Postoperative Gut Microbiota Changes after Colorectal Cancer Surgery: A Comparative Study Based on Resection Sites

Area of Science:

• Microbiology
• Gastroenterology
• Oncology

Background:

• Colorectal cancer (CRC) necessitates surgical resection, the primary treatment.
• The impact of diverse surgical procedures on gut microbiota and postoperative outcomes requires further investigation.

Purpose of the Study:

• To investigate gut microbiota alterations following three distinct CRC resection types: right-sided colectomy (RSC), left-sided colectomy (LSC), and low anterior resection (LAR).

Main Methods:

• Fecal samples from 34 CRC patients undergoing curative resection were analyzed using 16S rRNA gene amplicon sequencing.
• Microbiota profiles were compared between surgical groups and 85 healthy controls.

Main Results:

• Surgical groups showed significant gut microbiota deviations from controls.
• RSC led to the greatest alpha diversity reduction, potentially due to ileocecal valve loss.
• RSC decreased beneficial bacteria (e.g., *Faecalibacterium prausnitzii*) and increased *Escherichia coli*, indicating a pro-inflammatory shift. LSC and LAR enriched *Akkermansia muciniphila*, potentially enhancing gut barrier function.

Conclusions:

• CRC resection induces site-specific gut microbiota changes.
• These alterations may influence postoperative inflammation, metabolism, and cancer recurrence.
• Microbiome-targeted strategies could improve postoperative outcomes in CRC patients.