Protective role of arachidonic acid against diabetic myocardial ischemic injury: a translational study of pigs, rats, and humans.

AIM: Patients with diabetes mellitus have poor prognosis after myocardial ischemic injury. However, the mechanism is unclear and there are no related therapies. We aimed to identify regulators of diabetic myocardial ischemic injury. METHODS AND RESULTS: Mass spectrometry-based, non-targeted metabolomic approach was used to profile coronary sinus blood from diabetic and non-diabetic Bama-mini pigs at 0.5-h post coronary artery ligation. Six metabolites had a |log2 (Fold Change)|> 1.3. Among them, the most changed is arachidonic acid (AA), levels of which were 32 times lower in diabetic pigs than in non-diabetic pigs. The AA-derived products, PGI2 and 6-keto-PGF1α, were also significantly reduced. AA treatment of cultured cardiomyocytes protected against cell death by 30% at 48 h of high glucose and oxygen deprivation, which coincided with increased mitophagic activity (as indicated by increased LC3II/LC3I, decreased p62 and increased parkin & PINK1), improved mitochondrial renewal (upregulation of Drp1 and FIS1), reduced ROS generation and increased ATP production. These cardioprotective effects were abolished by PINK1(a crucial mitophagy protein) knockdown or the autophagy inhibitor 3-Methyladenine. The protective effect of AA was also inhibited by indomethacin and Cay10441, a prostacyclin receptor antagonist. Furthermore, diabetic Sprague Dawley rats were subjected to coronary ligation for 40 min and AA treatment (10 mg/day per animal gavaged) decreased myocardial infarct size, cell apoptosis index, inflammatory cytokines and improved heart function. Scanning electron microscopy showed more intact mitochondria in the border zone of infarcted myocardium in AA treated rats. Lastly, diabetic patients after myocardial infarction had lower plasma levels of AA and 6-keto-PGF1α and reduced cardiac ejection fraction, compared with non-diabetic patients after myocardial infarction. Plasma AA level was inversely correlated with fasting blood glucose. CONCLUSIONS: AA protects against diabetic ischemic myocardial damage by promoting mitochondrial autophagy and renewal, which is related to AA derived PGI2 signaling. AA may represent a new strategy to treat diabetic myocardial ischemic injury.

CircRNA Regulation of T Cells in Cancer: Unraveling Potential Targets.

T lymphocytes play a critical role in antitumor immunity, but their exhaustion poses a significant challenge for immune evasion by malignant cells. Circular RNAs (circRNAs), characterized by their covalently closed looped structure, have emerged as pivotal regulators within the neoplastic landscape. Recent studies have highlighted their multifaceted roles in cellular processes, including gene expression modulation and protein function regulation, which are often disrupted in cancer. In this review, we systematically explore the intricate interplay between circRNAs and T cell modulation within the tumor microenvironment. By dissecting the regulatory mechanisms through which circRNAs impact T cell exhaustion, we aim to uncover pathways crucial for immune evasion and T cell dysfunction. These insights can inform innovative immunotherapeutic strategies targeting circRNA-mediated molecular pathways. Additionally, we discuss the translational potential of circRNAs as biomarkers for therapeutic response prediction and as intervention targets. Our comprehensive analysis aims to enhance the understanding of immune evasion dynamics in the tumor microenvironment by facilitating the development of precision immunotherapy.

Purification and preparation of pure SiC with silicon cutting waste.

Recycling silicon cutting waste (SCW) plays a pivotal role in reducing environmental impact and enhancing resource efficiency within the semiconductor industry. Herein SCW was utilized to prepare SiC and ultrasound-assisted leaching was investigated to purify the obtained SiC and the leaching factors were optimized. The mixed acids of HF/H2SO4 works efficiently on the removal of Fe and SiO2 due to that HF can react with SiO2 and Si and then expose the Fe to H+. The assistance of ultrasound can greatly improve the leaching of Fe, accelerate the leaching rate, and lower the leaching temperature. The optimal leaching conditions are HF-H2SO4 ratio of 1:3, acid concentration of 3 mol/L, temperature of 50 °C, ultrasonic frequency of 45 kHz and power of 210 W, and stirring speed of 300 rpm. The optimal leaching ratio of Fe is 99.38%. Kinetic analysis shows that the leaching process fits the chemical reaction-controlled model.

Introduction of Cationic Vacancies into NiFe LDH by In Situ Etching To Improve Overall Water Splitting Performance.

