The therapeutic effects of traditional Chinese medicine on insulin resistance in obese mice by modulating intestinal functions.

Introduction: Obesity, mainly caused by excessive accumulation of visceral fat, excessive fat metabolism will cause hormone secretion imbalance and inflammation and other diseases. is extremely detrimental to human health. Although many treatments are available for obesity, most treatments fail to exert a radical effect or are associated with several side effects. Traditional Chinese medicine (TCM) for regulating the intestinal flora, lipid content and inflammation is considered effective. Based on previous studies, Artemisia capillaris, Astragalus propinquus, Phellodendron amurense, Salvia miltiorrhiza, Poria cocos, and Anemarrhena asphodeloides were selected to prepare an innovative herbal formula. Methods: TCM was characterized by UHPLC-Q-Orbitrap-MS. The anti-inflammatory and lipid-lowering effects of the TCM formula prepared were evaluated in a high-fat diet-fed obese mouse model. The effects of the TCM formula on the intestinal flora were also investigated. Results: Weights and insulin resistance, as well as inflammation, decreased in the mice after treatment. At the same time, lipid metabolism increased after the mice were gavaged with the TCM formula for 2 weeks. The intestinal motility of the drug administration group was enhanced, with partial restoration of the intestinal flora. Conclusion: In summary, our innovative Chinese herbal formula significantly reduced weight, reduced intestinal inflammation, improved intestinal motility, and improved lipid metabolism in obese mice. Furthermore, the innovative formula effectively prevented relevant obesity-induced metastatic diseases in the mice.

T-antigen as a biomarker of progression-free survival in patients with glioblastoma.

OBJECTIVE: Glioblastoma (GBM) is one of the most aggressive brain tumors and often leads to poor outcomes. Studies have indicated that glycan levels are significantly correlated with the pathogenesis and development of cancers. However, whether glycan levels can serve as diagnostic or prognostic biomarkers in GBM remains unclear. METHODS: We obtained glycomic profiles in tissue and serum samples from 55 individuals with GBM using a well-established lectin biochip platform probing with 11 specific lectins. RESULTS: Our univariate analysis showed that 5 out of the 11 lectin-probed glycans (LPGs) were significantly higher in GBM tissues than in peri-tumoral tissues. After logistic regression analyses, only the Jacalin-probed T-antigen difference between the two groups remained significant (p = 0.037). Moreover, survival-related analyses showed that the level of Jacalin-probed T-antigen was significantly associated with the progression-free survival (p = 0.038) of patients. However, none of the LPG levels were correlated with the overall survival or the chemosensitivity to temozolomide therapy. The correlation coefficient analysis showed a moderate-to-strong correlation in the Jacalin-probed T-antigen levels between GBM tissues and serum samples, indicating its potential usefulness as a non-invasive GBM progression biomarker. INTERPRETATION: Glycomics analyses can be helpful in the prediction of GBM recurrences and may provide information useful for GBM glycan-based target therapies or vaccine development.

Palladium-Catalyzed Esterification of Aryl Fluorosulfates with Aryl Formates.

An efficient palladium-catalyzed carbonylation of aryl fluorosulfates with aryl formates for the facile synthesis of esters was developed. The cross-coupling reactions proceeded effectively in the presence of a palladium catalyst, phosphine ligand, and triethylamine in DMF to produce the corresponding esters in moderate to good yields. Of note, functionalities or substituents, such as nitro, cyano, methoxycarbonyl, trifluoromethyl, methylsulfonyl, trifluoromethoxy, fluoro, chloro, bromo, methyl, methoxy, N,N-dimethyl, and [1,3]dioxolyl, were well-tolerated in the reactions, which could be kept for late-stage modification. The reactions employing readily available and relatively robust aryl fluorosulfates as coupling electrophiles could potentially serve as an attractive alternative to traditional cross-couplings with the use of aryl halides and pseudohalides as substrates.

