Coreopsis tinctoria improves energy metabolism in obese hyperglycemic mice.

Coreopsis tinctoria (CT) improves energy metabolism. However, the role of CT in alleviating obesity-induced hyperglycemia by targeting the liver remains unknown. Therefore, this article aims to explore the mechanism by which CT improves energy metabolism and resists hyperglycemia. The water and ethanol extracts of CT were administered to high-fat diet-induced (HFD) obese C57BL/6J mice at a dose of 4 g/kg.bw (low-dose water extract, WL; low-dose ethanol extract, EL) or 10 g/kg.bw (high-dose water extract, WH; high-dose ethanol extract, EH). Mice that consumed a maintenance diet (LFD) were included as blank controls. Network pharmacology, liquid chromatography-mass spectrometry (LC-MS), L02 cell cultivation, and liver transcriptomics were used to examine the mechanism and functional components of CT against obesity-induced hyperglycemia. The results indicated that WL significantly (p < 0.05) alleviated glucose intolerance and insulin resistance in obesity-induced hyperglycemia. Kaempferol is the main active compound of CT, which demonstrated significant (p < 0.05) anti-hyperglycemic effects in obese mice and L02 cells. Finally, kaempferol significantly (p < 0.05; fold change >1.2) shifted the genes involved in carbon metabolism, glycolysis/gluconeogenesis, and the mitogen-activated protein kinase (MAPK) pathways toward the trend of LFD, indicating that it exerts an anti-hyperglycemic effect through these molecular mechanisms. Overall, oral intake of CT lowers blood glucose and improves insulin sensitivity in mice with obesity-induced hyperglycemia. Kaempferol is the primary functional component of CT.

Oleuropein Supplementation Ameliorates Long-Course Diabetic Nephropathy and Diabetic Cardiomyopathy Induced by Advanced Stage of Type 2 Diabetes in db/db Mice.

Previous studies have reported the therapeutic effects of oleuropein (OP) consumption on the early stage of diabetic nephropathy and diabetic cardiomyopathy. However, the efficacy of OP on the long-course of these diabetes complications has not been investigated. Therefore, in this study, to investigate the relieving effects of OP intake on these diseases, and to explore the underlying mechanisms, db/db mice (17-week-old) were orally administrated with OP (200 mg/kg bodyweight) for 15 weeks. We found that OP reduced expansion of the glomerular mesangial matrix, renal inflammation, renal fibrosis, and renal apoptosis. Meanwhile, OP treatment exerted cardiac anti-fibrotic, anti-inflammatory, and anti-apoptosis effects. Notably, transcriptomic and bioinformatic analyses indicated 290 and 267 differentially expressed genes in the kidney and heart replying to OP treatment, respectively. For long-course diabetic nephropathy, OP supplementation significantly upregulated the cyclic guanosine monophosphate-dependent protein kinase (cGMP-PKG) signaling pathway. For long-course diabetic cardiomyopathy, p53 and cellular senescence signaling pathways were significantly downregulated in response to OP supplementation. Furthermore, OP treatment could significantly upregulate the transcriptional expression of the ATPase Na+/K+ transporting subunit alpha 3, which was enriched in the cGMP-PKG signaling pathway. In contrast, OP treatment could significantly downregulate the transcriptional expressions of cyclin-dependent kinase 1, G two S phase expressed protein 1, and cyclin B2, which were enriched in p53 and cellular senescence signal pathways; these genes were confirmed by qPCR validation. Overall, our findings demonstrate that OP ameliorated long-course diabetic nephropathy and cardiomyopathy in db/db mice and highlight the potential benefits of OP as a functional dietary supplement in diabetes complications treatment.

Unlocking the power of Lactoferrin: Exploring its role in early life and its preventive potential for adult chronic diseases.