Nickel-iron layered double hydroxide (NiFe LDH) is still one of the hot catalysts for electrochemical water decomposition applications, despite its drawbacks, such as intrinsic activity and poor stability. In this work, the NiFe LDH-D1 electrocatalyst with cationic vacancies is successfully prepared by alkaline etching of Zn ion-doped NiFe LDH. The tightly arranged flocculated nanosheet structure on its surface provided a large active area. The cationic vacancies formed by strong alkaline etching not only promote the conversion of active phases such as NiOOH but also strengthen the stability of the electrode and the binding ability with oxygen so that the material has excellent catalytic properties along with alkaline long-term stability. At a current density of 10 and 100 mA cm-2, NiFe LDH-D1 shows a small voltage of 1.56 and 1.94 V, and at a current density of 200 mA cm-2, it performs well in a 72 h electrochemical water decomposition stability test. The present work demonstrates a simple etching strategy for cation vacancy engineering and provides an example of the construction of efficient bifunctional electrocatalysts with long-term stability.

Realizing a Lattice Se Atom-Modified Co Hydroxide Catalyst via Electrochemical Reconstruction for Enhanced Oxygen Evolution Performance.

Realizing a highly efficient oxygen evolution reaction (OER) process is of great significance for hydrogen energy development. The main challenge still lies in fabricating superior electrocatalysts with favorable performance. Constructing electrocatalysts with ingenious lattice modifications is a considerable way for the rational design of highly active catalytic centers. Here, theoretical calculations predict that the lattice incorporation of Se atoms can effectively enhance the reaction activity of OER with a decreased energy barrier for the rate-determining step. To obtain the corresponding desired electrocatalyst, the optimized lattice Se-modified CoOOH, with the ideal OER performance of low overpotential and stability, was delicately designed and fabricated by the electrochemical activation of the Co0.85Se precatalyst. X-ray absorption spectroscopy (XAS) demonstrates that lattice incorporation is more likely to be generated in Co0.85Se compared to CoSe2 and CoO precatalysts, which promoted the subsequent OER process. This work clarified the correlation between the precatalyst and the lattice-modified final catalyst in connection with electrochemical reconstruction.

Multiple leadless pacemakers implanted in the right ventricle of swine.

AIMS: The miniaturized leadless pacemaker has recently emerged as a bradycardia therapy in humans, and many patients may need at least two pacemakers in their lifetime. Thus, the present study assessed the effect of two leadless pacemakers in the right ventricle (RV) on cardiac function in a swine model. METHODS AND RESULTS: Fourteen mini pigs were chronically studied. Each animal received two sequential leadless pacemakers in the RV with 1 month between two separate implantations. All animals were then followed for 6 months. Cardiac function was assessed with echocardiography at baseline, the second implantation, and the end of the 6-month follow-up. A necropsy at the end of the study was performed to measure the length of the fibrous tissue covering the devices and assess tricuspid valve integrity. Four animals died during the surgical procedure, and one animal died of infection during the follow-up period. In the remaining nine animals, there were no significant changes in left ventricular ejection fraction, aortic time integral, cardiac output, and left ventricular size from baseline to the end of the study. The mean length of fibrous tissue covering Micra devices was 14.3 ± 7.8 mm. No tricuspid valve injury was observed. CONCLUSION: Multiple leadless pacemakers implanted in the RV do not appear to impact cardiac function. Therefore, it appears safe to implant multiple leadless pacemakers in the same heart.

Crystalline/Amorphous Mo-Ni(OH)2/FexNiy(OH)3x+2y hierarchical nanotubes as efficient electrocatalyst for overall water splitting.

The development of efficient bifunctional catalysts for overall water splitting is highly desirable and essential for the advancement of hydrogen technology. In this work, Mo-Ni(OH)2/FexNiy(OH)3x+2y with hierarchical nanotube structure is constructed on flexible carbon cloth (CC) through simple electrochemical deposition and hydrothermal method. The hollow tube-structure is in favor of both exposing active sites and enhancing mass transfer capability. Moreover, the doping of Mo can enhance the electronic conductivity of heterostructures. The interfacial interaction between amorphous and crystal can enhance effectively the charge transfer kinetics across the interface. Therefore, Mo-Ni(OH)2/FexNiy(OH)3x+2y can achieve a low overpotential of 57 mV for hydrogen evolution reaction (HER) and 229 mV for oxygen evolution reaction (OER) at 10 mA·cm-2. In addition, Mo-Ni(OH)2/FexNiy(OH)3x+2y needs a potential of only 1.54 V at 10 mA·cm-2 for overall water splitting, and retains for a long period of time (60 h) reliable. The work will provide a valuable approach to the construction of highly efficient electrocatalysts for overall water splitting.

