It’s all good in balance.

“Your microbes actually outnumber your own cells by 10 to 1. “The current estimate is that humans have 10 trillion human cells and about 100 trillion bacterial cells,” says Dr. Martin J. Blaser at the New York University School of Medicine.”

This is from the National Institutes of Health

https://newsinhealth.nih.gov/2012/11/your-microbes-you