine, saliva, hair, nails and less common sweat, body oils and tears for needs like nutritious food, drinking water, shelter. Probably also perks like electricity and communication connections.
The excretions are put to good use, for research, medicine, fertilizer, 3D printer material, fuel generation, among others. There would be bins that automatically take the excretions where they need to go, in their properly tracked containers.
Now the real reason for this topic:, to live without having to worry about work, especially in these days of automation.
Though it's probably a good bet that there would always be work to do.
For a good in-depth, well written article on automation and jobs, check out: www.theguardian.com/sustainable-business/2016/feb/24/automation-end-work-obsessed-society-dystopia-jobs