Retrospective review:single- and multidonorwashed microbiota transplantation have equivalentefficacy in the treatmentofautism

Autism spectrum disorder (ASD) is a serious neurodevelopmental disorder that currently has no effective treatment. This study explored the short-term clinical effects and number of donors of washed microbiota transplantation (WMT) in patients with autism.Consecutive ASD patients treated with two continuous WMT courses from March 2020 to March 2022 at the First Affiliated Hospital of Guangdong Pharmaceutical University were retrospectively assessed. Basic information, Aberrant Behaviour Checklist (ABC) scores, Childhood Autism Rating Scale (CARS) scores, Sleep Disturbance Scale for Children (SDSC) scores, adverse reactions, and the faeces were collected.Forty-four patients were included (17 patients in the single-donor group and 27 patients in the multidonor group). The CARS, ABC or SDSC scores did not differ between the two groups before treatment. After two courses, the CARS, ABC and SDSC scores of the 44 patients were lower than those at baseline (P<0.05), and serious adverse reactions did not occur. After the first course, the mean ABC scores (P=0.049) and SDSC scores (P=0.019) were significantly different between the single-donor and multidonor groups, but the difference disappeared after two courses. The alpha diversity of the faecal flora in the effective group was greater than that in the ineffective group (Shannon index P=0.0018). At the genus level, Lactobacillus was the significant flora in the effective group, whereas Faecalibacterium, Campylobacter, and Sphingomonas were significant flora in the ineffective group.After two WMT courses, the symptoms of ASD improved, and the short-term treatment efficacy was good. The improvement in ASD symptoms between the single-donor and multidonor groups was not different. Changes in the alpha diversity and abundance of the faecal microbiota after WMT may be related to treatment efficacy.