[Establishment and preliminary clinical application of human intestinal fluid transplantation].

Objective: To explore and establish the preparation system of human intestinal fluid transplantation (HIFT) and HIFT capsule, and to preliminarily apply it to clinic. Methods: Strict standards for donor screening and management were established. The nasojejunal tube was catheterized into the distal jejunum, and then it was connected with an improved disposable sterile negative pressure collection device for the collection of human intestinal fluid. After that, it was prepared into capsules by filtering, adding 10% glycerin protectant and freeze-drying method. The amount of living bacteria was used as the standard of therapeutic dose. The living bacteria amount in fluid is ≥ 5.0×10⁸ /mL and the living bacteria proportion is ≥ 83%; the living bacteria amount in powder is ≥ 2.0×10⁶ /g and the living bacteria proportion is ≥ 81%; The observational indicators included: (1) the basic information of the donor, the amount of living bacteria in the HIF and powder. (2) Preliminary analysis of the treatment for ASD, which combined HIFT capsule with standard FMT capsule, from February to December 2021 (Clinical trial Registration Number: ChiCTR2100043929). Evaluation criteria: Trypan blue staining method was used to detect the living bacteria amount in fluid and powder. The Autism Behavior Checklist (ABC) and Childhood Autism Rating Scale (CARS) were used to evaluate the efficacy. Results: Compared with the parent donor, the standard donor was younger [(25.4±0.9) y vs. (30.7±3.2) y, t=-19.097, P=0.001] and had a lower body mass index [(19.7±0.5) kg/m² vs. (20.8±1.3) kg/m², t=-8.726, P=0.001], more in the living bacteria amount in powder [(7.47±1.52)×10⁶/g vs. (5.03±1.38)×10⁶/g, t=11.331, P=0.031], Chao index (205.4±6.8 vs. 194.2±7.2, t=10.415, P=0.001), and Shannon index (3.25±0.14 vs 2.72±0.27, t=19.465, P=0.001). The differences were statistically significant (all P<0.05). However, there were no significant differences in gender, drainage volume and total number of bacterial liquid colonies between the two groups (all P>0.05). Both the standard donor and the parent donor met the donor screening criteria, and the preparation fluid and powder met the treatment criteria. Eight patients received the treatment of HIFT combined with fecal microbiota transplantation (FMT). Preliminary statistical results showed that HIFT combined with FMT improved ABC and CARS at the 1st, 2nd, 3rd and 4th months. The differences were statistically significant (all P<0.05). No severe adverse reaction occurred. Conclusion: Based on the previous research on FMT preparation system and the clinical technology in our center, this study developed a high standard HIFT preparation system, and explored the clinical study of HIFT combined with FMT, in order to provide an innovative therapy for the treatment of diseases.