Published in Gut Microbes, the research examined large datasets of dietary intake data from colon cancer patients to compare how the presence of Bifidobacteria in the tumor tissue corresponded with patient outcomes, e. g. whether the abundance of the bacteria related positively or negatively to cancer incidence.
The theory was that the long-term intake of yogurt could reduce the risk of colorectal cancer.
While the study has limitation – e.g. it relies on self-reported data – it provides evidence in the long-term effects of yogurt consumption by comparing data taken at multiple time points – and also allows academics to glean into how yogurt consumptions is related to other lifestyle choices.
For example, the researchers found that participants who consumed higher amounts of yogurt were more likely to have higher folate, calcium and vitamin D levels; be more physically active, smoke less and consume less processed foods.
Of the 132,056 patient cohort, there were 3,079 incident colorectal cancer cases including 1,121 with available tissue Bifidobacterium data.
Based on the research, individuals who consumed two or more servings of yogurt per week had a lower tumor incidence than those who ate the dairy product less than once a month. However, patients who consumed yogurt daily had the lowest incidence.
Of the 1,121 colorectal cancer cases where tissue Bifidobacterium was available, 31% (346 cases) were Bifidobacterium-positive, and 775 (69%) were Bifidobacterium-negative.
“[W]e tested the hypothesis that the association of long-term yogurt intake with colorectal cancer incidence might differ by the abundance of tumor tissue Bifidobacterium.
“We observed such a differential association, especially for proximal colon cancer, with a trend of the association of yogurt intake with lower incidence of Bifidobacterium-positive proximal colon cancer (but not Bifidobacterium-negative subtype).
“Given considerable heterogeneity in colorectal cancer by tumor subtypes, our findings suggest a potential differential influence of yogurt intake on colorectal cancer risk according to the abundance of tumor tissue Bifidobacterium.”
Source:
Ugai, S., Liu, L., Kosumi, K., Kawamura, H., Hamada, T., Mima, K., … Ugai, T. (2025). Long-term yogurt intake and colorectal cancer incidence subclassified by Bifidobacterium abundance in tumor. Gut Microbes, 17(1). https://doi.org/10.1080/19490976.2025.2452237