Search Results (1,910)

Background: Secondhand exposure to heated tobacco products (HTPs) is increasingly common, but its impact on human milk composition is unclear. We investigated whether secondhand exposure to HTP aerosols affects major human milk components and cotinine concentrations in lactating women. Methods: This observational study included 15 lactating women whose household members used HTPs (secondhand HTP exposure group) and 33 lactating women who did not live with any smokers (non-exposed group). Human milk was analyzed for macronutrients, total solids, energy, lactoferrin, secretory immunoglobulin A (sIgA), calcium, inorganic phosphorus, zinc, and cotinine. Cotinine was measured in all women in the secondhand HTP exposure group and in three women in the non-exposed group. Results: Background characteristics did not differ significantly between groups. No significant differences were observed in lipid, protein, total solids, energy, true protein, lactoferrin, calcium, inorganic phosphorus, or zinc. Carbohydrate concentration differed significantly between the non-exposed and secondhand HTP exposure groups (non-exposed vs. secondhand HTP exposure: 8.20 vs. 8.10 g/dL, p = 0.032), although the absolute difference was small. sIgA tended to be higher in the secondhand HTP exposure group (non-exposed vs. secondhand HTP exposure: 1244 vs. 1706 μg/mL, p = 0.072). Cotinine concentrations did not differ significantly between groups; qualitative cotinine tests were negative in all samples. Conclusions: Secondhand exposure to HTPs was not associated with clear differences in major human milk components or cotinine concentrations. However, the findings should be interpreted cautiously because of the small sample size and limited cotinine assessment. Larger studies with objective exposure assessment and infant follow-up are needed. Full article

Lactic acid is a key metabolite in Baijiu fermentation and plays an important role in ester formation and overall flavor development. However, D-lactic acid commonly accumulates in Baijiu and often exceeds L-lactic acid, resulting in low L/D ratios that may negatively affect fermentation performance and sensory quality. Therefore, regulating the optical composition of lactic acid is of significant importance. In this study, an L-lactic acid-enriched wheat bran Qu was developed by inoculating Bacillus cereus B12 and applied in light-flavor Baijiu fermentation. The preparation conditions were optimized using single-factor experiments and orthogonal experimental design. The optimal conditions were an inoculation level of 3%, moisture content of 55%, cultivation temperature of 37 °C, and cultivation time of 60 h, under which the microbial biomass reached 2.02 × 10¹⁰ CFU/g. The L-lactic acid-enriched wheat bran Qu influenced fermentation characteristics, including substrate utilization and physicochemical parameters. Notably, it significantly increased lactic acid production, particularly L-lactic acid, thereby improving the optical composition of lactic acid. Meanwhile, the concentrations of key ester compounds, including ethyl lactate and ethyl acetate, were significantly enhanced (p < 0.05). Microbial community analysis revealed shifts in bacterial composition with enrichment of lactic acid-related genera. These findings demonstrate that L-lactic acid-enriched wheat bran Qu can regulate lactic acid production and promote ester formation, providing a potential strategy for improving flavor quality in light-flavor Baijiu fermentation. Full article

High-intensity 5 km running offers an ideal framework to analyze the organism’s multidimensional responses. Since previous research primarily analyzed isolated aspects of fatigue, this study aimed to examine the integrated acute neuromuscular, metabolic, and perceptual responses to a 5 km run. Twenty-one recreational male runners participated. Pre- and post-race assessments included body composition, blood lactate, m. rectus femoris ultrasound thickness, quadriceps maximal voluntary isometric contraction (MVIC), heart rate, perceived exertion (Borg CR10), and 5 km finish time. Statistical analysis was performed in the Jamovi software, utilizing descriptive statistics, the Shapiro–Wilk test of normality, the Wilcoxon signed-rank test with effect size calculation, and Spearman’s correlation coefficient, at a significance level of p < 0.05. Post-race measurements revealed a significant decrease in quadriceps MVIC (pre: 305 ± 99 N vs. post: 259 ± 88 N; p = 0.002) and an increase in blood lactate (pre: 0.8 ± 0.4 vs. post: 6.9 ± 1.4 mmol/L; p < 0.001), alongside high average heart rates (165 ± 16 bpm). However, ultrasound-assessed muscle architecture remained unchanged. The 5 km run induced pronounced neuromuscular and metabolic fatigue. Unchanged muscle architecture suggests that acute strength decline is primarily mediated by metabolic and neural mechanisms, rather than immediate structural–morphological factors. These findings highlight the value of an integrated assessment approach for understanding acute fatigue responses following high-intensity 5 km running and may contribute to more precise training-load prescription and recovery monitoring in recreational runners. Full article

