In this pilot case-control study of Egyptian patients with CRC, 16S rRNA sequencing showed greater microbial heterogeneity in CRC than in controls, enrichment or depletion of specific taxa in tumor versus control and adjacent normal samples, and exploratory associations of spicy food, processed meat, physical activity, and sex with particular taxa; all findings are hypothesis-generating given the small sample size and cross-sectional design.
CRC patients showed greater microbial heterogeneity than healthy controls, with higher Bray-Curtis distances.
Several taxa were more abundant in controls and adjacent normal tissue than in CRC samples.
Lachnospiraceae UCG-010 was increased in CRC samples.
Spicy food intake was linked to enrichment of Prevotellaceae and Christensenellaceae R-7.
Processed meat consumption was associated with reduced abundance of Fusicatenibacter.
Regular physical activity was associated with increased Akkermansia abundance among CRC patients.
Sex-specific microbial patterns were observed, with Collinsella, Eggerthella, and Prevotella_9 more abundant in males.
The authors characterize the findings as exploratory and hypothesis-generating, owing to limited sample size and cross-sectional design, and call for larger multi-center, multi-omics studies.
This small pilot study compared the gut bacteria of Egyptian patients with colorectal cancer to those of healthy people, using DNA sequencing of bacterial genes. Cancer patients had more varied and less uniform gut bacterial communities than controls. Some bacteria commonly linked with a healthy gut, such as Blautia, Dorea, Ruminococcus, and Coprococcus, were more abundant in healthy controls and in normal tissue next to tumors, while one group, Lachnospiraceae UCG-010, was more common in cancer samples. The researchers also looked at how diet, exercise, and sex related to the bacteria. Eating spicy food was linked to more Prevotellaceae and Christensenellaceae R-7, and eating processed meat was linked to less Fusicatenibacter. Among cancer patients, regular physical activity was linked to more Akkermansia, and some bacteria differed between men and women. These findings come from a small group of people at a single point in time, so they cannot show that lifestyle changes bacteria or that bacteria cause or prevent cancer. The authors stress that the results are exploratory. This research suggests that everyday habits may relate to gut bacteria patterns in colorectal cancer, and larger, multi-center studies are needed to confirm this.
ElAdawy S, Talkhan H, Orayj K, Balata G, Saeed M, Abdelkader A, et al.. (2026). Lifestyle-associated gut microbiota signatures in colorectal cancer patients: a pilot case-control study.. PeerJ. https://doi.org/10.7717/peerj.21829