I can comprehend a good deal of code but this medical jargon is making my head spin. Anyone care to summarize this for us feeble minded laypersons? Because it sounds like they found something in obese people that if eliminated could lead to weight loss. I know there are people that can benefit from that when extreme obesity makes regular, "simple" dieting very challenging and exercise impossible.
tl;dr: fat guy lost a ton of weight by a diet that reduced a specific kind of gut bacteria; this bacteria inserted into mice engineered to be thin caused the mice to gain weight.