SCFA and ketones directly regulate sympathetic nervous system via GPR41

[Emootje]

"In feeding, excessive energy is consumed by the enhancement of sympathetic function, resulting in increases in heart rate and diet-induced thermogenesis, whereas in fasting, energy use is saved by the suppression of the sympathetic function as a survival mechanism, resulting in the reduction in heart rate and activity. Under a fed condition, mammals use glucose as the main metabolic fuel, and short-chain fatty acids (SCFAs) produced by the colonic bacterial fermentation of dietary fiber also contribute a significant proportion of the daily energy requirement. Under ketogenic conditions such as fasting and diabetes, ketone bodies produced in the liver from fatty acids are used as the main energy sources"

"SCFA propionate promoted sympathetic outflow via GPR41. On the other hand, a ketone body, β-hydroxybutyrate, produced during starvation or diabetes, suppressed SNS activity by antagonizing GPR41"

Short-chain fatty acids and ketones directly regulate sympathetic nervous system via GPR41.

 

[cigana]

So we are better off eating carbs than low-carb?

 

[Seven7]

I have noticed I feel better energy wise on carbs but I don't like the taste of them. I am not sure why, but I always avoid, but when lazy and eat them, An I have much better energy.

 

[Emootje]

So we are better off eating carbs than low-carb?

If you have a low sympathetic tone, carbs and soluble fiber will be helpfull to raise your sympathetic tone by increasing SCFA and by decreasing your ketone levels. If you have an overactive sympathetic tone, like most CFS patients, you could try to lower the sympathetic tone by fasting.

 

[cigana]

I see. I tried fasting, could only last 3.5days. The fatigue became unbearable and I couldn't breathe properly. Obviously this isn't what should normally happen. I think it might be related to the fact that we use lactic acid as fuel when we fast (I believe) and lactic acid has been implicated in fatigue...