OBJECTIVES: Recent evidence suggests that the gut may be a primary site of metformin action. However, studies on the effects of metformin on gut microbiota remain limited, and its impact on gut microbial metabolites such as short-/medium-chain fatty acids is unclear. This study aims to investigate the effects of metformin on gut microbiota, short-/medium-chain fatty acids, and associated metabolic benefits in high-fat diet rats. METHODS: Twenty-four Sprague-Dawley rats were randomly divided into 3 groups: 1) Normal diet group (ND group), fed standard chow; 2) high-fat diet group (HFD group), fed a high-fat diet; 3) high-fat diet + metformin treatment group (HFD+Met group), fed a high-fat diet for 8 weeks, followed by daily intragastric administration of metformin solution (150 mg/kg body weight) starting in week 9. At the end of the experiment, all rats were sacrificed, and serum, liver, and colonic contents were collected for assessment of glucose and lipid metabolism, liver pathology, gut microbiota composition, and the concentrations of short-/medium-chain fatty acids. RESULTS: Metformin significantly improved HFD-induced glucose and lipid metabolic disorders and liver injury. Compared with the HFD group, the HFD+Met group showed reduced abundance of Blautia, Romboutsia, Bilophila, and Bacteroides, while Lactobacillus abundance significantly increased (all P<0.05). Colonic contents of butyric acid, 2-methyl butyric acid, valeric acid, octanoic acid, and lauric acid were significantly elevated (all P<0.05), whereas acetic acid, isoheptanoic acid, and nonanoic acid levels were significantly decreased (all P<0.05). Spearman correlation analysis revealed that Lactobacillus abundance was negatively correlated with body weight gain and insulin resistance, while butyrate and valerate levels were negatively correlated with insulin resistance and liver injury (all P<0.05). CONCLUSIONS Metformin significantly increases the abundance of beneficial bacteria such as Lactobacillus and promotes the production of short-/medium-chain fatty acids including butyric, valeric, and lauric acid in the colonic contents of HFD rats, suggesting that metformin may regulate host metabolism through modulation of the gut microbiota.
Animals ; Metformin/pharmacology* ; Rats, Sprague-Dawley ; Diet, High-Fat/adverse effects* ; Rats ; Gastrointestinal Microbiome/drug effects* ; Male ; Fatty Acids, Volatile/metabolism* ; Fatty Acids/metabolism*

With the development of clinical related disciplines, the update and establishment of relevant standards/guidelines at home and abroad, GBZ 185-2006 Diagnostic Criteria for Occupational Medicamentose-like Dermatitis due to Trichloroethylene (hereinafter referred to as “GBZ 185-2006”) was unable to meet clinical needs. Therefore, the GBZ 185-2006 was revised based on the principles of evidence-based medicine, in accordance with relevant laws/regulations and relevant standards/guidelines in combination with review of research data on occupational medicamentose-like dermatitis due to trichloroethylene (OMDT) home and abroad, and the development of clinical practice and clinical related disciplines. The main modifications include: adding terms and definitions of OMDT, modifying the description of clinical manifestations of the diagnostic principles, adjusting the description of latency, deleting the diagnostic requirement of the incidence probability, adding the specific allergen patch test as the etiological diagnostic index, standardizing the application scope, operating procedure and precautions of the specific allergen patch test. In addition, the relevant content of “Basic Characteristics and Clinical Types of Skin Damage of Medicamentose-like Dermatitis due to Trichloroethylene” in Appendix A is improved, the treatment principles are revised, and the content of new progress in treatment, artificial liver application, are added. The revised GBZ 185-2024 Diagnostic Standard for Occupational Medicamentose-like Dermatitis due to Trichloroethylene is more scientific and practical, and can provide technical basis for the standardized diagnosis and treatment of OMDT in medical and health institutions.

