Bacterial transplant could ease eczema symptoms, treat staph infections

Methicillin-resistant Staphylococcus aureus (MRSA), an antibiotic-resistant strain of a bacterium that aggravates skin conditions, such as atopic dermatits. Image: NIAID

The key to beating Staphylococcus aureus, an eczema-aggravating bacterium, could be other bacteria. UC San Diego scientists isolated “good bacteria” found on human skin and transplanted it to patients with eczema, finding that the treatment significantly cut down the amount of S. aureus on their skin.

While the current work focuses on treating atopic dermatitis, the most common form of eczema, it could have implications for treating other staph infections, including MRSA, an antibiotic-resistant strain of the bacterium that kills more than 11,000 people in the U.S. each year.

In search of bacteria that have antimicrobial properties, the team looked at 10,000 colonies of bacteria that live on human skin, according to a statement. The findings are published in Science Translational Medicine.

"We discovered that healthy people have many bacteria producing previously undiscovered antimicrobial peptides,” said Richard Gallo, a professor at UCSD’s School of Medicine. “But when you look at the skin of people with atopic dermatitis, their bacteria are not doing the same thing. They have the wrong type of bacteria.”

They first tested the method in mice, and then conducted a Phase I trial, in which an individual’s good bacteria were isolated, grown and then administered in a cream to the skin of eczema patients. Though the trial’s purpose was to assess the safety and efficacy of the bacterial transplant, the team noted each patient had a “significant decrease” in S. aureus on their skin.

The team has started a Phase II trial to determine if long-term bacterial transplant will translate to lasting protection against S. aureus and alleviate eczema symptoms. Gallo co-founded Matrisys BioScience in 2015 to advance this research, taking aim at the five most common skin conditions: acne, rosacea, psoriasis, skin infections and atopic dermatitis.

Bacterial transplant has shown potential in treating other conditions, as well, including obesity. In 2014, Cornell researchers studied more than 400 sets of twins and found that Christensenellaceae bacteria were more abundant in the leaner twin. They introduced the bacteria to mice via fecal transplant and found the treated animals weighed less than the control group after 21 days.

Using bacterial transplant rather than drugs has multiple benefits, said Teruaki Nakatsuji, first author of the eczema study. The antimicrobial activity selectively targets pathogenic bacteria without harming other good or protective bacteria. And because the transplanted bacteria attacks pathogenic bacteria in several different ways, S. aureus is unlikely to develop resistance to the treatment.