Nutrition during the early postnatal period exerts a profound impact on both infant development and later-life health. Breast milk, which contains lactoferrin, a dynamic protein, plays a crucial role in the growth of various biological systems and in preventing numerous chronic diseases. Based on the relationship between early infant development and chronic diseases later in life, this paper presents a review of the effects of lactoferrin in early life on neonates intestinal tract, immune system, nervous system, adipocyte development, and early intestinal microflora establishment, as well as the preventive and potential mechanisms of early postnatal lactoferrin against adult allergy, inflammatory bowel disease, depression, cancer, and obesity. Furthermore, we summarized the application status of lactoferrin in the early postnatal period and suggested directions for future research.

Heat-Killed Saccharomyces boulardii Alleviates Dextran Sulfate Sodium-Induced Ulcerative Colitis by Restoring the Intestinal Barrier, Reducing Inflammation, and Modulating the Gut Microbiota.

Ulcerative colitis (UC) is a global intestinal disease, and conventional therapeutic drugs often fail to meet the needs of patients. There is an urgent need to find efficient and affordable novel biological therapies. Saccharomyces boulardii has been widely used in food and pharmaceutical research due to its anti-inflammatory properties and gut health benefits. However, there is still a relatively limited comparison and evaluation of different forms of S. boulardii treatment for UC. This study aimed to compare the therapeutic effects of S. boulardii, heat-killed S. boulardii, and S. boulardii ß-glucan on UC, to explore the potential of heat-killed S. boulardii as a new biological therapy. The results demonstrate that all three treatments were able to restore body weight, reduce the disease activity index (DAI), inhibit splenomegaly, shorten colon length, and alleviate histopathological damage to colonic epithelial tissues in DSS-induced colitis mice. The oral administration of S. boulardii, heat-killed S. boulardii, and S. boulardii ß-glucan also increased the levels of tight junction proteins (Occludin and ZO-1), decreased the levels of pro-inflammatory cytokines (TNF-α, IL-1ß, and IL-6) in the serum, and suppressed the expressions of TNF-α, IL-1ß, and IL-6 mRNA in the colon. In particular, in terms of gut microbiota, S. boulardii, heat-killed S. boulardii, and S. boulardii ß-glucan exhibited varying degrees of modulation on DSS-induced dysbiosis. Among them, heat-killed S. boulardii maximally restored the composition, structure, and functionality of the intestinal microbiota to normal levels. In conclusion, heat-killed S. boulardii showed greater advantages over S. boulardii and S. boulardii ß-glucan in the treatment of intestinal diseases, and it holds promise as an effective novel biological therapy for UC. This study is of great importance in improving the quality of life for UC patients and reducing the burden of the disease.

Differential effects of four laboratory animal control diets on gut microbiota in mice.

BACKGROUND: The gut microbiota is intricate and susceptible to multiple factors, with diet being a major contributor. The present study aimed to investigate the impact of four commonly used laboratory animal control diets, namely Keao Xieli's maintenance diet (KX), HFK's 1025 (HF), Research Diets' D12450B (RD), and Lab Diet's 5CC4 (LD), on the gut microbiota of mice. RESULTS: A total of 40 mice were randomly assigned to four groups, and each group was fed one of the four diets for a duration of 8 weeks. The assessment of gut microbiota was conducted using 16S rRNA sequencing both at the beginning of the study (week 0) and the end (week 8), which served as the baseline and endpoint samples, respectively. Following the 8-week feeding period, no significant differences were observed in physiological parameters, including body weight, visceral weight, and blood biochemical indices, across the four groups. Nonetheless, relative to the baseline, discernible alterations in the gut microbiota were observed in all groups, encompassing shifts in beta-diversity, hierarchical clustering, and key genera. Among the four diets, HF diet exhibited a significant influence on alpha-diversity, RD diet brought about notable changes in microbial composition at the phylum level, and LD diet demonstrated an interconnected co-occurrence network. Mantel analysis indicated no significant correlation between physiological parameters and gut microbiota in the four groups. CONCLUSION: Overall, our study demonstrated that the four control diets had a minimal impact on physiological parameters, while exerting a distinct influence on the gut microbiota after 8 weeks. © 2024 Society of Chemical Industry.