This study evaluated the effects of replacing alfalfa hay with sulla [Sulla coronaria (L.) B.H. Choi & H. Ohashi] hay or sulla haylage in pasture-based diets for lactating Sarda ewes on milk production, milk composition, and nutrient utilization efficiency. Seventy-two mid-lactation ewes were assigned to three dietary treatments for 56 days—alfalfa hay (AH), sulla hay (SH), or sulla haylage (SHL)—all combined with 3 h/day grazing and a fixed amount of supplemental concentrate. The diets were formulated to be theoretically isoenergetic and isoproteic. Pasture nutritive value was generally comparable among the groups throughout the experimental period. Milk yield did not differ among treatments; however, fat- and protein-corrected milk (FPCM) and milk fat and protein concentrations were higher in AH compared with the sulla-based diets. Actual nutrient intake differed among treatments, with nitrogen intake (NI) being greatest in AH, consistent with the higher milk urea concentration observed in this group. Estimated apparent energy utilization efficiency (FPCM/UFL intake) showed treatment-associated differences in exploratory analyses, with lower values observed in SH compared with AH and SHL. Similarly, exploratory estimates of apparent nitrogen utilization efficiency (Milk N/NI) were highest in SHL, intermediate in SH, and lowest in AH (p < 0.001). Condensed tannins were not detected in the conserved sulla forages under the analytical conditions adopted in this study. Therefore, the observed responses were unlikely to be directly associated with detectable condensed tannin activity. Overall, the results suggest that forage conservation method may influence milk composition and estimated apparent nutrient utilization indices, with sulla haylage showing higher exploratory estimates of apparent nitrogen utilization efficiency without negative effects on milk yield under the conditions of the present study. Full article

Age-related hyperphosphatemia is increasingly recognized as a contributing factor in sarcopenia. This work studies the metabolic effects of elevated phosphate on muscle. C2C12 cells were differentiated in the absence or presence of 10 mM β-glycerophosphate (BGP), an exogenous phosphate donor. In addition, quadriceps muscles from four experimental groups of male C57BL/6J mice were analyzed: young (5 months) and old (24 months) fed with standard diet; old mice fed with hypophosphatemic diet or supplemented with the phosphate binder Velphoro^®, for the last three months of life. Mice were stratified according to sarcopenia degree based on muscle mass, strength and physical performance. Protein levels were determined by immunoblotting and mRNA expression by RT-qPCR. ATP levels were measured by luminescence and L-lactate production, citrate synthase and cytochrome c oxidase activities by colorimetric assays. Mitochondrial content, membrane potential and reactive oxygen species (ROS) were determined by fluorescence assay. BGP-treated cells showed increased glucose transporter 1 (GLUT1) and decreased NADH Dehydrogenase (CI-NDUFB8) protein expression, elevated hexokinase II (HK2), phosphoglycerate kinase 1 (PGK1) and lactate dehydrogenase A (LDHA) mRNA levels, reduced ATP levels, increased lactate production, and decreased mitochondrial enzyme activities. Moreover, BGP increased ROS, diminished mitochondrial membrane potential, and altered fusion–fission dynamics and mitophagy. In aged quadriceps, oxidative phosphorylation (OXPHOS) subunits and superoxide dismutase 2 (SOD2) expression were reduced. The hypophosphatemic diet improved all parameters, whereas Velphoro^® selectively increased Mitochondrial cytochrome C oxidase subunit 1 (CIV-MTCO1) expression. Several altered mitochondrial markers are associated with sarcopenia degree. Altogether, hyperphosphatemia induces metabolic changes that scale with the sarcopenic degree. Our findings show a relevant association between hyperphosphatemia and mitochondrial dysfunction, and they support the potential benefit of phosphate reduction as a strategy to prevent or mitigate sarcopenia. Full article

