OBJECTIVE To investigate the neuroprotective effect and mechanism of eleutheroside B （ELB） on Parkinson’s disease （PD） model mice by regulating the IκB kinase β （IKKβ）/nuclear factor-κB （NF-κB） signaling pathway. METHODS Fifty mice were randomly divided into normal control group， model group， positive control group （selegiline hydrochloride， 10 mg/kg）， and ELB low-dose and high-dose groups （80， 160 mg/kg）， with 10 mice in each group. Each group was given relevant medicine or normal saline intragastrically for 14 consecutive days. Starting from the 10th day of administration， the model group and all administration groups were intraperitoneally injected with 1-methyl-4-phenyl-1，2，3，6-tetrahydropyridine （MPTP） 30 mg/kg， for five consecutive days to establish the chronic PD model. After the last administration for 24 h， six mice were randomly selected from each group to test their behavioral abilities； detect the levels of interleukin-1β （IL-1β）， IL-10， tumor necrosis factor-α （TNF-α） in brain tissue and their mRNA expressions were measured， and positive expression of tyrosine hydroxylase （TH）， protein expressions of TH， α -synuclein （ α -syn）， ionized calcium-binding adaptor molecule 1 （Iba-1）， as well as phosphorylation levels of IKKβ and NF-κB p65 proteins in the brain tissue were detected. The ultrastructure of neurons in substantia nigra was observed. RESULTS Compared with the model group， rotarod endurance time and climbing score of each administration group （except for the ELB low-dose group） were increased significantly （ P ＜0.05）， while the levels and mRNA expressions of IL-1β， TNF-α， α -syn， and Iba-1， as well as phosphorylation levels of IKKβ and NF-κB p65 proteins in brain tissue were decreased significantly （except for TNF-α in the ELB low-dose group）. Conversely， the level and mRNA expression of IL-10 （except for the ELB low-dose group）， TH positive expression and protein expressions were significantly increased （ P ＜0.05）. Typical neurodegenerative pathological changes， such as neuronal karyopyknosis， mitochondrial swelling and vacuolization， and endoplasmic reticulum dilation， all showed varying degrees of improvement. CONCLUSIONS ELB may exert neuroprotective effects by inhibiting the activation of the IKKβ/NF-κB signaling pathway， alleviating inflammatory responses， reducing abnormal α -syn aggregation and neuronal loss， and further improving motor dysfunction in PD mice.

ObjectiveThe malaria parasites remodel the host erythrocyte structure by exporting parasite proteins that interact with the membrane skeleton proteins of red blood cells (RBCs), facilitating their intracellular survival and pathogenicity. Skeleton-binding protein 1 (SBP1) is a conserved exported protein across Plasmodium species. In Plasmodium falciparum, SBP1 has been reported to interact with erythrocyte membrane skeleton proteins 4.1R and spectrin, while its contribution to erythrocyte remodeling and parasite virulence in Plasmodium berghei (Pb) remains unclear. This study aims to determine whether PbSBP1 associates with the host cytoskeletal protein 4.1R and to investigate its role in the remodeling of host RBCs and the pathogenicity of Plasmodium berghei. MethodsIn Plasmodium berghei, the relationship between PbSBP1 and the erythrocyte cytoskeletal protein 4.1R was examined using co-immunoprecipitation. A Pbsbp1 gene knockout mutant of Plasmodium berghei (Pbsbp1∆) was generated based on the principle of double crossover homologous recombination. The deformability of erythrocytes infected with Pbsbp1∆ parasites was assessed using microfluidic methods. Microchannels with an array of cylindrical pillars were used to detect modifications in infected RBC deformability. The infected RBCs were squashed between the rows and recovered between the columns and the transit velocity (μm/s) of infected RBCs travelling through the microchannel was recorded. The component of the erythrocyte membrane skeleton junctional complex, tropomodulin (TMOD), was fluorescently labeled, and the cytoskeletal network of infected erythrocytes was imaged using super-resolution stochastic optical reconstruction