Insights into Food Intake, Overall Diet Quality, and Stool Short-Chain Fatty Acids during Treatment for Rectal Cancer: A Pilot Study

Abstract

Objective: To describe food intake and overall diet quality during neoadjuvant concomitant chemotherapy and radiation therapy (nCRT) for rectal cancer. We also explored associations between Prime Diet Quality Score (PDQS) and short-chain fatty acid (SCFA) levels in stool at the end of nCRT in a subset of participants.

Methods: Thirty-two participants provided a 24-hour dietary recall, while 18 provided stool samples for SCFA analysis.

Results: The reported intake of 11 healthy food groups (e.g., dark green vegetables, fish) was low (<50% of participants) before treatment, while 4 unhealthy food groups (e.g., processed meat, sugar-sweetened beverages) were high (>50%), both before and after treatment. Higher propionate levels were associated with higher PDQS values.

Conclusion: Participants reported reduced dietary intake and diet quality during nCRT. Additional study is warranted to determine whether gut metabolites may mediate the impact of low diet quality.

Keywords: Diet quality; Rectal cancer; Stool short chain fatty acids.