Background/Objectives: We investigated the association of serum ferritin and procalcitonin (PCT) with Sepsis-related Organ Failure Assessment (SOFA)-2 score-based organ dysfunction severity in intensive care patients with COVID-19-associated sepsis. Methods: Patients were stratified by day 5 ferritin (ng/mL) and PCT (μg/L) levels; associations were analysed across severity groups defined by an SOFA-2 score of <5 (mild) or ≥5 (severe). Results: Day 5 PCT did not predict the SOFA-2 score (p > 0.05). The optimal day 5 ferritin cut-off was >1191 ng/mL (35.78% sensitivity, 82.38% specificity; area under the curve (AUC) = 0.608). Day 5 ferritin was associated with SOFA-2 severity in the univariable analysis but did not remain an independent correlate after adjustment for C-reactive protein (CRP) and lactate dehydrogenase (LDH); in a mortality model, neither ferritin nor PCT independently predicted intensive care unit (ICU) death. PCT provided no predictive value beyond existing inflammatory markers, consistent with its suppression during viral infections. Conclusions: Day 5 ferritin reflects, rather than independently predicts, organ dysfunction severity and may complement, rather than replace, established multi-parameter scoring. Relative to the independent determinants of severity and mortality (PaO₂/FiO₂ ratio, LDH, CRP, and age), day 5 ferritin is a specific, rule-in adjunctive marker of concurrent organ dysfunction rather than a standalone prognostic tool. Whether these associations extend to non-COVID sepsis populations requires prospective study. Full article

Background and Objectives: Small lymphocytic lymphoma (SLL) represents the tissue-based manifestation of chronic lymphocytic leukemia (CLL). Despite their shared biological background, patients with SLL have been underrepresented in CLL-focused clinical trials, and data addressing the clinical behavior of pure nodal SLL remain scarce. The present study aimed to identify factors associated with time to first treatment (TTFT) and progression-only survival in patients with pure nodal SLL. Materials and Methods: In this prospective observational study, 46 patients with pure nodal SLL were included and followed for a median duration of approximately 5 years. Clinical, laboratory, histopathological, and TP53-related parameters were evaluated for their prognostic impact on TTFT and progression-only survival. Results: On univariable analysis, advanced-stage disease, hemoglobin < 10 g/dL, elevated serum β2M, elevated lactate dehydrogenase, del(17p), and aberrant p53 immunohistochemical expression were significantly associated with shorter TTFT and progression-only survival. Conclusions: Pure nodal SLL is a heterogeneous entity with a variable clinical course. Easily assessable clinical and biological parameters, including TP53 abnormalities, may help predict treatment requirement and disease progression, thereby contributing to better risk stratification and more individualized management. Kaplan–Meier analysis demonstrated significantly shorter time-to-first-treatment (TTFT) among patients with elevated β2M levels (≥3.5 mg/L), bulky lymphadenopathy (≥5 cm), and advanced-stage disease. Full article

Background: Critically ill patients experience rapid muscle wasting during their ICU stay. Ultrasound (US) and bioelectrical impedance analysis (BIA) are widely used to assess muscle mass; however, their accuracy may be affected by fluid balance alterations. This study aimed to compare the reliability of US and BIA in detecting muscle loss under varying fluid balance conditions in ICU patients. Methods: In this prospective observational study, adult ICU patients with an ICU stay of ≥7 days were evaluated on Days 1, 5, and 7. Muscle thickness was measured using US, and phase angle (PhA) using BIA. Cumulative fluid balance, C-reactive protein (CRP), and lactate levels were recorded. Patients were stratified according to cumulative fluid balance. Results: A total of 143 ICU patients were included in the final analysis. US demonstrated a progressive decrease in muscle thickness (−3.54% ± 10.90% from Day 1 to Day 5 and −7.56% ± 11.82% from Day 1 to Day 7 (both p < 0.0001)), whereas BIA showed no significant change in PhA. Positive fluid balance significantly reduced PhA compared with the negative balance group, p < 0.001, whereas no statistically significant effect on US measurements was detected. CRP > 200 mg/L was associated with greater US-detected muscle loss on Day 5, while lactate > 2.5 mmol/L was associated with lower PhA. Conclusions: Ultrasound reliably identified structural muscle wasting in critically ill patients, with no statistically significant effect of fluid balance detected in this cohort. Furthermore, ultrasound measurements were associated with inflammation-related muscle loss. In contrast, BIA was strongly influenced by hydration and perfusion status, limiting its ability to assess true muscle mass loss in the ICU setting. Full article

