Washed Microbiota Transplantation for Malnutrition After Upper Gastrointestinal Rerouting Surgery

This is a prospective, randomized, multicenter study to evaluate WMT in improving nutritional status in malnourished patients who underwent upper gastrointestinal rerouting surgery. In this multicenter trial, fifty-six patients will be enrolled in four Chinese sites. Participants will be randomized at a ratio of 1:1 to receive three WMTs through either mid-gut tube or colonic TET. After WMT, each participant will receive free diet plus 50% PEN. PEN should last for 4 weeks at home, with stool samples taken and stored at baseline, week 1, and 4 after WMT.