The mass concentration of microplastics in stools and influencing factors remain unclear. The aim was to investigate the types and mass concentrations of microplastics in the stools of young college students and to explore potential influencing factors. Twenty-six participants were recruited from colleges in each city using stratified simple sampling, including Changsha, Shanghai, and Changchun. Participants' dietary and fluid intake behavior was recorded using the 3-day 24-h dietary questionnaire and the 7-day 24-h fluid intake record, respectively. Lifestyle factor information related to microplastic exposure was collected through a microplastic exposure questionnaire. Stools were collected and detected using pyrolysis gas chromatography-mass spectrometry (Py-GCMS) method. Eventually, 78 participants completed the study. The detection rate of microplastics, including polyethylene (PE), polyvinyl chloride (PVC), polystyrene (PS), polypropylene (PP) and polyethylene terephthalate (PET), in stools was 98.7%, with a total mass concentration of 54.7 (10.1-102.7) μg/g. There were differences in the total mass concentrations of microplastics in the stools of participants in three cities, namely Changsha, Shanghai, and Changchun, which decreased sequentially (χ² = 47.819, P < 0.05). Participants with a relatively high frequency of takeaway food consumption had higher total mass concentrations of microplastics mass concentrations in stools (χ² = 7.390, P < 0.05). Participants with a relatively high frequency of consuming reheated food had a greater mass concentration of PET microplastics (χ² = 6.117, P < 0.05). The total mass concentration of microplastics, as well as the mass concentrations of PE, PVC, PP, and PA66, in the bottled water intake group were greater than those in the nonintake group (all P < 0.05). Overall, the total mass concentration of microplastics in stools was related to residential city, consumption of reheated food, and bottled water intake (all P < 0.05). Young college students generally experience microplastic exposure, with the main types being PE, PVC, PS, PP, PET, and PA66. Living location, reheated food consumption, and bottled water intake were factors influencing microplastic exposure.

Background: Obesity has been reported to be an important contributing factor for precocious puberty, especially in girls. The effect of green tea polyphenols on weight reduction in adult population has been shown, but few related studies have been conducted in children. This study was performed to examine the effectiveness and safety of decaffeinated green tea polyphenols (DGTP) on ameliorating obesity and early sexual development in girls with obesity.Design: This is a double-blinded randomized controlled trial. Girls with obesity aged 6–10 years old were randomly assigned to receive 400 mg/day DGTP or isodose placebo orally for 12 weeks. During this period, all participants received the same instruction on diet and exercise from trained dietitians. Anthropometric measurements, secondary sexual characteristics, B-scan ultrasonography of uterus, ovaries and breast tissues, and related biochemical parameters were examined and assessed pre- and post-treatment.Results: Between August 2018 and January 2020, 62 girls with obesity (DGTP group n = 31, control group n = 31) completed the intervention and were included in analysis. After the intervention, body mass index, waist circumference, and waist-to-hip ratio significantly decreased in both groups, but the percentage of body fat (PBF), serum uric acid (UA), and the volumes of ovaries decreased significantly only within the DGTP group. After controlling confounders, DGTP showed a significantly decreased effect on the change of PBF (β = 2.932, 95% CI: 0.214 to 5.650), serum UA (β = 52.601, 95% CI: 2.520 to 102.681), and ovarian volumes (right: β = 1.881, 95% CI: 0.062 to 3.699, left: β = 0.971, 95% CI: 0.019 to 1.923) in girls with obesity. No side effect was reported in both groups during the whole period.Conclusion: DGTP have shown beneficial effects of ameliorated obesity and postponed early sexual development in girls with obesity without any adverse effects. Clinical Trial Registration: [https://clinicaltrials.gov/ct2/show/NCT03628937], identifier [NCT03628937].

Objective: (-)-Epigallocatechin-3-gallate (EGCG) has preventive effects on obesity-related precocious puberty, but its underlying mechanism remains unclear. The aim of this study was to integrate metabolomics and network pharmacology to reveal the mechanism of EGCG in the prevention of obesity-related precocious puberty.Materials and methods: A high-performance liquid chromatography-electrospray ionization ion-trap tandem mass spectrometry (LC-ESI-MS/MS) was used to analyze the impact of EGCG on serum metabolomics and associated metabolic pathways in a randomized controlled trial. Twelve weeks of EGCG capsules were given to obese girls in this trail. Additionally, the targets and pathways of EGCG in preventing obesity-related precocious puberty network pharmacology were predicted using network pharmacology. Finally, the mechanism of EGCG prevention of obesity-related precocious puberty was elucidated through integrated metabolomics and network pharmacology.Results: Serum metabolomics screened 234 endogenous differential metabolites, and network pharmacology identified a total of 153 common targets. These metabolites and targets mainly enrichment pathways involving endocrine-related pathways (estrogen signaling pathway, insulin resistance, and insulin secretion), and signal transduction (PI3K-Akt, MAPK, and Jak-STAT signaling pathways). The integrated metabolomics and network pharmacology indicated that AKT1, EGFR, ESR1, STAT3, IGF1, and MAPK1 may be key targets for EGCG in preventing obesity-related precocious puberty.Conclusion: EGCG may contribute to preventing obesity-related precocious puberty through targets such as AKT1, EGFR, ESR1, STAT3, IGF1, and MAPK1 and multiple signaling pathways, including the estrogen, PI3K-Akt, MAPK, and Jak-STAT pathways. This study provided a theoretical foundation for future research.

It is still unclear if and at which trimester gestational weight gain is related to childhood adiposity. Thus we aimed to evaluate the association between trimester-specific gestational weight gain and body-fat compositions in Chinese children. Maternal gestational weight were measured by trained nurses every 2 to 4 weeks from the first prenatal care, and body-fat compositions of 407 children from the Shanghai Obesity Cohort at 5 years of age were measured by nutritionist through bioelectrical impedance analysis. Overweight/obesity of children was defined according to the criteria of International Obesity Task Force. Logistic and linear regression models adjusted for potential confounders were conducted to evaluate the associations of gestational weight gains with childhood obesity and body-fat compositions. Two-sided P-value < 0.05 was considered statistically significant. Greater gestational weight gain in the 1st-trimester was significantly associated with a higher risk of childhood overweight/obesity [OR: 1.40 (95% CI: 1.06, 1.86)], fat mass index [β: 0.25 (95% CI: 0.12, 0.38)], body fat percentage [β: 1.04 (95% CI: 0.43, 1.65)], and waist-to-height ratio [β: 0.005 (95% CI: 0.002, 0.008)]. A positive but nonsignificant association was found between greater 3rd-trimester gestational weight gain and a higher risk of offspring overweight/obesity, and we speculated that the association between 2nd-trimester gestational weight gain and offspring overweight/obesity is the “U” type. Weight gain in the first trimester gestation is positively correlated with the risk of childhood overweight/obesity and with body adiposity distributions of children at 5 years of age. Weight gain should be well controlled and monitored from early pregnancy.