Objective To investigate the characteristics of intestinal flora in patients with slow transit constipation (STC) and role of fecal microbiota transplantation (FMT) by 16S rDNA sequencing technology.

Methods A total of 30 patients with STC were selected as STC group, and they were treated with standardized FMT therapy for two courses; another 20 healthy adults in the same period were selected as control group. Fecal 16S rDNA sequencing technology was used to compare the intestinal flora between the control group and the STC group, and the intestinal flora before and after FMT in patients with STC was compared.

Results Compared with the control group, the diversity of intestinal flora in the STC group decreased significantly, the relative abundance of Firmicutes decreased significantly, and the relative abundances of Proteobacteria and Fusobacteria increased significantly (P < 0.05). After FMT treatment, the diversity of flora in patients with functional constipation increased significantly (P < 0.05); at the phylum level, the relative abundances of Bacteroidetes and Fusobacteria decreased significantly while the relative abundances of Firmicutes and Proteobacteria increased significantly in STC patients after implementing FMT (P < 0.05). The Gastrointestinal Quality of Life Index (GIQLI) score and Wexner constipation score in the STC group decreased significantly after treatment when compared to those before treatment (P < 0.05). The Self-rating Depression Scale (SDS) score, Self-rating Anxiety Scale (SAS) score and Pittsburgh Sleep Quality Index (PSQI) score in the STC group decreased significantly after treatment when compared to those before treatment (P < 0.05).

Conclusion STC patients are prone to disruption of intestinal flora, resulting in changes of microbial diversity and distribution. FMT can improve constipation symptoms and change the distribution and diversity of intestinal flora by regulating intestinal flora.