The gene expression and bioinformatic analysis of choline trimethylamine-lyase (CutC) and its activating enzyme (CutD) for gut microbes and comparison with their TMA production levels.

Recent studies revealed that some intestinal microorganisms anaerobically convert choline to trimethylamine (TMA) by choline TMA-lyase (cutC). TMA is further oxidized to trimethylamine-N-oxide (TMAO), by the liver enzyme flavin-dependent monooxygenase 3 (FMO3). TMA in the serum is correlated with the risk of cardiovascular disease and some other diseases in human. The objective of this study is to study the expression levels of cutC and its activating enzyme (cutD) gene for these microorganisms and their association with TMA production. In this study, we collected 20 TMA producing bacteria strains representing 20 species, and designed primers to evaluate their gene expression levels by reverse transcription quantitative PCR (RT-qPCR). In addition, TMA production was analyzed by UPLC-MS/MS. Results showed that gene expression levels of most individual strains were different when compared with the gene expression level of their glyceraldehyde-3 phosphate dehydrogenase (GAPDH) gene and the TMA production level of gut bacteria may not correlate with their cutC/cutD gene expression levels. Bioinformatic analysis of the CutC protein showed conserved choline binding site residues; cutD showed conserved S-adenosylmethionine (SAM) and two CX2-CX2-CX3 motifs. The present study reports that the TMA production level may not only depend on cutC/cutD gene expression. Other factors may need to be investigated.

Combined extractives of red yeast rice, bitter gourd, chlorella, soy protein, and licorice improve total cholesterol, low-density lipoprotein cholesterol, and triglyceride in subjects with metabolic syndrome.

In this study, we aimed to examine the effects of a plant-extractive compound on lipid profiles in subjects with metabolic syndrome. We hypothesized that extractives from red yeast rice, bitter gourd, chlorella, soy protein, and licorice have synergistic benefits on cholesterol and metabolic syndrome. In this double-blinded study, adult subjects with metabolic syndrome were randomized to receive a plant-extractive compound or a placebo treatment for 12 weeks. Both total cholesterol (5.4 ± 0.8 to 4.4 ± 0.6 mmol/L, P < .001) and low-density lipoprotein cholesterol (3.4 ± 0.7 to 2.7 ± 0.5 mmol/L, P < .001) were significantly reduced after treatment with the plant extractives, and the magnitudes of reduction were significantly greater than in the placebo group (-1.0 ± 0.6 vs 0.0 ± 0.6mmol/L, P < .001; -0.7 ± 0.6 vs 0.0 ± 0.6 mmol/L, P < .001). The reduction in the fasting triglycerides level was significantly greater in the plant-extractive group than in the placebo group (-0.5 ± 0.8 vs -0.2 ± 1.0 mmol/L, P = .039). There was also a significantly greater reduction in the proportion of subjects with hypertensive criteria in the plant-extractive group than in the placebo group (P = .040). In conclusion, the plant extractives from red yeast rice, bitter gourd, chlorella, soy protein, and licorice were effective in reducing total and low-density lipoprotein cholesterol. The plant extractives also showed potential for reducing triglyceride and normalizing blood pressure.