A bacteria that can create calories out of thin air sounds like it’d be useful, if true.
The belief in bacteria causing obesity is so prevalent in the medical world, that you can’t donate fecal matter for a fecal transplant if you’re above a certain body fat percentage, because it’s believed bacteria obese people carry that caused them to become obese will make a thin person obese if the bacteria is transplanted to the thin person from the obese person.
Because the actual theory is that certain bacteria in the gut biome make a person more prone to obesity both by increasing hunger signals to the brain and by changing digestive processes. It doesn’t “make calories out of thin air”.
Maybe read more of the articles than just the headlines?