The Effects of Yeast Protein on Gut Microbiota in Mice When Compared with Soybean Protein and Whey Protein Isolates

Different protein sources can impact gut microbiota composition and abundance, and also participate in health regulation. In this study, mice were gavaged with yeast protein (YP), soybean protein isolate (SPI), and whey protein isolate (WPI) for 28 days. Body weights showed similar patterns across different protein administration groups. The ileum in YP-supplemented mice exhibited good morphology, and tight-junction (TJ) proteins were slightly upregulated. Immunoglobulin (Ig)A, IgM, and IgG levels in the ileum of different protein groups were significantly increased (p < 0.05). Interleukin (IL)-10 levels were significantly increased, whereas IL-6 levels were significantly reduced in the YP group when compared with the control (C) (p < 0.05). Glutathione peroxidase (GSH-Px) levels in the ileum were significantly increased in the YP group (p < 0.05). These results indicate that YP potentially improved intestinal immunity and inflammatory profiles. The relative abundances of Parabacteroides, Prevotella, and Pseudobutyrivibrio in the YP group were more enriched when compared with the C and SPI groups, and Parabacteroides was significantly upregulated when compared with the WPI group (p < 0.05). Overall, the results indicate that YP upregulates the beneficial bacteria and improves ileal immunity and anti-inflammatory capabilities.