Scale-Aware Edge-Preserving Full Waveform Inversion with Diffusion Filter for Crosshole Sensor Arrays.

Full waveform inversion (FWI) is recognized as a leading data-fitting methodology, leveraging the detailed information contained in physical waveform data to construct accurate, high-resolution velocity models essential for crosshole surveys. Despite its effectiveness, FWI is often challenged by its sensitivity to data quality and inherent nonlinearity, which can lead to instability and the inadvertent incorporation of noise and extraneous data into inversion models. To address these challenges, we introduce the scale-aware edge-preserving FWI (SAEP-FWI) technique, which integrates a cutting-edge nonlinear anisotropic hybrid diffusion (NAHD) filter within the gradient computation process. This innovative filter effectively reduces noise while simultaneously enhancing critical small-scale structures and edges, significantly improving the fidelity and convergence of the FWI inversion results. The application of SAEP-FWI across a variety of experimental and authentic crosshole datasets clearly demonstrates its effectiveness in suppressing noise and preserving key scale-aware and edge-delineating features, ultimately leading to clear inversion outcomes. Comparative analyses with other FWI methods highlight the performance of our technique, showcasing its ability to produce images of notably higher quality. This improvement offers a robust solution that enhances the accuracy of subsurface imaging.

Association between ideal cardiovascular health and abnormal glucose metabolism in the elderly: evidence based on real-world data.

BACKGROUND: Limited information is available on the effect of ideal cardiovascular health (CVH) and abnormal glucose metabolism in elderly people. We aimed to analyze the prevalence of CVH behaviors, abnormal glucose metabolism, and their correlation in 65 and older people. METHODS: In this study, randomized cluster sampling, multivariate logistic regression, and mediating effects analysis were used. Recruiting was carried out between January 2020 and December 2020, and 1984 participants aged 65 years or older completed the study. RESULTS: The prevalence of abnormal glucose metabolism in this group was 26.7% (n = 529), among which the prevalence of impaired fasting glucose (IFG) was 9.5% (male vs. female: 8.7% vs 10.1%, P = 0.338), and the prevalence of type 2 diabetes mellitus (T2DM) was 19.0% (male vs. female: 17.8 vs. 19.8%, P = 0.256). The ideal CVH rate (number of ideal CVH metrics ≥ 5) was only 21.0%. The risk of IFG and T2DM decreased by 23% and 20% with each increase in one ideal CVH metrics, with OR (95%CI) of 0.77(0.65-0.92) and 0.80(0.71-0.90), respectively (P -trend < 0.001). TyG fully mediated the ideal CVH and the incidence of T2DM, and its mediating effect OR (95%CI) was 0.88(0.84-0.91). CONCLUSIONS: Each increase in an ideal CVH measure may effectively reduce the risk of abnormal glucose metabolism by more than 20%.

Detection of elevated levels of PINK1 in plasma from patients with idiopathic Parkinson's disease.

Backgrounds: Numerous lines of evidence support the intricate interplay between Parkinson's disease (PD) and the PINK1-dependent mitophagy process. This study aimed to evaluate differences in plasma PINK1 levels among idiopathic PD, PD syndromes (PDs), and healthy controls. Methods: A total of 354 participants were included, consisting of 197 PD patients, 50 PDs patients, and 107 healthy controls were divided into two cohorts, namely the modeling cohort (cohort 1) and the validated cohort (cohort 2). An enzyme-linked immunosorbent assay (ELISA)-based analysis was performed on PINK1 and α-synuclein oligomer (Asy-no). The utilization of the area under the curve (AUC) within the receiver-operating characteristic (ROC) curves served as a robust and comprehensive approach to evaluate and quantify the predictive efficacy of plasma biomarkers alone, as well as combined models, in distinguishing PD patients from controls. Results: PINK1 and Asy-no were elevated in the plasma of PD and PDs patients compared to healthy controls. The AUCs of PINK1 (0.771) and Asy-no (0.787) were supposed to be potentially eligible plasma biomarkers differentiating PD from controls but could not differentiate PD from PDs. Notably, the PINK + Asy-no + Clinical RBD model showed the highest performance in the modeling cohort and was comparable with the PINK1 + Clinical RBD in the validation cohort. Moreover, there is no significant correlation between PINK1 and UPDRS, MMSE, HAMD, HAMA, RBDQ-HK, and ADL scores. Conclusion: These findings suggest that elevated PINK1 in plasma holds the potential to serve as a non-invasive tool for distinguishing PD patients from controls. Moreover, the outcomes of our investigation lend support to the plausibility of implementing a feasible blood test in future clinical translation.

