> At that point though are we kinda arguing semantics? While our microbiome isn't composed of human cells, you can still argue it's a part of our functioning organism.

It's not semantics, because when more calories are used up by bacteria they only sustain the amount of bacteria inside you, which then die and leave your body on a relatively quick timescale.

It's like if your fat cells could only store fat for a month before it gets discarded.

So it's important to know how much is each, if they can both vary.