Researchers at Yonsei University have identified a microbial signature in saliva that could help distinguish people with gastrointestinal cancers, including colorectal cancer (CRC), from healthy individuals. The study, published in Cell Host & Microbe, explored whether microbes normally associated with the mouth could provide clues about what is happening in the GI tract.
The team analyzed saliva and stool samples from 507 people, including 86 patients with colorectal cancer, 77 with gastric cancer, 215 with metabolic conditions such as type 2 diabetes and metabolic syndrome, and 129 healthy controls. They developed a “mouth-to-feces” (MF) index to measure how much overlap existed between microbes found in an individual’s oral and fecal samples.
The MF index was significantly higher in people with GI cancers, suggesting that oral-associated bacteria may migrate to and persist in the gut differently in people with cancer. Interestingly, this increase was not seen in people with metabolic disorders, suggesting the microbial pattern may be more closely associated with cancer.