The Relationship between Pretreatment Dietary Habits, Gut Bacteria, and PD-1 Inhibitor Therapy in Lung Cancer Patients

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K20201
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 59040:Nutrition science and health science-related
• Research Institution: Mukogawa Women's University
• Principal Investigator: Yano Megumu 武庫川女子大学, 栄養科学研究所, 嘱託研究員 (70411973)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Keywords: 腸内細菌 / 肺がん / 免疫チェックポイント / 栄養調査

Outline of Final Research Achievements

Immune checkpoint inhibitors, approved for lung cancer treatment, can be used in critically ill patients for whom treatment options are limited. They have also been reported to improve outcomes when combined with conventional treatment methods and are now used as standard treatment. However, although the therapeutic efficacy is high in successful cases, the proportion of ineffective cases is still high. The factors contributing to the therapeutic effect need to be identified.
In this study, the intestinal bacterial diversity of patients was investigated. The results showed that the gut microbiota diversity before treatment initiation was maintained during treatment in successful patients treated with immune checkpoint inhibitors. In addition, bacteria species related to the frequency of protein intake were found in the successful group based on a dietary survey before the treatment initiation.

Free Research Field

栄養学

Academic Significance and Societal Importance of the Research Achievements

本研究では、肺がん患者における免疫チェックポイント治療の効果が得られる奏功例の割合を増やすため、治療効果に関連する要因の特定を目的とし、治療開始前、治療中の腸内細菌、および治療開始前の食事に着目をした。結果、免疫チェックポイント治療開始前の腸内細菌多様性が、奏功群では無奏功群に比し、有意に高い多様性を示した。
また、治療中の多様性が、非奏功群では低下したが奏功群は維持されることが明らかとなった。栄養調査では、奏功群は無効群と比べたんぱく質摂取頻度が高く、特異的菌種が確認された。このことから、治療開始前の腸内細菌の多様性を高く維持することは治療効果の奏功例を高める1つの要因であることが示唆された。