The findings of the study, by Assistant Professor Boaz Mizrahi and his student Maayan Lupton and Dr. Ayelet Orbach of the Technion-Israel Institute of Technology’s Faculty of Biotechnology and Food Engineering, were recently published recently in Advanced Functional Materials.
Fungal infections are common among animals, including humans. One of the primary sources of such infections is Candida, a yeast regularly found in our bodies. Candida exploits abnormal functioning in the organism to spread and harm the host. Most people will experience a fungal infection at least once in their lifetime, in some part of their body — on the skin, in the digestive system or genitals.
The frequency of fungal infections is constantly on the rise due to the aging population and possibly global warming. Additional reasons include use of drugs, which suppress the immune system, and the increased use of broad-spectrum antibiotics, which indirectly enhance the proliferation of Candida by disrupting the bacteria balance in the body.
In the current standard pharmaceutical model the drug passes through the entire body and portions of it may be broken down in the process, the researchers said.
The team studied the option of treating Candida using the Bacillus subtilis bacterium, which naturally produces and secretes substances that inhibit Candida growth, as the bacteria tends to compete with Candida on common growth areas, around the roots of plants in nature. Bacillus subtilis is already used by farmers and growers to fight Candida on their plants. The Technion researchers are now using this bacteria to fight the fungus in animals and hopefully in humans too.
“Our first challenge,” said Mizrahi, “was to develop a transport system that would enable application of the live bacteria on the infected lesion without impairing their ability to proliferate and secrete their therapeutic substances in the target site.”
To do so, the researchers developed a gel that takes a liquid form in the refrigerator and at room temperature. “Its liquid form allows the gel to better penetrate a deeper layer of the skin,” where the fungus generally resides, said Mizrahi in a phone interview.
Within seconds after being applied to the infected area, the gel hardens. It contains food substances, “a sort of a food hamper,” Mizrahi explained, which makes sure that the bacteria stays alive and produces the Candida-destroying molecules.
“We have developed a formula that creates a small factory of live bacteria that continue to grow and secrete,” he said. That is the team’s innovation, he said
The researchers applied the gel to the skin of mice suffering from a fungal infection, after marking the gel with a fluorescent substance that would allow for monitoring. The formulation penetrated into the skin without reaching the underlying blood vessels, indicating that the effect of the formula is limited to the diseased area, the researchers said.
Following up on the procedure, researchers found that the group of mice treated with the Technion-developed bacterial gel showed rapid skin healing, while in the control groups — treated with bacteria-free gel or not treated at all — the infection continued to develop.
The researchers said they hope their model of using live bacteria to treat fungal infections and their “minuscule factory” that produces the active substance on the site, will be used in the future to treat a whole range of diseases, including psoriasis, acne, a variety of inflammations and even cancer.