Eosinophilic sinusitis and regulation of inflammation by short-chain fatty acids

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K18310
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 56050:Otorhinolaryngology-related
• Research Institution: University of the Ryukyus (2021-2022); Shiga University of Medical Science (2020)
• Principal Investigator: Toyama Masatomo 琉球大学, 病院, 専門指導医 (60838275)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 好酸球性副鼻腔炎 / 酪酸 / 2型炎症

Outline of Final Research Achievements

Eosinophilic sinusitis (ECRS) is a recurrent and intractable disease that easily becomes recurrent after surgery. Although butyrate suppresses inflammation, the role of butyrate in the regulation of inflammation in the upper respiratory tract remains unclear. We investigated the effect of butyrate on ECRS inflammation. Nasal administration of a complex antigen and butyrate to mice suppressed type 2 inflammation in butyrate-treated mice. Human ILC2, Th2 cells, and CD19-positive B cells also showed suppression of type 2 inflammation when treated with butyrate in addition to inflammatory cytokines. Blood samples and polyps from patients with ECRS also showed similar inhibition of inflammatory cytokine production. These results indicate that butyric acid may be effective in suppressing type 2 inflammation in ECRS patients.

Free Research Field

耳鼻咽喉科

Academic Significance and Societal Importance of the Research Achievements

好酸球性副鼻腔炎の治療法として手術や高額な生物学的製剤、また長期的なステロイド投与が必要となる。手術や生物学的製剤は社会的、金銭的な負担があり、ステロイドはさらに身体的な合併症を生じさせる可能性がある。酪酸を含めた短鎖脂肪酸は元来生体内の細菌叢で産生されるので副作用が少なく、この研究で好酸球性副鼻腔炎の新しい治療戦略を検討し患者の負担を減らすことをができる意義がある。