Problem to be solved: to provide a novel and convenient intestinal environmental improvement composition for improving intestinal environment.Solution 3: an intestinal environmental improvement composition containing hydroxybutyric acid as an effective ingredient and improving intestinal environment.Diagram【課題】腸内環境を改善する新規かつ簡便な腸内環境改善組成物を提供する。【解決手段】3-ヒドロキシ酪酸を有効成分として含有し、腸内環境を改善する腸内環境改善組成物。【選択図】図1