Revitalizing Photoaging Skin through Eugenol in UVB-Exposed Hairless Mice: Mechanistic Insights from Integrated Multi-Omics.

Chronic ultraviolet (UV) exposure causes photoaging, which is primarily responsible for skin damage. Nutritional intervention is a viable strategy for preventing and treating skin photoaging. Eugenol (EU) presents anti-inflammatory and antioxidant properties, promotes wound healing, and provides contact dermatitis relief. This study explored the ability of EU to mitigate skin photoaging caused by UVB exposure in vitro and in vivo. EU alleviated UVB-induced skin photodamage in skin cells, including oxidative stress damage and extracellular matrix (ECM) decline. Dietary EU alleviated skin photoaging by promoting skin barrier repair, facilitating skin tissue regeneration, and modulating the skin microenvironment in photoaged mice. The transcriptome sequencing results revealed that EU changed the skin gene expression profiles. Subsequent pathway enrichment analyses indicated that EU might reverse the pivotal ECM-receptor interaction and cytokine-cytokine receptor interaction signaling pathways. Furthermore, EU alleviated the intestinal dysbiosis induced by chronic UVB exposure. Spearman analysis results further revealed the close connection between gut microbiota and skin photoaging. Considering the near-inevitable UVB exposure in modern living, the findings showed that the EU effectively reverted skin photoaging, offering a potential strategy for addressing extrinsic skin aging.

Dietary Isoeugenol Supplementation Attenuates Chronic UVB-Induced Skin Photoaging and Modulates Gut Microbiota in Mice.

Photoaging, the primary cause of skin aging damage, results from chronic ultraviolet (UV) exposure, leading to dryness and wrinkle formation. Nutritional intervention has emerged as a practical approach for preventing and addressing the effect of skin photoaging. The primary aromatic compound isolated from clove oil, isoeugenol (IE), has antibacterial, anti-inflammatory, and antioxidant qualities that work to effectively restrict skin cancer cell proliferation. This investigation delved into the advantages of IE in alleviating skin photoaging using UVB-irradiated skin fibroblasts and female SKH-1 hairless mouse models. IE alleviated UVB-induced photodamage in Hs68 dermal fibroblasts by inhibiting matrix metalloproteinase secretion and promoting extracellular matrix synthesis. In photoaged mice, dietary IE reduced wrinkles, relieved skin dryness, inhibited epidermal thickening, and prevented collagen loss. Additionally, the intestinal dysbiosis caused by prolonged UVB exposure was reduced with an IE intervention. The results of Spearman's analysis showed a strong correlation between skin photoaging and gut microbiota. Given the almost unavoidable UVB exposure in contemporary living, this research demonstrated the efficacy of dietary IE in reversing skin photoaging, presenting a promising approach to tackle concerns related to extrinsic skin aging.

Dietary supplementation with α-ionone alleviates chronic UVB exposure-induced skin photoaging in mice.

