Background: Data from the 2010–2012 Chinese National Nutrition and Health Survey showed that the vast majority of postmenopausal women in China had dual deficiencies in calcium and estrogen. Objective: This study aimed to clarify whether calcium supplementation alleviated bone loss caused by calcium restriction combined with estrogen deficiency in rats. Methods: Forty-eight female rats aged 9 weeks were assigned to 4 groups and fed a low-calcium diet: sham-operated (SHAM-LC), ovariectomized (OVX-LC), and ovariectomized rats treated with 750 mg/kg (OVX-LC-M) or 2800 mg/kg CaCO₃ (OVX-LC-H). CaCO₃ or distilled water was administered orally for 13 weeks. Bone mineral density (BMD) and histomorphometry of the femur, serum biochemical parameters, and serum metabolites were analyzed. Results: The OVX-LC rats showed a significant increase in body weight and serum levels of lipid markers, a significant decrease in serum estradiol, calcium, phosphorus, and 25(OH)D levels, and deterioration of the femur. At 750 mg/kg and 2800 mg/kg, CaCO₃ reduced the deterioration of trabecular bone and increased the trabecular area percentage (Tb.Ar %) and BMD of the femur. Serum estradiol levels increased in a dose-dependent manner after CaCO₃ supplementation (p < 0.01). The administration of 2800 mg/kg CaCO₃ decreased serum triglyceride and high-density lipoprotein levels (p < 0.05) and decreased the levels of the bone turnover markers osteocalcin, N-telopeptide of type I collagen and β-crosslaps. The results of the metabolomics analysis showed that the glycerophospholipid metabolism pathway was closely related to calcium supplementation, and more DG (44:6 n3), LysoPC (22:2) and PE (P-34:3) and less Cer (d43:0) and PE-NMe2 (46:3) were produced. Conclusions: The results clearly indicated that calcium supplementation was beneficial for decreasing bone loss in OVX-LC rats. The present study is the first to show that calcium supplementation increased the estradiol content in OVX-LC rats, and the effect of calcium on bone loss may be partially attributed to the increase in the estrogen level that subsequently induced the changes in metabolite levels, eventually increasing the bone mineral density to a relatively higher level to reduce bone deterioration.

Background/Objectives: Individuals with childhood obesity exhibit significant metabolic heterogeneity, necessitating precise biomarkers for risk stratification and assessment. This multi-omics investigation characterizes metabolic and microbial signatures underlying divergent metabolic phenotypes in the context of pediatric obesity. Methods: We analyzed 285 Chinese children (5–7 years) stratified into five groups: wasting (WAS, n = 55), metabolically healthy/unhealthy and normal weight (MHWH, n = 54; MUWH, n = 67), and metabolically healthy/unhealthy obesity (MHO, n = 36; MUO, n = 73). Untargeted metabolomics (Orbitrap ID-X Tribrid™) and 16S rRNA sequencing were integrated with multivariate analyses (OPLS-DA with VIP > 1, FDR < 0.05; Maaslin 2 with TSS normalization and BH correction, FDR < 0.10). Results: Analysis identified 225 differential metabolites and 12 bacterial genera. The proportion of steroids and their derivatives among differential metabolites in the MUO/MHO group was significantly lower than that in the OVOB/NOR and OVOB/WAS groups (2.12% vs. 7.9–14.1%). MUO displayed elevated C17 sphinganine and LysoPC (O-18:0) levels but reduced PI (16:0/14:1) levels. In contrast, OVOB showed upregulated glycerol phospholipids (LPCs and PSs) and downregulated PE species (e.g., PE(16:0/16:0)) as well as gut microbiota dysbiosis characterized by a higher Firmicutes/Bacteroidetes (F/B) ratio (2.07 vs. 1.24 in controls, p = 0.009) and reduced α diversity (Ace index, Chao1 index, and Shannon index values were lower in the OVOB group, Shannon index: 2.96 vs. 3.45, p = 0.03). SCFA-producing genera were negatively correlated with the OVOB group, while positively associated with PE(16:0/16:0). Internal validation showed differential metabolites had potential predictive efficacy for MUO/MHO (AUC = 0.967) and OVOB/NOR (AUC = 0.888). Conclusions: We identified distinct lipid disruptions characterizing obesity subtypes, including steroid/terpene deficits and sphingolipid/ether lipid dysregulation in the MUO/MHO groups as well as phospholipid imbalance (↑LPC/PS↓PE) in the OVOB/NOR groups. The gut microbiota exhibited a profile characterized by low diversity, an increased F/B ratio, and a reduced abundance of SCFA-producing genera. These findings suggest potential biomarkers for childhood obesity stratification, though further validation is warranted.

