Safety and efficacy of adding postbiotics in infant formula: a systematic review and meta-analysis.

Postbiotics, as emerging products, were added to infant formula, but their safety and efficacy are unclear. To clarify this issue, we wrote this meta-analysis. We searched PubMed, Embase, Web of Science and ProQuest from its establishment to February 2023. The review was registered on PROSPERO database (CRD42022352405). The effects of infant formula with and without postbiotics were compared, and the incidence of serious adverse events (SAEs), digestive symptoms, concentration of stool secretory immunoglobulin A (SIgA), and growth and development indexes were analyzed. Nine randomized controlled trials with 2065 participants were included. The addition of postbiotics to infant formula was found to increase the concentration of stool SIgA (P < 0.05) with very low certainty of evidence, without significantly impacting the incidence of SAEs, infantile colic, flatulence, diarrhea, vomiting, abdominal pain and gastrointestinal disorders, the daily weight gain, the total gain in body length and the daily head circumference gain (all P > 0.05). Adding postbiotics to the formula is safe for infants, which would not increase the incidence of SAEs, infantile colic, flatulence, diarrhea, vomiting, abdominal pain, and gastrointestinal disorders, and could increase the concentration of stool SIgA. IMPACT: Our study provides evidence that the addition of postbiotics to infant formula is safe but not effective. This is the first systematic review and meta-analysis of postbiotics. This study provides strong evidence for the safety of postbiotics and lays a foundation for related clinical trials.

Association between the gut microbiota and nonalcoholic fatty liver disease: A two-sample Mendelian randomization study.

BACKGROUND: Increasing studies have shown that there is a significant association between gut microbiota and non-alcoholic fatty liver disease. AIMS: To show the potential association between gut microbiota and non-alcoholic fatty liver disease, we performed a two-sample Mendelian randomization analysis. METHODS: We analyzed summary statistics from genome-wide association studies of gut microbiota and non-alcoholic fatty liver disease and conducted Mendelian randomization studies to evaluate relationships between these factors. RESULTS: Of the 211 gut microbiota taxa examined, the inverse variance weighted method identified Lactobacillaceae (OR = 0.83, 95% CI = 0.72 - 0.95, P = 0.007), Christensenellaceae (OR = 0.74, 95% CI = 0.59 - 0.92, P = 0.007), and Intestinibacter (OR = 0.85, 95% CI = 0.73 - 0.99, P = 0.035) were negatively correlated with non-alcoholic fatty liver disease. And Coriobacteriia (OR = 1.22, 95% CI = 1.01 - 1.42, P = 0.038), Actinomycetales (OR = 1.25, 95% CI = 1.02 - 1.53, P = 0.031), Oxalobacteraceae (OR = 1.10, 95% CI = 1.01 - 1.21, P = 0.036), Ruminococcaceae_UCG005 (OR = 1.18, 95% CI = 1.01 - 1.38, P = 0.033) are positively associated with non-alcoholic fatty liver disease. CONCLUSIONS: Our study found that the abundance of certain strains was associated with the progression of nonalcoholic fatty liver disease.

SKIL/SnoN attenuates TGF-ß1/SMAD signaling-dependent collagen synthesis in hepatic fibrosis.

The ski-related novel gene (SnoN), encoded by the SKIL gene, has been shown to negatively regulated transforming growth factor-ß1 (TGF-ß1) signaling pathway. However, the roles of SnoN in hepatic stellate cell (HSC) activation and hepatic fibrosis (HF) are still unclear. To evaluate the role of SnoN in HF, we combined bulk RNA sequencing analysis and single-cell RNA sequencing analysis to analyse patients with HF. The role of SKIL/SnoN was verified using liver samples from rat model transfected HSC-T6 and LX-2 cell lines. Immunohistochemistry, immunofluorescence, PCR, and western blotting techniques were used to demonstrate the expression of SnoN and its regulatory effects on TGF-ß1 signaling in fibrotic liver tissues and cells. Furthermore, we constructed competitive endogenous RNA regulatory network and potential drug network associated with the SnoN gene. We identified SKIL gene as a differentially expressed gene in hepatic fibrosis. SnoN protein was found to be widely expressed in the cytoplasm of normal hepatic tissues, whereas it was almost absent in HF tissues. In the rat group subjected to bile duct ligation (BDL), SnoN protein expression decreased, while TGF-ß1, collagen III, tissue inhibitor of metalloproteinase 1 (TIMP-1), and fibronectin levels increased. We observed the interaction of SnoN with p-SMAD2 and p-SMAD3 in the cytoplasm. Following SnoN overexpression, apoptosis of HSCs was promoted, and the expression of HF-associated proteins, including collagen I, collagen III, and TIMP-1, was reduced. Conversely, downregulation of SnoN inhibited HSC apoptosis, increased collagen III and TIMP-1 levels, and decreased matrix metalloproteinase 13 (MMP-13) expression. In conclusion, SnoN expression is downregulated in fibrotic livers, and could attenuate TGF-ß1/SMADs signaling-dependent de-repression of collagen synthesis.

