Gut microbiota is key to the relationship between obesity and colorectal cancer: a new Andalusian study sheds light on this connection.
An Andalusian study reveals that intestinal bacteria could be the key to explaining why obesity increases the risk of colon cancer.
A research team led by the group MP16 Intestinal Immunomodulation of the Biosanitary Research Institute of Granada (ibs.GRANADA) in collaboration with the group of Hepatogastroenterology, Pharmacology and Translational Clinical Therapeutics IBIMA's BIONAND Platform has published a scientific review that could change our understanding of the link between obesity and colorectal cancer: the intestinal microbiota plays a leading role.
The study, titled “Systematic review: The gut microbiota as a link between colorectal cancer and obesity”, has been published in the prestigious magazine Obesity Reviews, and analyzes more than 100 studies that explore how alterations in intestinal flora can explain why obese people have a higher risk of developing colon cancer.
“Our work shows that intestinal bacteria are not mere bystanders, but active agents in tumor development. Specifically, intestinal dysbiosis—an alteration in microbial balance—could act as a bridge between two of the major epidemics of the 21st century: obesity and colorectal cancer,” explains Dr. Antonio Jesús Ruiz-Malagón, principal investigator of the study.
Ruiz-Malagón, together with Dr. Maria Jesus Rodriguez-Sojo, have led this research as co-principal authors, also counting on the participation of scientists Eduardo Redondo, Maria Elena Rodriguez-Cabezas, Julio Gálvez y Alba Rodríguez-Nogales, all of them leaders in the study of the microbiome and its impact on health.
“Detecting changes in the microbiota could become a tool for early diagnosis. Furthermore, this opens the door to personalized treatments based on probiotics, diet, or even fecal microbiota transplants,” adds Ruiz-Malagón.
The research highlights how obesity creates a chronic inflammatory environment and alters gut bacteria, producing compounds that can promote tumor growth. Furthermore, a specific microbial profile shared by obese individuals and those with colorectal cancer has been identified, reinforcing the hypothesis of a causal relationship.
“This work is an example of how translational research can help us understand complex and multifactorial diseases like cancer,” says Dr. Raúl J. Andrade Bellido, Scientific Deputy Director of IBIMA's BIONAND Platform and head of the research group to which Dr. Ruiz-Malagón belongs. "Furthermore, it highlights the need to address obesity not only as a metabolic problem, but also as a cancer risk factor."
This finding comes at a crucial time, as colorectal cancer is the second most deadly cancer worldwide, and its incidence continues to rise. According to recent data, more than 1,9 million new cases are diagnosed globally each year, and obesity is one of the main modifiable factors associated with its development.
Bibliographic reference
Ruiz-Malagón AJ, Rodríguez-Sojo MJ, Redondo E, Rodríguez-Cabezas ME, Gálvez J, Rodríguez-Nogales A. Systematic review: The gut microbiota as a link between colorectal cancer and obesity. Obes Rev. 2025 Apr;26(4):e13872. doi: 10.1111/obr.13872. Epub 2024 Nov 29. PMID: 39614602; PMCID: PMC11884970.
