Deviation Of Composition Research Articles

SnRNA-seq of human ovaries reveals heat shock proteins are associated with obesity related cancer risk

BackgroundObesity significantly impacts female reproductive health and increases the risk of gynecological tumors. However, the specific transcriptional changes that occur in the ovarian microenvironment during obesity-induced stress and the relationship between obesity and ovarian cancer remain unclear.MethodsOur study investigated the single-cell landscape of the ovarian cortex in individuals with varying BMI levels by snRNA-seq, revealing weight-stage related cellular composition deviations and expression profile irregularities. Results: Using single-cell high-dimensional Weighted Gene Co-expression Network Analysis (hdWGCNA), we identified distinct obesity-related gene modules within various subpopulations of stroma cells and blood vascular endothelial cells. Notably, we observed a negative correlation between BMI and heat shock protein (HSP) family genes. Specifically, we found that HSPD1 might function as a potential regulator of ovarian carcinogenesis and progression under conditions of obesity, as supported by our co-analysis with data from three bulk RNA-seq ovarian cancer databases. Our findings suggested that lower expression of HSPD1 indicated a poorer prognosis for ovarian cancer.ConclusionsOur study identified a cluster of genes in ovarian cells that are suppressed by obesity, including those belonging to HSP family genes. These findings provide valuable insights for investigating the link between obesity and ovarian diseases.

Comprehensive investigation of flue gas component separation and CO2 sequestration in water-saturated porous media of subsurface formation

Flue gas poses subsurface direct storage inefficiency due to its high non-CO2 content, while surface separation, desulfurization and denitrification processes require additional equipment and financial resources. To address these challenges, flue gas subsurface component separation and CO2 sequestration within aquifer were proposed in this paper. CO2 migrates notably slower than N2, leading to the gathering of N2 at gas flooding front and the occurrence of CO2 hysteresis during flue gas filtration within the aquifer. The phenomenon, characterized by gas composition deviations from the original injection mole fractions of N2 and CO2, is referred to as the flue gas component separation. Numerical simulation results indicate that the solubility difference between N2 and CO2 is the primary force driving the separation of components, and the asynchronous filtration velocities of the gas and aqueous phases further promote the separation. Thus, simultaneous N2 separation and CO2 storage can achieve by the optimized gas-water alternate injection, and the efficiencies of N2 separation and CO2 storage are inversely correlated. Increasing N2 mole fraction within the injected flue gas enhances the efficiency of N2 separation, while having a slight effect on CO2 storage. Water vapor in flue gas condenses and integrates into the liquid phase, while O₂ component is produced slightly later than N₂, leading to a marginal reduction in N₂ separation efficiency. The synergistic influences of aquifer temperature and pressure exhibit bidirectionality, stemming from the shift between the dominant factors between CO2 dissolution and gas sweep efficiency. Conditions of relatively lower aquifer temperatures and moderate pressures, particularly in medium permeability aquifers, are more favorable for enhancing N₂ separation and CO₂ storage. This proposal method holds the potential for efficient subsurface separation of flue gas components and concurrent underground storage of CO2, thereby contributing to the reduction of greenhouse gas emissions and mitigation of climate change.

Stimulative piezoelectric nanofibrous scaffolds for enhanced small extracellular vesicle production in 3D cultures.

Small extracellular vesicles (sEVs) have great promise as effective carriers for drug delivery. However, the challenges associated with the efficient production of sEVs hinder their clinical applications. Herein, we report a stimulative 3D culture platform for enhanced sEV production. The proposed platform consists of a piezoelectric nanofibrous scaffold (PES) coupled with acoustic stimulation to enhance sEV production of cells in a 3D biomimetic microenvironment. Combining cell stimulation with a 3D culture platform in this stimulative PES enables a 15.7-fold increase in the production rate per cell with minimal deviations in particle size and protein composition compared with standard 2D cultures. We find that the enhanced sEV production is attributable to the activation and upregulation of crucial sEV production steps through the synergistic effect of stimulation and the 3D microenvironment. Moreover, changes in cell morphology lead to cytoskeleton redistribution through cell-matrix interactions in the 3D cultures. This in turn facilitates intracellular EV trafficking, which impacts the production rate. Overall, our work provides a promising 3D cell culture platform based on piezoelectric biomaterials for enhanced sEV production. This platform is expected to accelerate the potential use of sEVs for drug delivery and broad biomedical applications.

