Donor Screening for Fecal Microbiota Transplantation in China: Evaluation of 8483 Candidates

Therapeutic application of fecal material has been described as early as 4th century China.1Zhang F. et al.Am J Gastroenterol. 2012; 107 ([author reply, 1755–1756]): 1755Crossref PubMed Scopus (456) Google Scholar Subsequently, the intervention has evolved, and fecal microbiota transplantation (FMT) has become a recommended treatment from the American College of Gastroenterology guideline for a second recurrent Clostridioides difficile infection2Kelly C.R. et al.Am J Gastroenterol. 2021; 116: 1124-1147Crossref PubMed Scopus (202) Google Scholar and has emerged as a promising intervention to address dysbiosis linked to a number of diseases.3Lynch S.V. et al.N Engl J Med. 2016; 375: 2369-2379Crossref PubMed Scopus (2102) Google Scholar A robust donor screening program is an important element of safe FMT; however, data are limited, with variable screening rates.4Craven L.J. et al.Open Forum Infect Dis. 2017; 4: ofx243Crossref PubMed Scopus (35) Google Scholar,5Costello S.P. et al.Clin Infect Dis. 2016; 62: 908-914Crossref PubMed Scopus (82) Google Scholar Recently, a large FMT program in the United States reported data that suggested a qualification rate of approximately 2.5%6Kassam Z. et al.N Engl J Med. 2019; 381: 2070-2072Crossref PubMed Scopus (89) Google Scholar; however, the qualification rate for donors in Asia has been only described in literature review analysis.7Ng S.C. et al.Gut. 2020; 69: 83-91Crossref PubMed Scopus (83) Google Scholar Real-world data on candidate donors in Asia with a distinct health and risk factor profile for the donation of biologic material to be processed for FMT are limited. Accordingly, we outline the eligibility rate and etiology of exclusion for the largest FMT center in China (10th People's Hospital, Tongji University, Shanghai, China) where over 60,000 FMTs across more than 5000 patients have been conducted since 2012 for various gastrointestinal diseases (eg, recurrent C. difficile infection, inflammatory bowel disease, irritable bowel syndrome) and extraintestinal diseases (eg, autism spectrum disorder, Parkinson disease). The standardized donor screening program today is based on the Chinese Expert Consensus FMT guideline, which recommends evaluation of donor screening across the following 6 dimensions: physiology, psychology, personal history, stability, persistence, and tolerance to dietary restriction.8Alliance C.M.T.I. Association MCoSPM. Chin J Gastrointest Surg. 2020; 23: 14-20Google Scholar The clinical protocol of recruiting the FMT donor evolves depending on different time periods. Starting from 2012, a 3-step protocol was used, whereas from 2015 to 2019 a fourth step of evaluating candidates' lifestyle was adjoined. Until now, enrollment of candidate donors was extended prospectively into a 5-step protocol (Figure 1). In the first step, candidate donors are excluded based on age, body mass index (BMI), and high-risk sexual behaviors and personal history. In the second step, a more detailed, clinical evaluation is conducted for microbiome-mediated diseases and risk factors for transmissible infection. This step also excludes candidates with a history of chronic diseases and mental health conditions as per assessment by both a trained physician and senior psychiatrist. In the third step, candidate donors undergo stool testing, including 16S sequencing to evaluate dysbiosis (Shannon's diversity index lower than 50% normal population excluded), and a full panel test of infectious pathogens, and in the fourth step they undergo hematologic and serologic testing to exclude bloodborne pathogens and systemic organ dysfunction (Appendix 1). In the fifth step, donors are evaluated for diet restriction if material is for a recipient with significant food allergies and for logistical and quality control factors. Initially, when we started the screening project of FMT donors in 2012 (phase I), a simple 3-step protocol based on age limitation, BMI restriction, and clinical and laboratory assessments were used, leading to a rate of 8.38% to screen out the standard donors. After 2015 we started to incorporate a lifestyle evaluation (phase II) to exclude candidates without sufficient amounts of exercise (walking < 6000 steps a day) and unqualified eating habits (including consuming irritant spicy food, saturated fatty acid food, not enough fresh fruits or vegetables<300 g/d), decreasing the success rate of obtaining donors by 3.93%. However, the overall FMT efficiency was increased from 42.8% to 58.6%. Retrospectively, from December 2020, 8483 donor candidates were evaluated (Figure 1). The most common exclusion criteria at each step were age (n = 1364) or nonoptimal BMI (n = 1383) at step 1, history of chronic disease (n = 461) at step 2, intestinal dysbiosis (n = 280) at step 3, abnormal liver panel (n = 104) at step 4, and unqualified amounts of exercise (n = 193) at step 5. Overall, 145 candidate donors qualified, resulting in a 1.7% qualification rate and leading to an even higher efficiency (68.7%) but a lower adverse effect (20.1%), among which only one "super donor" is observed (Appendix 2, Supplementary Figure 1). When we started the donor screening projects within the phase I protocol, few laboratory assessments were used because of limitations in technology. After 