Can Eating Yogurt Help Lower Your Risk of Colorectal Cancer?

Healthy Aging Research: What Two Studies and a Scientific Review Reveal About Yogurt, Gut Bacteria, and Colorectal Cancer

Colorectal cancer is one of the most common cancers worldwide, and researchers are constantly looking for simple lifestyle habits that might help lower the risk. 

One food that has attracted growing scientific interest is yogurt. Known for its live bacteria and potential benefits for gut health, yogurt may do more than support digestion.

Recent studies have explored whether regularly eating yogurt is linked to a lower risk of colorectal cancer and whether changes in the gut microbiome could help explain the connection. While the findings are encouraging, the relationship is more complex than simply adding another food to your diet.

Why Did Researchers Study Yogurt and Colorectal Cancer?

Colorectal cancer remains a leading cause of cancer-related deaths. Although genetics play a role, researchers estimate that many cases are influenced by lifestyle factors such as diet, physical activity, smoking, alcohol consumption, and body weight.

In recent years, scientists have become increasingly interested in the gut microbiome—the trillions of bacteria, viruses, and other microorganisms that live in the digestive tract. 

These microbes help digest food, produce beneficial compounds, support the immune system, and help maintain the protective lining of the intestine. Yogurt naturally contains live bacteria, often referred to as probiotics, which may influence the balance of the gut microbiome. 

Researchers wanted to find out whether people who regularly eat yogurt have a different risk of developing colorectal cancer and whether certain beneficial bacteria, particularly Bifidobacterium, might help explain any observed differences.

To answer these questions, scientists analyzed data from large population studies, long-term health studies, and research into the gut microbiome itself.

Study	Participants	What Was Investigated
NHANES 2026	9,405	Yogurt, probiotics, prebiotics & colorectal cancer
Gut Microbes 2025	132,000	Long-term yogurt intake & specific colorectal cancer subtypes
J Biomed Sci 2025	Narrative Review	Gut microbiome, aging & longevity

How Were the Studies Conducted?

Rather than relying on a single piece of research, this article brings together evidence from three complementary studies. Each approached the question from a different perspective, helping to build a broader picture of how yogurt, the gut microbiome, and colorectal cancer may be connected.

Study 1: NHANES Population Study (2026)

Researchers analyzed data from the National Health and Nutrition Examination Survey (NHANES) collected between 2001 and 2020, including 9,405 adults aged 50 years and older, representing an estimated 37 million U.S. adults. 

Participants reported their intake of yogurt, probiotic supplements, and prebiotic supplements, along with information about lifestyle, diet, and medical history. 

Researchers then examined whether these dietary habits were associated with a history of colorectal cancer while adjusting for many other factors that can influence cancer risk, including age, sex, smoking, body weight, red meat intake, fibre intake, and chronic diseases.

Study 2: Harvard Long-Term Cohort Study (2025)

Researchers from Harvard analyzed data from more than 132,000 women and men participating in two long-running U.S. health studies: the Nurses’ Health Study (NHS) and the Health Professionals Follow-up Study (HPFS). 

Participants regularly completed dietary questionnaires over several decades, allowing researchers to compare long-term yogurt intake with the later development of colorectal cancer. 

For participants who developed colorectal cancer, tumor tissue was also analyzed to determine whether it contained Bifidobacterium, a beneficial bacterium commonly found in the gut.

Study 3: Gut Microbiome Review (2025)

The third paper was a narrative review rather than a clinical study. Instead of recruiting participants, the authors reviewed a wide range of scientific research examining how changes in the gut microbiome influence inflammation, immune function, aging, and disease.

This review provides important biological context for understanding why foods such as yogurt might influence long-term health.

What The Studies Found

Study 1: NHANES Population Study (2026)

Researchers found that people who reported consuming probiotics, prebiotics, or yogurt had about a 50% lower chance of having a history of colorectal cancer than those who reported consuming none of these products. This was even after taking other factors that can affect colorectal cancer risk into account.

These findings suggest that eating foods that support a healthy gut microbiome may be linked to better colon health.

However, because the researchers looked at people’s diets and whether they already had colorectal cancer at the same point in time, they couldn’t tell whether these foods actually reduced the risk of developing cancer later. The study found a link, but it couldn’t prove that one caused the other.

Study 2: Harvard Long-Term Cohort Study (2025)

The Harvard study reached a more nuanced conclusion. Overall, researchers did not find that eating more yogurt reduced the total number of colorectal cancer cases across the entire study population.

However, when they examined the tumor tissue more closely, they found that people who ate two or more servings of yogurt each week were less likely to develop a specific type of colorectal cancer. 

This association was seen in Bifidobacterium-positive cancers in the proximal (right side) of the colon and was not seen for colorectal cancer overall.

These findings suggest that the relationship between yogurt, the gut microbiome, and colorectal cancer may differ depending on the type of tumor. More research is needed to understand why this association was seen in this particular subgroup.