Melittin (Mel) is a membrane-active peptide with potential anticancer activity, but its direct therapeutic application may be limited by nonspecific toxicity and delivery-related challenges. The study aimed to assess melittin-functionalized magnetic nanoparticles (MNPs-Mel) as a strategy to enhance antitumor activity in Caco-2 cells, with/without magnetic hyperthermia (MH) association. BJ fibroblasts were used as a normal human in vitro cellular model. The effects of free Mel (2.5 µg/mL), MNPs, and MNPs-Mel (50 µg/mL both) + MH (30 min at 355 kHz and 25 kA/m) were assessed using colorimetry (for viability), luminescence (ATP), and spectrophotometry (lactate) following different exposure conditions. The mechanism of apoptosis induction was evaluated by ELISA (caspase 8 and 9 levels). Transmission electron microscopy (TEM) was also used to evaluate nanoparticle morphology and treatment-associated cellular ultrastructural changes. Free Mel reduced viability in both cell lines, with Caco-2 cells showing greater sensitivity at lower concentrations. MNPs (with/without MH) produced limited and less consistent effects, whereas MNPs-Mel significantly reduced Caco-2 viability and ATP levels and increased LDH and caspase 9. MH further enhanced the effects of MNPs-Mel: reduced viability (57–58% of the control at 24 h and 72 h), decreased ATP levels (67% of the control at 24 h and 53% at 72 h), increased LDH levels (206% of the control at 24 h and 301% at 72 h), and induced the mitochondrial apoptotic pathway (caspase 9 increased with 2164% of the control at 72 h). TEM proved the internalization of both MNPs and MNPs-Mel and revealed extensive ultrastructural alterations concerning mitochondria and lysosomes produced by MNPs-Mel, particularly in the Caco-2 cells. These modifications were heavily increased by MNPs-Mel + MH exposure. Overall, these findings demonstrate that Mel functionalization increases the antitumor activity of Mel at lower doses and that MH further potentiates this effect in Caco-2 cells. Full article

Background: Lepidium meyenii Walp (L. meyenii), traditionally known as maca, is widely recognized for its health-promoting properties, including potential protection against exercise-induced muscle damage (EIMD). However, its precise effect on post-exercise blood biomarkers remains unclear. Objective: This study aimed to qualitatively review research published until April 2026 examining L. meyenii supplementation to reduce blood markers of muscle damage and protein degradation post-exertion in animal studies. Specifically, the effect size (ES) of L. meyenii supplementation on post-exercise levels of creatine kinase (CK), lactate dehydrogenase (LDH), and blood urea nitrogen (BUN) was estimated. Methods: This systematic review and meta-analysis were conducted in accordance with the PRISMA guidelines. The certainty of the evidence was assessed using the GRADE framework. Relevant studies were identified through Web of Science, Scopus, SPORTDiscus, PubMed, and MEDLINE. Eligible studies included in vivo experiments in animals with controlled designs and pre-/post-intervention assessments. Methodological quality and risk of bias were evaluated using the CAMARADES tool. Statistical analysis involved standardized mean differences (SMD) using Hedges’ g with 95% confidence intervals. Results: 15 studies were included in the systematic review, and 14 studies in animals in the meta-analysis. The CAMARADES scores ranged from 5 to 7 points, indicating moderate methodological quality. Supplementation with L. meyenii was not associated with statistically significant changes in LDH (SMD = −1.37; 95% CI −3.34 to 0.59), BUN (SMD = −0.37; 95% CI −2.16 to 1.42) nor CK (SMD = 0.29; 95% CI −5.45 to 6.03), with very high heterogeneity (I² > 97%). Exploratory subgroup analyses and meta-regression analyses by formulation type and dose did not identify any moderators that could robustly explain this heterogeneity. Conclusions: The available evidence does not support a robust overall effect of L. meyenii supplementation on blood biomarkers of muscle damage or protein catabolism in animals subjected to physical stress. The high degree of heterogeneity could not be robustly explained by either the type of formulation or the dose. These findings, which are exploratory and hypothesis-generating in nature, highlight the need for standardized, well-characterized formulations and trials with adequate statistical power. Full article

