Changes in Gut Microbiome Associated With Co-Occurring Symptoms Development During Chemo-Radiation for Rectal Cancer: A Proof of Concept Study

Biol Res Nurs. 2021 Jan;23(1):31-41. doi: 10.1177/1099800420942830. Epub 2020 Jul 23.

Abstract

Purpose: To examine a) whether there are significant differences in the severity of symptoms of fatigue, sleep disturbance, or depression between patients with rectal cancer who develop co-occurring symptoms and those with no symptoms before and at the end of chemotherapy and radiation therapy (CRT); b) differences in gut microbial diversity between those with co-occurring symptoms and those with no symptoms; and c) whether before-treatment diversity measurements and taxa abundances can predict co-occurrence of symptoms.

Methods: Stool samples and symptom ratings were collected from 31 patients with rectal cancer prior to and at the end of (24-28 treatments) CRT. Descriptive statistics were computed and the Mann-Whitney U test was performed for symptoms. Gut microbiome data were analyzed using R's vegan package software.

Results: Participants with co-occurring symptoms reported greater severity of fatigue at the end of CRT than those with no symptoms. Bacteroides and Blautia2 abundances differed between participants with co-occurring symptoms and those with no symptoms. Our random forest classification (unsupervised learning algorithm) predicted participants who developed co-occurring symptoms with 74% accuracy, using specific phylum, family, and genera abundances as predictors.

Conclusion: Our preliminary results point to an association between the gut microbiota and co-occurring symptoms in rectal cancer patients and serves as a first step in potential identification of a microbiota-based classifier.

Keywords: chemotherapy and radiation therapy; co-occurrence of symptoms; gut microbiome; rectal cancer.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Bacteria / classification
  • Bacteria / genetics
  • Bacteria / isolation & purification
  • Chemoradiotherapy
  • Depression / microbiology
  • Fatigue / microbiology
  • Female
  • Gastrointestinal Microbiome*
  • Humans
  • Male
  • Middle Aged
  • Predictive Value of Tests
  • Proof of Concept Study
  • Rectal Neoplasms / microbiology*
  • Rectal Neoplasms / therapy*
  • Sleep Wake Disorders / microbiology