2015, during the phase II protocol, 16sRNA sequencing was widely applied and greatly increased the overall efficiency and lowered adverse effects. In the phase III protocol we differentiated the fecal assessment and peripheral blood assessment, but in both levels we use 16sRNA sequencing to screen out possible infectious diseases including coronavirus disease 2019 (COVID-19) and to rule out dysbiosis. The donor screening qualification rate in China is in keeping with that from a large US stool bank.6Kassam Z. et al.N Engl J Med. 2019; 381: 2070-2072Crossref PubMed Scopus (89) Google Scholar However, stricter criteria, including narrower age and BMI ranges, assessment of intestinal dysbiosis by 16sRNA sequencing, and additional screening dimensions (eg, exercise, restricted eating habits), may contribute to the lower qualification rate reported here. Different regimes of oriental and occidental country might greatly impact human intestinal microbiota,9Frame L.A. et al.Nutr Rev. 2020; 78: 798-812Crossref PubMed Scopus (60) Google Scholar which should be taken into account when applying similar protocol to other ethnics groups. The 3 phases of the FMT donor screening strategy are summarized in Figure 1. In phase I (2012–2015) only 3 steps were used, leading to an overall efficiency of 42.8% and adverse effects of 30.7% (only minor adverse effects: abdominal distention, nausea, vomiting, diarrhea, abdominal pain, sore throat or fever; no major adverse effects like gastrointestinal bleeding or enterogenous infection). In phase II (2015–2019) another step of evaluating donors' lifestyle was added, leading to an overall efficiency of 58.6% and adverse effects of 26.3%. In phase III (after the 2019 COVID-19 pandemic) screening for COVID-19 in both peripheral blood and feces was widely applied among candidates. Therefore, enrollment of candidate donors was conducted prospectively in a 5-step protocol: step 1, candidate donors are excluded based on age, BMI, high-risk sexual behaviors, and personal history; step 2, detailed clinical evaluation is conducted for microbiome-mediated diseases and risk factors for transmissible infection, excluding candidates with a history of chronic and mental disease; step 3, a 16S sequencing screening strategy is applied to evaluate dysbiosis and infectious pathogens; step 4, hematologic and serologic testing is used to exclude bloodborne pathogens and systemic organ dysfunction; and step 5, diet restriction eligibility, logistical, and quality control is applied. The overall efficiency of FMT donors is increased to 68.7% and adverse effects are decreased to 20.1%. I.Standard donor screening criteria1.Physiologic dimension, screening criteria evaluated as follows:a.No clinically meaningful medical or surgical history;b.Age 18–30 years old, BMI 18.5–23.9 kg/m2;c.Hematologic examination: normal blood count, liver and renal function, electrolytes and C-reactive protein, and negative for hepatitis A, B, C, D, and E; HIV; syphilis; Epstein-Barr virus; herpes simplex virus types 1 and 2; cytomegalovirus; nematode, amoeba, and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2; aka COVID-19) IgM/IgG;d.Feces examination: normal stool routine, negative for occult blood test, negative for C. difficile, Campylobacter, Salmonella, Shigella, Helicobacter pylori, enterotoxigenic E. coli and their eggs, vesicles, parasites, spores, norovirus, rotavirus, and other pathogens; negative for multidrug-resistance genes (carbapenem-resistant Enterobacteriaceae, extended-spectrum β-lactamase–producing bacteria, methicillin-resistant Staphylococcus aureus, and other drug-resistant bacteria;e.Negative for monogenetic inherited disease;f.Negative stool test for SARS-CoV-2 (COVID-19);g.Negative nasal swab for SARS-CoV-2 (COVID-19) nucleic acid;h.Negative nasal swab for methicillin-resistant S. aureus.2.Psychologically dimension, which evaluated the following:a.Clinical assessment by psychiatrists or counselors to ensure donor candidate was in good psychological condition;b.Self-rating depression scale, self-rating anxiety scale, Pittsburgh sleep quality index, and the psychological status of the donor candidate should be normal.3.Personal history evaluateda.Previous medical history:I.No gastrointestinal discomfort in the past 2 weeks;II.No use of antibiotics, proton inhibitors, immunosuppressants, chemotherapy drugs, or other medications impacting that may impact the microbiome;III.No chronic pain in the past 3 months;IV.No history of gastrointestinal surgery;V.No history of infectious diseases or risk of exposure to infectious diseases;VI.No history of allergic diseases, autoimmune diseases;VII.No chronic disease including metabolic diseases (eg, diabetes), cardiovascular diseases (eg, hypertension, stroke, and coronary heart disease), chronic respiratory diseases (eg, chronic bronchitis or chronic obstructive pulmonary disease);VIII.No neurologic or psychiatric diseases;IX.No history of malignant tumors;X.No history of receiving growth hormone, insulin, coagulation factors and other intravenous injection;b.Personal risk factors evaluatedI.Regular work and rest, healthy diet, family stressors;II.Not a healthcare worker or animal care worker;III.No high-risk sexual behavior;IV.No smoking, drinking, or drug addiction;V.No drug addiction;VI.No vaccination or drug trial in the past 6 months;VII.No tattoos