Uterine infections (metritis and endometritis) are a leading cause of culling and reproductive failure in transition dairy cows, and antibiotic-resistant Gram-negative pathogens limit conventional therapy. This randomized, controlled, multi-farm field trial evaluated whether four intravaginal infusions of a host-adapted lactic acid bacteria (LAB) cocktail (Lactobacillus sakei FUA3089, Pediococcus acidilactici FUA3138, P. acidilactici FUA3140; 10⁸–10⁹ cfu/dose) at −3, −2, +3, and +4 weeks relative to calving reduce periparturient disease and improve milk production. A total of 526 pregnant cows (426 Holstein, 100 Jersey) from four commercial Alberta farms (automatic-milking, parlor, and certified-organic systems) were block-randomized within farm and parity to TRT1 (saline; n = 175), TRT2 (saline + skim milk; n = 176), or TRT3 (LAB cocktail in saline + skim milk; n = 175). Uterine infection incidence was assessed by Metricheck™ mucus scoring and transrectal ultrasonography at +3 and +4 weeks postpartum. Across the principal peripartum infectious outcomes, TRT3 showed a consistent protective effect: uterine infection incidence was lowest in TRT3 (18.8% vs. 25.1% in pooled controls; OR = 0.69; 95% CI, 0.44–1.09; an approximately 25% relative reduction; exact p = 0.12), and this metritis signal was additionally supported by a repeated-measures mixed model accounting for farm, parity, and week (p = 0.0175), although the Bonferroni-adjusted pairwise contrasts were tendencies (adjusted p ≈ 0.12), and the effect did not differ by parity (treatment × lactation interaction, p = 0.97). Subclinical mastitis was numerically lower in TRT3 than in pooled controls (5.3% vs. 8.9%; OR = 0.57; 95% CI, 0.27–1.24; exact p = 0.16), whereas retained placenta, milk fever, displaced abomasum, and lameness showed no clear cow-level treatment effect in the cow-level exact analyses. Milk yield increased significantly in multiparous cows, which produced 4.6 L/day more milk than TRT1 and 3.22 L/day more than TRT2 over the first 50 days in milk (p < 0.01 for both contrasts; treatment × parity interaction, p = 0.01). No effect was seen on milk composition, uterine involution, or reproductive performance. The trial supports intravaginal LAB as a candidate antibiotic-free prophylactic whose response depends on farm- and cow-level contexts and whose mechanisms require confirmation through microbiological and metabolic measurements. Full article

Background/Objectives: Immune checkpoints are critical regulatory pathways that maintain peripheral tolerance and prevent autoimmunity. Among these, the programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) axis serves as a major inhibitory pathway that terminates T cell responses. While protein-based checkpoint blockade (ICB) targeting this axis has revolutionized clinical cancer therapy, its clinical efficacy is frequently limited by low response rates, immune-related adverse events (irAEs), and the emergence of adaptive resistance. To break through these bottlenecks, genetic interruption has emerged as a high-precision alternative to modulate the PD-1/PD-L1 pathway at the nucleotide level. Methods: A comprehensive systematic review of literature was performed across major databases (PubMed, Web of Science), with a focus on high quality studies published up to 2026. Results: Direct genomic disruption via CRISPR/Cas9 and post-transcriptional silencing through RNA interference can effectively neutralize inhibitory signaling at its source. Recent advances demonstrate that targeting upstream regulatory nodes—including metabolic checkpoints (e.g., lactate metabolism) and biophysical mechanisms (e.g., liquid–liquid phase separation)—provides superior transcriptional control over PD-L1. Furthermore, engineering CAR-T cells with multiplex gene editing (e.g., TCR/B2M/PD-1 knockout) or localized scFv secretion significantly enhances antitumor potency while reducing systemic toxicity. Innovations in organ-targeted lipid nanoparticles and stimuli-responsive biomimetic carriers further address the delivery barriers in solid tumors. Conclusions: Gene therapy provides a high-precision platform for PD-1/PD-L1 modulation, offering a viable strategy to overcome adaptive resistance. Future clinical application depends on the refinement of safer editing tools, such as base editing, and the standardization of intelligent delivery systems to ensure controllable and scalable cancer immunotherapy. Full article

Introduction: Temperature is a key environmental factor influencing the physiological and biochemical processes of aquatic organisms, including xenobiotic metabolism. Understanding how temperature modulates the toxicological effects of pollutants such as polycyclic aromatic hydrocarbons (PAHs) is crucial in the context of climate change. Among these compounds, benzo[a]pyrene (BaP) and benzo[a]anthracene (BaA) are priority pollutants in aquatic environments, resulting from incomplete combustion. Their relevance is attributed to persistence and metabolic bioactivation potential. Fish primary hepatocyte cultures represent a relevant in vitro model for studying combined effects of thermal stress and chemical exposures, while supporting the 3Rs principles (Replacement, Reduction, and Refinement). Objective: This study aims to assess temperature-dependent effects of BaP and BaA, and their mixtures in brown trout hepatocytes using cytochrome P450 1A (CYP1A) immunohistochemistry as an indicator of xenobiotic metabolism. Methodology: Primary hepatocytes were isolated using a two-step collagenase perfusion method and cultured in 24-well plates at 18 °C and 22 °C. Cells were exposed for 72 h to supplemented L-15 medium (control) or to 0.1% dimethyl sulfoxide in supplemented L-15 medium (solvent control), as well as to single exposures of 1 and 10 µM of BaP and BaA and to equimolar mixtures of both compounds (1 and 10 µM). Viability was assessed using the lactate dehydrogenase (LDH) assay. CYP1A immunostaining was quantified based on cytoplasmic staining intensity relative to background area. Results: No significant effects on cell viability were observed under any condition. Temperature significantly reduced CYP1A expression in single exposures at 22 °C compared to 18 °C. BaP induced a significant dose-dependent increase, while BaA differed from controls only at 10 µM. In mixtures, only treatment- and dose-dependent effects were observed, with no temperature influence detected. Conclusions: Overall, the data highlight temperature as a key modulator of biochemical responses to PAHs, with single and mixed exposures eliciting distinct effects and suggesting potential synergism in mixtures. Full article

