LOS ANGELES (April 2, 2026) -- Microbes in the gut use specialized chemical signaling molecules to communicate, and one day, these molecules may help doctors understand which ulcerative colitis patients are most likely to develop colon cancer. In a study co-led by researchers at Cedars-Sinai Health Sciences University and published in Gastroenterology1, investigators found that the molecules—called quorum sensing molecules, or QSMs—are a link between the gut microbiome and cancer risk.
Ulcerative colitis is a type of inflammatory bowel disease (IBD) that causes chronic inflammation and sores in the colon.
“Ulcerative colitis greatly increases a person’s risk of developing colorectal cancer, but we don’t have a noninvasive way to determine how great each patient’s risk might be,” said Hajar Hazime, PhD, a project scientist in the Abreu Lab at Cedars-Sinai and co-first author of the study. “Undergoing frequent surveillance colonoscopies can help, but preparing for that procedure is especially difficult for someone with ulcerative colitis.”
Additionally, colonoscopy results can be inconclusive, forcing the physician and patient to decide whether to remove all or part of the colon to prevent cancer from developing, Hazime said. Investigators hoped to find a more conclusive and less invasive way to screen these patients.
“Our physician-scientists are continually working to improve cancer screening for our patients.”Robert Figlin, MD, Interim Director of Cedars-Sinai Cancer
“We treat more than 60 types of cancer, but our ultimate goal is prevention,” said Robert Figlin, MD, interim director of Cedars-Sinai Cancer.
Each person’s gut is populated with trillions of microbes—bacteria, viruses, fungi and other organisms too small to see with the naked eye. These interact with each other and appear to influence several aspects of a person’s health, including IBD.
Hazime said that these microbes use QSMs to communicate and coordinate their behavior, and that a goal of the study was to determine whether QSMs play a role in causing colon cancer in patients with ulcerative colitis.
When the investigators examined blood samples from human patients with ulcerative colitis and conducted experiments using colon organoids and laboratory mice, they found:
In the blood of ulcerative colitis patients, there were higher levels of QSMs in patients at higher risk for cancer, who had experienced symptoms for 10 years or longer, than in patients at lower cancer risk, with symptoms for five years or less.
In colon organoids—tiny clusters of cells that mimic some functions of the human colon—exposure to QSMs caused inflammation, which is a risk factor for tumor development. Because organoids do not contain gut microbes, this showed that elevated QSM levels and the activity of microbes they regulate can increase cancer risk.
In laboratory mice with a condition that mirrors ulcerative colitis, investigators found higher levels of QSMs in the blood of those that developed tumors than in those that did not. Also, mice exposed to extra levels of QSMs developed more tumors, more quickly, than those not exposed.
“These results show us that quorum sensing molecules are not only associated with colon cancer risk in patients with ulcerative colitis, but that they actually contribute to the formation of these tumors,” said Maria T. Abreu, MD, executive director of the F. Widjaja Inflammatory Bowel Disease Institute and co-corresponding author of the study. “That makes these molecules a potential way to screen patients for cancer risk, but also a possible target for reducing risk.”
Investigators will next focus on pinpointing how QSMs contribute to tumor formation, studying the molecules as a biomarker to predict cancer development, and finding ways to target these molecules to disrupt cancer development, Abreu said.
Reference:
1) https://www.gastrojournal.org/article/S0016-5085(26)00090-9/fulltext
(Newswise/HG)