Researchers have been making significant efforts to reveal the relationships between the gut microbiota and diabetes mellitus. As a special bacterial population in the intestinal tract, probiotics have unique advantages in delaying and controlling the occurrence of diabetes. In this article, the mechanisms of action and superiorities of probiotics in the prevention and control of diabetes are reviewed and some future development trends are also predicted.

Low molecular weight (LMW) levan was prepared from high molecular weight (HMW) levan produced by Paenibacillus bovis sp. nov BD3526 by the trichloroacetic acid (TCA) method with simultaneous removal of protein in HMW levan. The LMW levan was purified by anion-exchange chromatography. The molecular weight of the purified sample was determined by gel permeation chromatography (GPC). Its chemical structure was confirmed by nuclear magnetic resonance (NMR) and fourier transform infrared spectrometry (FT-IR). An atomic force microscope (AFM) was used to characterize its conformation in aqueous solution. To determine its potential impact on gut microbiota composition, in vitro fermentations using adult faecal inoculum treated with purified LMW levan and FOS were performed in a fermentation screening platform established by TNO (the Netherland). The results demonstrated the purified LMW levan could improve the growth of Bifidobacterium, especially B. infantis and B. longum. Furthermore, the levan was better than FOS in promoting the proliferation of B. infantis and B. longum.

The aim of this study was to explore the effects of parity and lactation stage on somatic cell counts in dairy herd improvement (DHI) milk samples and milk production loss in dairy cows. The results indicated that the somatic cell score (SCS) was increased with parity, and SCSs at different stages of lactation performance in different parities were different. SCS was increased with lactation time in first-parity dairy cows and SCS values were significantly different at three lactation stages (P < 0.05). The same trend was observed for SCS in second- and third-parity cows; SCS was higher at the early lactation stage than at the middle lactation stage, and its values at the two stages were significantly lower than that at the late lactation stage (P < 0.05). Milk production loss in dairy cows generally rose with parity and was higher at the early and late stages of lactation than at the middle stage.