Khaberni - Scientists have devised a new method that relies on genetically modified bacteria encapsulated in gel capsules, to detect intestinal bleeding in just 20 minutes—a significant improvement compared to the usual time span of 10 hours or more according to current methods.
According to "Study Finds," experiments conducted on mice have shown the success of these capsules, where the genetically modified bacteria light up when they encounter blood markers in the intestines.
Magnetic particles allow researchers to extract the sensors from stool samples within 15 minutes using a magnet.
Bacteria programmed to detect disease
The research team at East China University of Science and Technology has named this system MagGel-BS. It combines three elements: a gel capsule that protects the bacteria, magnetic particles that facilitate the collection of the capsules, and bacteria specifically programmed to act as disease detectors.
Studies on mice have shown no short-term side effects, as the bacteria remain confined within their gel capsules (less than 1% of them leaking during 10 hours).
Current methods for testing bacterial sensors are complex, sometimes taking more than 10 hours from start to finish.
The new method is simpler. It provides results in just 20 minutes after sample collection.
Bacteria light up when blood is found
Bacterial sensors are modified versions of Escherichia coli Nissle 1917, a beneficial bacterial strain. Scientists developed it to detect heme, a part of blood that appears when there is bleeding in the intestines.
Measuring the level of glow
When heme enters bacterial cells, it activates a genetic switch that causes the bacteria to produce light. The more heme, the greater the light intensity, enabling researchers to determine the severity of the bleeding by measuring the glow.
The role of the gel casing is not only to trap the bacteria but also to allow the passage of nutrients and disease markers, while protecting the bacteria from stomach acid and digestive enzymes. It prevents the bacteria from causing inflammation.
After 30 minutes of exposure to simulated stomach acid, the bacteria inside the gel remained viable at 100%. Unprotected bacteria? Only 25% survived. After an hour, the performance of the protected bacteria was more than 10 times better.
The researchers compared their system with the ortho-tolidine method, a chemical test for detecting latent blood in stool. Although fast, it gives false positive results when samples contain vitamin C or certain enzymes. The new method provides more accurate results and can detect intestinal bleeding earlier.