Involvement of Chemosensory Protein CrufCSP3 in Perception of the Host Location in a Parasitic Wasp Cotesia ruficrus.

Chemosensory proteins (CSPs) constitute a class of olfactory proteins localized in insect sensory organs that serve a crucial function in decoding external chemical stimuli. This study aims to elucidate the involvement of CrufCSP3 in olfactory perception within the context of Cotesia ruficrus, an indigenous endoparasitoid targeting the invasive pest Spodoptera frugiperda. Through fluorescence-competitive binding assays and site-directed mutagenesis, we pinpointed four amino acids as pivotal residues involved in the interaction between CrufCSP3 and five host-related compounds. Subsequent RNA interference experiments targeting CrufCSP3 unveiled a reduced sensitivity to specific host-related compounds and a decline in the parasitism rate of the FAW larvae. These findings unequivocally indicate the essential role of CrufCSP3 in the chemoreception process of C. ruficrus. Consequently, our study not only sheds light on the functional importance of CSPs in parasitic wasp behavior but also contributes to the development of eco-friendly and efficacious wasp behavior modifiers for effectively mitigating pest population surges.

Fully Floatable Mortise-and-Tenon Architecture for Synergistically Photo/Sono-Driven Evaporation Desalination and Plastic-Enabled Value-Added Co-Conversion of H2O and CO2.

Establishing an advanced ecosystem incorporating freshwater harvesting, plastic utilization, and clean fuel acquisition is profoundly significant. However, low-efficiency evaporation, single energy utilization, and catalyst leakage severely hinder sustainable development. Herein, a nanofiber-based mortise-and-tenon structural Janus aerogel (MTSJA) is strategically designed in the first attempt and supports Z-scheme catalysts. By harnessing of the upper hydrophilic layer with hydrophilic channels embedding into the hydrophobic bottom layer to achieve tailoring bottom wettability states. MTSJA is capable of a fully-floating function for lower heat loss, water supply, and high-efficiency solar-to-vapor conversion. Benefiting from the ultrasonic cavitation effect and high sensitivity of materials to mechanical forces, this is also the first demonstration of synergistic solar and ultrasound fields to power simultaneous evaporation desalination and waste plastics as reusable substrates generating fuel energy. The system enables persistent desalination with an exceptional evaporation rate of 3.1 kg m-2 h-1 and 82.3% efficiency (21 wt.% NaCl solution and 1 sun), and realizes H2, CO, and CH4 yields with 16.1, 9.5, and 3 µmol h-1 g-1, respectively. This strategy holds great potential for desalination and plastics value-added transformation toward clean energy and carbon neutrality.

Global diversity of airborne pathogenic bacteria and fungi from wastewater treatment plants.

