What is bile?

Bile Acid

Based on Hippocratic medicine, it is believed that to have a completely healthy body, there should be a balance between the four vital internal fluids: blood, phlegm, black bile and yellow bile (choler). An excess on one or two of these fluids will result to depression or aggression, a complete internal imbalance.

There are many contexts associated with the word bile. Because of the Hippocratic theory of balance, terms like “melancholia” and “cholera” had been derived from it. Some English terms like “bilious” and “gall” are used to denote frustration as well as insolence or impertinence.

Scientifically speaking though, bile or gall is characterized as a yellowish brown to dark green, bitter-tasting fluid. The color I said to resemble that of a freshly cut grass. It is produced by the liver and gall bladder and human adults produce approximately four hundred to eight hundred milliliters of bile everyday.

In many vertebrates, bile is stored in the gall bladder.  Generally, it is 85% water, 10% bile salts, 3% pigments and mucus, 1% fats, 0.7% inorganic salts and 0.3% cholesterol. It is produced when the hepatocytes, cells from the main tissue of the liver, secretes bile into thin tubes called canaliculi that collects it and flows into the bile ducts. As it flows through the ducts, a watery secretion from the ductal epithelial cells rich in bicarbonate will be added.

Bile acts as surfactants, a compound that is similar to emulsifiers or dispersants. It reduces the surface tension of fats in food, aiding in the digestion of lipids or fat in the small intestines by increasing the absorption of fats. It is the most effective way to expel bad cholesterol from the body. It also enhances the absorption of fat-soluble substances like Vitamins A, D, E and K. Without it, fats inside the body will become indigestible and can lead to fat-soluble vitamin and essential fatty acids deficiencies. It can also cause problems in the large intestine and consequently produce greasy feces that are white or gray in color. This is referred to as steatorrhea.

Food fat (phospholipids and triglycerides) is shaped into micelles, an amassed surfactant molecule that is dispersed in the other parts of the biliary tract. The flow of dispersion is controlled by the muscular valve called the sphincter of ampulla or sphincter of Oddi, aptly named after Ruggero Oddi, the one who discovered the sphincter. The sphincter of Oddi controls the digestive fluids like bile and pancreatic juice from flowing to and from the gall bladder, liver, pancreas and into the duodenum (the first section of the small intestines). The sphincter can be relaxed by the Cholecystokinin hormone or CCK through the vasoactive intestinal polypeptide.

A malfunctioning sphincter of ampulla can result to biliary dyskinesia, which is a rare condition but can likely affect those who had gone through cholecystectomy or gall bladder removal or had undergone gastric bypass or other weight loss surgery. This condition can cause the retention of bile and pancreatic juices in the gall bladder, pancreas and liver, causing the cholesterol contained in bile to solidify into crystalline formations called gall stones.

These concrete formations can pass through the other parts of the biliary tract. However, there are instances wherein these crystalline formations, which is composed mostly of cholesterol, may grind down through the gall bladder and subsequently joining bowel that will potentially cause a barrier called gall stone ileus.

Gall stones in the gall bladder can lead to an inflammatory condition called cholecystitis due to retention of bile. Intestinal microorganisms like E. coli can accumulate without the proper flow of bile, resulting to secondary infection. It can also affect other parts of the biliary tract and can cause barriers in the bile ducts, leading to severe, life-threatening conditions like pancreatitis or ascending cholangitis.

Vomiting with an empty stomach releases bitter fluids that are often greenish or yellowish in color. It is believed that it can either be bile or other digestive juices. Sometimes, the presence of alcohol and drugs can influence duodenal spasm and muscular contractions that will force bile to the stomach and eventually be regurgitated. Either way, the experience will leave the stomach and the esophagus sore and inflamed.

Apart from being an important catalyst in digestion, bile also acts as a means to expel bilirubin, a byproduct of the red blood cells’ hemoglobin that is recycled by the liver.

Bile collected from slaughtered animals are used to mixed in with soap to form a detergent that is very effective in removing tough stains from textiles, a slightly unpleasant yet a proven concoction.