fig1

Figure 1. Microbial TMA production is substrate-specific. In-vitro anaerobic fermentation of human stool with different choline derivatives was performed, and relative TMA levels were measured by NMR analysis. Trendlines illustrating the TMA conversion levels of different substrates at time points 0 h, 4 h, 8 h, and 24 h across (A) young female (n = 4); (B) young male (n = 5); (C) elderly female (n = 4); and (D) elderly male subjects (n = 5) were plotted. Choline (Cho) and its derivatives Glycerophosphocholine (GPC), Phosphoric choline (PC), phosphatidylcholine (Pchol), and sphingomyelin (SM) were added to the ex vivo fermentations. C₀ - concentration at time 0, C_i - concentration at individual time point. A t-test was performed to compare TMA production from choline derivatives at individual time points. Data are presented as mean ± standard deviation. ***: P value < 0.001, **: P value < 0.01, *: P value < 0.05. All experiments were performed in triplicates with individual subjects. TMA: trimethylamine; NMR: nuclear magnetic resonance.