Laser-based directed energy deposition and characterisation of cBN-reinforced NiAl-based coatings

Within this study, the alloy NiAl–2.5Ta–7.5Cr is investigated as a new matrix material for cBN-reinforced abrasive turbine blade tip coatings as currently used NiCoCrAlY matrix alloys suffer from insufficient strength at the high operating temperatures. Laser-based directed energy deposition with blown powder was applied to produce cBN reinforced NiAl-based coatings on monocrystalline CMSX-4 substrates. For this, powdery titanium-coated cBN and NiAl–2.5Ta–7.5Cr material were co-injected into the process zone to achieve an in situ formation of a NiAl–2.5Ta–7.5Cr/cBN composite. In order to overcome challenges such as cracking susceptibility, inductive preheating of the substrate up to 800 °C was used. Optical and scanning electron microscopy, energy dispersive X-ray spectroscopy, as well as electron backscatter diffraction were applied to analyse the fabricated samples’ microstructure. Additionally, the mechanical properties were evaluated by means of microhardness mappings. This work demonstrates the feasibility of in situ forming a metal matrix composite with a homogeneous distribution of cBN particles. The results show the beneficial effect of high-temperature preheating on the crack formation. However, the study also reveals challenges such as cracking induced by the injected cBN particles as well as severe intermixing of substrate and coating, which yields spatially resolved deviations in the chemical composition and resulting variations in microstructure and hardness.Graphical abstract

Diagnostics of phase composition of lithium niobate films on sapphire by principal component analysis using Raman spectra

Thin films of lithium niobate were deposited by RF diode sputtering of a LiNbO3 single-crystal target on a heated sapphire substrate (R-cut, 650 °C). Radial distributions of the phase composition of the films along the substrate were obtained by principal component analysis (PCA) using Raman spectra. It was found that at small target-substrate distances (12 mm is the distance between the target and the substrate, 76 mm is the diameters of the target and the substrate holder, 30 mm is the size of the film deposition area in axial geometry), the effects of resputtering of the deposited film do not lead to a considerable decrease in the lithium content: no phases other than LiNbO3 are formed in the extended central part of the film, the edge of the film contains no more than 2 % of the undesirable LiNb3O8 phase, and the difference in the measured values of deviation of LiNbO3 phase composition from stoichiometry in the film compared to the target is 0.7 mol% Li2O. These results indicate that the technology for depositing of lithium niobate films can be improved since there is no need to produce a target additionally enriched with Li2O.

The composition of trees from Straseni forest compared with the productive potential

In the present article it is studied the composition of stands by species and their correspondence with the productive potential offered, in the conditions of the central area of the Republic of Moldova, located in the Straseni district, Straseni forest entity. The most valuable natural and fundamental trees were preserved here. The main species is present – the Quercus petrea, followed by the Quercus robur. Deviation of current compositions from optimal ones is the resoult of of poor forest management in the past. Accurately establishing the reason for the deviation from the optimal compositions will ensure the comparisons also made according to climatic conditions. The species structure of the volume reflects the ability to capitalize on the natural conditions of the territory where it is installed.

Classification of acacia, rape and multifloral Hungarian honey types

The composition of honey is mostly determined by the species-specific characteristics of flowering plants, which is reflected in the significant deviations in composition of honey varieties. The high-quality acacia honey is assessed based on both physical-chemical parameters and melissopalynology. The appearance of rape pollen in acacia honey makes the acacia honey be sorted into the multifloral honey category. Over carrying out melissopalynology, the149 samples of various honeys (acacia, rape and multifloral) have also been analysed by using physical-chemical and elemental analysis. Multivariate data analysis revealed that multifloral honey is much closer to acacia honey than to rape honey, as it can be observed from the examined unique parameters. By the PCA (Principal Component Analysis) analysis based on united set of physico-chemical and melissopalynology results the acacia and rape honey samples are entirely separated for each other, while multifloral honey samples are very close to acacia honey group and partially overlap with it. On ignoring the pollen analysis and based on the rest of the results, the multifloral honey category is almost indistinguishable from the declared and verified acacia honey category.

