Dietary Fiber and Probiotics in Advanced Colorectal Cancer

Effects of Combined Dietary Fiber and Probiotic Supplementation on Gut Microbiota, Immune Function, and Clinical Outcomes in Patients With Advanced Colorectal Cancer: A Prospective Randomized Controlled Trial

This single-center, prospective, randomized controlled trial was conducted to evaluate the efficacy of a 12-week combined dietary fiber and probiotic supplementation on gut microbiota, immune function, nutritional status, and survival outcomes in malnourished patients with advanced colorectal cancer undergoing conventional therapy, compared to standard nutritional support alone.

Patients with advanced colorectal cancer often suffer from malnutrition and immune suppression, which can negatively impact treatment outcomes. This study investigated whether modulating the gut microbiota could improve clinical outcomes. A total of 80 eligible patients were randomly assigned in a 1:1 ratio to an intervention group or a control group. The intervention group (n=40) received standard nutritional support plus a daily supplement of mixed dietary fiber and multi-strain probiotics for 12 weeks. The control group (n=40) received standard nutritional support alone. Key endpoints, including immune markers (IgA, IgG, CD4+/CD8+ ratio), gut microbiota composition (16S rRNA sequencing), nutritional status (BMI, PG-SGA), and quality of life (WHOQOL-100), were assessed at baseline and after 12 weeks. Survival was monitored for 18 months to determine the impact on short-term prognosis.

Inclusion Criteria:

• Pathologically confirmed diagnosis of stage II-IV colorectal cancer post-resection.
• Receiving active adjuvant chemotherapy.
• Documented moderate-to-severe malnutrition (PG-SGA score ≥ 4).
• Ability to tolerate oral intake.
• Voluntarily signed the informed consent form.

Exclusion Criteria:

• Presence of complete bowel obstruction.
• Severe, uncontrolled organ dysfunction (cardiac, hepatic, renal).
• Known allergy to any component of the nutritional supplements.
• Concurrent participation in another interventional trial.