Researchers at Severance Hospital have confirmed that anti-inflammatory intestinal symbiotic microbes, also known as probiotics, can reduce the inflammatory factor in atopic and contact dermatitis.
The team’s finding comes as research on the intestinal microflora has become active, leading to the revelation of the link between the imbalance of the intestinal microflora and the disease. Such imbalances have shown that they affect digestive diseases, respiratory diseases, infectious diseases, cancer, metabolic diseases, heart diseases, and psychiatric diseases.
Studies on inflammatory skin allergic diseases, such as atopy or contact dermatitis, have also shown that the imbalance of intestinal microbes of a patient induces an inflammatory response and worsens symptoms, increasing interest in the development of inflammatory skin disease treatments through probiotics.
Professor Kwon Ho-geun at the hospital led the search, and Professor Im Shin-hyuk of Pohang University of Science and Technology also took part in the study.
To confirm that probiotics can treat inflammatory skin diseases, the team isolated intestinal immune cells from mice, cultured them with various intestinal microorganisms, and classified them according to their immunological characteristics. Among the intestinal microbes classified, it selected immunosuppressive strains to find five combinations of intestinal microbes (IRT5) -- Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus reuteri, Bifidobacterium bifidum, and Streptococcus thermophiles.
Afterward, the research team verified the effect of treating inflammatory skin allergy in animal models of atopic dermatitis and contact dermatitis using dust mites.
The result showed that all inflammatory factors, including inflammatory cell penetration into tissues and pathological immune, improved by more than 50 percent in the IRT5-administered group.
Specifically, the team confirmed that immunomodulatory T cells -- immune cells that inhibit inflammation -- in the IRT5 group were 7.5 percent, more than four times the control group’s 1.8 percent.
The researchers also investigated the specific immunoregulatory mechanism of IRT5 and confirmed the involvement of IRT5 in increasing propionate, a secondary metabolite in the intestine.
“The study suggests a reference point for the study of the immune regulation mechanism of various intestinal microorganisms as it confirmed a series of processes, from the evaluation of the immune regulation of intestinal microbes to the discovery of immunomodulatory substances and the identification of the mechanism,” Professor Kwon said.
Based on the study results, it has become possible to provide a platform for developing microbiome therapeutics based on the immune-modulating ability of intestinal microbes in various immune diseases, he added.
The Journal of Allergy and Clinical Immunology published the results of the study in its latest issue.