Hyperlipidemia is a medical condition characterized by elevated levels of blood lipids, especially triglycerides (TG). However, it remains unclear whether TG levels remain consistently elevated throughout the entire developmental stage of the high-lipid state. In our animal experiment, we found that TG levels were significantly higher in the early stage of the high-lipid model but significantly decreased at the 14th week of the late stage, reaching levels similar to those of the control group. This suggests that TG levels in the high-lipid model are not always higher than those of the control group. To determine the reason for this observation, we used in situ mass spectrometry imaging (MSI) to detect the distribution of metabolites in the liver of rats. The metabolite distribution of the control rats at different stages was significantly different from that of the model rats, and the high-lipid model differed significantly from the control rats. We identified nine functional metabolites that showed differences throughout the period, namely, PA(20:3-OH/i-21:0), PA(20:4-OH/22:6), PG(20:5-OH/i-16:0), PG(22:6-2OH/i-13:0), PG(O-18:0/20:4), PGP(18:3-OH/i-12:0), PGP(PGJ2/i-15:0), SM(d18:0/18:1-2OH), and TG(14:0/14:0/16:0), among which TG was most significantly correlated with hyperlipidemia and high lipid. This study is unique in that it used MSI to reveal the changes in metabolites in situ, showing the distribution of different metabolites or the same metabolite in liver tissue. The findings highlight the importance of considering the animal’s age when using TG as a biomarker for hyperlipidemia. Additionally, the MSI images of the liver in the high-lipid model clearly indicated the distribution and differences of more significant metabolites, providing valuable data for further research into new biomarkers and mechanisms of hyperlipidemia. This new pathway of in situ, visualized, and data-rich metabolomics research provides a more comprehensive understanding of the characteristics of high lipid and its implications for disease prevention and treatment.

Objective: The purpose of this study was to assess the safety of transgenic maize CC-2 through a 90-day feeding study in Sprague-Dawley rats. Methods: Transgenic maize CC-2 and its parental counterpart maize Zhengdan 958 were respectively incorporated into diets at levels of 70%, 35% or 17.5% (w/w) and were administrated to rats (n = 10/sex/group) for 90 days. An additional control group of rats (n = 10/sex/group) were fed with the AIN93 breeding diet. All formulated diets were nutritionally balanced. Results: There was no death and obvious toxic symptom in all rats. Food consumption, body weight, total food consumption rate, hematology, urinalysis, organ weight and organ coefficient were comparable between transgenic groups and the corresponding dose parental groups. There were significant differences of food consumption rate on some timepoint between high dose transgenic group and high dose parental group; male rats in high dose transgenic group showed significantly higher ALT/AST than high dose parental group on the middle or end of the experiment; but the differences showed no biological significance. There were no significant differences of other serum biochemistry parameters and pathological changes. Conclusion: The results in this study demonstrated that the transgenic maize CC-2 didn't cause any related toxicity in rats.

Background/Objectives: Subnormal folate levels have a detrimental impact on the growth and development of preschoolers. We aimed to investigate the association between independent/synergistic effects of the gene polymorphisms (methyltetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms, alongside methionine synthase reductase (MTRR) A66G polymorphism and the methionine synthase (MTR) A2756G polymorphism) and serum folate levels as well as cognitive levels in Chinese preschoolers aged 5–7 years. Methods: Data were sourced from 614 children, acquired through the “Long-term Health Effects Assessment Project of Infants and Toddlers Nutritional Pack (LHEAITNP)” program were used. Folate serum concentrations were measured using a microbiologically modified technique. The genotypes of MTHFR A1298C and C677T, together with MTRR A66G, were identified by Kramer’s Allele-Specific PCR (KASP) technique. The cognitive scores of children were assessed by questionnaire. Results: MTHFR 677TT and MTR 2756AG + GG correlated negatively with serum folate levels (TT vs. CC + CT, p = 0.0009 and AG + GG vs. AA, p = 0.0057, respectively). MTHFR C677T and A1298C were independently linked to an elevated risk of suboptimal cognitive development (TT vs. CC + CT, p = 0.0009 and AA vs. CA + CC, p < 0.0001, respectively). The joint impact of these risk genotypes showed significantly increased risk of folate deficiency and inferior cognitive function compared to non-risk genotypes, particularly in those with more than two risk genotypes. The findings were corroborated by a cumulative effects model (p < 0.05). Conclusions: Our results indicate the substantial association between folate-homocysteine metabolism gene variants and serum folate status/cognitive performance in Chinese preschoolers. Potential gene-nutrient interactions worthy of longitudinal investigation.