Table 1

Inclusion and exclusion criteria for participation and fecal donors in the randomised controlled trial of fecal microbiota transplantation in severe obesity

Inclusion	Exclusion
Study participants
Must be at least 18 years of age and under 69 years	Symptomatic cardiovascular disease, lung disease, cirrhosis or significant renal failure
Sign consent form	Patients who are pregnant or breast feeding
BMI ≥ 40 kg/m² or BMI ≥ 35 kg/m² combined with comorbidity related to obesity	Patients who have a confirmed malignancy or cancer
	Patients who are immunocompromised
	Previous gastric or small intestinal surgery that alters gut anatomy such as fundoplication, gastric resection, gastric bypass or small bowel resection
	Established drug or alcohol abuse or particularly unstable psychosocial circumstances
	History of cholecystectomy
	New drugs the last 3 months or during the follow-up period that can impact on metabolism or body weight
	Antibiotic treatment the last 3 months
	Serious food allergies
Fecal donors
Age 16–40	Use of peroral antibiotics the past 6 months
Sign consent form	Tattoo or piercing the past 6 months
Healthy	Close relatives with serious autoimmune disease, psychiatric disorder or obesity
BMI 18–25	Former imprisonment
	History of Chronic diarrhoea Constipation Inflammatory bowel disease Irritable bowel syndrome Colorectal polyps Immunosuppression Obesity Metabolic syndrome CFS/ME Psychiatric disorders Other serious autoimmune diseases Cancer
	High-risk sexual behaviour
	Bowel movements that do not correspond to a Bristol Stool Scale type 3 or 4
	Journeys abroad the last 6 months to countries high in antibiotic resistance
	Use of food supplements, prebiotics, probiotics or symbiotics
	Positive cultures for extended spectrum beta-lactamase (ESBL), VRE and MRSA, Salmonella spp, Shigella spp, Campylobacter spp,Yersinia spp and toxin-producing Clostridioides difficile. Fecal tests for viruses (norovirus, rotavirus, sapovirus and adenovirus) and occult blood and a GA-map dysbiosis test: with dysbiosis grade 3 or more*17.
	Blood samples for glycated haemoglobin, serology for HIV, Treponema pallidum and hepatitis A, B, C and E

*The bacteria measured with the GA-map dysbiosis test do not represent entire phyla, but only specific parts of the phyla. This is a clear limitation of the test, which the study personnel is aware of.
BMI, body mass index; CFS, chronic fatigue syndrome; ESBL, extended spectrum beta-lactamase; ME, myalgic encephalomyelitis; MRSA, methicillin-resistant Staphylococcus aureus; VRE, vancomycin-resistant enterococci.