The present invention relates to an agent for enhancingand stabilizing the activity of Bifidus factor, containing atleast one member selected from the group consisting of ascorbicacid, hyposulfurous acid and acetic anhydride as the effectiveingredient, and by preparing the agent singly or in combinationwith Bifidus factor as a food and drink type or as a compositionof pharmaceutical type, intestinal microflora can beamelio-rated. The agent can be used as a selective medium forassaying the number of bifidobacteria.