Introduction: The temperature of rivers in the Iberian Peninsula has increased due to global warming. In addition, these rivers are polluted by contaminants of emerging concern, such as polycyclic aromatic hydrocarbons (PAHs). Higher temperatures and pollution concurrently impose threats to the Iberian Peninsula’s endemic species, including the brown trout (Salmo trutta), a cold-water species widely used in ecotoxicological studies. Because the liver is the main biotransformation organ, and is particularly sensitive to both chemical and temperature changes, in vitro liver models may represent valuable alternatives for assessing combined stressor effects, complying with the 3Rs principle. Objective: In line with the above, the present study aimed to evaluate the combined effects of a 4 °C temperature increase and the model PAH benzo[k]fluoranthene (B[k]F) on fish liver cells using a primary brown trout hepatocyte culture as a model. Methodology: Primary hepatocytes were seeded in 6-well plates at a density of 1.0 × 10⁶ cells/mL and exposed for 48 h to 1, 10, and 20 µM B[k]F at 18 °C (normothermia) and 22 °C (warming scenario). Cell viability was assessed using trypan blue, alamarBlue, and lactate dehydrogenase (LDH) assays. Cytochrome P450 (CYP)1A was evaluated in terms of its gene expression by RT-qPCR and its protein expression through immunocytochemistry (ICC). The immunostaining was quantified using a score system which considered five intensity staining levels. Results: Exposure to B[k]F and to the higher temperature increased LDH leakage without interaction effects. In contrast, the other viability assays did not show significant differences across conditions. Regarding CYP1A, both gene and protein expression increased with all B[k]F concentrations in relation to the controls, but were not influenced by temperature. Notably, the lowest B[k]F concentration (1 µM) elicited the highest CYP1A gene expression, suggesting a non-monotonic response. Conclusions: Overall, the model was responsive to both temperature (4 °C) increase and to B[k]F, validating its usefulness for assessing liver pollutant effects in the context of global warming. These findings support the application of fish primary hepatocyte models as relevant tools in ecotoxicology under environmentally realistic multi-stressor scenarios. Full article

Early microbial exposure during embryogenesis may shape post-hatch gut development in poultry, yet the effects of sublethal pathogenic exposure and in ovo synbiotics remain unclear. This model-establishment study preliminarily established in ovo Salmonella Enteritidis (SE) infection and synbiotic (SYN) delivery models and evaluated their effects on hatchability, cecal microbiota, intestinal morphology, epithelial turnover, and barrier function in newly hatched chicks. In one group, the air cells of specific pathogen-free White Leghorn eggs were injected with SE on embryonic day 12; in another group, a synbiotic consisting of Lactobacillus plantarum, Pediococcus acidilactici, and inulin was injected into the amniotic cavity on embryonic day 17.5. Sterile saline was injected as the vehicle-only procedural control at the corresponding time points and injection sites. Based on their impacts on hatchability, SE1-L and SYN-H were selected. SE1-L reduced cecal microbial diversity, expanded Proteobacteria and Escherichia–Shigella, increased ileal apoptosis and crypt depth, decreased the villus height-to-crypt depth ratio, downregulated jejunal tight-junction genes, upregulated ileal MYD88 and TNF-α, and increased plasma lipopolysaccharide and D-lactate. In contrast, SYN-H maintained hatchability, promoted early Pediococcus colonization, suppressed potential pathogens, increased ileal villus height and villus height-to-crypt depth ratio, enhanced proliferation, reduced apoptosis, and improved mucosal barrier-related indices. These findings provide preliminary evidence that embryonic SE infection and synbiotic delivery differentially influence early intestinal microbiota succession and gut development in newly hatched chicks. Full article