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Getting the latest healthcare news for you
Getting the latest healthcare news for you
Oral bacteria that "leak" into the gut may be a powerful new tool for detecting gastrointestinal cancers. Researchers developed a "mouth-to-feces" transmission index that outperformed standard fecal occult blood testing (FOBT) in identifying colorectal and gastric cancers. Even an oral rinse alone showed strong diagnostic accuracy — potentially paving the way for a simpler, less invasive cancer screening option.
Researchers have discovered that oral bacteria colonizing the gut — quantified through a novel "mouth-to-feces" (MF) transmission index — are significantly more abundant in patients with gastric and colorectal cancer compared to healthy individuals. The finding, published in Cell Host & Microbe, suggests that this microbial "leak" could serve as a powerful, noninvasive biomarker for GI cancer detection.
The study analyzed paired oral and fecal microbiome samples from 507 participants in South Korea, using machine learning models to build diagnostic classifiers. These models were validated across seven independent international cohorts, demonstrating consistent performance. Crucially, the oral-sample-based classifier alone showed strong results — raising the prospect of a simple oral rinse replacing or supplementing stool-based screening.
By the Numbers:
Why it matters: Current stool-based screening tools like FOBT miss a significant portion of cancers. A noninvasive oral rinse test could dramatically improve early detection rates, reduce patient burden, and help prioritize who needs colonoscopy or endoscopy — potentially saving lives through earlier intervention.
