Scientists at Israel’s Weizmann Institute have found from a study of over 1,000 Israelis that there is no genetic link to the good bacteria in your gut (microbiome). A person’s health (cholesterol, weight, blood glucose levels etc.) however, can be controlled by maintaining a healthy stomach.
https://wis-wander.weizmann.ac.il/life-sciences/genetics-or-lifestyle-what-it-shapes-our-microbiome