Epidemiological studies have indicated that branched-chain amino acids (BCAAs) increased and gut microbiota disordered in type 2 diabetes mellitus (T2DM). This study aimed to investigate the mechanism of Lactiplantibacillus plantarum strain 84-3 (Lp84-3) combined with Staphylococcus aureus bacteriophage on ameliorating T2DM. Here we perform a case-control study and identify that Staphylococcus_phage was inversely correlated with fasting blood glucose (FBG). It revealed that Lp84-3 could inhibit the growth of S. aureus, and Lp84-3 contains BCAAs degradation enzymes in its genome. Furthermore, Lp84-3 alone or combined with S. aureus bacteriophage interventions can improve blood glucose, insulin resistance, triglycerides, interleukin-1β, tumor necrosis factor-α (TNF-α), BCAAs, and acetyllactate synthase (ALS) in db/db mice. Lp84-3 and S. aureus bacteriophage decreased S. aureus, Malacoplasma iowae, and Oscillibacter sp., and increased some beneficial such as L. plantarum and Muribaculaceae bacterium. Transcriptomic analyses revealed that Lp84-3 and S. aureus bacteriophage activated the PI3K/AKT/GLUT4 signaling pathway and upregulated key genes of Il22, Hgf, Col6a1, Gh, Itga10, Fgf23, and Prl involved in glucose metabolism in hypothalamus. Collectively, Lp84-3 and S. aureus bacteriophage alleviate T2DM by modulating gut microbiota and enhancing glucose metabolism in hypothalamus, supporting its potential use as a promising functional compound microecological agent for alleviating T2DM.

The worldwide distribution of Staphylococcus aureus across food types is an important food safety concern. This study aimed to estimate the prevalence of S. aureus in food products and its relationship with the occurrence and development of diabetes mellitus. A total of 55 articles were included. The pooled prevalence of S. aureus was 30.2%. The highest prevalence of S. aureus was observed in cereals, followed by meat and bean products, and the lowest in confectionery, egg products, and vegetables. The prevalence in dairy and seafood products was similar. Combinations of culture and molecular methods have been used for S. aureus detection. Furthermore, the prevalence of S. aureus in developed countries (Europe and North America) was higher than that in developing countries (Asia and Africa). In addition, the prevalence was higher in the provinces of Xinjiang and Shaanxi than that in Sichuan and Shandong in China, which may be due to the difference in climate and dietary habits. The results revealed that food type, bacterial detection methods, and location can influence the prevalence of S. aureus contamination. Resistance rates to preferred antibiotics against S. aureus were the highest for cephradine, polymyxin B, and penicillin at 82.9%, 82.0%, and 81.3%, respectively. In addition, 17 studies were system reviewed that the S. aureus infections are closely associated with the development of diabetes, and the treatment of probiotic, prebiotic, FMT, and bacteriophage can prevent and control S. aureus infections. This review emphasizes the high prevalence of S. aureus contamination in food, suggesting a potential diabetic infection risk and importance of observing principles of food safety and hygiene to reduce S. aureus.