Objective:To analyze the association between the pre-pregnancy oral microbiota of women and fetal overgrowth, and the possible mechanisms involved.Methods:A nested case-control study design based on a pre-pregnancy cohort was used to select 51 mothers who delivered macrosomia and/or large-for-gestational-age (LGA) infants from the population recruited at the Maternal and Child Health Care Hospital of Jiading District in Shanghai from October 2016 to December 2021 as the case group. A control group was formed by selecting 204 mothers who delivered infants with normal birth weight and appropriate for gestational age during the same period, in a 1:4 ratio. The LGA subgroup consisted of 48 mothers who delivered LGA infants from the total population, and a corresponding control group of 192 was randomly selected from the remaining mothers who delivered non-LGA infants in a 1∶4 ratio for the LGA subgroup analysis. The 16S rRNA gene sequencing technique was utilized to detect pre-pregnancy saliva samples to compare the characteristics of the oral microbiota, differential microorganisms, and differential functional pathways between groups. Nonparametric Wilcoxon rank-sum tests, two independent samples t-tests, or Chi-square (or Fisher's exact) tests were used for statistical analysis. Factor analysis was conducted on the pre-pregnancy diet data of women, and the primary dietary pattern of each study subject was identified based on the highest score of the dietary pattern factors. For microbiota count data, α and β diversity indices were calculated using R and QIIME2 software, and the corresponding microbiota functional count data were acquired through PICRUSt2. Results:(1) General data: There was no significant difference in the time interval from pre-pregnancy sampling to pregnancy and from sampling to delivery between the two groups. In the case group, there were three cases of macrosomia and 48 cases (94.1%) of LGA. The corresponding control group for the LGA subgroup consisted of 192 cases. There were no significant differences in dietary patterns between the case group and the control group. (2) α diversity analysis: The species richness index of the case group was lower than that of the control group [(367.27±84.57) vs. (408.71±93.08), multivariate analysis, P=0.009], while no significant differences were found between the two groups in the Shannon and Simpson indices; the species richness index of the LGA subgroup was also lower than that of the corresponding control group [(371.04±83.92) vs. (408.04±94.21), multivariate analysis, P=0.033], with no significant differences in the Shannon and Simpson indices. (3) β diversity analysis: There was a statistically significant difference in the unweighted UniFrac distance of the oral microbiota between the case group and the control group ( R2=0.006, F=1.479, P=0.048). No significant differences were found in the β diversity indices of the oral microbiota between the LGA subgroup and the corresponding control group. (4) Differential microbiota analysis: There were 14 differential microbiotas from phylum to genus between the case group and the control group. At the genus level, members of the G1 genus of the Streptococcaceae were enriched in the case group, while the Lautropia, Dialister, Leptotrichia, and Rothia were enriched in the control group. In the LGA subgroup and its corresponding control group, there were 14 differential microbiota from phylum to genus; at the genus level, Leptotrichia, Rothia, G6 genus of the Saccharibacteria, and Selenomonas were enriched in the control group (all LDA value>2, and all P<0.05). (5) Differential functional analysis: In the case group, metabolic pathways such as nicotinate degradation [log 2 fold change ( FC)=3.510, q=0.005], de novo synthesis of pyrimidine nucleotides (log 2FC=0.078, q=0.005), and L-tyrosine degradation pathway (log 2FC=0.710, q=0.034) were enriched in the oral microbiota of women. In the LGA subgroup, compared to the corresponding control group, metabolic pathways related to nicotinate degradation were enriched in the oral microbiota (log 2FC=3.660, q=0.012). Conclusions:There are differences in the structure of the pre-pregnancy oral microbiota of mothers with overgrown fetuses compared to those with normally grown fetuses, and mothers of normally grown fetuses show higher diversity in their pre-pregnancy oral microbiota. The enrichment of certain pathogenic bacteria and the reduction of symbiotic bacteria in the pre-pregnancy oral microbiota are associated with fetal overgrowth, and this association may be mediated by functional pathways such as nicotinate degradation.

Ghrelin, a hormone mainly produced and released by the stomach, has numerous functions, including releasing growth hormones, regulating appetite, and processing sugar and lipids. Researchers have made great efforts to study the relationship between ghrelin and metabolic diseases. It is believed that human butyrylcholinesterase (hBChE) could hydrolyze ghrelin to the inactive form (desacyl-ghrelin). However, the low catalytic activity of wild hBChE against ghrelin hinders the clinical application. Recently, a soluble catalytically active hBChE mutant was successfully expressed in Escherichia coli for the first time. We then adopted HotSpot Wizard 3.0 to analyze the mutant structure and rationally selected 10 mutants. Furthermore, we determined the catalytic activities of the mutants against several substrates and the thermostability of these mutants. The results showed that the mutants E197D and A199S improved catalytic activity against ghrelin by 4.6 times and 3.5 times, respectively. The findings provide clues for treating endocrine diseases with the agents for regulating ghrelin.
Ghrelin/genetics* ; Butyrylcholinesterase/genetics* ; Humans ; Escherichia coli/metabolism* ; Mutation ; Catalysis ; Recombinant Proteins/metabolism*

Objective The present study was conducted to study the oxidation damage effects of DBP on organs of mice and the molecular mechanisms of the effects. Methods The cells of the organs (liver,kidney,testis,lung) were exposed to different concentration of DBP (0?mol/L,5?mol/L,20?mol/L,80?mol/L) for one hour in vitro,and then the superoxide dismutase (SOD) activities of those cells of different organs were measured. Results With statistical significance,the SOD activities in liver,kidney,testis,lung cells were increased gradually with the increase of DBP concentrations. Conclusion The results suggested that DBP could induce the oxidative damage in liver,lung,kidney and testis cells of mice.