Hawthorn pectin plays a protective role in myocardial ischaemia by regulating intestinal flora and short chain fatty acids.

Studies have shown that there is a close relationship between acute myocardial ischaemia (AMI) and intestinal flora imbalance. And pectin has a protective effect on AMI and regulates intestinal flora. Raw hawthorn pectin from hawthorn (RHP) is high methoxyl pectin, which is able to protect injury induced by AMI. After stir-frying of hawthorn, pectin from stir-fried hawthorn (FHP) transformed to low methoxyl pectin, the protective mechanisms against AMI is not well-understood. In this study, the protective effects of RHP and FHP against AMI rats were explored. The results revealed that FHP regulated myocardial enzymes including CK, CK-MB and CTn-1, oxidative stress-related indicator SOD more significantly than RHP. According to the determination of proportion of different kinds of short-chain fatty acids (SCFAs) and abundance of microbiota producing SCFAs, it was speculated that RHP and FHP were fermented by these microbiota. RHP increased the proportion of acetic acid and butyric acid, while FHP increased the proportion of acetic acid in feces. Pretreatment with RHP and FHP enriched the beneficial microbiota and maintained the levels of SCFAs, which significantly increased after modeling. These results revealed that RHP and FHP played a protective role in myocardial ischaemia by regulating intestinal flora and SCFAs.

Regulation of electron density redistribution for efficient alkaline hydrogen evolution reaction and overall water splitting.

The rational design of morphology and heterogeneous interfaces for non-precious metal electrocatalysts is crucial in electrochemical water decomposition. In this paper, a bifunctional electrocatalyst (Ni/NiFe LDH), which coupling nickel with nickel-iron layer double hydroxide (NiFe LDH), is synthesized on carbon cloth. At current density of 10 mA cm-2, the Ni/NiFe LDH exhibits a low hydrogen evolution reaction (HER) overpotential of only 36 mV due to the accelerated electrolyte penetration, which is caused by superhydrophilic interface. Moreover, an alkaline electrolyzer is formed and provide a current density of 10 mA cm-2 with a voltage of only 1.49 V. It is confirmed by the density functional theory (DFT) that electron from the Ni layer is transferred to NiFe LDH layer, redistributing the local electron density around the heterogeneous phase interface. Thus, the Gibbs free energy for hydrogen adsorption is optimized. This work provides a promising strategy for the rational regulation of electrons at heterogeneous interfaces and the synthesis of flexible electrocatalysts.

Long-term observation of polycaprolactone small-diameter vascular grafts with thickened outer layer and heparinized inner layer in rabbit carotid arteries.

In our previous study, the pristine bilayer small-diameterin situtissue engineered vascular grafts (pTEVGs) were electrospun from a heparinized polycaprolactone (PCL45k) as an inner layer and a non-heparinized PCL80k as an outer layer in the thickness of about 131 µm and 202 µm, respectively. However, the hydrophilic enhancement of inner layer stemmed from the heparinization accelerated the degradation of grafts leading to the early formation of arterial aneurysms in a period of 3 months, severely hindering the perennial observation of the neo-tissue regeneration, host cell infiltration and graft remodeling in those implanted pTEVGs. Herein to address this drawback, the thickness of the outer layers was increased with PCL80k to around 268 µm, while the inner layer remained unchangeable. The thickened TEVGs named as tTEVGs were evaluated in six rabbits via a carotid artery interpositional model for a period of 9 months. All the animals kept alive and the grafts remained patent until explantation except for one whose one side of arterial blood vessels was occluded after an aneurysm occurred at 6 months. Although a significant degradation was observed in the implanted grafts at 9 month, the occurrence of aneurysms was obviously delayed compared to pTEVGs. The tissue stainings indicated that the endothelial cell remodeling was substantially completed by 3 months, while the regeneration of elastin and collagen remained smaller and unevenly distributed in comparison to autologous vessels. Additionally, the proliferation of macrophages and smooth muscle cells reached the maximum by 3 months. These tTEVGs possessing a heparinized inner layer and a thickened outer layer exhibited good patency and significantly delayed onset time of aneurysms.