Rapid estimation of γ' solvus temperature for composition design of Ni-based superalloy via physics-informed generative artificial intelligence

The exceptional high-temperature mechanical properties of Ni-based superalloys are mainly stemmed from the L12 γ' phase, therefore it is crucial to discover Ni-based superalloys with high γ' solvus temperatures. Utilizing generative artificial intelligence, we have developed a framework to swiftly evaluate the γ' solvus temperature and tailor Ni-based superalloys, accelerating the process of discovering Ni-based superalloys. Physics-informed artificial neural network emerged as the optimal choice for reverse engineering, outperforming other models with an R2 score of 0.917 and a mean absolute error of 15 K. In the reverse design process, 20,000 virtual alloy samples were generated based on divide-and-conquer variational autoencoder which divides the dataset into distinct clusters by K-means algorithm provides a structured representation of the alloy composition space, thereby facilitating a more nuanced understanding of its inherent complexities. In a specific alloy design example, 563 samples were identified through screening based on criteria like γ' solvus temperature, composition deviation index, price, and density. Thermodynamic calculations were used to further screen Ni-based superalloys with exceptional high-temperature properties. The showcase of BA alloy discovery through generative artificial intelligence demonstrates the potential of our research to steer the creation of novel compositions for Ni-based superalloys with outstanding high-temperature properties.

The choice of rational adjustment of the chemical composition of iron melted in an electric arc furnace on the basis of technological audit of serial films

The object of research in the work is cast iron of the SCh20 grade according to GOST 1412-85 (DSTU EN 1561, EN-GJL-200), which is melted in an electric arc furnace. In this work, the parameters of serial smeltings of cast iron used for machine-building castings were determined, which were used to select the content of elements of the chemical composition. The existing problem is that the impossibility of taking into account many factors influencing the formation of the chemical composition of cast iron during smelting leads to deviations of the chemical composition from the requirements regulated by the technical conditions. The main reason for this is the uncontrollability of the chemical composition of the charge materials and the difficulty of accurately determining the soot of the elements during the smelting process. This can lead to the formation of a shortage of cast iron, or to excessive costs for smelting, associated with the need for additional technological operations and the use of additional materials to eliminate detected deviations of the composition from the requirements. The procedure of technological audit of serial smeltings is proposed, the feature of which is a comprehensive assessment of the actual indicators of smelting. They include: mathematical expectations of the content of the elements of the chemical composition, estimates of their dispersions, root mean square deviations, systematic errors, scattering fields and deviations of the lower and upper limits of the content of each element from the lower and upper limits required by the technical conditions. The results of such an audit are the possibility of calculating corrective combinations of charge materials and ferroalloys, which eliminate inaccuracies in the calculation of the charge and the determination of the heat of the elements during the smelting process. As a result of the audit of a sample of 31 serial smelters, it was established that the average content of the elements C, Mn, Si, Cr exceeds the average required by technical conditions. These deviations are: +0.04 % C, +0.06 % Mn, +0.038 % Si, +0.06 % Cr. To compensate for these deviations, the following combination of charge materials and ferroalloys, which are introduced into the melt before delivering the cast iron to the casting area, is proposed: 44 kg of steel scrap +88 kg of recycled iron. The presented study will be useful for machine-building enterprises that have foundries in their structure, where iron is melted for the production of castings.

Isotope engineering achieved by local coordination design in Ti-Pd co-doped ZrCo-based alloys

Deuterium/Tritium (D/T) handling in defined proportions are pivotal to maintain steady-state operation for fusion reactors. However, the hydrogen isotope effect in metal-hydrogen systems always disturbs precise D/T ratio control. Here, we reveal the dominance of kinetic isotope effect during desorption. To reconcile the thermodynamic stability and isotope effect, we demonstrate a quantitative indicator of Tgap and further a local coordination design strategy that comprises thermodynamic destabilization with vibration enhancement of interstitial isotopes for isotope engineering. Based on theoretical screening analysis, an optimized Ti-Pd co-doped Zr0.8Ti0.2Co0.8Pd0.2 alloy is designed and prepared. Compared to ZrCo alloy, the optimal alloy enables consistent isotope delivery together with a three-fold lower Tgap, a five-fold lower energy barrier difference, a one-third lower isotopic composition deviation during desorption and an over two-fold higher cycling capacity. This work provides insights into the interaction between alloy and hydrogen isotopes, thus opening up feasible approaches to support high-performance fusion reactors.

