I believe it absolutely can. It has gone the other way where someone got FMT from an obese person and they needed up obese themselves! makes perfect sense sin

I believe it absolutely can. It has gone the other way where someone got FMT from an obese person and they needed up obese themselves! makes perfect sense since the gut bacteria is the actual digester of your meals. They will determine how to digest the various fat/protein/carb/sugar you eat. So people with say.. thyroid problem who typically gain weight out of their control probably stems from gut bac imbalance I'm conjecturing because believe or not the gut bac also has a say in productions of hormone from all your glands. I would bet those individuals if gotten FMT from a healthy donor would reverse that course.