microscopy (STORM) to analyze ultrastructural changes in the cytoskeleton of wild-type (WT) and Pbsbp1∆-infected erythrocytes. Actin-based junctional complexes were displayed as individual clusters by the labeled TMOD in the STORM images, and the cluster densities and distances between adjacent clusters of infected RBCs were calculated. Additionally, rodent malaria models (BALB/c mice) and experimental cerebral malaria models (C57BL/6 mice) were employed to monitor the growth of Pbsbp1∆ and WT parasites during the intraerythrocytic stage and their capacity to induce cerebral malaria in mice. ResultsPbSBP1 may participate in the remodeling of infected erythrocytes through direct or indirect interaction with the erythrocyte cytoskeletal protein 4.1R. Microfluidic assays revealed that the deformability of erythrocytes infected with Pbsbp1∆ parasites was significantly enhanced compared to those infected with WT parasites. STORM imaging further demonstrated that the ultrastructure of the erythrocyte cytoskeleton in Pbsbp1∆-infected cells was altered relative to that in WT-infected erythrocytes. The distances between nearest neighbors of clusters had a tendency to increase while the cluster densities were decreased in Pbsbp1∆-infected RBCs compared to WT-infected RBCs. Subsequent phenotypic analysis indicated that the growth rate of Pbsbp1∆ parasites during the intraerythrocytic stage was significantly slower than that of WT parasites, and their ability to induce cerebral malaria in mice was also attenuated. These findings suggest that PbSBP1 is involved in the remodeling of the erythrocyte membrane skeleton, likely through its direct or indirect interaction with protein 4.1R, thereby regulating the deformability of infected erythrocytes and influencing the pathogenicity of the blood-stage parasites. ConclusionThis study establishes a role for PbSBP1 in host erythrocyte remodeling and parasite virulence, providing new research strategies for the prevention and treatment of malaria.

The Type III Secretion System (T3SS) serves as a pivotal virulence apparatus for numerous Gram-negative bacterial pathogens, enabling them to infect both animal and plant hosts. Functioning as a molecular syringe, the T3SS directly translocates bacterial effector proteins from the bacterial cytoplasm into the interior of eukaryotic host cells. These effectors are central weapons that precisely manipulate a wide spectrum of host cellular physiological processes, ranging from cytoskeletal dynamics to immune signaling, to establish a favorable niche for bacterial survival and proliferation. Among the diverse arsenal of T3SS effectors, the YopJ family constitutes a critical group of virulence factors. Members of this family are characterized by a conserved catalytic triad structure—a hallmark of the CE clan of cysteine proteases that has been evolutionarily repurposed to confer acetyltransferase activity. A defining and intriguing feature of these enzymes is their stringent dependence on a host-derived eukaryotic cofactor, inositol hexakisphosphate (IP₆), for allosteric activation. This requirement acts as a sophisticated molecular safeguard, ensuring enzymatic activity only within the appropriate host environment, thereby preventing detrimental effects on the bacterium itself. While seminal studies on individual members such as Yersinia’s YopJ and Salmonella’s AvrA have provided deep mechanistic insights, a systematic and integrative understanding of the structure-function relationships across the entire family remains fragmented. Key questions persist regarding how a conserved catalytic core has diverged to recognize distinct host substrates in different kingdoms of life. To address this gap, this article provides a systematic review of the YopJ family, focusing on three interconnected aspects: their structural features, their catalytic mechanism, and their divergent immunosuppressive strategies in animal versus plant hosts. By conducting a comparative analysis of the sequences and resolved three-dimensional structures of three representative members (e.g., HopZ1a, PopP2, AvrA), we elucidate regions