COVID-19 is mainly associated with respiratory distress syndrome, but a subset of patients often present gastrointestinal (GI) symptoms. Imbalances of gut microbiota have been previously linked to respiratory virus infection. Understanding how the gut–lung axis affects the progression of COVID-19 can provide a novel framework for therapies and management. In this study, we examined the gut microbiota of patients with COVID-19 (n = 47) and compared it to healthy controls (n = 19). Using shotgun metagenomic sequencing, we have identified four microorganisms unique in COVID-19 patients, namely Streptococcus thermophilus, Bacteroides oleiciplenus, Fusobacterium ulcerans, and Prevotella bivia. The abundances of Bacteroides stercoris, B. vulgatus, B. massiliensis, Bifidobacterium longum, Streptococcus thermophilus, Lachnospiraceae bacterium 5163FAA, Prevotella bivia, Erysipelotrichaceae bacterium 6145, and Erysipelotrichaceae bacterium 2244A were enriched in COVID-19 patients, whereas the abundances of Clostridium nexile, Streptococcus salivarius, Coprococcus catus, Eubacterium hallii, Enterobacter aerogenes, and Adlercreutzia equolifaciens were decreased (p < 0.05). The relative abundance of butyrate-producing Roseburia inulinivorans is evidently depleted in COVID-19 patients, while the relative abundances of Paraprevotella sp. and the probiotic Streptococcus thermophilus were increased. We further identified 30 KEGG orthology (KO) modules overrepresented, with 7 increasing and 23 decreasing modules. Notably, 15 optimal microbial markers were identified using the random forest model to have strong diagnostic potential in distinguishing COVID-19. Based on Spearman’s correlation, eight species were associated with eight clinical indices. Moreover, the increased abundance of Bacteroidetes and decreased abundance of Firmicutes were also found across clinical types of COVID-19. Our findings suggest that the alterations of gut microbiota in patients with COVID-19 may influence disease severity. Our COVID-19 classifier, which was cross-regionally verified, provides a proof of concept that a set of microbial species markers can distinguish the presence of COVID-19.

Purpose: As there have been few studies on the effects of the receptor for activated C kinase 1 (RACK1) on gastric cancer (GC), we aimed to explore such effects and the mechanism that may be involved. Patients and methods: Normal gastric epithelial cells and six GC cell lines were used to detect the mRNA expression of RACK1. Overexpressing RACK1 was transfected in HGC27 and MGC803 cells. The effects of overexpressing RACK1 on cell viability, migration, and invasion were determined by cell counting kit-8, wound scratch, and Transwell assay, respectively. The expressions of epithelial–mesenchymal transition (EMT) and Wnt/β-catenin signaling related genes were detected using quantitative real-time PCR or Western blot. Wnt pathway agonist LiCl was added into RACK1 overexpressing GC cells, and then cell viability, migration, and invasion were also detected. Results: RACK1 was downregulated in GC cell lines. Under the circumstance that overexpressing RACK1 was successfully transfected in the two lowest RACK1-expressing GC cells, significant inhibition of cell viability, migration, and invasion, promotion to the mRNA and protein expression of E-cadherin, as well as a decrease in the N-cadherin and Snail expressions could be observed. Overexpressing RACK1 also enhanced the protein level of phosphorylation-β-catenin/β-catenin and attenuated c-Jun protein expression. Additionally, LiCl could partially reverse the inhibitory effects of cell viability, migration and invasion by overexpressing RACK. Conclusion: We found RACK1 possibly inhibited epithelial–mesenchymal transition of GC cells through limitation of the Wnt/β-catenin pathway, thereby suppressing cell migration and invasion; RACK1 could also suppress cell growth.