Comparative Analysis of Out-of-Plane Deformation Mechanisms of Vertex-Based Hierarchical Structures for Crashworthiness.

This study examines a hierarchical vertex-based structure that improves the crashworthiness of the conventional multi-cell square, a biological hierarchy of natural origin with exceptional mechanical properties. The vertex-based hierarchical square structure (VHS) is explored for its geometric properties, including infinite repetition and self-similarity. The cut-and-patch method is used to derive an equation for the material thicknesses of different orders of the VHS based on the principle of the same weight. A thorough parametric study of VHS was conducted using LS-DYNA, which examined the effects of material thickness, orders, and various structural ratios. The results were evaluated based on common crashworthiness criteria and demonstrated that the total energy absorption (TEA), specific energy absorption (SEA), and mean crushing force (Pm) of VHS exhibited similar monotonicity concerning the orders. SEA of the first-order VHS with λ1=0.3 and the second-order VHS with λ1=0.3 and λ2=0.1 are improved by at most 59.9% and 102.4% respectively; the second-order VHS with 0.2≤λ1≤0.4 and 0.1≤λ2≤0.15 have the better overall performance of crashworthiness. Then, the half-wavelength equation of VHS and Pm of each fold was established based on the Super-Folding Element method. Meanwhile, a comparative analysis with the simulation results reveals three different out-of-plane deformation mechanisms of VHS. The study indicated that material thickness had a greater impact on crashworthiness. Finally, the comparison with conventional honeycombs demonstrated that VHS holds great promise as a structure for crashworthiness. These results provide a solid foundation for further research and development of new bionic energy-absorbing devices.

Numerical analysis of the slipstream development around a high-speed train in a double-track tunnel.

Analysis of the slipstream development around the high-speed trains in tunnels would provide references for assessing the transient gust loads on trackside workers and trackside furniture in tunnels. This paper focuses on the computational analysis of the slipstream caused by high-speed trains passing through double-track tunnels with a cross-sectional area of 100 m2. Three-dimensional unsteady compressible Reynolds-averaged Navier-Stokes equations and a realizable k-ε turbulence model were used to describe the airflow characteristics around a high-speed train in the tunnel. The moving boundary problem was treated using the sliding mesh technology. Three cases were simulated in this paper, including two tunnel lengths and two different configurations of the train. The train speed in these three cases was 250 km/h. The accuracy of the numerical method was validated by the experimental data from full-scale tests, and reasonable consistency was obtained. The results show that the flow field around the high-speed trains can be divided into three distinct regions: the region in front of the train nose, the annular region and the wake region. The slipstream development along the two sides of train is not in balance and offsets to the narrow side in the double-track tunnels. Due to the piston effect, the slipstream has a larger peak value in the tunnel than in open air. The tunnel length, train length and length ratio affect the slipstream velocities; in particular, the velocities increase with longer trains. Moreover, the propagation of pressure waves also induces the slipstream fluctuations: substantial velocity fluctuations mainly occur in front of the train, and weaken with the decrease in amplitude of the pressure wave.

Multi-Objective Aerodynamic Optimization of the Streamlined Shape of High-Speed Trains Based on the Kriging Model.

Minimizing the aerodynamic drag and the lift of the train coach remains a key issue for high-speed trains. With the development of computing technology and computational fluid dynamics (CFD) in the engineering field, CFD has been successfully applied to the design process of high-speed trains. However, developing a new streamlined shape for high-speed trains with excellent aerodynamic performance requires huge computational costs. Furthermore, relationships between multiple design variables and the aerodynamic loads are seldom obtained. In the present study, the Kriging surrogate model is used to perform a multi-objective optimization of the streamlined shape of high-speed trains, where the drag and the lift of the train coach are the optimization objectives. To improve the prediction accuracy of the Kriging model, the cross-validation method is used to construct the optimal Kriging model. The optimization results show that the two objectives are efficiently optimized, indicating that the optimization strategy used in the present study can greatly improve the optimization efficiency and meet the engineering requirements.

Performance of underground heat storage system in a double-film-covered greenhouse.

An underground heat storage system in a double-film-covered greenhouse and an adjacent greenhouse without the heat storage system were designed on the basis of plant physiology to reduce the energy consumption in greenhouses. The results indicated that the floor temperature was respectively 5.2 degrees C, 4.6 degrees C and 2.0 degrees C higher than that of the soil in the adjacent reference greenhouse after heat storage in a clear, cloudy and overcast sky in winter. Results showed that the temperature and humidity were feasible for plant growth in the heat saving greenhouse.