of significant variation embedded within the conserved core catalytic architecture. These variable regions, often involving surface loops and substrate-binding interfaces, are crucial determinants of target specificity and functional specialization. The functional divergence of this effector family is most apparent when comparing their modes of action in different hosts. In animal hosts, YopJ-family effectors primarily sabotage innate immune signaling pathways. They achieve this by acetylating key serine and threonine residues within the activation loops of critical kinases in the MAPK and NF‑κB pathways. This post-translational modification blocks the phosphorylation and subsequent activation of these kinases, leading to potent suppression of inflammatory cytokine production. Conversely, in plant hosts, the strategy broadens to dismantle the two-tiered plant immune system. YopJ homologs target a more diverse set of substrates, including immune-associated receptor-like cytoplasmic kinases (RLCKs), microtubule networks via tubulin acetylation (which disrupts cellular trafficking and signaling), and transcription factors central to defense gene regulation. This multi-target approach effectively suppresses both Pattern-Triggered Immunity (PTI) and Effector-Triggered Immunity (ETI). In conclusion, this synthesis aims to deepen the mechanistic understanding of YopJ family-mediated pathogenesis by integrating structural biology with cellular function across host kingdoms. Elucidating the precise molecular basis for substrate selection—how conserved platforms achieve target diversity—is a major frontier. Furthermore, this knowledge provides a vital theoretical foundation for developing novel anti-virulence strategies. Targeting the conserved IP₆-binding pocket or the catalytic acetyltransferase activity itself represents a promising avenue for designing broad-spectrum inhibitors that could disarm this critical family of bacterial effectors, potentially offering new therapeutic approaches against a range of pathogenic bacteria.

Objective To describe the clinical characteristics and nutritional management status of hospitalized elderly patients with multimorbidity in a tertiary hospital's geriatric center in 2024, and to analyze the correlation between nutritional status and hospitalization outcomes, thereby providing a basis for optimizing nutritional management pathways for this population. Methods A retrospective study was conducted, including 2 937 elderly patients with multimorbidity. Data on general information, clinical indicators, nutritional risk screening and assessment, nutritional therapy, and costs were collected for descriptive analysis. The relationship between nutritional status (based on BMI and serum albumin levels) and hospitalization outcomes was explored. Results The average age of the patients was (77.45±10.70) years, with 57.17% being male. The average number of chronic diseases diagnosed was (11.56±5.08) per patient, and 26.01% were critically ill. The nutritional risk screening rate was 80.40%, with a screening positivity rate of 33.44%. The nutritional assessment rate was 31.63%, and the malnutrition prevalence was 23.08%. The low BMI group had the longest median hospital stay [15 (9.75, 22) days] and the highest hospitalization costs [15 057.2 (8 980.48, 28 160.46) CNY]. Serum albumin levels were negatively correlated with hospital stay duration (rs=-0.276, P< 0.01) and hospitalization costs (rs=-0.276, P<0.01). Conclusion Hospitalized elderly patients with multimorbidity are characterized by multiple comorbidities and high healthcare resource consumption. While the nutritional risk screening rate is relatively high, there remains room for improvement in nutritional assessment and therapy. It is necessary to strengthen standardized management throughout the entire process. Nutritional status is a significant variable affecting hospital stay duration and costs, with poorer nutritional status significantly associated with prolonged hospitalization and higher costs, suggesting that it may be an important factor influencing hospitalization outcomes.

