Gut microbiota associated with precancerous lesions and future development of colorectal cancer

Important points:

• Overall microbiome composition was associated with preexisting lesions and future adenoma development.
• Individuals who developed colonic lesions after fecal collection had reduced microbiome diversity.

The gut microbiome is associated not only with existing colorectal lesions but also with the progression of future lesions, according to UEG Week presenters, and the inclusion of microbiome biomarkers could provide a non-invasive test for colorectal cancer. There is a possibility that this could be improved.

“The gut microbiome has been found to be associated with colorectal cancer not only directly by inducing nephrotoxicity and long-term inflammation, but also indirectly through a variety of mechanisms.” Ranko Gasisa Master’s degree, Ph.D. said the postdoctoral fellow at Groningen University Medical Center in the Netherlands during a presentation.

“One of the questions we are trying to answer with this study is what comes first: Does colorectal cancer cause changes in the gut microbiome, or does the gut microbiome change? Does it actually cause cancer, or at least occur before cancer? It’s important both for diagnosis and for the basis of science… Ideally, cancer is already difficult to treat, so We don’t want to detect cancer if it’s present. We want to detect it as early in development as possible.”

Gacesa et al. used the Dutch Microbiome Project and the Dutch National Pathology Database to identify 8,208 people who had undergone a colon biopsy over the past 50 years. The researchers examined the intestinal tract of individuals who developed precancerous colorectal lesions before fecal collection from 2000 to 2015 (n = 219) and after fecal collection from 2015 to 2022 (n = 315). We assessed microbiota function and composition and compared them to 2,123 matched controls.

Furthermore, the researchers investigated specific bacterial strains and their functions by reconstructing their genomes from metagenomic data.

Dr. Gacesa found that participants with precancerous lesions before sampling had 26 cases of colorectal cancer, 24 advanced adenomas, 131 adenomas, and 68 serrated polyps, while participants who developed lesions after sampling had It noted that there were 29 cases of colorectal cancer, 73 advanced adenomas, 128 adenomas, and 51 serrated polyps.

Results showed that microbiome diversity was reduced in individuals who developed colonic lesions after fecal collection.

“Adenomas are both pre-existing and those that develop later. [fecal] “Sampling has a lot to do with the overall composition of the microbiome,” Gacesa said.

In addition, the composition and function of the microbiome is different in people who already have or will have lesions, and it also differs depending on lesions such as colorectal cancer, high- or low-grade dysplasia, and serrated polyps, researchers say. reported.

It should be noted that Lachnospiraceae and genus rosebria and eubacteria was associated with future lesion progression.

Gacesa told Healio that these findings need to be validated in other populations and clinical trials before being implemented in patient care. “Further research, if successful, could improve colorectal cancer prevention in the future by contributing to new and better non-invasive tests for colorectal cancer.”

Professor Gasseza said: “Our next step is to examine the bacterial metabolites associated with colorectal pathologies and the bacteria detected in this study. “It is also important for understanding the science that it is easier and more practical to develop tests for metabolites and chemicals as opposed to tests for bacteria.”

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