Long-term outcomes of 328 patients with of autism spectrum disorder after fecal microbiota transplantation

Abstract

Objective: To evaluate the efficacy and safety of fecal microbiota transplantation (FMT) in the treatment of autism spectrum disorder (ASD). Methods: A longitudinal study was conducted. Clinical data from ASD patients with gastrointestinal symptoms and who underwent FMT in the Tenth People's Hospital affiliated to Tongji University or Jinling Hospital between May 2012 to May 2021 were retrospectively collected. Scores derived from the autism behavior checklist (ABC), the childhood autism rating scale (CARS), the Bristol stool form scale (BSFS), and the gastrointestinal symptom rating scale (GSRS) were analyzed at baseline and at the 1st, 3rd, 6th, 12th, 24th, 36th, 48th and 60th month after FMT. Records of any adverse reactions were collected. Generalized estimating equations were used for analysis of data on time points before and after FMT. Results: A total of 328 patients met the inclusion criteria for this study. Their mean age was 6.1±3.4 years old. The cohort included 271 boys and 57 girls. The percentage of patients remaining in the study for post-treatment follow-up at the 1st, 3rd, 12th, 24th, 36th, 48th and 60th month were as follows: 303 (92.4%), 284 (86.7%), 213 (64.9%), 190 (57.9%), 143 (43.6%), 79 (24.1%), 46 (14.0%), 31 (9.5%). After FMT, the average ABC score was significantly improved in the first 36 months and remained improved at the 48th month. However, the average score was not significantly different from baseline by the 60th month (1st-36th month, P<0.001; 48th month, P=0.008; 60th month, P=0.108). The average CARS score improved significantly during the first 48 months and remained improved at the 60th month (1st-48th month, P<0.001; 60th month, P=0.010). The average BSFS score was also significantly improved in the first 36 months (with an accompanying stool morphology that resembled type 4). This improvement was maintained at the 48th month. However, the average score was similar to baseline at the 60th month (1st-36th month, P<0.001; 48th month, P=0.008; 60th month, P=0.109). The average GSRS score was significantly improved during the first 24 months, but not afterwards (1st-24th month, P<0.001; 36th month, P=0.209; 48th month, P=0.996; 60th month, P=0.668). The adverse events recorded during treatment included abdominal distension in 21 cases (6.4%), nausea in 14 cases (4.3%), vomiting in 9 cases (2.7%), abdominal pain in 15 cases (4.6%), diarrhea in 18 cases (5.5%), fever in 13 cases (4.0%), and excitement in 24 cases (7.3%). All adverse reactions were mild to moderate and improved immediately after suspension of FMT or on treatment of symptoms. No serious adverse reactions occurred. Conclusion: FMT has satisfactory long-term efficacy and safety for the treatment of ASD with gastrointestinal symptoms.