Meropenem （MEM） is one of the important drugs for the treatment of severe infections， but the standard dose is often difficult to achieve an effective therapeutic concentration target. This article reviews the related studies on the population pharmacokinetics of MEM in patients with severe infection. It is found that the apparent volume of distribution （Vd） and clearance rate are the most important factors affecting the dose adjustment， and the factors affecting Vd include serum albumin， age， overall weight， shock status， and chest/abdomen/cerebrospinal fluid drainage. The main factors affecting the clearance rate were renal function， renal replacement therapy treatment mode and combination therapy. For adult patients with severe infections in China， MEM is recommended to be administered in an individualized manner based on glomerular filtration rate， with a dosage range of 500 to 1 500 mg given every 4 to 6 hours， and prolonged infusion is preferred. When the minimum inhibitory concentration （MIC） of the pathogenic bacteria reaches 64 mg/L， therapeutic drug monitoring is required. For therapeutic efficacy， it is essential to ensure that the trough concentration remains above the MIC； to prevent drug resistance， it should be maintained above 4×MIC. Regarding safety， it is recommended that the upper limit of the trough concentration be 32 mg/L， and blood sampling for monitoring can be conducted as early as after 1 to 2 doses of administration.

AIM: To study the effects of trigliptin succinate on gut microbiota of type 2 diabetic mice. METHODS: 16S rRNA high-throughput sequencing method was used to sequence the intestinal flora of mice in the healthy group, the T2DM group, the trigliptin succinate group and the sitagliptin phosphate group. QIME was used to filter the data, classify and annotate the species. Alpha diversity index and Beta diversity index of the samples were analyzed.The richness and diversity of bacteria in the four groups were compared. RESULTS: The gut microbiota structure of mice in the healthy group, the T2DM group, the trigliptin succinate group and the setagliptin phosphate group were significantly different. The results showed that the ratio of Firmicutes to Bacteroidetes was decreased compared with that in the healthy group. Cyanobacteria, Verrucomicrobia and Tenericutes had significant differences (P< 0.05). Potential biomarkers for T2DM group were Bacilli, Lactobacillales, Lactococcus and Streptococcaceae. Candidate biomarkers of trigliptin succinate group may be Bacteroidia, Bacteroidetes, Bacteroidales, Prevotella, Paraprevotellaceae, Parabacteroides, Porphyromonadaceae; The candidate biomarkers of sitagliptin phosphate group may be Lactobacillus, Lactobacillaceae and Helicobacter. CONCLUSION: The intestinal flora of mice in the trigliptin succinate group was significantly different from that in the healthy group and the T2DM group. Using trigliptin succinate to improve the intestinal flora of mice might achieve the hypoglycemic effect by improving the intestinal flora.