Insights into gut microbiota communities of Poecilobdella manillensis, a prevalent Asian medicinal leech

AIMS: Medicinal leeches (Annelida: Hirudinea) are fresh water ectoparasitic species which have been applied as traditional therapy. However, gut microbiota could bring high risks of opportunistic infections after leeching and arouses great interests. Here, gut bacterial and fungal communities of an Asian prevalent leech Poecilobdella manillensis were characterized and analysed through culture-independent sequencing. METHODS AND RESULTS: With high coverage in 18 samples (>0.999), a more complicated community was apparent after comparing with previous leech studies. A total of 779/939 OTUs of bacteria and fungi were detected from leech guts. The bacterial community was dominated by the phylum Bacteroidetes and Synergistetes. Genera Mucinivorans and Fretibacterium accounted mostly at the genus level, and genus Aeromonas showed an extremely low abundance (2.02%) on average. The fungal community was dominated by the phylum Ascomycota and Basidiomycota. At the genus level, the dominant OTUs included Mortierella, Geminibasidium and Fusarium. The analysis of core taxa included those above dominant genera and some low-abundance genera (>1%). The functional annotation of the bacterial community showed a close correlation with metabolism (34.8 ± 0.6%). Some fungal species were predicted as opportunistic human pathogens including Fusarium and Chaetomiaceae. CONCLUSIONS: The present study provides fundamental rationales for further studies of such issues as bacteria-fungi-host interactions, host fitness, potential pathogens, and infecting risks after leeching. It shall facilitate in-depth explorations on the safe utilization of leech therapy. SIGNIFICANCE AND IMPACT OF STUDY: Present paper is the first-ever exploration on microbiota of a prevalent Asian medicinal leech based on culture-independent technical. And it is also the first report of gut fungi community of medicinal leech. The diversity and composition of bacteria in P. manillensis was far different from that of the European leech. The main components and core OTUs indicate a particular gut environment of medicinal leech. Unknown bacterial and fungal species were also recovered from leech gut.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

16S rRNA-based microbiome profiling of Poecilobdella manillensis identifying dominant Aeromonas, Bacteroidetes and Firmicutes communities — assesses zoonotic potential.

Explore how this research connects to clinical practice

More peer-reviewed studies in Safety & Infection Control.

• Leech-Assisted Flap Salvage — Systematic Review of 277 Cases — Whitaker et al. (2012)
• Effects of hirudotherapy on liver functions, lipid profile, and insulin sensitivity in rats with metabolic syndrome — Bilden A et al. (2026)
• AIF-1 and RNASET2 Play Complementary Roles in the Innate Immune Response of Medicinal Leech — Baranzini N et al. (2019)
• [Hirudo medicinalis-leech applications in plastic and reconstructive microsurgery--a literature review] — Knobloch K et al. (2007)
• Bacterial symbioses of the medicinal leech Hirudo verbana — Nelson M, Graf J (2012)
• Leech related Aeromonas complex infection after reconstruction with a microvascular forearm flap — Beger B, von Loewenich F, Goetze E, Moergel M, Walter C (2016)
• Aeromonas septicemia after medicinal leech use following replantation of severed digits — Levine SM, Frangos SG, Hanna B, Colen K, Levine JP (2009)
• Outcomes of flap salvage with medicinal leech therapy — Nguyen MQ et al. (2012)
• The role of leech water sampling in choice of prophylactic antibiotics in medical leech therapy — Wilmer A et al. (2013)
• The development and application of mini-barcodes from mitochondrial DNA for identifying medicinal leeches from traditional medicines — Liu Y et al. (2025)

Browse all ASH-analysed research →