The goal of brushing one's teeth is to have fresh breath and prevent cavities. But the effect of toothpaste on the complex ecosystem of bacteria in our mouths—the oral microbiome—is often overlooked.

Toothpaste has always been a means to a fresh mouth and clean teeth for most of us since we first learned to brush. This is how the routine goes; brush, spit, and rinse. But this habit is costing us ...