The purpose of the present invention is to provide a means whereby a physical strength improving effect and/or an anti-fatigue effect can be achieved. A composition to be used for improving physical strength and/or fatigue resistance, said composition comprising Bacteroides uniformis or a processed product thereof.本發明之目的在於提供一種能發揮體力提升作用及抗疲勞作用中一種以上的手段。一種組成物,含有單形擬桿菌或其處理物,用於提升體力及疲勞耐性中之一種以上。