Wastewater treatment plants (WWTPs) have been recognized as one of the major potential sources of the spread of airborne pathogenic microorganisms under the global pandemic of COVID-19. The differences in research regions, wastewater treatment processes, environmental conditions, and other aspects in the existing case studies have caused some confusion in the understanding of bioaerosol pollution characteristics. In this study, we integrated and analyzed data from field sampling and performed a systematic literature search to determine the abundance of airborne microorganisms in 13 countries and 37 cities across four continents (Asia, Europe, North America, and Africa). We analyzed the concentrations of bioaerosols, the core composition, global diversity, determinants, and potential risks of airborne pathogen communities in WWTPs. Our findings showed that the culturable bioaerosol concentrations of global WWTPs are 102-105 CFU/m3. Three core bacterial pathogens, namely Bacillus, Acinetobacter, and Pseudomonas, as well as two core fungal pathogens, Cladosporium and Aspergillus, were identified in the air across global WWTPs. WWTPs have unique core pathogenic communities and distinct continental divergence. The sources of airborne microorganisms (wastewater) and environmental variables (relative humidity and air contaminants) have impacts on the distribution of airborne pathogens. Potential health risks are associated with the core airborne pathogens in WWTPs. Our study showed the specificity, multifactorial influences, and potential pathogenicity of airborne pathogenic communities in WWTPs. Our findings can improve the understanding of the global diversity and biogeography of airborne pathogens in WWTPs, guiding risk assessment and control strategies for such pathogens. Furthermore, they provide a theoretical basis for safeguarding the health of WWTP workers and ensuring regional ecological security.

SIRT5 exacerbates eosinophilic chronic rhinosinusitis through promoting polarization of M2 macrophage.

BACKGROUND: Previous study implied that local M2 polarization of macrophage promoted mucosal edema and exacerbates Th2 type inflammation in chronic rhinosinusitis with nasal polyps (CRSwNP). However, the specific pathogenic role of M2 macrophages and the intrinsic regulators in the development of CRS remains elusive. OBJECTIVE: We thought to investigate the regulatory role of SIRT5 in the polarization of M2 macrophages and its potential contribution to the development of CRSwNP. METHODS: RT-qPCR and Western blot analyses were performed to examine the expression levels of SIRT5 and markers of M2 macrophages in sinonasal mucosa samples obtained from both CRS and control groups. Wild-type and Sirt5 knockout mice were used to establish nasal polyp model with Th2 inflammation and investigate the effects of SIRT5 in macrophages on disease development. Furthermore, in vitro experiments were conducted to elucidate the regulatory role of SIRT5 in polarization of M2 macrophages. RESULTS: Clinical investigations showed that SIRT5 was highly expressed and positively correlated with M2 macrophages markers in eosinophilic polyps. The expression of SIRT5 in M2 macrophages was found to contribute to the development of the disease, which was impaired in Sirt5 deficiency mice. Mechanistically, SIRT5 was shown to enhance the alternative polarization of macrophages through promoting glutaminolysis. CONCLUSIONS: SIRT5 plays a crucial role in promoting the development of CRSwNP by supporting the alternative polarization of macrophage and thus provides a potential target for CRSwNP interventions.

Synergistic cooperation between the ß-catenin and SF1 regulates progesterone synthesis in laying hen ovarian granulosa cells.

The development of ovarian follicles in poultry is a key factor affecting the performance of egg production. Ovarian follicle development is regulated via the Wnt/ß-catenin signaling pathway, and ß-catenin, encoded by CTNNB1, is a core component of this pathway. In this study, using ovary GCs from laying hens, we investigated the regulatory role of CTNNB1 in steroid synthesis. We found that CTNNB1 significantly regulates the expression of StAR and CYP11A1 (key genes related to progesterone synthesis) and the secretion of progesterone (P4). Furthermore, simultaneous overexpression of CTNNB1 and SF1 resulted in significantly higher levels of CYP11A1 and secretion of P4 than in cells overexpressing CTNNB1 or SF1 alone. We also found that in GCs overexpressing SF1, levels of CYP11A1 and secreted P4 were significantly greater than in controls. Silencing of CYP11A1 resulted in the inhibition of P4 secretion while overexpression of SF1 in CYP11A1-silenced cells restored P4 secretion to normal levels. Together, these results indicate that synergistic cooperation between the ß-catenin and SF1 regulates progesterone synthesis in laying hen ovarian hierarchical granulosa cells to promote CYP11A1 expression.