ObjectiveTo investigate the effect and mechanism of Shengxian Yixin Granule （升陷益心颗粒， SYG） in treating heart failure with preserved ejection fraction （HFpEF）. MethodsExperiment 1： Forty male C57BL/6 mice were randomly divided into control group， model group， low-dose ［25 mg/（kg·d）］， medium-dose ［50 mg/（kg·d）］， and high-dose ［（75 mg/（kg·d）］ SYG groups， with 8 mice per group. Except for the control group， HFpEF was induced by a high-fat diet combined with Nω-nitro-L-arginine methyl ester in drinking water for 16 weeks. After 10 weeks of modeling， treatment groups received corresponding doses of SYG by gavage， while the control group and model group received equal volume of normal saline， for 6 weeks. After 6 weeks of administration， the body weight， blood pressure including systolic blood pressure （SBP） and diastolic blood pressure （DBP）， and heart weight-to-tibia length ratio （HW/TL） were recorded. Echocardiography was used to evaluate left ventricular ejection fraction （LVEF） and the ratio of early to late diastolic transmitral flow velocity （E/A）. Plasma N-terminal pro-brain natriuretic peptide （NT-proBNP） and C-reactive protein （CRP） levels were measured by ELISA. The expression level of brain natriuretic peptide （BNP） in heart tissue was detected by qRT-PCR. Blood lipid levels， including low-density lipoprotein cholesterol （LDL-C）， triglycerides （TG）， and total cholesterol （TC）， were determined by a biochemical analyzer. Splenic proportions of M1 macrophages， M2 macrophages， T helper 17 （Th17） cells， and regulatory T （Treg） cells were analyzed by flow cytometry. Experiment 2： RAW 264.7 cells were stimulated with lipopolysaccharide （LPS） to establish an M1 macrophage polarization model， and then treated with SYG-containing serum for 24 h. The cells were divided into four groups， including blank serum group， high-dose SYG-containing serum group， LPS group， and LPS plus high-dose SYG-containing serum group. Combined with asignal transducer and activator of transcription 3 （Stat3） inhibitor for 24 h， the cells were divided into a lipopolysaccharide group， a high-dose SYG-containing serum group， an inhibitor group， and high-dose SYG-containing serum plus inhibitor group. The expression levels of inducible nitric oxide synthase （iNOS） and interleukin-1β （IL-1β） in each group were detected by qRT-PCR. The protein levels of iNOS， IL-1β， Stat3， and phosphorylated Stat3 （p-Stat3） were detected by Western Blotting. ResultsExperiment 1： Compared to the control group， the model group showed significantly decreased E/A ratio， and increased cardiac BNP expression， plasma NT-proBNP，HW/TL ratio， body weight， TC， LDL-C， SBP， and DBP， as well as shortened exhaustion distance and exhaustion time （P＜0.05 or P＜0.01）. Compared to the model group， the E/A ratio increased in the low-， medium-， and high-dose SYG groups； cardiac BNP expression decreased in the low- and high-dose groups， and plasma NT-proBNP levels decreased in the high-dose group； the HW/TL ratio and body weight decreased， while exhaustion distance and exhaustion time increased in the medium- and high-dose groups； TG levels decreased in the low- and medium-dose groups， and LDL-C levels decreased in the medium- and high-dose groups； SBP and DBP decreased in the low-， medium-， and high-dose groups （P＜0.05 or P＜0.01）. Compared to the low-dose SYG group， body weight decreased， and both exhaustion distance and exhaustion time increased in the medium- and high-dose groups （P＜0.05 or P＜0.01）. Compared to the medium-dose SYG group， the exhaustion time increased in the high-dose SYG group （P＜0.01）. Experiment 2： In the LPS‑induced M1 macrophage polarization model， compared to the blank serum group， the LPS group showed significantly increased mRNA and protein expression of iNOS and IL‑1β， as well as the p‑Stat3/Stat3 ratio （P＜0.01）. Compared to the LPS group， the high‑dose SYG-containing serum plus LPS group showed significantly decreased mRNA and protein expression of iNOS and IL‑1β， as well as the p‑Stat3/Stat3 ratio （P＜0.05 or P＜0.01）. Compared to the LPS group， the inhibitor group also showed significantly reduced these parameters （P＜0.05 or P＜0.01）. ConclusionSYG can improve cardiac function， ventricular remodeling， exercise capacity， and lipid metabolism in HFpEF mice， while inhibiting inflammatory responses. Its mechanism may be related to the regulation of the Stat3 signaling pathway and inhibition of M1 macrophage polarization.

