Role of intestinal testosterone-degrading bacteria and 3/17β-HSD in the pathogenesis of testosterone deficiency-induced hyperlipidemia in males

Abstract

Testosterone deficiency can cause abnormal lipid metabolism in men, leading to hyperlipidemia. We identified the testosterone-degrading bacterium Pseudomonas nitroreducens in the fecal samples of male patients with hyperlipidemia. Gastric administration of P. nitroreducens in mice led to testosterone deficiency and elevated blood lipid levels. Whole-genome sequencing of P. nitroreducens revealed the presence of 3/17β-hydroxysteroid dehydrogenase (3/17β-HSD), a gene responsible for testosterone degradation, which is also associated with hyperlipidemia. Microbiota analysis of fecal samples collected from 158 patients with hyperlipidemia and 151 controls revealed that the relative abundance of P. nitroreducens and 3/17β-HSD in the fecal samples of patients with hyperlipidemia was significantly higher than that in controls. These results suggest that P. nitroreducens and 3/17β-HSD may be related to the onset of testosterone deficiency-induced hyperlipidemia. Therefore, treatments targeted at eradicating testosterone-degrading bacteria are a potential future option for patients with testosterone-induced hyperlipidemia and should thus be studied further.

Fig. 1. Differences in serum testosterone, TC, TG, LDL-C, and HDL-C levels and atherosclerotic lipid deposits between the three groups of mice.

A Experimental design. B Serum testosterone levels (n = 6). C Serum TC levels (n = 6). D Serum TG levels (n = 6). E Serum LDL-C levels (n = 6). F Lipid deposit in mouse aorta and aortic valve plaque; G Lesion area of aortic sinus (n = 3). H Lesion area of whole aorta (n = 3). HLD hyperlipidemia, FMT transplantation of fecal microbiota, LDL-C low-density lipoprotein cholesterol, TC total cholesterol, TG triglyceride. Data are presented as means ± SEM, and one-way ANOVA with Tukey’s multiple comparisons tests was performed to calculate statistical significance (*P < 0.05, **P < 0.01, ***P < 0.001).

Fig. 2. Testosterone metabolism ability of Pseudomonas nitroreducens.

A Colony of P. nitroreducens. B Decreasing peak of testosterone displayed by HPLC. C Changes in testosterone concentration levels in culture medium. D The chemical formula for the degradation of testosterone to androstenedione. HPLC high-performance liquid chromatography.

Fig. 3. Differences in serum testosterone, TC, TG, LDL-C, and HDL-C levels and atherosclerotic lipid deposits among the three groups of mice.

A Experimental design. B Serum testosterone levels (n = 6). C Serum TC levels (n = 6). D Serum TG levels (n = 6). E Serum LDL-C levels (n = 6). F Lipid deposit in mouse aorta and aortic valve plaque. G Lesion area of aortic sinus (n = 3). H Lesion area of whole aorta (n = 3). IPM imipenem, LDL-C low-density lipoprotein cholesterol, TC total cholesterol, TG triglyceride. Data are presented as means ± SEM, and one-way ANOVA with Tukey’s multiple comparisons tests was performed to calculate statistical significance (*P < 0.05, **P < 0.01, ***P < 0.001).

Fig. 4. Testosterone degradation ability of Escherichia coli BL21 (DE3)/pet28a and E. coli BL21 (DE3)/pjt06.

A 3/17β-HSD gene in P. nitroreducens. B Decreasing peak of testosterone displayed by HPLC. C Changes in testosterone concentration levels in culture medium.

Fig. 5. Differences in serum testosterone, TC, TG, LDL-C, and HDL-C levels and atherosclerotic lipid deposits among the five groups of mice.

A Experimental design. B Serum testosterone levels (n = 6). C Serum TC levels (n = 6). D Serum TG levels (n = 6). E Serum LDL-C levels (n = 6). F Lipid deposit in mouse aorta and aortic valve plaque. G Lesion area of aortic sinus (n = 3). H Lesion area of whole aorta (n = 3). T testosterone, LDL-C low-density lipoprotein cholesterol, TC total cholesterol, TG triglyceride. Data are presented as means ± SEM, and one-way ANOVA with Tukey’s multiple comparisons tests was performed to calculate statistical significance (*P < 0.05, **P < 0.01, ***P < 0.001).

Fig. 6. Abundance of P. nitroreducens and 3/17β-HSD in male patients with hyperlipidemia.

A Abundance of P. nitroreducens in the hyperlipidemia group (n = 158) and control group (n = 151); B Abundance of 3/17β-HSD in the hyperlipidemia group (n = 158) and control group (n = 151). Data are presented as interquartile range, and Mann–Whitney U-test was performed to calculate statistical significance (*P < 0.05, **P < 0.01, ***P < 0.001).