The masking phenomenon of microplastics additives on oxidative stress responses in freshwater food chains.

The variability and intrinsic mechanisms of oxidative stress induced by microplastics at different trophic levels in freshwater food chains are not well understood. To comprehensively assess the oxidative stress induced by polystyrene microplastics (PS-MPs) in freshwater food chains, the present study first quantified the oxidative stress induced by PS-MPs in organisms at different trophic levels using factorial experimental design and molecular dynamics methods. Then focuses on analyzing the variability of these responses across different trophic levels using mathematical statistical analysis. Notably, higher trophic level organisms exhibit diminished responses under PS-MPs exposure. Furthermore, the coexistence of multiple additives was found to mask these responses, with antioxidant plastic additives significantly influencing oxidative stress responses. Mechanism analysis using computational chemistry simulation determines that protein structure and amino acid characteristics are key factors driving PS-MPs induced oxidative stress variation in freshwater organisms at different nutrient levels. Increased hydrophobic additives induce protein helicalization and amino acid residue aggregation. This study systematically reveals the variability of biological oxidative stress response under different nutrient levels, emphasizing the pivotal role of chemical additives. Overall, this study offers crucial insights into PS-MPs' impact on oxidative stress responses in freshwater ecosystems, informing future environmental risk assessment.

Window of opportunity with PD1 blockade before chemoradiotherapy for an advanced stage clear cell carcinoma of the cervix.

Clear cell carcinoma is a rare and very aggressive subset of cervical cancer, with poor outcome if diagnosed at advanced stage. There are few data available on the optimal management of this histotype, and treatment recommendations that include surgery and chemoradiotherapy, are essentially based on those for squamous cell carcinoma. Here we report the case of a young patient newly diagnosed with advanced stage (FIGO IIB) clear cell carcinoma of the uterine cervix who received a window of opportunity one injection of nivolumab followed by standard chemoradiotherapy. She showed a persistent complete remission after 28 months of follow-up, but developed hypothyroidism, as a consequence of immunotherapy, and required lifelong thyroid hormone replacement.

A Novel Cocrystal of Daidzein with Piperazine to Optimize the Solubility, Permeability and Bioavailability of Daidzein.

It is well known that daidzein has various significant medicinal values and health benefits, such as anti-oxidant, anti-inflammatory, anti-cancer, anti-diabetic, cholesterol lowering, neuroprotective, cardioprotective and so on. To our disappointment, poor solubility, low permeability and inferior bioavailability seriously limit its clinical application and market development. To optimize the solubility, permeability and bioavailability of daidzein, the cocrystal of daidzein and piperazine was prepared through a scientific and reasonable design, which was thoroughly characterized by single-crystal X-ray diffraction, powder X-ray diffraction, Fourier transform infrared spectroscopy, differential scanning calorimetry and thermogravimetric analysis. Combining single-crystal X-ray diffraction analysis with theoretical calculation, detailed structural information on the cocrystal was clarified and validated. In addition, a series of evaluations on the pharmacogenetic properties of the cocrystal were investigated. The results indicated that the cocrystal of daidzein and piperazine possessed the favorable stability, increased solubility, improved permeability and optimized bioavailability of daidzein. Compared with the parent drug, the formation of cocrystal, respectively, resulted in 3.9-, 3.1-, 4.9- and 60.8-fold enhancement in the solubility in four different media, 4.8-fold elevation in the permeability and 3.2-fold in the bioavailability of daidzein. Targeting the pharmaceutical defects of daidzein, the surprising elevation in the solubility, permeability and bioavailability of daidzein was realized by a clever cocrystal strategy, which not only devoted assistance to the market development and clinical application of daidzein but also paved a new path to address the drug-forming defects of insoluble drugs.

Identifying serum metabolite biomarkers for autoimmune diseases: a two-sample mendelian randomization and meta-analysis.

