How is the calorie theory of fat loss scientifically valid when?

Researchers took obese mice and extracted gut flora , then transplanted it into thin mice. The thin mice became fat. All the mice were identical genetically , and all ate the exact same amount of calories and food.

The controlled thin mice remained thin.

This experiment shows you can have a result ranging from thin to obese with ABSOLUTELY ZERO MODULATION OF CALORIES

RESEARCH "gut flora obesity"

Did you know obese persons have RADICALLY DIFFERENT intestinal flroa than that of thin persons?

There is no way that all of the mice could have been genetically identical. Only identical twins (or triplets, etc) have exactly the same DNA.