ObjectiveTo investigate the effect and mechanism of Shengxian Yixin Granule （升陷益心颗粒， SYG） in treating heart failure with preserved ejection fraction （HFpEF）. MethodsExperiment 1： Forty male C57BL/6 mice were randomly divided into control group， model group， low-dose ［25 mg/（kg·d）］， medium-dose ［50 mg/（kg·d）］， and high-dose ［（75 mg/（kg·d）］ SYG groups， with 8 mice per group. Except for the control group， HFpEF was induced by a high-fat diet combined with Nω-nitro-L-arginine methyl ester in drinking water for 16 weeks. After 10 weeks of modeling， treatment groups received corresponding doses of SYG by gavage， while the control group and model group received equal volume of normal saline， for 6 weeks. After 6 weeks of administration， the body weight， blood pressure including systolic blood pressure （SBP） and diastolic blood pressure （DBP）， and heart weight-to-tibia length ratio （HW/TL） were recorded. Echocardiography was used to evaluate left ventricular ejection fraction （LVEF） and the ratio of early to late diastolic transmitral flow velocity （E/A）. Plasma N-terminal pro-brain natriuretic peptide （NT-proBNP） and C-reactive protein （CRP） levels were measured by ELISA. The expression level of brain natriuretic peptide （BNP） in heart tissue was detected by qRT-PCR. Blood lipid levels， including low-density lipoprotein cholesterol （LDL-C）， triglycerides （TG）， and total cholesterol （TC）， were determined by a biochemical analyzer. Splenic proportions of M1 macrophages， M2 macrophages， T helper 17 （Th17） cells， and regulatory T （Treg） cells were analyzed by flow cytometry. Experiment 2： RAW 264.7 cells were stimulated with lipopolysaccharide （LPS） to establish an M1 macrophage polarization model， and then treated with SYG-containing serum for 24 h. The cells were divided into four groups， including blank serum group， high-dose SYG-containing serum group， LPS group， and LPS plus high-dose SYG-containing serum group. Combined with asignal transducer and activator of transcription 3 （Stat3） inhibitor for 24 h， the cells were divided into a lipopolysaccharide group， a high-dose SYG-containing serum group， an inhibitor group， and high-dose SYG-containing serum plus inhibitor group. The expression levels of inducible nitric oxide synthase （iNOS） and interleukin-1β （IL-1β） in each group were detected by qRT-PCR. The protein levels of iNOS， IL-1β， Stat3， and phosphorylated Stat3 （p-Stat3） were detected by Western Blotting. ResultsExperiment 1： Compared to the control group， the model group showed significantly decreased E/A ratio， and increased cardiac BNP expression， plasma NT-proBNP，HW/TL ratio， body weight， TC， LDL-C， SBP， and DBP， as well as shortened exhaustion distance and exhaustion time （P＜0.05 or P＜0.01）. Compared to the model group， the E/A ratio increased in the low-， medium-， and high-dose SYG groups； cardiac BNP expression decreased in the low- and high-dose groups， and plasma NT-proBNP levels decreased in the high-dose group； the HW/TL ratio and body weight decreased， while exhaustion distance and exhaustion time increased in the medium- and high-dose groups； TG levels decreased in the low- and medium-dose groups， and LDL-C levels decreased in the medium- and high-dose groups； SBP and DBP decreased in the low-， medium-， and high-dose groups （P＜0.05 or P＜0.01）. Compared to the low-dose SYG group， body weight decreased， and both exhaustion distance and exhaustion time increased in the medium- and high-dose groups （P＜0.05 or P＜0.01）. Compared to the medium-dose SYG group， the exhaustion time increased in the high-dose SYG group （P＜0.01）. Experiment 2： In the LPS‑induced M1 macrophage polarization model， compared to the blank serum group， the LPS group showed significantly increased mRNA and protein expression of iNOS and IL‑1β， as well as the p‑Stat3/Stat3 ratio （P＜0.01）. Compared to the LPS group， the high‑dose SYG-containing serum plus LPS group showed significantly decreased mRNA and protein expression of iNOS and IL‑1β， as well as the p‑Stat3/Stat3 ratio （P＜0.05 or P＜0.01）. Compared to the LPS group， the inhibitor group also showed significantly reduced these parameters （P＜0.05 or P＜0.01）. ConclusionSYG can improve cardiac function， ventricular remodeling， exercise capacity， and lipid metabolism in HFpEF mice， while inhibiting inflammatory responses. Its mechanism may be related to the regulation of the Stat3 signaling pathway and inhibition of M1 macrophage polarization.

