Why does human waste smell bad?
the reason human waste smells has very little to do with the
human per say. when we dispel our waste it is made up of 50% dead
bacteria. The bacteria lives in our intestines to break down the
food we eat so the body can withdraw the nutrients. And that
bacteria then dies on the way out and it is the dead bacteria that
smells. Proper intake of that bacteria from the foods we eat like
yogurt and other things is essential for good health.
Around 33% of feces are made up of dead bacteria, these bacteria come from the intestines that assist us in the digestion of food, around another 33% is made up of material that we cannot digest, like fiber. The remainder is made up of cholesterol, inorganic salts, dead cells, mucus from the lining of our intestine, live bacteria and protein. The bad smell is due to bacterial action that produces sulfur or nitrogen rich organic compounds like mercaptans, indole and skatole and hydrogen sulphide. The same reason that farts smell also.