Assessing whether rectal swabs reflect appendiceal microbiota profiles in acute appendicitis: a 16S rRNA-based...

Area of Science:

• Microbiome research
• Gastrointestinal health
• Infectious disease diagnostics

Background:

• Acute appendicitis is linked to gut microbiota alterations.
• Direct appendiceal sampling is invasive and not feasible in healthy individuals.
• Investigating alternative methods for microbiome profiling in appendicitis is crucial.

Purpose of the Study:

• To determine if rectal swabs can capture appendiceal microbiome signatures in adults with acute appendicitis.
• To compare the microbiome composition and function between appendiceal contents, rectal swabs, and fecal samples.
• To assess the concordance between appendiceal contents and rectal swabs.

Main Methods:

• Prospective cross-sectional study involving patients with acute appendicitis and healthy controls.
• Collection of appendiceal contents, intraoperative rectal swabs, postoperative feces, and control feces.
• 16S rRNA gene sequencing and bioinformatics analysis (QIIME2, PICRUSt2) to assess microbial diversity, composition, and function.

Main Results:

• Appendiceal contents (AC) and rectal swabs (RS) showed higher phylogenetic diversity than healthy controls (HC).
• AC, RS, and postoperative feces (IF) were enriched in Escherichia/Shigella and Fusobacterium, and depleted in butyrate-producers compared to HC.
• Genus-level and functional concordance was observed between paired AC and RS samples, indicating RS partially captures appendiceal dysbiosis.

Conclusions:

• Intraoperative rectal swabs may serve as a minimally invasive adjunct for profiling appendiceal microbiome alterations.
• Rectal swabs can partially reflect appendiceal dysbiosis at genus and predicted functional pathway levels.
• Findings require validation with shotgun metagenomics in larger, diverse populations.