Identification of the microbial diversity after fecal microbiota transplantation therapy for chronic intractable constipation using 16s rRNA amplicon sequencing

BACKGROUND: Fecal microbiota transplantation (FMT) is an effective therapeutic approach for the treatment of functional gastrointestinal disease by restoring gut microbiota; however, there is a lack of sufficient understanding regarding which microbial populations successfully colonize the recipient gut. This study characterized microbial composition and diversity in patients diagnosed with chronic constipation at 1 month and 1 year after FMT. METHODS: We explored the microbial diversity of pre- and posttransplant stool specimens from patients using 16S rRNA gene sequencing, followed by functional analysis. RESULTS: The results identified 22 species of microorganisms colonized in the recipients from the donors at 1 month after FMT. One-year follow-up of the patient identified the colonization of 18 species of microorganisms, resulting in identification of species in significant abundance, including Bacteroides fragilis and Hungatella hathewayi in the recipient at 1 month after FMT and Dialister succinatiphilus, Coprococcus catus, and Sutterella stercoricanis at 1 year after FMT. The majority of the colonized species belong to the phylum Firmicutes and carry genes related to polysaccharide metabolism and that enhance the energy-harvesting efficiency of the host. CONCLUSION: These results suggest that FMT is effective for the treatment of chronic constipation through the restoration and colonization of donor microbiota in the recipient gut up to 1 year after FMT.