Establishment of acquired tracheoesophageal fistula using a modified magnetic compression technique in rabbits and its postmodeling evaluation.

BACKGROUND: Previous studies have validated the efficacy of both magnetic compression and surgical techniques in creating rabbit tracheoesophageal fistula (TEF) models. Magnetic compression achieves a 100% success rate but requires more time, while surgery, though less frequently successful, offers rapid model establishment and technical maturity in larger animal models. AIM: To determine the optimal approach for rabbit disease modeling and refine the process. METHODS: TEF models were created in 12 rabbits using both the modified magnetic compression technique and surgery. Comparisons of the time to model establishment, success rate, food and water intake, weight changes, activity levels, bronchoscopy findings, white blood cell counts, and biopsies were performed. In response to the failures encountered during modified magnetic compression modeling, we increased the sample size to 15 rabbit models and assessed the repeatability and stability of the models, comparing them with the original magnetic compression technique. RESULTS: The modified magnetic compression technique achieved a 66.7% success rate, whereas the success rate of the surgery technique was 33.3%. Surviving surgical rabbits might not meet subsequent experimental requirements due to TEF-related inflammation. In the modified magnetic compression group, one rabbit died, possibly due to magnet corrosion, and another died from tracheal magnet obstruction. Similar events occurred during the second round of modified magnetic compression modeling, with one rabbit possibly succumbing to aggravated lung infection. The operation time of the first round of modified magnetic compression was 3.2 ± 0.6 min, which was significantly reduced to 2.1 ± 0.4 min in the second round, compared to both the first round and that of the original technique. CONCLUSION: The modified magnetic compression technique exhibits lower stress responses, a simple procedure, a high success rate, and lower modeling costs, making it a more appropriate choice for constructing TEF models in rabbits.

The lipid-lowering effects of fenugreek gum, hawthorn pectin, and burdock inulin.

Objective: The present study aimed to investigate the lipid-lowering effects and mechanisms of fenugreek gum (FG), hawthorn pectin (HP), and burdock inulin (BI) on high-fat diet (HFD)-induced hyperlipidemic rats. Methods: In this study, high-fat diet (HFD) together with fat emulsion administration were used to establish hyperlipidemia model. The biochemical indices were assayed after administration of FG, HP, and BI. Their effects were evaluated by factor analysis. Alterations of gut microbiota and short chain fatty acids (SCFAs) in the cecal were assessed to illustrate the mechanism of lipid lowering. Results: The supplementation of FG, HP, and BI on HFD-fed rats decreased the levels of serum lipid and reduced the HFD-related liver and testicle damage. In the scatter plot of factor analysis, HP and BI were closer to normal fat diet (NFD) group in restoring the severity of hyperlipidemia, while FG and HP enhanced the excretion of cholesterol and bile acids (BAs). The levels of total SCFAs, especially butyric acid reduced by HFD were increased by HP. The ratio of Firmicutes to Bacteroidetes increased by HFD was reduced by HP and BI. FG, HP, and BI enriched intestinal probiotics, which were related to bile acid excretion or lipid-lowering. Conclusions: FG inhibited the absorption of cholesterol and enhanced the excretion of it, as well as increased the abundance of beneficial bacteria. While BI restored the imbalance of intestinal microbiota. HP enhanced the excretion of cholesterol and BAs, and restored the imbalance of intestinal microbiota. It was also utilized by intestinal microorganisms to yield SCFAs. This study suggested that FG, HP, and BI possessed the potential to be utilized as dietary supplements for obesity management.

Interface strong-coupled 3D Mo-NiS@Ni-Fe LDH flower-cluster as exceptionally efficient electrocatalyst for water splitting in wide pH range.

