Your body recycles all of its red blood cells over a six week period. During this process heme is released from your red blood cells in your spleen and converted to unconjugated bilirubin. For a variety of reasons (which I will explain shortly) a person can wind up with too much of this compound in their digestive tract, which promotes highly inflammatory damage to the lining of your digestive tract. This has become known as the "leaky gut," wherein toxic compounds in your digestive tract leak back into your circulation and cause multiple health problems. In a new study a strain of friendly flora, called Lactobacillus plantarum, was shown to offset the digestive damage of unconjugated bilirubin.
Yes, I know, it sounds like a lot to understand-and it is. First, it requires more explanation so you will understand how the issue relates to your health. For any of you with digestive problems, it's worth taking the time to understand, as it may help you to improve your digestive health.
Unconjugated bilirubin (also called indirect bilirubin) is a fat-soluble compound that your body would like to make water-soluble. It is attached to albumin in your blood and carried to your liver where it is conjugated to (bound to) glucuronic acid. At this point, the bilirubin is now water-soluble (also called conjugated or direct bilirubin) and what is not recycled is sent into bile for excretion into your digestive tract.
Jaundice is a condition of too much unconjugated bilirubin in the blood, causing the yellow appearance in the whites of eyes and possibly skin. This can be a significant problem in a newborn baby if it persists for any length of time. This fat-soluble substance can readily cross the immature blood-brain barrier and damage evolving brain structure during a critical two weeks of metabolic development. In others words, leptin and thyroid brain circuitry can be injured for life, to a greater of lesser degree, by this problem. Individuals with anxiety were often jaundiced following birth, reflecting damage to core brain structure. Much more serious brain damage can occur than these functional issues. In some cases, liver health is compromised-especially in premature babies-leading to a perpetually higher level of unconjugated bilirubin (Gilbert's syndrome). While this is likely to result in an adult with chemical sensitivity, inflammatory digestive issues (including leaky gut), and energy/metabolic problems are not as serious in the first few weeks of life, as the blood-brain barrier is better able to defend against the unconjugated bilirubin entering the brain.
In addition to these readily definable medical issues with unconjugated bilirubin there are also less obvious issues with unconjugated bilirubin that pose rather significant challenges to digestive health. One key sign of a problem is that your stool color is pale, yellow, or lighter as opposed to darker brown. Your intestinal bacteria act on conjugated bilirubin by changing it into various compounds that end up darker brown. Lighter color stools indicate a lack of friendly flora as well as the likelihood that the clearance process of conjugated bilirubin isn't working properly. This means that there is a significant likelihood that conjugated bilirubin is simply turning back into unconjugated bilirubin and piling up in your digestive tract in excess. Too much unconjugated bilirubin is caustic on contact, thus having the potential to injure the lining of your digestive tract. In the current study, researchers meticulously showed how unconjugated bilirubin in the digestive tract damaged multiple tight protein junctions and blocked repair of the injured areas-which obviously leads to leaky gut. They also showed that friendly flora can prevent such damage.
In addition to lighter color stools, indigestion is another sign you could be having a problem. The burning or pain across your abdominal region is contributed to by the unconjugated bilirubin. This isn't the only reason for indigestion, but it is one. Of course, simply being deficient in friendly flora from the excess consumption of sugar, alcohol use, and/or antibiotics use are other common factors that set the stage for this problem.
There is also the issue of poor liver function, or your red blood cells may be breaking down too fast by inflammatory stress. One of the first signs of unconjugated bilirubin in your blood is when the whites of your eyes look a bit yellowish. Such issues are common in overweight people, and in people whose hemoglobin and red blood cell scores are on the lower edge of the normal range. Of course, someone with anemia because their red blood cells are being broken down too fast (hemolytic anemia) would be the classic example of this. However, many people without blatant anemia experience this problem to some degree simply from wear and tear. This health issue can turn into a nasty catch 22, as the leaky gut problem allows toxins back into the blood which then damages red blood cells and increases the load of unconjugated bilirubin that further perpetuates the leaky gut. While all this may sound rather complex, it is happening to many people who have ongoing digestive stress of one type or another.
If you have a history of high bilirubin following birth, then this topic may be of special importance. Your body may be sensitized to higher levels of digestive unconjugated bilirubin, similar to having an old injury that flares up later in life. One sign of this would be sensitivity to alcohol, as unconjugated bilirubin highly reacts with alcohol. In other words, alcohol intake should be minimized in individuals with this problem as the "benefits" of moderate alcohol intake is most likely a joke.
It is quite interesting that friendly flora can help break this problematic cycle, and will promote a more competent digestive lining while helping to guard against higher levels of unconjugated bilirubin in your digestive tract.