Colorectal cancer: The "invisible" disorder that accelerates its progression

A new study suggests that the workings of our internal clock may contribute to gut health and reduce colon cancer.

Colorectal cancer is one of the most common forms of cancer, and in recent years, there has been an alarming increase in cases in people under the age of 50. Many risk factors have been linked to the occurrence of this cancer, such as heredity, eating habits and smoking.

However, a recent study from the University of California at Irvine reveals a new and important factor: the disruption of the circadian rhythm, i.e. the body's internal biological clock.

Circadian rhythm function

The circadian rhythm is the "internal clock" that regulates many of our body's functions on a 24-hour cycle. This biological system affects sleep, hormone release, body temperature and our immune system.

However, external factors, such as excessive exposure to light at night or late-night meals, can cause disturbances in this rhythm, known as "circadian dysfunctions".

The research discovered a link between circadian rhythm disruption and the progression of colon cancer.

What the research showed

According to the study published in Science Advances, circadian rhythm disruption appears to significantly affect the gut microbiome—that is, the set of microorganisms that live in the gut.

“Our findings suggest that disruption of the circadian clock plays a significant role in altering the gut microbiome and compromising intestinal barrier integrity, both of which may contribute to colorectal cancer development,” says the study’s corresponding author, Selma Masri, UC Irvine associate professor of biological chemistry. “Maintaining a healthy rhythm in our lives might be more important than we thought, especially when it comes to preventing serious diseases like cancer.”

The study was carried out in mouse models of colon cancer, and the researchers observed that when the circadian rhythm was disrupted, the gut microbiome significantly changed.

In particular, the diversity and abundance of bacteria decreased, while the microbial metabolic mechanisms related to the metabolism of nucleic acids, amino acids and carbohydrates were altered.

These changes decreased the levels of intestinal mucus, which protects the gut wall from harmful bacteria.

The gut microbiome is important for our health. Microorganisms that live in the gut help digest food, strengthen the immune system, and protect it from pathogenic microorganisms.

But when the balance of the microbiome is disturbed, the gut becomes more vulnerable.

In the study, the researchers observed that disrupting the circadian rhythm made the gut more permeable, allowing toxins and bacteria to pass into the bloodstream.

This can accelerate the progression of cancer, as the body is no longer able to effectively control the inflammation and toxic effects caused by pathogenic bacteria.

The researchers emphasise that their findings open new avenues for preventing and treating colon cancer.

“While these findings are important, more work needs to be done,” Masri said.

“In particular, we now want to know if changes in the timing and abundance of certain gut bacteria could directly lead to colorectal cancer development over time.

"Long-term studies will be critical in determining whether circadian misalignment drives cancer and how we might prevent it in the future.

"Deeper insights into how the body’s internal clock shapes the gut’s ecosystem could pave the way for treatments that not only address cancer but also improve overall gut health.”

READ MORE: People Living to 100 on the Beautiful Greek Island Swear by a Daily Spoonful of This Superfood.