I believe lecithin comes from soy...http://en.wikipedia.org/wiki/Lecithin. It looks like the are starting to make it from sunflower now too. I'm taking the granular version, it says on the canister - soy lecithin.
The term lecithin is like the term soap. The term is referring to what the substance does, not necessarily what it is made from. Lecithin is a substance that acts as an emulsifier. You can have various forms of lecithin, (like the lecithin in your bile, the powdered lecithin from soy, lecithin from sunflower oil, etc). The point is that it is a substance that emulsifies fats.
The components of bile are:
* Water
* Cholesterol
* Lecithin (a phospholipid)
* Bile pigments (bilirubin & biliverdin)
* Bile salts (sodium glycocholate & sodium taurocholate)
* Bicarbonate ions
taken from
http://en.wikipedia.org/wiki/Bile
So, lecithin is an emulsifier. That's why its used in all sorts of products, like margarine or snacks, to bind together the fat with everything else. Bile is also an emulsifier. Seems to me like they work in the same way.
Here is the summary of bile taken from Britannica (http://www.answers.com/topic/bile)...
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bile
Greenish-yellow liver secretion passed to the gallbladder for concentration, storage, or transport into the duodenum for fat digestion. Bile contains bile acids and salts, cholesterol, and electrolyte chemicals that keep it slightly acidic. In the intestine, products of the acids and salts emulsify fat and reduce its surface tension to prepare it for the action of pancreatic and intestinal fat-splitting enzymes.
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Since it is a fat emulsifier, it would make sense that it helps to break up gall stones, as they are usually cholesteral. But more importantly to me, it also makes sense that it helps break down the fat in you digestive tract and make it more easily digestable. Therefore, it acts somewhat as a substitute for bile.
Does this make any sense?