It is crucial to create a bifunctional catalyst with high efficiency and low cost for electrochemical water splitting under alkaline and neutral pH conditions. This study investigated the in-situ creation of ultrafine Mo-NiS and NiFe LDH nanosheets as an effective and stable electrocatalyst with a three-dimensional (3D) flower-cluster hierarchical structure (Mo-NiS@NiFe LDH). The strong interfacial connection between Mo-NiS and NiFe LDH enhances the formation of metal higher chemical states in the material, optimizes the electronic structure, increases OH- adsorption capacity improves electron transfer/mass diffusion, and promotes O2/H2 gas release. As a result, at 10 mA cm-2, Mo-NiS@NiFe LDH/NF demonstrates the outstanding bifunctional electrocatalytic activity of just 107 mV (HER, hydrogen evolution reaction) and 184 mV (hydrogen evolution reaction) (OER, oxygen evolution reaction). The catalytic performance is remarkably stable after 72 h of continuous operation in 1 M KOH at high current densities (300 mA cm-2). More interestingly, in the overall water splitting system, the cell voltages for anode and cathode in both alkaline and neutral electrolytes for Mo-NiS@NiFe LDH/NF are only 1.54 V (alkaline) and 2.06 V (neutral) at 10 mA cm-2. These results demonstrated that the bifunctional electrocatalyst design concept is a viable solution for water splitting in both alkaline and neutral systems.

Comprehensive evaluation of the prebiotic properties of Dendrobium officinale polysaccharides, ß-glucan, and inulin during in vitro fermentation via multi-omics analysis.

Dietary fiber is crucial for human health mainly due to its impact on gut microbiota structure and metabolites. This study aimed to investigate the impact of Dendrobium officinale polysaccharides (DOP) and two common fibers (ß-glucan and inulin) on the gut microbiome structure and metabolic profile in vitro. Fecal samples were obtained from 30 healthy volunteers, which were then individually subjected to fermentation with each type of fiber. The results revealed that all fibers were efficiently degraded by gut microbiota, with DOP exhibiting a slower fermentation rate compared to ß-glucan and inulin. The fermentation of all fibers led to a significant increase in the production of short-chain fatty acids (SCFAs) and a reduction in branched-chain fatty acids (BCFAs), sulfides, phenols, and indole. Moreover, the abundance of unclassified Enterobacteriaceae, which was positively correlated with sulfide, phenols, and indole levels, was significantly reduced by all fibers. Additionally, DOP specifically promoted the growth of Parabacteroides, while ß-glucan and inulin promoted the growth of Bifidobacterium and Faecalibacterium. Taken together, these findings enhance our understanding of the role of DOP, ß-glucan, and inulin in modulating gut microbiota and metabolites, where the fermentation with fecal bacteria from different volunteers could provide valuable insights for personalized therapeutic approaches.

Parabacteroides distasonis ameliorates insulin resistance via activation of intestinal GPR109a.

Gut microbiota plays a key role in insulin resistance (IR). Here we perform a case-control study of Chinese adults (ChiCTR2200065715) and identify that Parabacteroides distasonis is inversely correlated with IR. Treatment with P. distasonis improves IR, strengthens intestinal integrity, and reduces systemic inflammation in mice. We further demonstrate that P. distasonis-derived nicotinic acid (NA) is a vital bioactive molecule that fortifies intestinal barrier function via activating intestinal G-protein-coupled receptor 109a (GPR109a), leading to ameliorating IR. We also conduct a bioactive dietary fiber screening to induce P. distasonis growth. Dendrobium officinale polysaccharide (DOP) shows favorable growth-promoting effects on P. distasonis and protects against IR in mice simultaneously. Finally, the reduced P. distasonis and NA levels were also validated in another human type 2 diabetes mellitus cohort. These findings reveal the unique mechanisms of P. distasonis on IR and provide viable strategies for the treatment and prevention of IR by bioactive dietary fiber.

Acquisition of suppressive function by conventional T cells limits antitumor immunity upon Treg depletion.

Regulatory T (Treg) cells contribute to immune homeostasis but suppress immune responses to cancer. Strategies to disrupt Treg cell-mediated cancer immunosuppression have been met with limited clinical success, but the underlying mechanisms for treatment failure are poorly understood. By modeling Treg cell-targeted immunotherapy in mice, we find that CD4+ Foxp3- conventional T (Tconv) cells acquire suppressive function upon depletion of Foxp3+ Treg cells, limiting therapeutic efficacy. Foxp3- Tconv cells within tumors adopt a Treg cell-like transcriptional profile upon ablation of Treg cells and acquire the ability to suppress T cell activation and proliferation ex vivo. Suppressive activity is enriched among CD4+ Tconv cells marked by expression of C-C motif receptor 8 (CCR8), which are found in mouse and human tumors. Upon Treg cell depletion, CCR8+ Tconv cells undergo systemic and intratumoral activation and expansion, and mediate IL-10-dependent suppression of antitumor immunity. Consequently, conditional deletion of Il10 within T cells augments antitumor immunity upon Treg cell depletion in mice, and antibody blockade of IL-10 signaling synergizes with Treg cell depletion to overcome treatment resistance. These findings reveal a secondary layer of immunosuppression by Tconv cells released upon therapeutic Treg cell depletion and suggest that broader consideration of suppressive function within the T cell lineage is required for development of effective Treg cell-targeted therapies.