Objective:To evaluate the effect of long non-coding RNA (lncRNA) nuclear enriched abundant transcript 1 (NEAT1) on the radiosensitivity in breast cancer cells by regulating the miR-149-5p/ glutamic pyruvic transaminase 2 (GPT2) axis.Methods:Real-time reverse transcription PCR (RT-qPCR) was used to detect NEAT1, miR-149-5p and glutamic pyruvic transaminase 2 (GPT2) mRNA levels in human breast cells MCF-10A, and human breast cancer cells MCF-7, MDA-MB-231 and MDA-MB-468, respectively. MCF-7 cells were divided into 0, 2, 4, 6 and 8 Gy irradiation groups. MCF-7 cells were divided into NEAT1 knockdown (si-NEAT1) group and control (si-NC) group, NEAT1 knockdown +miR-149-5p knockdown (si-NEAT1+anti-miR-149-5p) group and control (si-NEAT1+anti-miR-NC) group, NEAT1 knockdown + GPT2 overexpression (si-NEAT1+GPT2) group and control (si-NEAT1+NC) group. On the basis of the above grouping, irradiate each group of cells with 4 Gy radiation for 2 h, denoted as IR+si-NEAT1, IR+si-NC, IR+si-NEAT1+anti-miR-149-5p, IR+si-NEAT1+anti-miR-NC, IR+si-NEAT1+GPT2, IR+si-NEAT1+NC groups. Subsequently, MCF-7 cells were irradiated at a dose of 4 Gy and divided into the IR+si-NEAT1, IR+si-NC, IR+si-NEAT1+anti-miR-149-5p, IR+si-NEAT1+anti-miR-NC, IR+si-NEAT1+GPT2 and IR+si-NEAT1+NC groups. RT-qPCR was used to detect NEAT1, miR-149-5p, GPT2 mRNA levels in cells. Colony formation assay was used to detect cell radiosensitivity. CCK-8 assay was adopted to detect cell proliferation ability. The binding sites of NEAT1 and miR-149-5p were predicted by StarBase database. The binding sites of miR-149-5p and GPT2 were predicted by Targetscan database, and validated by dual luciferase assay. Single factor ANOVA was used for inter-group comparisons. LSD- t test was used for pairwise comparison. Results:Compared with MCF-10A cells, NEAT1 and GPT2 mRNA levels in cell lines were up-regulated, whereas miR-149-5p level was down-regulated (all P<0.05). Compared with the 0 Gy dose group, NEAT1 and GPT2 mRNA levels were down-regulated, while miR-149-5p levels were up-regulated in the 2, 4, 6, and 8 Gy dose groups (all P<0.05). Knockdown of NEAT1 expression or radiation alone could enhance cell radiosensitivity, and reduce cell proliferation ability (all P<0.05). Simultaneous radiation treatment with knockdown of NEAT1 expression could strengthen the above effects upon cells (all P<0.05). Knockdown of miR-149-5p expression or overexpression of GPT2 could partially reverse the aforementioned effects of knockdown of NEAT1 expression (all P<0.05). Conclusion:Knockdown of NEAT1 expression enhances breast cancer cell radiosensitivity, and reduces cell proliferation ability by regulating the miR-149-5p/GPT2 signal axis.

Objective:To investigate the effects of breast milk to total milk intake ratio during hospitalization on the duration of antibiotic therapy in preterm infants less than 34 weeks of gestation.Methods:Clinical data of preterm infants ( n=1 792) less than 34 gestational weeks were retrospectively collected in 16 hospitals of Jiangsu Province Neonatal-Perinatal Cooperation Network from January 1, 2019, to December 31, 2021. The days of therapy (DOT) were used to evaluate the duration of antibiotic administration. The median DOT was 15.0 d (7.0-27.0 d). The patients were divided into four groups based on the quartiles of DOT: Q 1 (DOT≤7.0 d), Q 2 (7.0 d27.0 d) groups. According to the breast milk intake ratio (breast milk intake to total milk intake during hospitalization×100%), they were also divided into four groups: very-low-ratio breastfeeding group (breast milk intake ratio≤25%), low-ratio breastfeeding group (25%75%). Univariate analysis ( Chi-square test and Kruskal-Wallis rank-sum test) was used to analyze the factors influencing DOT. Spearman correlation analysis and trend Chi-square test were used to explore the relationship between breast milk intake ratio and DOT. After using multiple imputations to address missing data, two models were constructed after adjusting for different factors, and multinomial logistic regression model was applied to evaluate the effects of the breast milk intake ratio on DOT. Finally, sensitivity analysis was conducted to assess the stability of the models. Results:(1) Of the 1 792 preterm infants, there were 507 (28.3%) in the Q 1 group, 422 (23.5%) in the Q 2 group, 438 (24.4%) in the Q 3 group and 425 (23.7%) in the Q 4 group. (2) The median values of DOT in the very-low-ratio, low-ratio, medium-ratio and high-ratio breastfeeding groups were 20.0 d (11.0-31.0 d), 20.0 d (11.0-32.0 d), 13.0 d (6.0-25.8 d) and 10.0 d (4.0-21.0 d), respectively. Compared with the very-low-ratio and low-ratio breastfeeding groups, the medium-ratio and high-ratio breastfeeding groups had shorter DOT (all P<0.05). (3) After adjusting for factors with P<0.1 (prenatal glucocorticoid exposure, antimicrobial use within 24 h before delivery, gestational age at delivery, birth weight, Apgar score≤7 at 1 min, neonatal respiratory distress syndrome, infectious pneumonia and early-onset neonatal sepsis) between the DOT quartile groups, it showed that medium-ratio and high-ratio breastfeeding were protective factors in contrast to very-low-ratio breastfeeding in the Q 2, Q 3 and Q 4 groups as compared with the Q 1 group [Q 2 group: OR=0.50 (95% CI: 0.30-0.85) and OR=0.36 (95% CI: 0.26-0.51); Q 3 group: OR=0.31 (95% CI: 0.18-0.55) and OR=0.20 (95% CI: 0.14-0.29); Q 4 group: OR=0.22 (95% CI: 0.12-0.42) and OR=0.17 (95% CI: 0.12-0.26)]. Conclusion:Breast milk intake accounting for over 50% of total milk intake has a positive impact on reducing DOT in premature infants requiring antibiotics, which suggests that breastfeeding should be actively encouraged.