Objective To explore the effect and mechanism of Gegen Qinlian decoction (GQD) on myocardial injury induced by high-fat diet combined with streptozotocin in type 2 diabetic mice through network pharmacology and animal experiments. MethodsNetwork pharmacology was applied to screen the potential signaling pathways of GQD in the intervention of diabetic heart disease (DHD). A total of 36 specific pathogen-free (SPF) male C57BL/6J mice aged 8 weeks were acclimatized for 1 week and randomly divided into a normal control group (n=6) and a model group (n=30). Mice in the model group were fed a 60% high-fat diet and 5% glucose water for 4 weeks, and were intraperitoneally injected with 100 mg/kg streptozotocin after 12 h of fasting to establish the type 2 diabetes model. Mice in the normal control group were given a conventional diet and drinking water, and were intraperitoneally injected with an equal volume of citrate buffer after 12 h of fasting at the same time point. After successful establishment of the diabetic mouse model, the model mice were randomly divided into five groups according to body weight: model control group, GQD low-dose group, GQD medium-dose group, GQD high-dose group, and metformin positive control group, with 6 mice in each group. After 6 weeks of intragastric administration of corresponding doses of GQD, metformin, and ddH₂O respectively, all mice in the six groups (one normal control group and five model groups) were anesthetized with inhaled 2% isoflurane, blood samples were collected via eyeball enucleation, and heart tissues were harvested after euthanasia by cardiac exsanguination. Hematoxylin-eosin (HE) staining and wheat germ agglutinin (WGA) staining were performed to observe the pathological damage of myocardial tissues and measure the cross-sectional area of cardiomyocytes. Enzyme-linked immunosorbent assay (ELISA) was used to measure the levels of pro-inflammatory cytokines in serum. Immunohistochemical staining was adopted to determine the protein expression levels of receptor for advanced glycation end products (RAGE), nucleotide-binding domain leucine-rich repeat and pyrin domain-containing receptor 3 (NLRP3), and phosphorylated nuclear factor-κB p65 (p-p65) in myocardial tissues. ResultsNetwork pharmacology analysis revealed that the targets of GQD against DHD were significantly enriched in inflammatory pathways, including the advanced glycation end products (AGEs)-RAGE axis, tumor necrosis factor (TNF) and interleukin-17 (IL-17) signaling pathways. HE and WGA staining results showed that, compared with the normal control group, the model control group exhibited myocardial fiber rupture, cardiomyocyte swelling, and significantly increased cardiomyocyte cross-sectional area (P<0.05). Compared with the model control group, GQD intervention significantly ameliorated the pathological changes, including myocardial fiber rupture, cell swelling, and cardiomyocyte hypertrophy. The results of immunohistochemical staining and ELISA indicated that compared with the model control group, GQD intervention markedly downregulated the protein expression of RAGE, NLRP3, and p-p65 in myocardial tissues, as well as the levels of serum pro-inflammatory cytokines (P<0.05). ConclusionGQD can effectively alleviate myocardial pathological injury in diet-induced type 2 diabetic mice, and its mechanism may be related to inhibiting the activation of the RAGE/p-p65/NLRP3 signaling pathway and reducing myocardial inflammatory response.