Circular RNAs (circRNAs) are a new class of single-stranded RNAs that form a continuous loop with crucial role in regulation of gene expression. Because their circular conformation conforms numerous properties, circRNAs have been investigated recently to demonstrate their important role in the development and progression of various cancers. However, the function of circRNAs and their regulatory outcomes in cervical cancer (CC) have rarely been explored. In this study, the role and molecular mechanism of hsa_circ_0107593 in cervical cancer are demonstrated. Quantitative polymerase chain reaction (qRT-PCR) was used to determine the expression of hsa_circ_0107593 and three miRNAs (hsa-miR-20a-5p, 93-5p, and 106b-5p) in paired CC tissues (tumor tissue vs. adjacent normal cervical tissue), CC cell lines, and human normal cervical epithelial immortalized cell line. A series of functional experiments were conducted to assess the function of hsa_circ_0107593 in CC development. The Receiver Operating Characteristic (ROC) curve was plotted to estimate the diagnostic value of hsa_circ_0107593 in CC. The dual-luciferase reporter assay was used to explore the interaction between hsa_circ_0107593 and hsa-miR-20a-5p/93-5p/106b-5p. Bioinformatic analysis was conducted to predict the target mRNAs, pathways, and functional enrichment. The results revealed that hsa_circ_0107593 has low expression in CC tissues and CC cell lines. Moreover, negative correlations of hsa_circ_0107593 expression were found against tumor diameter, FIGO stage, and myometrial invasion. Also, hsa_circ_0107593 impedes CC cell proliferation, migration, and invasion. Based on ROC curve analysis, hsa_circ_0107593 could serve as a diagnostic biomarker. Its low expression may indicate increased patient’s risk to developing cervical cancer. Mechanistically, hsa_circ_0107593 serves as a sponge of hsa-miR-20a-5p, hsa-miR-93-5p, and hsa-miR-106b-5p. Collectively, our study implies that hsa_circ_0107593 has tumor-suppressing activity in CC by physically binding with hsa-miR-20a-5p, hsa-miR-93-5p, and hsa-miR-106b-5p.

Our study reveals an unprecedented role of β-catenin in enabling innate immune evasion in CRC.

Aims: Some probiotics used as food additives or food supplements had an anti-inflammatory effect. We tested the potential protective effects of probiotic Lacticaseibacillus rhamnosus Hao9 (Hao9) in mice with dextran sulphate sodium (DSS)-induced ulcerative colitis (UC) and determined whether these effects were related to the modulation of gut microbiota and amelioration of inflammation. Methods and Results: Ulcerative colitis mouse model was established by feeding mice with 2.5% (w/v) DSS in drinking water for 7 days. We analysed the disease activity index (DAI), colon length and histological changes in the colon. In addition, we investigated the effects of Hao9 (1 × 10 9 colony forming unit/day) and curcumin (CUR) (200 mg/kg/day) on gut microbiota and serum inflammatory cytokines. In this study, CUR was used as a positive control. The results showed that both Hao9 and CUR effectively reduced body mass loss and DAI, restored colon length, alleviated colonic pathological variations and reduced histological scores compared with the UC group. Hao9 reduced the serum concentrations of proinflammatory cytokines (tumour necrosis factor alpha, interleukin [IL]-6 and IL-1β) and increased the concentration of the anti-inflammatory cytokine IL-10. In addition, Hao9 promoted the growth of Faecalibaculum and Romboutsia in the gut and helped to maintain intestinal homeostasis. Conclusions: Hao9 had a protective effect against DSS-induced colitis, and the mechanisms underlying Hao9 may involve controlling inflammation and maintaining host micro-ecological balance. This study provided experimental evidence for the application of Hao9 in the treatment of ulcerative colitis and suggested that Hao9 may be a promising candidate as a dietary supplement against colitis. Significance and Impact of the Study: The comparison of probiotics and prebiotics in terms of therapeutic efficacy in UC helps us to understand their different patterns of regulation of intestinal microbiota.

