Interventions Targeting the Gut Microbiome to Improve Cancer Treatment Outcomes and Their Gastrointestinal Side Effects: A Systematic Review and Meta-analysis.
- 2026-02
- The Journal of nutrition 156(2)
- PubMed: 41475679
- DOI: 10.1016/j.tjnut.2025.101300
Study Design
- Type
- Meta-Analysis
- Sample size
- n = 37
- Population
- studies assessing GM interventions during cancer treatment
- Methods
- Three databases (PubMed, Web of Science, and Cochrane Library) were systematically searched up to February 2025; risk of bias was evaluated using the Effective Public Healthcare Panacea Project Quality Assessment tool; meta-analyses were conducted in Stata 18 using random-effects models
Background
Improvements in cancer treatment are essential to reduce premature mortality. Emerging evidence highlights the role of the gut microbiome (GM) in influencing treatment responses and modulating gastrointestinal adverse events (GIAEs). Because cancer therapy disrupts GM composition, restoring gut health may help mitigate side effects and support gut-associated immunity.Objectives
This study aimed to systematically evaluate and assess the effectiveness of GM interventions on the occurrence of GIAEs and clinical responses to cancer treatment.Methods
Three databases (PubMed, Web of Science, and Cochrane Library) were systematically searched up to February 2025 for studies assessing GM interventions during cancer treatment. Risk of bias was evaluated using the Effective Public Healthcare Panacea Project Quality Assessment tool. Meta-analyses were conducted in Stata 18 using random-effects models to estimate the pooled relative risk of GM interventions on gut microbiome interventions, gastrointestinal adverse events (GIAEs) (primary outcome) and objective disease response rates (secondary outcome).Results
Fifty-six studies were included in the systematic review, and 40 were meta-analyzed (n = 37 for GIAE outcomes, n = 8 for treatment response). GM interventions reduced the overall risk of GIAEs 95% CI: 0.53, 0.65; I2: 76.8%; 95% prediction interval (PI): 0.32, 1.08], including diarrhea, constipation, nausea, and vomiting, but with considerable heterogeneity between studies. There was insufficient evidence to suggest improvements in objective disease response rates (RR: 1.06; 95% CI: 0.93, 1.20; I2: 0%; 95% PI: 0.93, 1.20).Conclusions
GM interventions show promise in improving cancer care by reducing GIAEs, although evidence for direct effects on-treatment response remains limited. Standardizing intervention protocols and outcome reporting in future RCTs is essential to strengthen the evidence base and guide clinical recommendations. This trial was registered at PROSPERO as CRD42023443332 (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023443332).Research Insights
| Supplement | Dose | Health Outcome | Effect Type | Effect Size | Source |
|---|---|---|---|---|---|
| Bifidobacterium breve Bb-18 | — | Improved Cancer Treatment Tolerance | Beneficial | Moderate | View sourceEmerging evidence highlights the role of the gut microbiome (GM) in influencing treatment responses and modulating gastrointestinal adverse events (GIAEs). Because cancer therapy disrupts GM composition, restoring gut health may help mitigate side effects and support gut-associated immunity. |
| Bifidobacterium breve Bb-18 | — | Reduced Gastrointestinal Adverse Events | Beneficial | Moderate | View sourceGM interventions reduced the overall risk of GIAEs [relative risk (RR): 0.59; 95% CI: 0.53, 0.65; I2: 76.8%; 95% prediction interval (PI): 0.32, 1.08], including diarrhea, constipation, nausea, and vomiting |
| Lactobacillus acidophilus L-92 | — | Improved Treatment Response Rate | Neutral | Small | View sourceThere was insufficient evidence to suggest improvements in objective disease response rates (RR: 1.06; 95% CI: 0.93, 1.20; I2: 0%; 95% PI: 0.93, 1.20). |
| Lactobacillus acidophilus L-92 | — | No Improvement in Objective Cancer Treatment Response | Neutral | Small | View sourceThere was insufficient evidence to suggest improvements in objective disease response rates (RR: 1.06; 95% CI: 0.93, 1.20; I2: 0%; 95% PI: 0.93, 1.20). |
| Lactobacillus acidophilus L-92 | — | Reduced Gastrointestinal Adverse Events | Beneficial | Moderate | View sourceGM interventions reduced the overall risk of GIAEs [relative risk (RR): 0.59; 95% CI: 0.53, 0.65; I2: 76.8%; 95% prediction interval (PI): 0.32, 1.08], including diarrhea, constipation, nausea, and vomiting |