Background: Extensive evidence suggests a link between alterations in serum metabolite composition and various autoimmune diseases (ADs). Nevertheless, the causal relationship underlying these correlations and their potential utility as dependable biomarkers for early AD detection remain uncertain. Objective: The objective of this study was to employ a two-sample Mendelian randomization (MR) approach to ascertain the causal relationship between serum metabolites and ADs. Additionally, a meta-analysis incorporating data from diverse samples was conducted to enhance the validation of this causal effect. Materials and methods: A two-sample MR analysis was performed to investigate the association between 486 human serum metabolites and six prevalent autoimmune diseases: systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), inflammatory bowel disease (IBD), dermatomyositis (DM), type 1 diabetes (T1D), and celiac disease (CeD). The inverse variance weighted (IVW) model was employed as the primary analytical technique for the two-sample MR analysis, aiming to identify blood metabolites linked with autoimmune diseases. Independent outcome samples were utilized for further validation of significant blood metabolites. Additional sensitivity analyses, including heterogeneity test, horizontal pleiotropy test, and retention rate analysis, were conducted. The results from these analyses were subsequently meta-integrated. Finally, metabolic pathway analysis was performed using the KEGG and Small Molecule Pathway Databases (SMPD). Results: Following the discovery and replication phases, eight metabolites were identified as causally associated with various autoimmune diseases, encompassing five lipid metabolism types: 1-oleoylglycerophosphoethanolamine, 1-arachidonoylglycerophosphoethanolamine, 1-myristoylglycerophosphocholine, arachidonate (20:4 n6), and glycerol. The meta-analysis indicated that three out of these eight metabolites exhibited a protective effect, while the remaining five were designated as pathogenic factors. The robustness of these associations was further confirmed through sensitivity analysis. Moreover, an investigation into metabolic pathways revealed a significant correlation between galactose metabolism and autoimmune diseases. Conclusion: This study revealed a causal relationship between lipid metabolites and ADs, providing novel insights into the mechanism of AD development mediated by serum metabolites and possible biomarkers for early diagnosis.

Identification and characterization of a PL35 GAGs lyase with 4-O-sulfated N-acetylgalactosamine (A-type)-rich structures producing property.

Glycosaminoglycan (GAG) lyases are important tools for investigating the structure of GAGs and preparing low-molecular-weight GAGs. The PL35 family, a recently established polysaccharide lyase family, should be further investigated. In this study, we discovered a new GAG lyase, CHa1, which belongs to the PL35 family. When expressed heterologously in Escherichia coli (BL21), CHa1 exhibited high expression levels and solubility. The optimal activity was observed in Tris-HCl buffer (pH 7.0) or sodium phosphate buffer (pH 8.0) at 30 °C. The specific activities towards HA, CSA, CSC, CSD, CSE, and HS were 3.81, 13.03, 36.47, 18.46, 6.46, and 0.50 U/mg protein, respectively. CHa1 digests substrate chains randomly that acting as an endolytic lyase and shows a significant preference for GlcA-containing structures, prefers larger oligosaccharides (≥UDP8) and can generate a series of oligosaccharides composed mainly of the A unit when digesting CSA. These oligosaccharides include ΔC-A, ΔC-A-A, ΔC-A-A-A, ΔC-A-A-A-A, and ΔC-A-A-A-A-A. The residues Tyr257 and His421 play crucial roles in the catalytic process, and Ser211, Asn212, Asn213, Trp214, Gln216, Lys360, Arg460 and Gln462 may participate in the binding process of CHa1. This study on CHa1 contributes to our understanding of the PL35 family and provides valuable tools for investigating the structure of GAGs.

Intraepithelial mast cells drive gasdermin C-mediated type 2 immunity.