Photoaging is widely regarded as the most significant contributor to skin aging damage. It is triggered by prolonged exposure to ultraviolet (UV) light and typically manifests as dryness and the formation of wrinkles. Nutritional intervention is a viable strategy for preventing and treating skin photoaging. In previous studies, we demonstrated that α-ionone had ameliorating effects on photoaging in both epidermal keratinocytes and dermal fibroblasts. Here, we investigated the potential anti-photoaging effects of dietary α-ionone using a UVB-irradiated male C57BL/6N mouse model. Our findings provided compelling evidence that dietary α-ionone alleviates wrinkle formation, skin dryness, and epidermal thickening in chronic UVB-exposed mice. α-Ionone accumulated in mouse skin after 14 weeks of dietary intake of α-ionone. α-Ionone increased collagen density and boosted the expression of collagen genes, while attenuating the UVB-induced increase of matrix metalloproteinase genes in the skin tissues. Furthermore, α-ionone suppressed the expression of senescence-associated secretory phenotypes and reduced the expression of the senescence marker p21 and DNA damage marker p53 in the skin of UVB-irradiated mice. Transcriptome sequencing results showed that α-ionone modifies gene expression profiles of skin. Multiple pathway enrichment analyses on both the differential genes and the entire genes revealed that α-ionone significantly affects multiple physiological processes and signaling pathways associated with skin health and diseases, of which the p53 signaling pathway may be the key signaling pathway. Taken together, our findings reveal that dietary α-ionone intervention holds promise in reducing the risks of skin photoaging, offering a potential strategy to address skin aging concerns.

Artemether Attenuates Gut Barrier Dysfunction and Intestinal Flora Imbalance in High-Fat and High-Fructose Diet-Fed Mice.

Intestinal inflammation is a key determinant of intestinal and systemic health, and when our intestines are damaged, there is disruption of the intestinal barrier, which in turn induces a systemic inflammatory response. However, the etiology and pathogenesis of inflammatory diseases of the intestine are still not fully understood. Artemether (ART), one of the artemisinin derivatives, has been widely used to treat malaria. Nevertheless, the effect of ART on intestinal inflammation remains unclear. The present study intended to elucidate the potential mechanism of ART in diet-induced intestinal injury. A high-fat and high-fructose (HFHF) diet-induced mouse model of intestinal injury was constructed, and the mice were treated with ART to examine their role in intestinal injury. RT-qPCR, Western blotting, immunohistochemical staining, and 16S rRNA gene sequencing were used to investigate the anti-intestinal inflammation effect and mechanism of ART. The results indicated that ART intervention may significantly ameliorate the intestinal flora imbalance caused by the HFHF diet and alleviate intestinal barrier function disorders and inflammatory responses by raising the expression of tight junction proteins ZO-1 and occludin and decreasing the expression of pro-inflammatory factors TNF-α and IL-1ß. Moreover, ART intervention restrained HFHF-induced activation of the TLR4/NF-κB p65 pathway in colon tissue, which may be concerned with the potential protective effect of ART on intestinal inflammation. ART might provide new insights into further explaining the mechanism of action of other metabolic diseases caused by intestinal disorders.

Lactoferrin deficiency during lactation increases the risk of depressive-like behavior in adult mice.

BACKGROUND: Lactoferrin is an active protein in breast milk that plays an important role in the growth and development of infants and is implicated as a neuroprotective agent. The incidence of depression is currently increasing, and it is unclear whether the lack of lactoferrin during lactation affects the incidence of depressive-like behavior in adulthood. RESULTS: Lack of lactoferrin feeding during lactation affected the barrier and innate immune functions of the intestine, disrupted the intestinal microflora, and led to neuroimmune dysfunction and neurodevelopmental delay in the hippocampus. When exposed to external stimulation, adult lactoferrin feeding-deficient mice presented with worse depression-like symptoms; the mechanisms involved were activation of the LPS-TLR4 signalling pathway in the intestine and hippocampus, reduced BDNF-CREB signaling pathway in hippocampus, increased abundance of depression-related bacteria, and decreased abundance of beneficial bacteria. CONCLUSIONS: Overall, our findings reveal that lactoferrin feeding deficient during lactation can increase the risk of depressive-like behavior in adults. The mechanism is related to the regulatory effect of lactoferrin on the development of the "microbial-intestinal-brain" axis.

Recent Advances in Personal Glucose Meter-Based Biosensors for Food Safety Hazard Detection.

