Appendiceal microbiome in uncomplicated and complicated acute appendicitis: A prospective cohort study

Sanja Vanhatalo; Eveliina Munukka; Teemu Kallonen; Suvi Sippola; Juha Grönroos; Jussi Haijanen; Antti J Hakanen; Paulina Salminen

doi:10.1371/journal.pone.0276007

Appendiceal microbiome in uncomplicated and complicated acute appendicitis: A prospective cohort study

PLoS One. 2022 Oct 14;17(10):e0276007. doi: 10.1371/journal.pone.0276007. eCollection 2022.

Authors

Sanja Vanhatalo^{1

2}, Eveliina Munukka^{3

4}, Teemu Kallonen^{1

2

3}, Suvi Sippola^{5

6}, Juha Grönroos^{5

6}, Jussi Haijanen^{5

6}, Antti J Hakanen^{1

2

3}, Paulina Salminen^{5

6}

Affiliations

¹ Research Center for Infections and Immunity, Institute of Biomedicine, University of Turku, Turku, Finland.
² Laboratory Division, Department of Clinical Microbiology, Turku University Hospital, Turku, Finland.
³ Faculty of Medicine, Microbiome Biobank, University of Turku and Turku University Hospital, Turku, Finland.
⁴ Biocodex Nordics, Espoo, Finland.
⁵ Division of Digestive Surgery and Urology, Turku University Hospital, Turku, Finland.
⁶ Department of Surgery, University of Turku, Turku, Finland.

Abstract

Background: Uncomplicated and complicated acute appendicitis seem to be two different forms of this common abdominal emergency. The contribution of appendiceal microbiota to appendicitis pathogenesis has been suggested, but differences between uncomplicated and complicated appendicitis are largely unknown. We compared the appendiceal microbiota in uncomplicated and complicated acute appendicitis.

Methods: This prospective single-center clinical cohort study was conducted as part of larger multicenter MAPPAC trial enrolling adult patients with computed tomography or clinically confirmed uncomplicated or complicated acute appendicitis. The microbial composition of the appendiceal lumen was determined using 16S rRNA gene amplicon sequencing.

Results: Between April 11, 2017, and March 29, 2019, 118 samples (41 uncomplicated and 77 complicated appendicitis) were available. After adjusting for age, sex, and BMI, alpha diversity in complicated appendicitis was higher (Shannon p = 0.011, Chao1 p = 0.006) compared to uncomplicated appendicitis. Microbial compositions were different between uncomplicated and complicated appendicitis (Bray-Curtis distance, P = 0.002). Species poor appendiceal microbiota composition with specific predominant bacteria was present in some patients regardless of appendicitis severity.

Conclusion: Uncomplicated and complicated acute appendicitis have different appendiceal microbiome profiles further supporting the disconnection between these two different forms of acute appendicitis.

Study registration: ClinicalTrials.gov NCT03257423.

Publication types

Multicenter Study
Research Support, Non-U.S. Gov't

MeSH terms

Acute Disease
Adult
Appendectomy
Appendicitis* / complications
Cohort Studies
Humans
Microbiota*
Prospective Studies
RNA, Ribosomal, 16S / genetics

Substances

RNA, Ribosomal, 16S

Associated data

ClinicalTrials.gov/NCT03257423

Grants and funding

The MAPPAC study was supported by research grants from the Mary and Georg C. Ehrnrooth Foundation, the Sigrid Jusélius Foundation, the Finnish Academy, Government research grant awarded to Turku University Hospital (EVO foundation), The Maud Kuistila Memorial Foundation, Paulo Foundation, Doctoral Program in Clinical Research at the University of Turku, and Turku University foundation. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.