Microstructure evolution and solidification behaviour of ZrB2-SiC composite ceramics fabricated by laser surface zone-melting

Microstructure evolution and solidification behaviour of ZrB2-SiC composite ceramics fabricated by laser surface zone-melting were investigated. Microstructure coarsening at high scanning speed and microstructure refining after turning off the laser was observed due to the changes in the solidification rate. The solidification behaviour from bottom to top of the molten pool was studied, where there are some coarsen eutectic bands caused by the secondary heating of the melting pool on the solidified eutectic zone in the molten pool. The deviation of melt composition from the eutectic ratio due to the volatilization of SiC can form a coarse primary ZrB2 phase among fine eutectic structure (single-phase instability), and the constitutional supercooling due to the accumulation of impurity elements can form coarse eutectic dendrites among fine eutectic structure (two-phase instability). Both single-phase instability and two-phase instability are adverse to the mechanical properties, which should be prevented by adjusting the composition of raw materials and the solidification process.

The effect of electrode composition on bimetallic AgAu nanoparticles produced by spark ablation

A flexible way to generate bimetallic nanoparticles with high control of their composition is to use spark ablation of alloyed electrodes. It has been generally accepted and stated that particles produced using spark ablation of alloyed electrodes obtain the same chemical composition as the electrodes. However, we identify a lack of studies fully supporting the connection between electrode and particle composition, presented in a small literature survey. The aim of the study is, hence, to explore the validity of the statement by analysing the relation between alloyed electrodes and their resulting particle composition using three sets of AgAu electrodes containing Au and 25, 50, and 75 atomic % Ag, respectively. The resulting composition is thoroughly investigated using both single particle (scanning- and transmission electron microscopy) and ensemble particle techniques (inductive coupled plasma-mass spectroscopy, x-ray photoelectron spectroscopy, x-ray fluorescence, and optical measurements of surface plasmon resonance. We also investigate how sample size (e.g., the number of particles analysed) affects the reliability of the resulting sample mean. For single-particle measurements of a sample with a compositional standard deviation of a few atomic percentage points, a sample size of 20 particles is a good benchmark for obtaining reliable results of the sample mean. Furthermore, this article aims to challenge the practice in which the composition of nanoparticles is measured, presented, and interpreted, to improve and facilitate future research related to this topic. From the results of this study, it could be concluded that for the investigated Ag–Au material system, the particles obtained a composition very similar to the alloyed AgAu electrodes.

Stimulative piezoelectric nanofibrous scaffolds for enhanced small extracellular vesicle production in 3D cultures.

Small extracellular vesicles (sEVs) have great promise as effective carriers for drug delivery. However, the challenges associated with the efficient production of sEVs hinder their clinical applications. Herein, we report a stimulative 3D culture platform for enhanced sEV production. The proposed platform consists of a piezoelectric nanofibrous scaffold (PES) coupled with acoustic stimulation to enhance sEV production of cells in a 3D biomimetic microenvironment. Combining cell stimulation with a 3D culture platform in this stimulative PES enables a 15.7-fold increase in the production rate per cell with minimal deviations in particle size and protein composition compared with standard 2D cultures. We find that the enhanced sEV production is attributable to the activation and upregulation of crucial sEV production steps through the synergistic effect of stimulation and the 3D microenvironment. Moreover, changes in cell morphology lead to cytoskeleton redistribution through cell-matrix interactions in the 3D cultures. This in turn facilitates intracellular EV trafficking, which impacts the production rate. Overall, our work provides a promising 3D cell culture platform based on piezoelectric biomaterials for enhanced sEV production. This platform is expected to accelerate the potential use of sEVs for drug delivery and broad biomedical applications.

Isobaric Vapor-Liquid Equilibrium of Methyl Salicylate + Ethyl Salicylate and Methyl Salicylate + α-Pinene Binary Systems at 20.0 and 50.0 kPa

Gandapura oil, also called wintergreen oil in international trade, is evaluated based on the purity of its methyl salicylate content. Gandapura oil has several impurities including mainly ethyl salicylate and α-pinene, which can lower its quality and price. Indonesian local farmer’s gandapura oil has a low methyl salicylate content of only 82.23%, and appears in a dark red colour instead of clear. The low grade product may have been caused by thermal degradation of compounds within gandapura oil by constant heating during atmospheric distillation at temperature above its thermal threshold. The determination of their vapor-liquid equilibrium data can provide basic data for the separation and purification of methyl salicylate towards its two main impurities in gandapura oil. The vacuum pressure condition was selected to lower the distillation temperature, aiming to reduce the chance of thermal decomposition. The vapor-liquid equilibrium under isobaric conditions in the binary systems of methyl salicylate + ethyl salicylate and methyl salicylate + α-Pinene at 20.0 and 50.0 kPa were measured experimentally using modified Glass Othmer-Still. Gas Chromatography (GC) was utilized to analyze the composition of both the liquid and vapor phases in the samples. The thermodynamic consistency of experimental data was confirmed through the L-W Wisniak method. The experimental results were successfully correlated with Wilson, NRTL, and UNIQUAC models. The average absolute deviations of temperature (AAD T) and vapor phase composition (AAD y) between experimental data and models are less than 0.8058 and 0.0196, respectively for all systems. In terms of quality, all samples collected post-experiment maintained a clear color, suggesting that vacuum pressure distillation effectively prevents the thermal decomposition of compounds in gandapura oil.

