bile reflux

Dear readers,

Bile reflux in patients with diaphragmatic hernia and reflux is of particular importance. It is referred to as DGER, or DuodenoGastroEsophageal Reflux. DGER describes the reflux from the duodenum into the stomach and from the stomach up into the esophagus. DGER is becoming more and more of a focus of science. But studies on DGER are methodologically difficult and the results are not easy to interpret. I will explain what is interesting to you here, but you will need a little patience to read.

First of all: In humans, we distinguish very different compartments in the digestive system with different chemical and mechanical functions. One station is the stomach: here there is an extremely acidic environment with a pH value of 1-2 (!). Proteins in food are immediately denatured, i.e. their structure is destroyed. All digestive enzymes in the stomach, such as pepsin, are precisely adjusted to this acid bath and they are most active in this environment. Once this part of digestion is complete and the stomach contents are deemed to be harmless, the pylorus opens and passes the food pulp in small portions into the duodenum.

The duodenum is another important station: here, a completely different, exactly opposite environment prevails. In the duodenum, everything is alkaline, i.e. with a pH value of 8-8.5 (!). This is because the multitude of digestive enzymes, including their precursors from the pancreas, love the high pH value in order to be able to break down food effectively. And this is where the "bile" comes into play: the so-called primary bile acids are made available by the liver in conjugated form as cholic acid and chenodeoxycholic acid, temporarily stored in the gallbladder and, when required, flushed into the duodenum by the contraction of the gallbladder.

Important for you: These so-called "acids" in the bile also have a pH value of 7.5-9! This is therefore exactly right to create the alkaline environment in the duodenum for effective enzyme digestion. At the same time, the sharp acids from the stomach that are introduced with the chyme can be neutralized and made less harmful to the sensitive tissue of the small intestine.

Between these extremely opposing compartments, stomach and duodenum, lies only the pyloric sphincter. It controls this interface and ensures that the sensitive balance in both spaces is maintained. In healthy people, no bile should flow back into the stomach. We only know this to happen in patients after certain stomach operations, gallbladder removal or when there is limited peristaltic movement in the gastrointestinal tract.

It has now been noticed that patients with reflux problems often experience bile reflux into the stomach. It even seems that the worse the inflammation in the esophagus, up to and including Barrett's, the more pronounced the bile reflux from the duodenum into the stomach. The concentration of bile acids in the gastric juice increases. This finding is worrying because the bile acids themselves can cause considerable cell damage (see below). It is therefore being discussed whether these same bile acids could also be involved in the formation of Barrett's or even cause it. It is known that C gastritis can also be triggered by bile acids. And we actually find this very frequently in gastroscopy as a secondary finding in reflux patients.

Since the closure system at the top is defective in these patients, the bile acids can rise even further. This means that DGER is increasingly becoming the focus of attention in cases of pathological changes in the laryngopharyngeal region.

But how does it happen that bile acids also flow up from the duodenum in reflux patients? Isn't it enough if the stomach doesn't close properly at the top?

To answer this, please put yourself in your own body's shoes: Day and night you notice how the rising acid from the stomach "eats away" at the esophagus, inflaming and tormenting the tissue. But what can you do? The body cannot repair the defective closure to the esophagus and acid production continues at full speed depending on the diet. How can we protect the suffering esophagus?

Your body shows an impressive reaction: It uses the alkaline reservoir from the duodenum! Depending on the severity of the burns, the pyloric sphincter allows more and more alkaline bile acids to flow back into the stomach. Duodeno-gastric reflux occurs. This actually succeeds in neutralizing the stomach acid. Measurements in the stomach and esophagus show that a pH value of even 7(!) can be reached in the stomach. Accordingly, these patients also experience "alkaline reflux", which many patients with acidic heartburn are rightly surprised about.

At the same time, it has been observed that PPI medication in these patients leads to a reduction in the concentration of bile in the gastric juice. But why? Because of course this has nothing to do with the actual medicinal effect of acid blockers?

Let's look at the "human system" again: The PPI medication blocks the formation of acid in the stomach. This medication allows the esophagus to "breathe a sigh of relief"; it is now relatively well protected! An unnatural neutralization of stomach acid by the alkaline bile acids from the duodenum is no longer necessary. The pyloric sphincter begins to regularly control the transition to the duodenum and to prevent alkaline reflux. The bile concentration in the gastric juice decreases again, but may not return to normal!

Unfortunately, the influx of bile acids is both a blessing and a curse in DGER. This is because the bile acids in the stomach now act in a completely different pH environment! It has been proven that various subgroups of bile acids, particularly secondary deoxycholic acid, develop a high cell-damaging potential on the membranes of esophageal cells in an acidic environment. This is apparently triggered by the formation of toxic oxygen radicals in the cells. These changing properties under the influence of pH, the activation of different cell receptors and many other questions have not yet been researched.

Until then, the following applies to you as a patient: DGER is associated with gastroesophageal reflux disease. DGER is to be assessed as critical. Especially in cases of severe chronic inflammation or even Barrett's changes, it is essential to prevent this double burden on the tissue. Regular intake of PPIs appears to be suitable for at least "reactively" reducing this bile reflux. Antioxidants in the diet may be helpful. The other way is clear: the anatomically correct surgical reconstruction of the complicated closure system between the stomach and esophagus. Because then the body's emergency situation is finally resolved, all the acids and enzymes in our digestive system remain where they belong and the disease is overcome.

With this perspective on the “human system” I hope to have given you a feeling for the fascinating ways in which our body reacts when dysfunctions occur.

Yours

Dr. med. Eckhard Löhde