or skin lesions;VIII.No traveling to epidemic areas or tropical areas.c.Family history evaluatedI.No family history of gastrointestinal diseases;II.No family history of malignant tumors;III.No family history of infectious diseases.d.OthersI.Nonpregnancy;II.Nonmenstrual period.4.The stability of donors is the consistent result of the clinical and laboratory examinations and microbiome sequencing.a.The above items will be reexamined every 2 months and the outcomes can still meet the above criterions;b.Each donated feces will be sampled for 16S rRNA sequencing to ensure the stable microbiome composition and diversity.5.Establish clinical records and follow-up system to ensure the persistence of the donor. Donors should ensure long-term fecal donation, at least twice a week, with at least 100 g each time.6.Donors' tolerance to dietary restriction is accomplished through voluntary food restriction. Because some patients who receive FMT have food allergies and food intolerances (eg, eggs, milk, etc), food type restriction may be implemented for donors providing material for recipients with food allergies. Donors will eliminate food allergens 5 days before donation, and if the donor is intolerant, he or she cannot serve as a donor for recipients who have food allergens.II.Quality control factors for routine qualified donors1.For donors who have provided material for FMT, a quality control model is used to ensure effectiveness. Specifically, using the donor–patient efficiency analyze model, a single donor's overall effectiveness of ≥75% is considered a "super donor" based on retrospective statistical analysis on the effectiveness of 50 patients treated for each condition. Of note, initial donor candidate screening does not incorporate the quality control model, which is only applied for routine qualified donors.2.The threshold of the effectiveness is 60%, and the characteristics of the microbiome variety and metabolites between groups with therapeutic effectiveness ≥ or <60% are analyzed and are considered as exploratory indicators for subsequent donor screening strategy for each condition.3.The Chinese version of the Big Five personality trait model, which includes the 5 dimensions of extraversion, agreeableness, conscientiousness, neuroticism, and openness, is used to evaluate donors' personality traits.III.Donor management criteria1.A donor manager at the FMT center is responsible for the management of donors.2.Before starting the screening process, donor candidates should sign a written informed consent form and complete a questionnaire each time they donate feces to assess any changes in their health status. The collection of donors' social and biologic information is both reviewed and approved by the ethical abroad of Ethics Committee of Tongji University, Shanghai.3.Donors complete clinical and laboratory every 8–12 weeks.4.Real-time monitoring mobile app systems are applied to follow-up on the donor. Donor managers communicate with donors via the "优菌客Youjunke" mobile app. The ""优菌客Youjunke" mobile phone app collects vital signs and daily behavioral records of the donors. Qualified donors walk at least 10,000 steps and consume at least 5 different fruits (provided in the form of fruit purchasing coupons).5.Donors are required to donate stool at least 2 times a week, with the amount ≥100 g (Bristol stool scale type 3–4) each time. The donor, WMX, was a 24-year-old woman, with a weight of 57 kg, height of 164 cm, BMI of 21.2 kg/m2; she had been an FMT donor since 2019. WMX had been compliant with monthly follow-ups with all donor criteria (Appendix 1) met at each visit. 16S rRNA sequencing was performed using her original stool samples, FMT microbe solutions, and FMT microbe capsules. No pernicious or pathogenic microbes were detected. Her microbiota was notable for a high Shannon's diversity index (Supplementary Figure 1A) and abundance of Bacteroides, Faecalibacterium, and Lachnospira (Supplementary Figure 1B and C). Colony counting using trypan blue showed a high level of living bacteria in both the FMT microbe solutions and FMT microbe capsules (Supplementary Figure 1D). WMX is considered as a "super donor" for 3 reasons. First, WMX has consistently been a qualified FMT donor since a young age. Second, WMX is compliant with food restrictions, physical exercise requirements, and maintains a BMI in the normal range. Third, 16S rRNA sequencing of her microbiota showed abundance in diversity and enrichment of certain species of the genus of Bacteroides, Faecalibacterium and Lachnospira, which previous studies considered as probiotics.1Pellegrini M. et al.Nutrition. 2020; 74: 110749Crossref PubMed Scopus (37) Google Scholar, 2Nakajima A. et al.Appl Environ Microbiol. 2020; 86: e00405-20Crossref PubMed Scopus (53) Google Scholar, 3Geirnaert A. et al.Sci Rep. 2017; 7: 1-14Crossref PubMed Scopus (281) Google Scholar The diversity of her microbiota is likely the major reason for its efficiency for FMT, which is consistent with previous findings of an association between FMT success and microbial diversity of the donor.4Craven L.J. et al.Open Forum Infect Dis. 2017; 4: ofx243Crossref PubMed Scopus (35) Google Scholar,5Costello S.P. et al.Clin Infect Dis. 2016; 62: 908-914Crossref PubMed Scopus (82) Google Scholar Further studies of super donor and donor–recipient interactions are in process at our center.