The phrase "normal byproduct" refers to something that is produced naturally or regularly as a result of a specific process or activity. Full definition
Free radicals are natural and inescapable; though they often come from unhealthy foods and environmental toxins, they are also normal byproducts of the everyday processes that keep your bunny breathing. (petconsider.com)
However, if bacteria make normal byproducts and less acid, the bowels are considered protected and well maintained. (yurielkaim.com)
Gas is a healthy, normal byproduct of digestion, after all. (health.com)