Effects of periodontitis on bone and tryptophan metabolism of gut microbiota in estrogen-deficient mice
10.3760/cma.j.cn112144-20231225-00307
- VernacularTitle:牙周炎对雌激素缺乏小鼠骨组织及肠道色氨酸代谢影响的研究
- Author:
Yuan WEI
1
;
Nannan WANG
;
Min WANG
;
Jun QIAN
;
Hua NIE
;
Ruiyang GE
;
Wenzheng LIAO
;
Fuhua YAN
Author Information
1. 南京大学医学院附属口腔医院·南京市口腔医院牙周病科 南京大学口腔医学研究所，南京 210008
- Keywords:
Periodontitis;
Osteoporosis, postmenopausal;
Gut microbiota;
Bone metabolism;
Tryptophan metabolism
- From:
Chinese Journal of Stomatology
2024;59(4):354-363
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To study the effects of periodontitis on bone and tryptophan metabolism of gut microbiota in the context of estrogen deficiency.Methods:Thirty-two female C57BL6/J mice were randomly divided into four groups based on table of random numbers ( n=8 in each group): Sham group, in which mice were given sham surgery; Sham_Lig group, in which mice were given sham surgery and were induced to periodontitis by ligating the bilateral maxillary second molars with 5-0 silk threads at the fourth week; Ovx group, in which mice were given bilateral ovariectomy; Ovx_Lig group, in which mice were given bilateral ovariectomy and were induced to periodontitis at the fourth week. After 8 weeks of ligation, the mice of 4 groups were euthanized for collecting the samples of femur, tibia, mandible and skull. Those samples were scanned by micro-CT to measure the bone mineral density (BMD), bone volume versus total volume ratio (BV/TV), trabecular number (Tb.N), trabecular thickness (Tb.Th) and trabecular spacing (Tb.Sp). The cecum contents of 4 groups of mice were collected for gut microbiota 16S rRNA gene sequencing. The tryptophan and its metabolites in intestinal tracts were detected by liquid chromatography-mass spectrometry. Pearson correlation analysis was performed to analyze the correlation between the abundance of gut microbiota and the content of tryptophan and its metabolites. Results:Femur BMD [(82.23±3.97) mg/cm 3], BV/TV [(9.25±1.37)%] and Tb.Th [(70.95±5.70) μm] in Ovx_Lig group were significantly lower than Ovx group [(96.30±3.76) mg/cm 3 ( P=0.004); (14.45±1.55)% ( P=0.022) and (87.58±8.02) μm ( P<0.001), respectively]. The β-diversity analysis of gut microbiota based on Bray-Curtis distance showed that samples of Ovx_Lig group and Ovx group were obviously grouped. Linear discriminant analysis effect size (LEfSe) showed that Alistipes was the representative genus in Ovx_Lig group. The relative abundance of Alistipes in Ovx_Lig group [(0.42±0.14)%] were significantly higher than that in Ovx group [(0.17±0.05)%] ( t=4.45, P<0.001). Tryptophan metabolism analysis showed that the content of kynurenic acid [(531.12±158.60) ng/g] in Ovx_Lig group were significantly higher than that in Ovx group [(400.42±57.96) ng/g] ( t=2.19, P=0.046). And the content of indole-3-carbaldehyde [(383.37±144.06) ng/g] in Ovx_Lig group were significantly lower than Ovx group [(701.72±141.93) ng/g] ( t=4.45, P<0.001). Correlation analysis showed that relative abundance of Alistipes was positively correlated with kynurenic acid ( r=0.32, P=0.088), while negatively correlated with indole-3-carbaldehyde ( r=-0.32, P=0.088). Conclusions:Periodontitis can induce bone destruction of femur in estrogen-deficient mice, the mechanism of which may be related to Alistipes in gut and the tryptophan metabolites kynurenic acid and indole-3-carbaldehyde.
