Why the Threat Lingers After a Polyp Is Removed
Even after a benign adenoma is excised during colonoscopy, the chance of developing colorectal cancer does not drop back to baseline. Recent research from Harvard reveals that the gut microbiome— the dense community of bacteria living in our intestines—remains altered for more than a decade, and this lingering disruption appears to sustain a higher cancer risk.
Microbial fingerprints persist for twelve years
Scientists compared stool samples from 354 women who had previously undergone adenoma removal with those from 354 women with no polyp history. The samples were collected on average twelve years after the procedure. Strikingly, the microbial composition of the former group still differed markedly from the control group, showing an increased abundance of bacteria that are also common in patients diagnosed with colorectal cancer.
Diet, exercise and age amplify the effect
The investigators also examined lifestyle factors. Participants who both carried a past adenoma and followed an unhealthy diet or led a sedentary life harboured the most cancer‑associated microbes. In contrast, the link between lifestyle and bacterial shifts was far weaker among people without a polyp history. This suggests that nutrition and physical activity could modulate the gut environment especially in those already at elevated risk.
What the study does—and does not—prove
Importantly, the research establishes a correlation, not a direct cause‑and‑effect relationship. It remains uncertain whether the altered microbes actively drive cancer formation or simply reflect an underlying vulnerability. The authors propose future trials that would test whether targeted dietary changes or exercise programs can reshape the microbiome and, in turn, lower the incidence of colorectal cancer.
Potential clinical implications
If subsequent experiments confirm a causal link, doctors might begin to monitor the microbiome after polyp removal as a new risk marker. Interventions such as personalized nutrition plans, pre‑biotics, or probiotics could become part of standard follow‑up care for patients who have undergone adenoma resection.
Overall, the findings underscore how deeply our health is intertwined with microscopic residents of the gut. While colonoscopy remains the most effective tool for catching early lesions, the lasting microbial imprint left by a removed polyp reminds us that preventive strategies must extend beyond the procedure itself.
Source: https://scientias.nl/jaren-na-verwijdering-poliep-heb-je-nog-steeds-meer-kans-op-darmkanker/