I would add that our excretions are not particularly “dirty”.
The urine of a healthy person is sterile. Urine contains ammonia which is a cleaning agent. In ancient Rome, people collected urine and then used it to wash their laundry. I think at one point Rome was taxing it because it was so necessary. Urine is also useful in making leather. Some scientists in South African have used it to make bricks.
Animal dung is used as fertilizer to improve soil and make our food grow better. Treated human waste is often used in the same way in USA; for centuries it was used untreated all over the world, and we only treat it now to reduce the risk of certain diseases spread through human waste.
So you’re probably eating food that was grown in some kind of excrement.
Excrement can also be burned to keep warm or for cooking, which is very helpful in some parts of the world where there isn’t a lot of other stuff available for fuel. Some people have even worked on ways to use it to run cars and machines. In some parts of the world, animal feces are used as a building material, such as to coat the floors of homes.
It’s us humans who have this attitude of aversion to our waste. The attitude is cultural. Our waste isn’t necessarily bad.