Alzheimer’s disease (AD) is a prevalent neurodegenerative condition characterized by progressive cognitive decline and memory loss. As the incidence of AD continues to rise annually, researchers have shown keen interest in the active components found in natural plants and their neuroprotective effects against AD. Quercetin, a flavonol widely present in fruits and vegetables, has multiple biological effects including anticancer, anti-inflammatory, and antioxidant. Oxidative stress plays a central role in the pathogenesis of AD, and the antioxidant properties of quercetin are essential for its neuroprotective function. Quercetin can modulate multiple signaling pathways related to AD, such as Nrf2-ARE, JNK, p38 MAPK, PON2, PI3K/Akt, and PKC, all of which are closely related to oxidative stress. Furthermore, quercetin is capable of inhibiting the aggregation of β‑amyloid protein (Aβ) and the phosphorylation of tau protein, as well as the activity of β‑secretase 1 and acetylcholinesterase, thus slowing down the progression of the disease.The review also provides insights into the pharmacokinetic properties of quercetin, including its absorption, metabolism, and excretion, as well as its bioavailability challenges and clinical applications. To improve the bioavailability and enhance the targeting of quercetin, the potential of quercetin nanomedicine delivery systems in the treatment of AD is also discussed. In summary, the multifaceted mechanisms of quercetin against AD provide a new perspective for drug development. However, translating these findings into clinical practice requires overcoming current limitations and ongoing research. In this way, its therapeutic potential in the treatment of AD can be fully utilized.

Champagne bottle neck sign (CBNS) is an important morphological feature of extracranial artery damage in patients with moyamoya disease (MMD), and more than half of them have this sign. Carotid ultrasound is the most convenient imaging examination method for diagnosing CBNS. CBNS can have a serious impact on cerebral hemodynamics and is closely associated with the staging of MMD, stroke risk, stroke characteristics, MMD-related headaches, and the risk of postoperative complications. This article comprehensively reviews the pathology and pathogenesis, imaging examination, correlation with clinical symptoms, and intervention of CBNS in patients with MMD, aiming to provide reference for the clinical diagnosis, treatment, and research of MMD combined with CBNS.

Objective To investigate the impact of different antibiotic courses on intestinal floras and immune function in 28-day-old premature infants.Methods A retrospective analysis was conducted on 120 premature infants admitted to the First People's Hospital of Nanyang City between March 2021 and March 2024.According to different courses of antibiotics,they were divided into short-course group(n=82,antibiotics use≤3 d)and long-course group(n=38,antibiotics use≥7 d).General data were collected,and intestinal floras and immune function were assessed at 28 days of age.Shannon and Simpson indexes of intestinal flora α-diversity,bacterial phylum and genus distribution of intestinal floras,and peripheral blood CD8+,CD4+T cell percentages,and CD4+/CD8+ratio were compared between the two groups.Pearson correlation analysis was used to explore the relationship between intestinal floras and immune function,and adverse outcomes were recorded.Results The Shannon and Simpson indexes of intestinal flora α-diversity in long-course group were lower than those in short-course group(P<0.05).No significant differences were found between the two groups in the distribution of Actinobacteria,Bacteroidetes,Firmicutes or Proteobacteria at the bacterial phylum level and Bacteroides,Enterococcus,or Veillonella at genus distribution level(P>0.05).However,the long-course group had lower proportions of Clostridioides,Clostridium sensu stricto 1,Escherichia and Klebsiella,and higher proportions of Enterococcus,Robinsoniella and Streptococcus than those in short-course group(P<0.05).After antibiotics use,levels of CD4+and CD4+/CD8+were decreased(P<0.05),while CD8+was increased in both groups(P<0.05).Compared with short-course group,levels of CD4+and CD4+/CD8+were lower,while CD8+was higher in short-course group(P<0.05).Pearson correlation analysis revealed that Clostridioides,Clostridium sensu stricto 1,Escherichia,Klebsiella were positively correlated with CD4+and CD4+/CD8+,while negatively correlated with CD8+(P<0.05).Conversely,Enterococcus,Robinsoniella and Streptococcus were negatively correlated with CD4+and CD4+/CD8+,while positively correlated with CD8+(P<0.05).No adverse outcomes occurred in two groups.Conclusion Compared with short-term antibiotic use,long-term use affects the colonization and diversity of intestinal floras in premature infants,and cause intestinal flora disturbance,potentially impairing immune function.