[Association between the clinical efficacy of fecal microbiota transplantation in recipients and the choice of donor].

Objective: To examine the association between the clinical efficacy of fecal microbiota transplantation (FMT) in recipients and the choice of donor, and to observe the characteristics of intestinal flora and metabolites among different donors. Methods: A retrospective case-control study was conducted. Donor whose feces was administrated for more than 30 recipients was enrolled. Data of 20 FMT donors and corresponding recipients at Intestinal Microecology Diagnosis and Treatment Center of the Tenth People's Hospital from October 2018 to December 2019 were collected retrospectively. During follow-up, the efficacy of each recipient 8-week after FMT treatment was recorded and analyzed. Based on the efficacy of each donor, the donors were divided into three groups: high efficacy group (effective rate >60%, 10 donors), moderate efficacy group (effective rate 30%-60%, 6 donors) and low efficacy group (effective rate <30%, 4 donors). The structure of the bacterial flora and the content of fecal short-chain fatty acids in each group of donors were detected and compared among groups. Association of the efficacy of each donor group with the morbidity of complications, and association of efficacy of recipients with donors were analyzed. The evaluation indicators of FMT efficacy included objective clinical effectiveness and/or subjective effectiveness. Objective effectiveness indicated clinical cure plus clinical improvement, and subjective effectiveness indicated marked effectiveness plus medium effectiveness through questionnaire during follow-up. Results: A total of 1387 recipients were treated by 20 donors, including 749 cases of chronic constipation, 141 cases of chronic diarrhea, 107 cases of inflammatory bowel disease (IBD), 121 cases of irritable bowel syndrome (IBS), 83 cases of autism, and 186 cases of other diseases, such as radiation bowel injury, intestinal pseudo-obstruction, paralytic intestinal obstruction, functional bloating and allergic diseases. There were 829 cases, 403 cases, and 155 cases in high efficacy group, moderate efficacy group and low efficacy group respectively. Baseline data among 3 groups were not significantly different (all P> 0.05). In comparison of bacterial abundance (operational taxonomic unit, OTU) among different effective donor groups, the high efficacy group was the highest (330.68±57.28), the moderate efficacy group was the second (237.79±41.89), and the low efficacy group was the lowest (160.60±49.61), whose difference was statistically significant (F=16.910, P<0.001). In comparison of bacterial diversity (Shannon index), the high efficacy group and the moderate efficacy group were higher (2.96±0.36 and 2.67±0.54, respectively), and the low efficacy group was lower (2.09±0.55), whose difference was statistically significant (F=5.255, P=0.017). In comparison of butyric acid content among three groups, the high efficacy group had the highest [(59.20±9.00) μmol/g], followed by middle efficacy group [(46.92±9.48) μmol/g], and the low efficacy group had the lowest [(37.23±5.03) μmol/g], whose difference was statistically significant (F=10.383, P=0.001). The differences of acetic acid and propionic acid among three groups were not statistically significant (all P>0.05). A total of 418 cases developed complications (30.1%). Morbidity of complication in low efficacy group, moderate efficacy group and high efficacy group was 40.6% (63/155), 30.0% (121/403) and 28.2% (243/829) respectively, and the difference was statistically significant (χ(2)=9.568, P=0.008). The incidence of diarrhea in low efficacy group, moderate efficacy group and high efficacy group was 7.1% (11/155), 4.0% (16/403) and 2.8% (23/829) respectively, and the difference was statistically significant (χ(2)=7.239, P=0.027). Comparing the incidences of other types of complications, no statistically significant differences were found (all P>0.05). Follow up began 8 weeks after the FMT treatment. The total follow-up rate was 83.6% (1160/1387). The overall effective rate 58.3% (676/1160). Effective rates of various diseases were as follows: chronic constipation 54.3% (328/604), chronic diarrhea 88.5% (115/130), IBD 56.1% (55/98), IBS 55.1% (59/107), autism 61.6% (45/73), and other diseases 50.0% (74/148). Comparing the effective rate of three groups of donors for different diseases, there was no statistically significant difference in chronic diarrhea (P>0.05); there was a positive correlation trend in IBD, IBS and autism, but the differences were not statistically significant (all P>0.05). For chronic constipation and other diseases, high efficacy group had the highest effective rate [65.0% (243/374) and 63.2% (55/87)], followed by moderate efficacy group [49.4% (86/174) and 38.1% (16/42)], and low efficacy group had the lowest [16.1% (9/56) and 15.8% (3/19)], whose differences were significant (all P<0.05). Conclusions: Different donors have different efficacy in different diseases. Chronic constipation, radiation bowel injury, etc. need to choose donors with high efficacy. IBD, IBS and autism may also be related to the effectiveness of donors, while chronic diarrhea is not associated to the donor. The efficiency of the donor is negatively correlated to the morbidity of complications. The abundance and diversity of intestinal flora and the content of butyric acid may affect the efficacy of the donor.