This study was conducted to explore the therapeutic effect of the probiotic Bifidobacterium animalis subsp. lactis BLa80 on inflammatory bowel disease. A model of ulcerative colitis (UC) was induced in C57BL/6 mice by administering of 2.5% dextran sulphate sodium (DSS) for 8 days. After developing UC, some mice were treated via intragastric administration of BLa80 at a dose of 109 colony-forming units to assess the preventive effects of BLa80 on DSS-induced UC. Compared with non-treated UC model mice, BLa80-treated mice had reduced colon shortening and improvements in colonic tissue structure. Treatment with BLa80 also decreased the serum concentrations of the proinflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin (IL) 6 and IL-17 in mice. 16S rRNA gene sequencing revealed that BLa80 increased gut microbial diversity in mice and modulated UC-associated imbalances in the gut microbiota. BLa80 selectively promoted the growth of beneficial bacteria, including Romboutsia and Adlercreutzia, the abundances of which were negatively correlated with concentration of cellular inflammatory factors. In summary, the study results demonstrated that pretreatment with B. lactis BLa80 reduced intestinal inflammation and altered the gut microbiota, implying that BLa80 is a promising probiotic strain with potential therapeutic function in UC.

Objective To explore the application effect of the clinical basic integration teaching mode constructed by case studies and the MOOC platform in obstetrics and gynecology internship teaching in the face of public health emergencies. Methods One hundred ten clinical medical students of grade 2020 were selected as the experimental group, and 110 clinical medical students of grade 2021 were selected as the control group. The experimental group adopted the online teaching mode combined with case studies and the MOOC platform, while the control group adopted the offline traditional probation teaching method. Comprehensive test and questionnaire were used to evaluate and compare the teaching effect of the two groups of students. Results The experimental group was found to be superior to the control group in the quality assessment of complete medical record writing and the ability assessment of diagnosis and analysis of typical obstetrics and gynecology cases (P < 0. 05). However, the score of professional knowledge was lower than that of the control group (P < 0. 05). The results of questionnaire survey showed that the satisfaction of the experimental group in stimulating learning interest, enhancing problem solving ability, enhancing communication and clinical thinking ability, enhancing team cooperation awareness and independent innovation ability was higher than that of the control group (P < 0.01). The satisfaction of teacher-student interaction was also better (P < 0.05). However, in terms of strengthening theoretical understanding, the satisfaction of the experimental group was lower than that of the control group, but with no significant difference (P > 0.05). Conclusion During the epidemic period, we designed a new online teaching mode, which can be applied to the probation teaching of obstetrics and gynecology. In our study, compared with traditional offline teaching, the new online teaching mode could improve students’ ability of case writing and case analysis. However, more teaching practice is needed to complete this online teaching mode.

Yes-associated protein 1 (YAP1) is an important signaling pathway activator molecule. Studies have shown that it is involved in the occurrence of malignant tumors. This study identified a microRNA (miR/miRNA) targeting the 3′ untranslated region (3″ utr) of the YAP1 gene and evaluated its biological impact on human cervical cancer cells and related molecular mechanisms. qPCR and western blotting were used to detect the levels of miR-375 and YAP1 in HeLa cells. TargetScan software was used to identify the binding sites of YAP1 and miR-375. The MTT method was used to determine the viability of HeLa cells transfected with miR-375 mimic and YAP1 interference vector, the Transwell chamber experiment was used to detect the invasion of HeLa cells after transfection, the apoptosis of HeLa cells after transfection was detected by flow cytometry, and the western blotting was used to detect the epithelial mesenchymal transition (EMT) of HeLa cells after transfection. The expression of miR-375 in HeLa cells was significantly lower than that of normal control cervical cells, and the expression of YAP1 in HeLa cells was significantly higher than that of normal control cervical cells. TargetScan analysis showed that miR-375 was bound to the 3′ UTR of YAP1. qPCR and western blot analysis showed that transfection of miR-375 mimics inhibited YAP1 expression in HeLa cells. Transfection of miR-375 mimic and YAP1 interference vector inhibited HeLa cell invasion and EMT and promoted HeLa cell apoptosis. These findings indicate that miR-375 inhibits the malignant development of human cervical cancer cells by regulating the expression of YAP1.