A systematic review of the effects of diet on the gut microbiota in individuals at elevated risk for colorectal cancer
- 1Division of Food, Nutrition, and Exercise Sciences, College of Agriculture, Food and Natural Resources, University of Missouri , , ,
Abstract
Background: Colorectal cancer (CRC) poses a major public health concern, with emerging evidence highlighting the critical role of the gut microbiota in CRC progression. Considering that diet is a major modifiable factor influencing CRC risk, partly through its interaction with the gut microbiome, this systematic review evaluated the effects of dietary intervention RCTs, including supplements, functional foods, whole foods, and dietary patterns, on the gut microbiome in elevated-risk individuals.
Methods: A search of PubMed, Scopus, and Web of Science, and manual sourcing of systematic reviews, meta-analyses, and reference lists of relevant papers identified 5,558 records.
Results: Following screening, seven studies met inclusion criteria, focusing on microbial diversity and taxonomic composition. Findings demonstrate that effects on microbial diversity metrics were minimal and were observed only with a general healthy eating dietary pattern, navy bean powder interventions, and with one rice bran intervention. No consistent patterns emerged by intervention type (functional compounds, whole foods, or dietary pattern), intervention duration, or by diversity metric. In contrast, genus-level compositional shifts were more frequently reported, although directionality varied by dietary exposure. Enrichment of Faecalibacterium, Bifidobacterium, and Lactobacillus was reported in some rice bran and navy bean interventions, whereas reductions in Akkermansia, Ruminococcus, Bacteroides, Prevotella, and Porphyromonas were observed in others. Among the four trials assessing microbial-derived metabolites, some were associated with increased short-chain fatty acids and plant-derived metabolites while others reported reductions in secondary bile acids, p-cresol sulfate, and branched-chain bacterial fatty acids.
Conclusion: Overall, this review highlights the potential of dietary strategies to modulate the gut microbiome in populations at risk for CRC, while also addressing critical gaps in the current evidence and offering direction for the development of evidence-based dietary interventions that incorporate microbiome assessment. Limited RCTs and heterogeneity in outcomes limit generalizability. Future research should conduct rigorous RCTs across the lifespan, using microbiome and metabolite analyses such as shotgun metagenomics, meta-transcriptomics, or metabolomics and examining understudied dietary patterns to guide CRC prevention.
Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD42024530038, identifier CRD42024530038.
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BibTeX
@article{pandey2026systematic,
title = {{A systematic review of the effects of diet on the gut microbiota in individuals at elevated risk for colorectal cancer}},
author = {Saurabh Pandey and Jenna Skidmore and Jaapna Dhillon},
journal = {Frontiers in nutrition},
year = {2026},
month = oct,
doi = {10.3389/fnut.2026.1818522},
url = {https://europepmc.org/article/PMC/PMC13719305},
note = {CC BY},
}
RIS
TY - JOUR
TI - A systematic review of the effects of diet on the gut microbiota in individuals at elevated risk for colorectal cancer
AU - Saurabh Pandey
AU - Jenna Skidmore
AU - Jaapna Dhillon
PY - 2026
DA - 2026/10/16
JO - Frontiers in nutrition
DO - 10.3389/fnut.2026.1818522
UR - https://europepmc.org/article/PMC/PMC13719305
AB - Background: Colorectal cancer (CRC) poses a major public health concern, with emerging evidence highlighting the critical role of the gut microbiota in CRC progression. Considering that diet is a major modifiable factor influencing CRC risk, partly through its interaction with the gut microbiome, this systematic review evaluated the effects of dietary intervention RCTs, including supplements, functional foods, whole foods, and dietary patterns, on the gut microbiome in elevated-risk individuals. Methods: A search of PubMed, Scopus, and Web of Science, and manual sourcing of systematic reviews, meta-analyses, and reference lists of relevant papers identified 5,558 records. Results: Following screening, seven studies met inclusion criteria, focusing on microbial diversity and taxonomic composition. Findings demonstrate that effects on microbial diversity metrics were minimal and were observed only with a general healthy eating dietary pattern, navy bean powder interventions, and with one rice bran intervention. No consistent patterns emerged by intervention type (functional compounds, whole foods, or dietary pattern), intervention duration, or by diversity metric. In contrast, genus-level compositional shifts were more frequently reported, although directionality varied by dietary exposure. Enrichment of Faecalibacterium, Bifidobacterium, and Lactobacillus was reported in some rice bran and navy bean interventions, whereas reductions in Akkermansia, Ruminococcus, Bacteroides, Prevotella, and Porphyromonas were observed in others. Among the four trials assessing microbial-derived metabolites, some were associated with increased short-chain fatty acids and plant-derived metabolites while others reported reductions in secondary bile acids, p-cresol sulfate, and branched-chain bacterial fatty acids. Conclusion: Overall, this review highlights the potential of dietary strategies to modulate the gut microbiome in populations at risk for CRC, while also addressing critical gaps in the current evidence and offering direction for the development of evidence-based dietary interventions that incorporate microbiome assessment. Limited RCTs and heterogeneity in outcomes limit generalizability. Future research should conduct rigorous RCTs across the lifespan, using microbiome and metabolite analyses such as shotgun metagenomics, meta-transcriptomics, or metabolomics and examining understudied dietary patterns to guide CRC prevention. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD42024530038, identifier CRD42024530038.
SN - 2296-861X
ER -