Differences in microbiome observed in patients with psoriasis

Growing understanding of the skin microbiome opens up the potential for new therapeutic targets, according to the President of the Canadian Dermatology Association and Clinical Associate Professor at the University of Alberta in Edmonton, Alberta, Canada.

"There is a symbiotic relationship between us and our microbiome," explains Mariusz Sapijaszko MD, FRCPC, in an interview with Dermatology Times. "The disruption of that relationship can occur through our diet, our habits, our upbringing, and antibiotic treatments. These have been shown to have profound effects on our health. There is more and more evidence that dysregulation of the microbiome has a tremendously negative impact on how we feel, how we think, and the way our body manifests health and disease."

At the recently held annual meeting of the Canadian Dermatology Association, a symposium on the role of the microbiome in skin pathologies was held. Topics such as preserving the natural ecosystem of the various niches, upsetting the balance in the microbiome, and characterizing the diversity of the microbiome to correct imbalances were raised.

"When it comes to the skin, the research (about the skin microbiome) is quite recent," says Dr. Sapijaszko. "It is well-known that our intestinal flora is critical to our well-being and disruption of it has profound long-lasting effects that can be very serious."

The subject of the microbiome and dysbiosis is gaining popularity and wider acceptance, says Dr. Sapijaszko. "Clearly, there are differences in the microbiome   between lesional skin and non-lesional skin, and (the microbiome of) individuals who have psoriasis and those who do not," he says. "It is quite complex because there are thousands of different organisms and tremendous genetic variability between patients."

The fact that there are differences between lesional and non-lesional skin and between psoriatics and non-psoriatics represents a new area for research into future therapies, says Dr. Sapijaszko.

"You can imagine new technologies," he says. "If we look at an individual person's microbiome, and know from research that certain organisms are under-represented or over-represented, then we could perhaps use something as simple as soap or topical cream designed to decrease certain types of bacteria or introduce some other types of bacteria or fungi for that matter. That topical therapy could be as powerful as our systemic agents."

Next: Potential new therapies

Potential new therapies could either act in an adjunctive capacity or as a monotherapy. "I would not be surprised if new modalities, based on our understanding of the microbiome, are able to control the condition (psoriasis)," says Dr. Sapijaszko, pointing out a new therapy may end up being a daily oral supplement for patients with psoriasis.

Dr. Sapijaszko notes other areas of medicine are using the principle of ridding or replenishing various organisms in the microbiome to treat disease. "There are already treatments for inflammatory bowel disease involving fecal transplants," he notes.

There is evidence to suggest consumption of probiotics, found in foods like yogurt, and consumption of prebiotics, found in cruciferous vegetables, foster growth of a healthy microbiome, according to Dr. Sapijaszko.

The challenge is that the microbiome becomes established in the first few years of life. "It is not easy to significantly alter it later in life," notes Dr. Sapijaszko. "It is an ongoing effort to change the microbiome."

Happily, technology is emerging that allows for genetic sequencing of the organisms that make up the microbiome. "DNA analysis tells us about species in the microbiome," explains Dr. Sapijaszko. "We do not have to culture them. The DNA analysis will give us a complete picture whereas the culture will not. Much of our evidence (in the past) has been based on cultures, which are inherently unreliable."

Tremendous strides in the management of psoriasis, such as the advent of biologic agents that target the immune systems of patients with psoriasis, have been made owing to the accumulation of greater knowledge of the disease, and that accumulation of knowledge continues. "The acquisition of knowledge does not stop," says Dr. Sapijaszko. "Emerging knowledge about the dysbiosis seen in patients with psoriasis may result in us, as dermatologists, using therapies that we cannot imagine now. This may see other treatments relegated to second-line and third-line therapies."

The prescription of antibiotics, both topical and systemic, should be curtailed in dermatology in an effort to maintain a healthy skin microbiome, maintained Dr. Sapijaszko.

William W. Mohn, PhD, Professor in the Department of Microbiology and Immunology at the University of British Columbia in Vancouver, British Columbia, Canada, echoed Dr. Sapijaszko's sentiments about overprescribing of antibiotics.

"They (antibiotics) upset the microbial community that is largely in the gut," says Dr. Mohn.  "Upsetting the microbiome early in life appears to cause dysregulation of the immune system that can last a lifetime. We should aim to avoid upsetting the microbiome and let it develop naturally as much as possible."

Pathogenic organisms are less likely to infect an individual whose microbiome is intact and who has normal flora, explains Dr. Mohn.

Many immune-mediated diseases, including skin diseases like psoriasis, are linked to an overactive immune system, says Dr. Mohn. 

Dr. Sapijaszko and Dr. Mohn had no relevant disclosures.

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