That's it exactly. Some beneficial species play an active role in suppressing the pathogenic species (those that release acid or cause gum disease) and have other benefits including helping us break down dietary nitrate into nitric oxide, which is critical for heart/brain health.
My company tests/researches the oral microbiome and we're starting to discover the signatures of what puts people in one group vs. the other, with hopes of helping develop more personalized approaches down the road, but for now helping people understand what will work best for them.
Here's my company for anyone who is interested in learning more: https://www.bristlehealth.com/