Food safety has emerged as a significant concern for global public health and sustainable development. The development of analytical tools capable of rapidly, conveniently, and sensitively detecting food safety hazards is imperative. Over the past few decades, personal glucose meters (PGMs), characterized by their rapid response, low cost, and high degree of commercialization, have served as portable signal output devices extensively utilized in the construction of biosensors. This paper provides a comprehensive overview of the mechanism underlying the construction of PGM-based biosensors, which consists of three fundamental components: recognition, signal transduction, and signal output. It also detailedly enumerates available recognition and signal transduction elements, and their modes of integration. Then, a multitude of instances is examined to present the latest advancements in the application of PGMs in food safety detection, including targets such as pathogenic bacteria, mycotoxins, agricultural and veterinary drug residues, heavy metal ions, and illegal additives. Finally, the challenges and prospects of PGM-based biosensors are highlighted, aiming to offer valuable references for the iterative refinement of detection techniques and provide a comprehensive framework and inspiration for further investigations.

Analysis of modified Holling-Tanner model with strong Allee effect.

In this paper, we study a predator-prey system, the modified Holling-Tanner model with strong Allee effect. The existence and stability of the non-negative equilibria are discussed first. Several kinds of bifurcation phenomena, which the model may undergo, such as saddle-node bifurcation, Hopf bifurcation, and Bogdanov-Takens bifurcation, are studied second. Bifurcation diagram for Bogdanov-Takens bifurcation of codimension 2 is given. Then, possible dynamical behaviors of this model are illustrated by numerical simulations. This paper appears to be the first study of the modified Holling-Tanner model that includes the influence of a strong Allee effect.

Recent Advances in Nanozyme-Mediated Strategies for Pathogen Detection and Control.

Pathogen detection and control have long presented formidable challenges in the domains of medicine and public health. This review paper underscores the potential of nanozymes as emerging bio-mimetic enzymes that hold promise in effectively tackling these challenges. The key features and advantages of nanozymes are introduced, encompassing their comparable catalytic activity to natural enzymes, enhanced stability and reliability, cost effectiveness, and straightforward preparation methods. Subsequently, the paper delves into the detailed utilization of nanozymes for pathogen detection. This includes their application as biosensors, facilitating rapid and sensitive identification of diverse pathogens, including bacteria, viruses, and plasmodium. Furthermore, the paper explores strategies employing nanozymes for pathogen control, such as the regulation of reactive oxygen species (ROS), HOBr/Cl regulation, and clearance of extracellular DNA to impede pathogen growth and transmission. The review underscores the vast potential of nanozymes in pathogen detection and control through numerous specific examples and case studies. The authors highlight the efficiency, rapidity, and specificity of pathogen detection achieved with nanozymes, employing various strategies. They also demonstrate the feasibility of nanozymes in hindering pathogen growth and transmission. These innovative approaches employing nanozymes are projected to provide novel options for early disease diagnoses, treatment, and prevention. Through a comprehensive discourse on the characteristics and advantages of nanozymes, as well as diverse application approaches, this paper serves as a crucial reference and guide for further research and development in nanozyme technology. The expectation is that such advancements will significantly contribute to enhancing disease control measures and improving public health outcomes.

Acid-resistant enzymes: the acquisition strategies and applications.

Enzymes have promising applications in chemicals, food, pharmaceuticals, and other variety products because of their high efficiency, specificity, and environmentally friendly properties. However, due to the complexity of raw materials, pH, temperature, solvents, etc., the application range of enzymes is greatly limited in the industry. Protein engineering and enzyme immobilization are classical strategies to overcome the limitations of industrial applications. Although the pH tendency of enzymes has been extensively researched, the mechanism underlying enzyme acid resistance is unclear, and a less practical strategy for altering the pH propensity of enzymes has been suggested. This review proposes that the optimum pH of enzyme is determined by the pKa values of active center ionizable amino acid residues. Three levels of acquiring acid-resistant enzymes are summarized: mining from extreme environments and enzyme databases, modification with protein engineering and enzyme microenvironment engineering, and de novo synthesis. The industrial applications of acid-resistant enzymes in chemicals, food, and pharmaceuticals are also summarized. KEY POINTS: • The mechanism of enzyme acid resistance is fundamentally determined. • The three aspects of the method for acquiring acid-resistant enzymes are summarized. • Computer-aided strategies and artificial intelligence are used to obtain acid-resistant enzymes.