Fabrication and characterization of novel ZnO-loaded mesoporous bioactive glass nanospheres with enhanced physiochemical properties and biocompatibility for bone tissue engineering

Novel ZnO-modified mesoporous bioactive glass nanospheres (MBNs) were developed by a modified sol-gel method and their physiochemical behavior and cytocompatibility were systematically evaluated. Compared to previous researches, an offered synthesis method resulted in much less compositional deviation between the nominal and real compositions, while retaining spherical shape and dispersion of the nanoparticles. The MBNs exhibited a higher specific surface area (280–343 m2/g) and a larger pore volume than various ZnO-loaded bioactive glasses prepared before. In contrast to most mesoporous bioceramics doped with ZnO, the current nanoparticles revealed an excellent bioactivity within 14 days immersion in simulated body fluid (SBF). Furthermore, an optimum ZnO content for enhanced viability of bone marrow mesenchymal stem cells cultured with ionic extracts of the nanoparticles is 0.5%. Thanks to a high particle dispersion, good textural properties, bioactivity, and high cytocompatibility, the prepared nanoparticles can be recommended as promising filler materials dental/bone tissue engineering.

Prediction of delta-ferrite formation in 17-4 PH steel using zero-inflated Gaussian process

Alloy composition plays a pivotal role in the formation of phases and precipitates. A compelling example of this phenomenon is evident in the case of 17-4 PH steel, where even slight deviations in alloy composition can notably influence the formation of phases such as δ-ferrite. While thermodynamic calculations are invaluable in predicting the formation of phases, the procedure can become rather time-intensive, particularly when dealing with a wide array of alloy compositions. This issue is further exacerbated by the complex non-linear relationships that exist between the constituent elements and phases. While data-driven analyses can help, traditional machine learning (ML) models struggle to accurately predict δ-ferrite formation due to its zero-inflated nature. This is a result of how combinations of elemental compositions can either result in the presence or absence of δ-ferrite. This paper proposes a zero-inflated Gaussian process (GP) model, ZIGP, to understand the effect of alloying elements on the formation of δ-ferrite. This hybrid model combines a classifier and a regressor, showing an exceptional mean root relative squared error value of 0.407 and 0.843 for the prediction of the maximum δ-ferrite fraction and the δ-ferrite formation temperature, respectively. The ZIGP model is also used to understand the sensitivities of the δ-ferrite phase formation to different constituent elements. The model outperforms other traditional ML models applied to the zero-inflated data. The results of this research, thus, not only provide an understanding of the phases but can also be extended to optimize material composition and design appropriate heat treatment cycles to achieve desired properties.

Understanding the gut microbiota by considering human evolution: a story of fire, cereals, cooking, molecular ingenuity, and functional cooperation.

SUMMARYThe microbial community inhabiting the human colon, referred to as the gut microbiota, is mostly composed of bacterial species that, through extensive metabolic networking, degrade and ferment components of food and human secretions. The taxonomic composition of the microbiota has been extensively investigated in metagenomic studies that have also revealed details of molecular processes by which common components of the human diet are metabolized by specific members of the microbiota. Most studies of the gut microbiota aim to detect deviations in microbiota composition in patients relative to controls in the hope of showing that some diseases and conditions are due to or exacerbated by alterations to the gut microbiota. The aim of this review is to consider the gut microbiota in relation to the evolution of Homo sapiens which was heavily influenced by the consumption of a nutrient-dense non-arboreal diet, limited gut storage capacity, and acquisition of skills relating to mastering fire, cooking, and cultivation of cereal crops. The review delves into the past to gain an appreciation of what is important in the present. A holistic view of "healthy" microbiota function is proposed based on the evolutionary pathway shared by humans and gut microbes.

Secondary Ion Mass Spectrometry of Single Giant Unilamellar Vesicles Reveals Compositional Variability.

