Bifidobacteria possess inhibitory activity against dipeptidyl peptidase‐IV. (1st March 2016) - Zeng, Z.
Abstract: The incretin hormones are extremely rapidly metabolized by the ubiquitous enzyme dipeptidyl peptidase IV (DPP‐IV). Therefore, DPP‐IV inhibitors which can prolong the incretin effect are the newest and promising drugs for management of type 2 diabetes. In this study, we investigated whether Bifidobacteria colonizing the human gut possess DPP‐IV inhibitory activity. Cell‐free intracellular extracts of 13 Bifidobacterium strains isolated from breast‐fed infant faecal samples were prepared and screened for DPP‐IV inhibitory activity, and two Bifidobacterium strains— Bif. longum BBMN68 and Bif. lactis Bb12—were used as reference strains. Most of the strains showed varying levels of DPP‐IV inhibitory property (7–27%). Strains of Bifidobacterium adolescentis IF1‐11 and Bifidobacterium bifidum IF3‐211 showed the greatest DPP‐IV inhibitory activity (27 and 25%) as well as good in vitro probiotic properties. This initial finding suggested that new beneficial function of Bifidobacteria is strain‐dependent and the strains or their components may have the potential application for management of type 2 diabetes via inhibiting gastrointestinal DPP‐IV activity. Further investigations into the isolation and identification of the bioactive components of Bifidobacteria are warranted. Significance and Impact of the Study: Our results show that Bifidobacteria isolated from breast‐fed infants' faecal samples possess DPP‐IV inhibitory activity. Strains of Bifidobacterium bifidum IF3‐211 and Bifidobacterium adolescentis IF1‐11, which showed excellent DPP‐IV inhibitory properties as well as good in vitro probiotic properties, are expected to be beneficial for application as anti‐diabetic probiotics.