Diallyl trisulfide ameliorates bone loss and alters specific gut microbiota and serum metabolites in natural aging mice.

Aging is a major cause of bone loss and osteoporosis. Diallyl trisulfide (DATS), one of the main organic sulfides in garlic oil, has been shown to alleviate arthritis in mice. However, further research is still needed to determine how DATS affects bone formation and bone loss in aging mice. Here, we established a mouse model of natural aging for dietary DATS intervention. DATS treatment improved the bone microstructure, including the disorganized arrangement of bone trabeculae and promoted collagen synthesis, as confirmed by micro-CT and histological analyses. The abundance of beneficial bacteria for bone formation, such as Clostridiaceae and Erysipelotrichaceae, and the microbial diversity and community richness were all altered by DATS, according to 16S rRNA sequencing data. 14 potential biomarkers and 9 important metabolic pathways were examined using serum metabolomics analysis. Additionally, there has been a significant reduction in sphingosine, which is directly associated with bone metabolism. The level of sphingosine and relative abundance of Clostridium were found to be negatively correlated by correlation analysis, indicating that bacteria may regulate bone reconstruction via influencing metabolites. Furthermore, Runx2 and ß-catenin gene expression levels increased in bones, which may be related to the ameliorative mechanism of DATS. Our results suggested that DATS may prevent age-related bone loss by upregulating osteogenic gene expression through altering gut microbes and serum metabolism.

Ultra-high-pressure passivation of soybean agglutinin and safety evaluations.

Soybean agglutinin (SBA) is a heat-sensitive anti-nutritional factor (ANF). It affects nutrient absorption and causes organism poisoning. This study explored the SBA passivation ability and mechanism by ultra-high pressure (HHP), a non-thermal food processing technology. The results indicated that more than 500 MPa HHP treatment reduced the SBA activity by destroying its secondary and tertiary structures. Also, the cell and animal experiments showed that HHP treatment reduced the cytotoxicity of SBA, improved the mice's body weight, and alleviated liver, kidney, and digestive tract damage in Vivo. These results demonstrated that HHP had a high passivation efficiency against the SBA, thereby HHP promoting the safety of soybean products. This study provided supporting evidence for ultra-high-pressure treatment applications in soybean processing.

Multifunctional rolling circle transcription-based nanomaterials for advanced drug delivery.

As the up-and-comer in the development of RNA nanotechnology, RNA nanomaterials based on functionalized rolling circle transcription (RCT) have become promising carriers for drug production and delivery. This is due to RCT technology can self-produce polyvalent tandem nucleic acid prodrugs for intervention in intracellular gene expression and protein production. RNA component strands participating in de novo assembly enable RCT-based nanomaterials to exhibit good mechanical properties, biostability, and biocompatibility as delivery carriers. The biostability makes it to suitable for thermodynamically/kinetically favorable assembly, enzyme resistance and efficient expression in vivo. Controllable RCT system combined with polymers enables customizable and adjustable size, shape, structure, and stoichiometry of RNA building materials, which provide groundwork for the delivery of advanced drugs. Here, we review the assembly strategies and the dynamic regulation of RCT-based nanomaterials, summarize its functional properties referring to the bottom-up design philosophy, and describe its advancements in tumor gene therapy, synergistic chemotherapy, and immunotherapy. Last, we elaborate on the unique and practical value of RCT-based nanomaterials, namely "self-production and self-sale", and their potential challenges in nanotechnology, material science and biomedicine.

Aptamer functionalized nucleic acid nano drug for targeted synergistic therapy for colon cancer.