Giant unilamellar vesicles (GUVs) are a widely used model system to interrogate lipid phase behavior, study biomembrane mechanics, reconstitute membrane proteins, and provide a chassis for synthetic cells. It is generally assumed that the composition of individual GUVs is the same as the nominal stock composition; however, there may be significant compositional variability between individual GUVs. Although this compositional heterogeneity likely impacts phase behavior, the function and incorporation of membrane proteins, and the encapsulation of biochemical reactions, it has yet to be directly quantified. To assess heterogeneity, we use secondary ion mass spectrometry (SIMS) to probe the composition of individual GUVs using non-perturbing isotopic labels. Both 13C- and 2H-labeled lipids are incorporated into a ternary mixture, which is then used to produce GUVs via gentle hydration or electroformation. Simultaneous detection of seven different ion species via SIMS allows for the concentration of 13C- and 2H-labeled lipids in single GUVs to be quantified using calibration curves, which correlate ion intensity to composition. Additionally, the relative concentration of 13C- and 2H-labeled lipids is assessed for each GUV via the ion ratio 2H-/13C-, which is highly sensitive to compositional differences between individual GUVs and circumvents the need for calibration by using standards. Both quantification methods suggest that gentle hydration produces GUVs with greater compositional variability than those formed by electroformation. However, both gentle hydration and electroformation display standard deviations in composition (n = 30 GUVs) on the order of 1-4 mol %, consistent with variability seen in previous indirect measurements.

Evading the refining-induced trade-off between performance enhancement and alloy composition deviation in Fe-based amorphous alloys

Understanding the slag-metal reactions in Fe-based amorphous alloys is of paramount importance to evade the refining-induced trade-off between performance enhancement and alloy composition deviation. In this study, the B2O3 and B2O3–CaO slags refining-induced alloy composition deviation was theoretically and experimentally verified in Fe83Si2B12P3 (at.%) amorphous alloy, and a quaternary SiO2–B2O3–CaO–Al2O3 slag suitable for FeSiBP amorphous alloy was designed after the careful calculation of slag-metal equilibrium, slag viscosity and melting point. After refining with simple B2O3 and B2O3–CaO slags, the enrichment of B element and depletion of Si element in the FeSiBP amorphous alloy was confirmed due to the oxidation of constituent Si element and the reduction of B2O3 in the slag. The refining-induced alloy composition deviation can be effectively alleviated by using our designed slags, and the 20%SiO2–55%B2O3–10%CaO–15%Al2O3 (wt.%) slag is effective in removing the impurities and enhancing the glass-forming ability (GFA). In terms of the removal of impurities, the high activity of B2O3 in slag is crucial for the oxidation and removal of Mn, Al, Ti impurities. These results are quite vital for the design of refining slags suitable for Fe-based amorphous alloys and pave the way for the large-scale production of high-performance soft magnetic materials.

Dynamic changes of fecal microbiota in a weight-change model of Bama minipigs.

Obesity is closely related to gut microbiota, however, the dynamic change of microbial diversity and composition during the occurrence and development process of obesity is not clear. A weight-change model of adult Bama pig (2 years, 58 individuals) was established, and weight gain (27 weeks) and weight loss (9 weeks) treatments were implemented. The diversity and community structures of fecal microbiota (418 samples) was investigated by using 16S rRNA (V3-V4) high-throughput sequencing. During the weight gain period (1~27 week), the alpha diversity of fecal microbiota exhibited a "down-up-down" fluctuations, initially decreasing, recovering in the mid-term, and decreasing again in the later stage. Beta diversity also significantly changed over time, indicating a gradual deviation of the microbiota composition from the initial time point. Bacteroides, Clostridium sensu stricto 1, and Escherichia-Shigella showed positive correlations with weight gain, while Streptococcus, Oscillospira, and Prevotellaceae UCG-001 exhibited negative correlations. In the weight loss period (30~38 week), the alpha diversity further decreased, and the composition structure underwent significant changes compared to the weight gain period. Christensenellaceae R-7 group demonstrated a significant increase during weight loss and showed a negative correlation with body weight. Porphyromonas and Campylobacter were positively correlated with weight loss. Both long-term fattening and weight loss induced by starvation led to substantial alterations in porcine gut microbiota, and the microbiota changes observed during weight gain could not be recovered during weight loss. This work provides valuable resources for both obesity-related research of human and microbiota of pigs.