Irritable bowel syndrome (IBS) is a world-wide problem and is no longer considered a psychosomatic disorder. At this time, IBS is believed to be related to abnormalities of the microbiome, the vast population of bacteria which inhabit the gastrointestinal tract. This large variety of friendly bacteria performs a number of functions which are beneficial to our health.
*The types of bacteria in the digestive system depend on the person’s age, diet, sex, geographical origin, and prior use of antibiotics. Alteration of the bacterial contents of the digestive system has been suggested to be a cause of IBS. An increase in the types of bacteria which increase production of short chain fatty acids (SCFA), such as butyrates, can lead to bloating, diarrhea, constipation, and IBS. Recent evidence suggests that IBS is associated with ongoing bowel inflammation due to immune system activation by pathogenic bowel bacteria.
Normal gut bacteria can either kill abnormal bacteria or prevent them from sticking to the gut wall where they can divide. **Firmicutes and Bacteroidetes are the major normal bacteria in humans. A doubling of the ratio of Firmicutes to Bacteroidetes has been seen in IBS. Post-infectious IBS (PI-IBS) sometimes occurs in people who have suffered a severe bacterial gastrointestinal infection. This can occur while traveling in developing countries. (Bacterial imbalance is often found in the gut with PI-IBS.)
Reduced glutamine amino acid levels are sometimes found in patients with IBS. Reduced glutamine leads to increased permeability of the intestinal wall to pathogenic bacteria. This can potentially cause infections in organs distant from the intestine. Glutamine can be given as a supplement to strengthen the intestinal barrier, as can probiotics.
Probiotics are live organisms which can reduce symptoms of IBS, improve gut lining, prevent pathogenic bacteria from sticking to the intestinal wall, and reduce inflammation. A combination probiotic called VSL#3 (containing 8 bacterial species) has been found to be beneficial in IBS.
On the other hand, prebiotics are poorly digested substances which increase the growth of beneficial bacterial species already living in the gut. Prebiotics can improve symptoms of IBS, such as gas and bloating. Inulin is an example of a prebiotic which can increase the growth of Bifidobacteria. Symbiotics are combinations of probiotics and prebiotics in the same supplement.
CONCLUSION: Gut microbes play a major role in the etiology of inflammatory bowel syndrome (IBS). Supplements which may be used as treatment for IBS include: probiotics, prebiotics, and glutamine.
NOTES: *“The small intestine consists of mainly Gram positive and aerobic bacteria, whereas the large intestine consists largely of Gram-negative and strictly anaerobic bacteria.” The Gram test depends on the color of the bacteria with Gram stain. Aerobic means the bacteria need oxygen to live. Anaerobic means the bacteria grow best with the least oxygen.
**Firmicutes and Bacteriodetes are two classifications of bacteria called phyla. Firmicutes bacteria are mostly gram positive and Bacteriodetes bacteria are mostly gram negative. A reduction of the Firmicutes/Bacteriodetes bacterial ratio is said to promote weight loss.
To read the author’s abstract of the article, click on the title of the article. Then, to read the full article, click on the full text icon.