Due to its complicated pathophysiology, propensity for metastasis, and poor prognosis, colon cancer is challenging to treat and must be managed with a combination of therapy. Using rolling circle transcription (RCT), this work created a nanosponge therapeutic medication system (AS1411@antimiR-21@Dox). Using the AS1411 aptamer, this approach accomplished targeted delivery to cancer cells. Furthermore, analysis of cell viability, cell apoptosis, cell cycle arrest, reactive oxygen species (ROS) content, and mitochondrial membrane potential (MMP) levels revealed that functional nucleic acid nanosponge drug (FND) can kill cancer cells. Moreover, transcriptomics uncovered a putative mechanism for the FND anti-tumor effect. These pathways, which included mitotic metaphase and anaphase as well as the SMAC-mediated dissociation of the IAP: caspase complexes, were principally linked to the cell cycle and cell death. In conclusion, by triggering cell cycle arrest and apoptosis, the nano-synergistic therapeutic system allowed for the intelligent and effective targeted administration of RNA and chemotherapeutic medicines for colon cancer treatment. The system allowed for payload efficiency while being customizable, targeted, reliable, stable, and affordable.

Toxicity and Impact of Silica Nanoparticles on the Configuration of Gut Microbiota in Immunodeficient Mice.

Nanoparticles (NPs), having exceptional physicochemical and electrical characteristics with lower toxicity, have evolved as dynamic drug delivery carriers in living organisms. Potentially, the intragastric gavage of silica nanoparticles (SiNPs) affects gut microbiota profiles in immunodeficient mice. In this study, the impact of SiNPs of variable size and dosage was investigated in cyclophosphamide (Cy)-induced immunodeficient mice, specifically on their immune functions and gut microbiota, through physicochemical and metagenomic analysis. SiNPs of different sizes and doses were gavaged to Cy-induced immunodeficient mice for 12 days at an interval of 24 h to investigate their effects on immunological functions and the gut microbiome of mice. Our results showed that SiNPs had no significant toxicological effects on the cellular and hematological activities of immunodeficient mice. Furthermore, after the administration of different levels of SiNPs, no immune dysfunction was found in the immunosuppressed mice groups. However, gut-microbial studies and comparisons of characteristic bacterial diversity and compositions demonstrated that SiNPs significantly affect the abundance of different bacterial communities. LEfSe analysis revealed that SiNPs significantly increased the abundance of Lactobacillus, Sphingomonas, Sutterella, Akkermansia, and Prevotella, and potentially reduced Ruminococcus and Allobaculum. Thus, SiNPs significantly regulate and modify the configuration of the gut microbiota in immunodeficient mice. These dynamic variations in the intestinal bacterial community, abundance, and diversity provide new insight into the regulation and administration of silica-based NPs. This would be helpful for the further demonstration of the mechanism of action and prediction of the potential effects of SiNPs.

Construction of a food-grade gene editing system based on CRISPR-Cas9 and its application in Lactococcus lactis NZ9000.

Clustered regularly interspaced short palindromic repeats-associated protein 9 (CRISPR/Cas9) system has been widely used in gene editing of various organisms. However, food-grade gene editing systems in lactic acid bacteria are still preliminary. Red/ET-dependent homologous recombination or CRISPR-based systems have been developed to gene editing in Lactococcus lactis, but these methods are overall inefficient. In the present study, a recombinant system based on CRISPR/Cas9 technology combined with Red/ET was developed using the plasmid pMG36e derived from Lactococcus lactis. Then, the developed recombinant system was applied to Lactococcus lactis. Knockout efficiency was significantly higher using the developed system (91%). In addition, this system showed the potential to be used as a high-throughput method for hierarchical screening. Finally, a gene-edited strain was obtained, and no antibiotics or exogenous genes were introduced using the developed gene editing system. Thus, the efficient system in lactic acid bacteria was constructed and optimized.