The articles I've seen don't talk about transplants to help people change their weight. Their thrust was more geared towards explaining (or disproving the significance of) measured differences, and detecting differences doctors can recommend the most likely most efficient diet for people with health problems who are currently having trouble shifting weight.
Supposedly, some people lose weight on low-fat diets, and some on low-carb diets. A few can lose weight on either. And most people need high-intensity exercise to lose weight, while a few only need low-intensity.
(I have both forms of genetic privilege, and have never had to worry about my weight.)
I'm also bullish on microbiome transplant for weight loss.