Narrative Review: Gut Microbiome Review (2025)

The narrative review did not investigate yogurt directly but helps explain why researchers believe foods such as yogurt deserve further study.

The review concluded that changes in the gut microbiome with age—often referred to as dysbiosis—can contribute to:

• chronic low-grade inflammation,
• reduced immune function,
• impaired gut barrier integrity,
• metabolic changes,
• and increased susceptibility to age-related diseases.

The authors also discussed growing evidence that maintaining a diverse and balanced gut microbiome may support healthy aging and could reduce processes linked to chronic diseases, including colorectal cancer.

Although the review does not prove that yogurt prevents cancer, it provides a biological explanation for why researchers continue to investigate probiotic-rich foods as part of a healthy dietary pattern.

Key Findings at a Glance

Study	Main Finding
NHANES (2026)	Regular yogurt consumption was associated with approximately 50% lower odds of colorectal cancer, although causation cannot be established.
Harvard Cohort (2025)	No reduction in overall colorectal cancer incidence, but lower risk of Bifidobacterium-positive proximal colorectal cancer among people eating two or more servings of yogurt per week.
Gut Microbiome Review (2025)	A healthy gut microbiome may help reduce inflammation and support healthy ageing, providing biological plausibility for further research into yogurt and colorectal cancer.

How Might Yogurt Help Support Colon Health?

Scientists believe the answer lies in the gut microbiome—the trillions of bacteria and other microorganisms that live naturally in the digestive tract.

A healthy gut microbiome plays an important role in digestion, immune function, and protecting the lining of the intestine. As we age, however, the balance of these microorganisms can change—a process known as dysbiosis, or an imbalance in the gut microbiome. This imbalance has been linked to increased inflammation and may contribute to the development of several chronic diseases, including colorectal cancer.

Yogurt contains live bacteria, commonly called probiotics, that may help support a healthier gut microbiome. Different yogurt products contain different bacterial strains. Some also contain additional probiotic bacteria, including species of Lactobacillus and Bifidobacterium.

Researchers have proposed several ways in which fermented foods and beneficial gut bacteria might support colon health, although these mechanisms were not directly tested in the two yogurt studies.

Researchers believe these bacteria may help support colon health in several ways:

• Helping maintain a healthy balance of gut bacteria.
• Producing beneficial compounds called short-chain fatty acids, which nourish the cells lining the colon.
• Strengthening the intestinal barrier, making it more difficult for harmful substances to enter the bloodstream.
• Supporting normal immune function within the digestive tract.
• Helping reduce chronic, low-grade inflammation.

The Harvard study added another interesting piece to the puzzle. Researchers found that people who regularly ate yogurt were less likely to develop a specific type of colorectal cancer that contained Bifidobacterium. This suggests that the relationship between yogurt, the gut microbiome, and colorectal cancer may differ depending on the type of tumor.

Although scientists are still investigating these mechanisms, the evidence suggests that maintaining a healthy gut microbiome may be one important part of supporting long-term colon health.

Limitations of the Research

No single study can prove that eating yogurt prevents colorectal cancer, and there are several important limitations to keep in mind.

Both the NHANES and Harvard studies were observational, meaning researchers observed people’s eating habits rather than assigning them specific diets. Because of this, they can identify associations but cannot prove that yogurt itself caused the lower risk.

People who regularly eat yogurt may also have other healthy habits. They may exercise more, eat more fruit and vegetables, consume less processed food, avoid smoking, or participate in regular cancer screening. Although researchers adjusted for many of these factors, it is impossible to account for every lifestyle difference.

The studies also did not examine every type of yogurt. Products vary considerably in their probiotic content, sugar levels, and bacterial strains, so the findings cannot automatically be applied to all yogurts available in supermarkets.

Finally, the Harvard study found an association only for a specific subtype of colorectal cancer, while the NHANES study relied on self-reported dietary information and cannot determine cause and effect.

For these reasons, the current evidence suggests that yogurt may contribute to better colon health as part of an overall healthy diet, but more long-term clinical research is needed before firm conclusions can be made.

Lillepin Takeaway

The latest research suggests that regularly eating yogurt may be associated with a lower risk of certain types of colorectal cancer and supports the growing evidence that a healthy gut microbiome plays an important role in long-term health.

However, yogurt should not be viewed as a single solution or a way to prevent colorectal cancer. The strongest evidence continues to support an overall healthy lifestyle that includes eating a balanced diet rich in fibre, fruits, vegetables, and whole grains, maintaining a healthy weight, staying physically active, limiting alcohol, avoiding smoking, and taking part in recommended colorectal cancer screening.

For people who already enjoy yogurt, choosing varieties that contain live and active cultures and are low in added sugar may be one simple way to support a healthy diet. For those who do not eat dairy, other fermented foods and fibre-rich plant foods may also help promote a diverse and healthy gut microbiome.

While scientists continue to investigate exactly how probiotics and beneficial gut bacteria influence colorectal cancer risk, these studies add to the growing body of evidence that caring for your gut health may be an important part of healthy aging.