The present invention pertains to a proliferation agent for increasing, or causing the proliferation of, beneficial intestinal bacteria (primarily, bifidobacteria and/or lactobacilli), the proliferation agent being characterized by containing, as an active ingredient, at least one cyclodipeptide compound of the same or different amino acids, and to a composition comprising a food, beverage or feed containing the proliferation agent.本發明係關於一種增殖劑、以及包含含有該增殖劑之飲食品或飼料之組合物,該增殖劑之特徵在於:其係用以使腸內有益菌(主要為雙叉桿菌及/或乳酸菌)增加或增殖者,且包含相同或不同之胺基酸之環二肽化合物之至少1種作為有效成分。