[Establishment and evaluation of acute pulmonary thromboembolism model in minipig].

OBJECTIVE: To establish and evaluate an acute pulmonary embolism (APTE) model by selective thromboembolism of lower left pulmonary artery in minipig. METHODS: Through intervention technique, a guiding catheter was inserted via femoral vein into pulmonary artery. And quantitative autologous venous thrombus was injected into the selected lower left pulmonary arteries in 8 minipigs. Thus the intended APTE model was established by selective thromboembolism of lower left pulmonary artery. Hemodynamic parameters were monitored. And computed tomography (CT) and macroscopic dissection were performed to evaluate the minipig APTE model. RESULTS: The measurements of mean pulmonary artery pressure (MPAP, mm Hg, 1 mm Hg = 0.133 kPa) and pulmonary capillary wedge pressure (PCWP, mm Hg) immediately increased significantly after thromboembolism versus the baseline values (MPAP: 42.0 ± 3.4 vs 20.2 ± 3.0, PCWP: 8 ± 2 vs 4 ± 3, both P < 0.05) and stayed at a higher level during the following 2 h. No significant difference existed between the value of cardiac output (CO) at 2 h post-thromboembolism and its baseline counterpart. Moreover, systemic arterial pressure (SAP, mm Hg) and heart rate (HR, beats/min) significantly increased after embolism versus the baseline values (SAP: 102 ± 12 vs 80 ± 7, HR: 119 ± 22 vs 86 ± 14, P = 0.008). Pulmonary arteriography, CT scan and gross anatomy all demonstrated that the selected lower left pulmonary arteries was successfully embolized. CONCLUSION: The establishment of APTE model by selective thromboembolism of lower left pulmonary artery is feasible, well-controlled and stable in minipigs.

Thermal Radiation Shielding and Mechanical Strengthening of Mullite Fiber/SiC Nanowire Aerogels Using In Situ Synthesized SiC Nanowires.

Traditional solid nanoparticle aerogels have been unable to meet the requirements of practical application due to their inherent brittleness and poor infrared shielding performance. Herein, combining vacuum impregnation and high-temperature pyrolysis, a novel micro/nano-composite fibrous aerogel was prepared via in situ synthesis of silicon carbide nanowires (SiC NWS) in mullite fiber (MF) preform. During this process, uniformly distributed SiC NWS in the MF preform serve as an enhancement phase and also act as an infrared shielding agent to reduce radiation heat transfer, which can significantly improve the mechanical properties of the mullite fiber/silicon carbide nanowire composite aerogels (MF/SiC NWS). The fabricated MF/SiC NWS exhibited excellent thermal stability (1400 °C), high compressive strength (~0.47 MPa), and outstanding infrared shielding performance (infrared transmittance reduced by ~70%). These superior properties make them appealing for their potential in practical application as high-temperature thermal insulators.

Gut microbial utilization of xylan and its implication in gut homeostasis and metabolic response.

Xylan as the second most abundant indigestible carbohydrate found in nature attracts great interests of researchers, nutritionist and consumers due to its various health benefits. However, accumulated studies indicate the interactions with gut microbiota greatly affect these benefits, and significant progress has been made over the past few years to understand how microbes utilize xylan at gene level. In this review, we focused on gut xylanolytic microbes and xylan's physico-chemical features, summarized the xylanases needed for complete xylan decomposition, their substrate specificity and the presence in gut microbes, as well as microbial degradation of xylan in single strain mode and cooperation mode. Xylan utilization system were discussed with different phyla. Furthermore, the implications on intestinal homeostasis and metabolic response were reviewed with clinical effects emphasized, and highlight is placed on specific gut microbes and the complexity of xylan structure to provide a clue for the inconsistent results in human studies. CHEMICAL COMPOUNDS: xylan; arabinoxylan, glucuronoxylans; glucuronoarabinoxylans; xylo-oligosaccharides; arabinoxylo-oligosaccharides.