An interventional study of Multistrain Probiotic Formulation and Placebo in Colorectal Cancer, sponsored by University of Malaga. Completed at 1 site in Spain. Open to participants aged 35 Years to 75 Years. Per ClinicalTrials.gov, last updated 2026-10-07.
Sponsored by University of Malaga · Not applicable, Interventional, and Supportive care
This prospective randomized, double-blind, placebo-controlled study evaluated the effects of multistrain probiotic supplementation in patients with stage II-III colorectal cancer undergoing neoadjuvant chemoradiotherapy. Participants received either a multistrain probiotic or placebo twice daily for five weeks during chemoradiotherapy. The study evaluated changes in gut microbiota composition and diversity, as well as fecal short-chain fatty acids, inflammatory cytokines, zonulin, gastrointestinal symptoms, and quality of life. Participants were assessed at baseline, during treatment, at the end of treatment, and seven weeks after completion of treatment.
Neoadjuvant chemoradiotherapy is commonly used in patients with locally advanced colorectal cancer, but treatment may be associated with gastrointestinal toxicity, intestinal dysbiosis, disruption of epithelial barrier function, systemic inflammation, and deterioration of health-related quality of life. Modulation of the intestinal microbiota using probiotics has been proposed as a potential supportive strategy to mitigate these treatment-related alterations.
This study was designed to evaluate the effects of a multistrain probiotic formulation administered during neoadjuvant chemoradiotherapy in patients with stage II-III colorectal cancer. The study focused on the potential effects of probiotic supplementation on treatment-related alterations in the intestinal microbiota and other biological and patient-reported parameters.
The primary objective was to evaluate the effect of multistrain probiotic supplementation on gut microbiota composition and diversity in patients with stage II-III colorectal cancer undergoing neoadjuvant chemoradiotherapy. Secondary objectives included evaluating the effects of probiotic supplementation on fecal short-chain fatty acid concentrations, systemic inflammatory cytokines, intestinal permeability, and gastrointestinal symptoms and health-related quality of life.
5,734 studies on the registry are indexed under Colorectal Neoplasms; 1,481 are open to participants now.
This study's enrollment of 58 is below the median of 77 across 4,222 interventional studies indexed under Colorectal Neoplasms.
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Participants received a multistrain probiotic formulation orally twice daily for five weeks during neoadjuvant chemoradiotherapy.
Dietary Supplement: Multistrain Probiotic Formulation
Participants received a placebo orally twice daily for five weeks during neoadjuvant chemoradiotherapy.
Dietary Supplement: Placebo
Multistrain probiotic formulation containing Saccharomyces boulardii 600 mg, Lactobacillus rhamnosus GG 6 × 10\^9 CFU, Lactobacillus helveticus 4 × 10\^9 CFU, Bifidobacterium longum 4 × 10\^9 CFU, fructooligosaccharides 500 mg, and vitamin D3 2.5 μg (100 IU). The probiotic was administered orally twice daily for five weeks during neoadjuvant chemoradiotherapy.
Placebo containing fructooligosaccharides 500 mg and vitamin D3 2.5 μg (100 IU), without probiotic strains or yeast. The placebo was administered orally twice daily for five weeks during neoadjuvant chemoradiotherapy.
Gut microbiota composition and diversity
Gut microbiota composition and diversity assessed in fecal samples using 16S rRNA gene sequencing, including alpha diversity, beta diversity, and taxonomic composition.
Time frame: At baseline (T0), week 2 (T1), week 5/end of treatment (T2), and seven weeks after completion of treatment (T3).
Fecal short-chain fatty acid concentrations
Fecal concentrations of acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids were determined by gas chromatography coupled to triple quadrupole mass spectrometry (GC-MS/MS).
Time frame: Baseline (T0) and 7 weeks after treatment completion (T3).
Serum inflammatory cytokine concentrations
Circulating concentrations of IL-6, IFN-α, IL-10, and IL-1β were quantified using enzyme-linked immunosorbent assays (ELISA) and compared between the probiotic and placebo groups.
Time frame: Baseline (T0) and 7 weeks after treatment completion (T3).
Circulating zonulin concentration as a marker of intestinal permeability
Zonulin concentrations were measured by ELISA as a marker of intestinal permeability and compared between the probiotic and placebo groups.
Time frame: Baseline (T0) and 7 weeks after treatment completion (T3).
Health-related quality of life and gastrointestinal symptoms assessed using the EORTC QLQ-C30
Health-related quality of life and symptom burden were evaluated using the EORTC QLQ-C30 version 3.0. The questionnaire assesses global health status/quality of life, functional domains, symptom scales, and individual symptoms including diarrhea, constipation, appetite loss, nausea and vomiting, fatigue, pain, dyspnea, insomnia/sleep disturbance, and other cancer-related symptoms. Scores were transformed to a 0-100 scale according to the EORTC scoring manual. Higher functional and global health scores indicate better functioning/quality of life, whereas higher symptom scores indicate greater symptom burden.
Time frame: 7 weeks after treatment completion (T3).
Plan to share: No
Ran from Nov 2015 to primary completion in Jul 2019, 44 months.
Of 801 non-industry interventional studies with no phase under Colorectal Neoplasms, half reached primary completion within 32 months of starting (the median), counting those still running; a quarter within 14 and three quarters within 60. This study's 44 months is above that.
Counting every sponsor, half of 845 studies reached it within 32 months; a quarter within 14 and three quarters within 60.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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