Understanding the relationship between chronic dermatitis mediated dysbiosis in the gut microbiota and inflammatory bowel disease

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K17503
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 53010:Gastroenterology-related
• Research Institution: Keio University
• Principal Investigator: Harada Yosuke 慶應義塾大学, 医学部(信濃町), 特任助教 (50725968)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 炎症性腸疾患 / 乾癬 / 腸内細菌叢 / 糞便移植 / 腸管免疫

Outline of Final Research Achievements

We hypothesized that dysbiosis of intestinal bacteria may be involved in the complication of psoriasis, a skin disease, and inflammatory bowel disease, and tried to elucidate the mechanism in an experimental animal model. IMQ dermatitis mice exhibit a marked reduction of Lactobacillus. Furthermore, we examined binding of various Ig antibodies on the intestinal bacteria of these mice and IgM-positive bacteria were decreased. We considered the involvement of blood-borne humoral factors as a mediator of the exacerbation of inflammation in the dermatitis and intestinal tract. We induced IMQ dermatitis in only one of the mouse pairs that exchanged blood by parabiosis and examined migrating B cells and found no evidence of humoral factors.

Free Research Field

免疫学

Academic Significance and Societal Importance of the Research Achievements

今回申請者らが提唱する腸内細菌の変化を包含した乾癬と腸炎の間にある皮膚-腸相関では、腸内細菌の変化が腸炎の発症に影響しており、臨床応用として乾癬に合併するIBDに対する、腸内細菌をターゲットとした新たな治療法の開発につながる可能性があると考える。また、実際の乾癬患者における腸内細菌叢の変化にはIBD患者の腸内細菌叢の変化と一部の共通点が報告されているが、乾癬患者におけるdysbiosisが実際にcolitogenicなものであるとすれば、ヒトにおいても同様の皮膚-腸相関が存在することを示唆し、ヒトにおける検討及び臨床応用に向けた研究が今後の課題といえる。