Table 3.

Concentrations of precursors of trimethylamine N-oxide (TMAO) in young (6 months, N = 8) and old (27 months, N = 12) mice

	Young	Old
Plasma
Choline (μM)	19 ± 1	77 ± 18*
Betaine (μM)	164.8 ± 18.2	55.4 ± 12.4*
l-Carnitine (μM)	20.3 ± 0.5	30.9 ± 2.6*
Whole-brain lysates
Choline (μM)	210 ± 34	90 ± 7*
Betaine (μM)	4.9 ± 0.6	9.1 ± 1.3*
l-Carnitine (μM)	20.0 ± 2.6	29.7 ± 2.5*

Data are mean ± SEM

*p<0.05 vs. young