A specialized population of mast cells residing within epithelial layers, currently known as intraepithelial mast cells (IEMCs), was originally observed over a century ago, yet their physiological functions have remained enigmatic. In this study, we unveil an unexpected and crucial role of IEMCs in driving gasdermin C-mediated type 2 immunity. During helminth infection, αEß7 integrin-positive IEMCs engaged in extensive intercellular crosstalk with neighboring intestinal epithelial cells (IECs). Through the action of IEMC-derived proteases, gasdermin C proteins intrinsic to the epithelial cells underwent cleavage, leading to the release of a critical type 2 cytokine, interleukin-33 (IL-33). Notably, mast cell deficiency abolished the gasdermin C-mediated immune cascade initiated by epithelium. These findings shed light on the functions of IEMCs, uncover a previously unrecognized phase of type 2 immunity involving mast cell-epithelial cell crosstalk, and advance our understanding of the cellular mechanisms underlying gasdermin C activation.

A Cost-Effective and Labor-Saving Method for Detecting Human Leukocyte Antigen B27 Status via Sequence-Encoded Fluorescence Amplification Assay.

Identification of human leukocyte antigen B27 (HLA-B27) by flow cytometry (FCM) has been widely applied in clinical practice for auxiliary diagnosis of ankylosing spondylitis (AS). However, FCM requires freshly prepared samples and relies on expensive equipment, reagents, and an experienced operator. To provide a cheaper and more convenient method for HLA-B27 detection, we proposed a new method termed sequence-encoded fluorescence amplification assay (SEFA), which specially recognized sequences of HLA-B27 gene (HLA-B∗27) covering current common subtypes in a single closed tube. SEFA could detect as low as 10 pg (equal to 3 copies) genomic DNA per reaction and distinguish HLA-B∗27 from other HLA-B alleles with highly similar sequences. A total of 288 clinical samples were tested by SEFA, including 181 patients with AS and 107 healthy controls. Compared with the detection results from FCM, two controversial samples of patients with AS were obtained and further confirmed to be consistent with SEFA by Sanger sequencing, indicating that our method was more accurate than FCM. Moreover, SEFA could detect HLA-B27 status by using supernatant from crude extract of 10-µL blood without commercial reagents. Overall, SEFA has the potential to be an alternative for HLA-B27 identification with the advantage of convenience and low cost, especially suitable for early diagnosis of AS in areas with limited medical resources.

A CTL - Lys immune function maintains insect metamorphosis by preventing gut bacterial dysbiosis and limiting opportunistic infections.

BACKGROUND: Gut bacteria are beneficial to the host, many of which must be passed on to host offspring. During metamorphosis, the midgut of holometabolous insects undergoes histolysis and remodeling, and thus risks losing gut bacteria. Strategies employed by holometabolous insects to minimize this risk are obscure. How gut bacteria affect host insects after entering the hemocoel and causing opportunistic infections remains largely elusive. RESULTS: We used holometabolous Helicoverpa armigera as a model and found low Lactobacillus load, high level of a C-type lectin (CTL) gene CD209 antigen-like protein 2 (CD209) and its downstream lysozyme 1 (Lys1) in the midgut of the wandering stage. CD209 or Lys1 depletion increased the load of midgut Lactobacillus, which further translocate to the hemocoel. In particular, CD209 or Lys1 depletion, injection of Lactobacillus plantarum, or translocation of midgut L. plantarum into the hemocoel suppressed 20-hydroxyecdysone (20E) signaling and delayed pupariation. Injection of L. plantarum decreased triacylglycerol and cholesterol storage, which may result in insufficient energy and 20E available for pupariation. Further, Lysine-type peptidoglycan, the major component of gram-positive bacterial cell wall, contributed to delayed pupariation and decreased levels of triacylglycerols, cholesterols, and 20E, in both H. armigera and Drosophila melanogaster. CONCLUSIONS: A mechanism by which (Lactobacillus-induced) opportunistic infections delay insect metamorphosis was found, namely by disturbing the homeostasis of lipid metabolism and reducing 20E production. Moreover, the immune function of CTL - Lys was characterized for insect metamorphosis by maintaining gut homeostasis and limiting the opportunistic infections.