gut microbiota metabolism of L-carnitine and cardiovascular risk Flashcards
liver converts microbiota-derived TMA to
TMAO
TMAO and CVD risk
TMAO enhances CVD risk
how does TMAO increase CVD risk
TMAO promotes artherosclerotic lesion development
TMA source via gut microbiota
phosphatidylcholine/choline, L-carnitine (red meats)
overall, __ causes CVD
overall, red meats causes CVD
consuming __ prevents metabolic disease
consuming L-carnitine prevents metabolic disease
__ is a good source of TMAO that actually has positive effects on CVD
fish is a good source of TMAO that actually has positive effects on CVD
goal of study?
determine if carnitine and choline are actually harmful
what enzyme turns TMA to TMAO
hepatic flavin monooxygenase (FMO)
TMAO is a __ compound associated with increased __, but mechanism is unclear
TMAO is a proartherogenic compound associated with increased CVD, but mechanism is unclear
TMAO (from dietary choline and carnitine diet) in mice may inhibit and reduce __
TMAO (from dietary choline and carnitine diet) in mice may inhibit and reduce reverse cholesterol transport (RCT)
choline/phosphatidylcholine is aka
lecithin
PC is primary phospholipid component of __ and __
PC is primary phospholipid component of VLDL and LDL
PC is cleaved into __, then gut microbiota release __
PC is cleaved into choline, then gut microbiota release TMA
PC is a significant component of __
PC is a significant component of bile
since PC is a major component of bile, we expect __ levels in humans to be consistently high
this would increase risk for artherosclerosis
this is true/false
since PC is a major component of bile, we expect TMAO levels in humans to be consistently high
this would increase risk for artherosclerosis
this is true/false
it is likely that PC is present in bile but reabsorbed in __ and does NOT reach __/__ to act as a precursor for __ (ultimately __) synthesis
it is likely that PC is present in bile but reabsorbed in ileum and does NOT reach colon/cecum to act as a precursor for TMA (ultimately TMAO) synthesis
L-carnitine is biosynthesized from __ and __
L-carnitine is biosynthesized from methionine and lysine
L-carnitine is found in
red meat
L-carnitine plays and essential role in __ metabolism
L-carnitine plays and essential role in energy (fat and carb) metabolism
marine fish are a significant source of __
marine fish are a significant source of TMAO
L-carnitine may cause a __ in all-cause mortality
L-carnitine may cause a 27% reduction in all-cause mortality
L-carnitine may be beneficial for
metabolic health and cardiovascular function
L-carnitine lowered __ and __ in elderly obese patients
L-carnitine lowered plasma glucose and plasma insulin in elderly obese patients
is there good evidence that L-carnitine suppementation increases CVD risk?
NO
is there good evidence that omega-3 FA from fish is cardioprotective?
NO
studies suggest that L-carnitine and PC/choline increase __ risk due to indirect production of __ by __
takeaway
studies suggest that L-carnitine and PC/choline increase CVD risk due to indirect production of TMAO by liver
why were these studies limited
- performed on rats
- rats were given large doses of carnitine
- carnitine contaiminated with choline (so which increased CVD risk)
- PC/choline and L-carnitine are both in bile –> its already in our system so we don’t know if they ever reach cecum to become TMA
