A Non-Interventional Pilot Study to Explore the Role of Gut Flora in ME/CFS

Inclusion Criteria: 1. Signed informed consent by patient 2. Male or female patients age 18 and older. 3. Diagnosis of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) based on the proposed diagnostic criteria of the National Academy of Medicine Exclusion Criteria: 1. Refusal by patient to sign informed consent form 2. Treatment with antibiotics within 2 weeks prior to screening 3. Treatment with probiotics within 6 weeks prior to screening 4. History of bariatric surgery, total colectomy with ileorectal anastomosis or proctocolectomy. 5. Postoperative stoma, ostomy, or ileoanal pouch 6. Participation in any experimental drug protocol within the past 12 weeks 7. Treatment with total parenteral nutrition 8. Any clinically significant evidence of disease that could interfere with the subject's ability to enter the trial 9. Inability of patient to adequately communicate with the investigator or their respective designee and/or comply with the requirements of the entire stud