Scientists at Guangzhou University of Chinese Medicine have discovered that the tongues of people with chronic heart failure look noticeably different from those of healthy individuals. Their research suggests that changes in tongue color and bacteria could be used as an early marker for diagnosing heart failure.
In a healthy person, the tongue is typically pale red with a light white coating. However, in patients with heart failure, the tongue appears redder with a yellowish coating. As the disease progresses, these changes become more pronounced.
The researchers also found that the types and amounts of bacteria on the tongue differ between heart failure patients and healthy individuals.
This idea is not entirely new. Previous studies have shown that the bacteria in the tongue coating can help identify patients with pancreatic cancer. Scientists believe that an imbalance in oral bacteria may contribute to inflammation, which plays a role in both cancer and heart disease.
To investigate the link between tongue bacteria and heart failure, researchers analyzed tongue samples from 42 heart failure patients and 28 healthy individuals. None of the participants had oral or dental diseases, recent infections, or had taken antibiotics or immunosuppressants in the past week. Pregnant or breastfeeding individuals were also excluded.
Samples were collected in the morning before participants ate or brushed their teeth, using stainless steel spoons to scrape the tongue coating. The researchers then used a genetic sequencing method (16S rRNA gene sequencing) to identify the bacteria present.
They found that heart failure patients had a distinct set of microorganisms on their tongues, completely different from those found in healthy individuals. There was no overlap in bacterial content between the two groups.
Further analysis showed that five types of bacteria were particularly effective in distinguishing heart failure patients from healthy people, with an accuracy score of 0.84 (on a scale where 1.0 is a perfect prediction and 0.5 is random). Additionally, as heart failure worsened, levels of two types of bacteria—Eubacterium and Solobacterium—gradually decreased.
These findings suggest that analyzing tongue bacteria could become a simple, non-invasive way to screen for heart failure. Since collecting tongue samples is easy, this method could be used for early diagnosis and long-term monitoring of patients. However, more research is needed to understand exactly how these bacteria affect heart function.
The study was conducted by Dr. Tianhui Yuan and published in Frontiers in Cardiovascular Medicine.
If you care about heart health, please read studies that vitamin K helps cut heart disease risk by a third, and a year of exercise reversed worrisome heart failure.
For more health information, please see recent studies about supplements that could help prevent heart disease, stroke, and results showing this food ingredient may strongly increase heart disease death risk.
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