Despite a stable and consistent prevalence over the years, Irritable Bowel Syndrome otherwise referred to as IBS, is actually rather unpopular these days. Come to think of it, IBS sounds almost antiquated when I hear doctors, or others in the health community refer to ‘this' condition as ‘IBS’. ‘This’ being a collection of frustrating, mysterious, and yes, irritating gastrointestinal symptoms which up until recently fell within an umbrella diagnosis of IBS. Symptoms such as rogue abdominal pain, bloating, cramping, diarrhea, and constipation stood as the standard criteria to diagnose this condition since the 1980s.
What has shed a new light on this otherwise ambiguous condition is evolving research over the past 20 years, identifying a physiological cause in IBS. This collection of symptoms is now pinpointed to the presence of a bacterial overgrowth in the small intestine, also known as SIBO. The two diagnoses have the same symptoms but are diagnosed differently. Where IBS is diagnosed based on patient reported symptoms, SIBO is diagnosed through the use of a breath test confirming physiological cause. Now the two seem almost synonymous as recent research has determined up to approximately 80% of IBS patients test positive for small intestinal bacterial overgrowth.
Previous to these new findings, IBS presented as mysterious with treatment severely lacking in effectiveness. I have heard an incredible number of patients describe a beyond frustrating experience of finally coming to a formal diagnosis of ‘IBS’ from a specialist, only to just be advised on stool softeners, laxatives, and fiber gummies that could never effectively address symptoms. What I did hear and find to be helpful through my nutrition travels, was the application of the low FODMAP diet. It seemed to allow increased control in an enigmatic and at times debilitating condition. Although it seems to help deal with symptoms, over time I came to recognize that this diet is really only a band aid solution. So here me out for a moment- this is mainly because it can only address the symptoms without ever really addressing the cause. Adhering to this diet means permanent restriction from a collection of foods, nutrients, and plant fibers, which under normal conditions could only contribute to an optimal way of living. This is important to recognize, you see, it is not the food you are reacting to, it is the presence of rogue bacteria camping out in your small intestine, wreaking havoc on your wellbeing.
Let me try to break all of this down for you (since you are here and interested!)… Bacteria in the intestinal tract naturally increases in population as you travel downwards from the stomach to the three segments of the small intestine- the duodenum, jejunum, and ileum- then finally the large intestine or colon, where a majority of intestinal bacteria lives. Even so, a healthy small intestine contains few microbes due to its proximity to the stomach and exposure to stomach acid, or hydrochloric acid. As a result, a majority of the good bacterial populations colonize and reside in the colon. Here they feast on plant fibers, also referred to as PREbiotics, which provide their nourishment. A majority of intestinal bacteria purposefully reside in the colon since it has an ecosystem and structure designed to handle the fermentation process that occurs between microbe and prebiotic fiber.
With SIBO, these prebiotics get prematurely fermented in the small intestine, causing methane and hydrogen production, not to mention terrible bloating, pressure, and gas. Typically fermentation of these plant fibers occurs when it reaches the colon, where it is designed to handle the production and release of these gases. Depending upon where the overgrowth exists- most likely in the jejunum or ileum- you may be troubled with bouts of diarrhea and/or alternating constipation. If that isn’t awkward and uncomfortable enough, symptoms can also present as a sign of a deeper more complicated issue about to evolve. From a nutritional standpoint, deficiencies manifested as a result of SIBO can ultimately cascade from malabsorption to potentially serious medical conditions such as anemia, osteoporosis, and even ocular issues such as cataracts or dare I say even blindness.
What is important to fundamentally understand is the true purpose of the intestinal tract; to receive the food we eat and absorb most of our biologically necessary nutrients (water, potassium, sodium are absorbed in the colon). With a contribution of digestive juices from other key GI players, these nutrients can now pass through the intestinal border and into the bloodstream, resulting in a cascade of other biochemical processes and eventual utilization. However with SIBO patients, what happens is a competition for these nutrients, between the patient and the bacterial overgrowth.
Depending upon where the bacterial overgrowth exists, varying nutrients are comprised. I more often tend to see bacterial overgrowth occur in the ileum, the last of the three segments of the small intestine. This makes sense, as naturally bacteria is meant to increase near and inside the colon, just not to the extent at which it occurs in SIBO. What ensues are a malabsorption of key nutrients, such as vitamin B12 and fat soluble vitamins such as vitamin D, A, and E. Malabsorption occurs as nutrients are competed for at the intestinal brush border and never allowed absorption through to the blood stream.
Fat malabsorption is found to be a clinical feature in SIBO, which I have frequently observed in my practice. In fact, it often stands as a confirming feature (to me) when patients begin to hesitantly describe their bowel movements as having a goldish hue and sticking to the toilet bowl. You see, bile from the gallbladder is provided to the small intestine allowing for absorption of, not only fat, but importantly those previously mentioned fat soluble vitamins. With SIBO, bile is unable to get properly absorbed. Without proper absorption of bile in the ileum, neither fat nor fat soluble vitamins can get absorbed and to travel into the bloodstream. What then ensues can be uncomfortable, unsightly, and painful. And that is just the start of it.
Over time, this prompts a cascade of deficiency, which can only go downstream toward chronic disease. I have seen patients effectively differently based upon where the overgrowth lives and the nutrients they will become deficient in. From a nutrition epidemiology standpoint, it become more and more intriguing to observe research evolve closer to connecting chronic and recurrent SIBO with chronic disease development. Without know what created it, what we do know is that the loss of fat soluble vitamins (A, E, D, K) can spawn a range of effects. Deficiency of such vitamins can be attributed to many chronic diseases including: cataracts, retinopathy, and blindness; osteopenia, osteoporosis, and generalized bone loss; poor immune function and frequent illlness; and even cancer and cardiovascular disease.
In the case of Vitamin K and its two versions, K1 and K2. We obtain K1 from sources such as leafy greens and it often stands as ‘nutrient to monitor’ for those on blood thinners or anticoagulant therapy. The K2 version is, interestingly, created by bacteria in the colon and is a essential nutrient in bone health. As a result, even individuals with or without SIBO, with high exposure to antibiotics are at higher risk for osteoporosis. And since this K2 is dependent upon healthy colonic bacteria, it would make sense NOT to starve them, such as in the long term application of a low FODMAP diet, which permanently avoids prebiotics, or high FODMAP foods. Keeping up with these prebiotic restrictions without treating the bacterial overgrowth, winds up actually neglecting the majority of bacteria residing in the colon. In this nutrition philosophy, I must ask, why must we cater to an unwanted bacteria in the small intestine, only to neglect and deprive the bacterial majority which are meant to be there ?!?!? This mentality just seems flawed to me. Mainly as it only calms the symptoms, never actually treats the issue, and even creates a host of other insufficiencies.
From an evolving medical and research community, we see how scenarios in SIBO can vary in symptoms and clinical features, yet there are connections that nutritionists, doctors, and clinicians are now able to better understand and look for. Effectively treating SIBO with herbal supplements and diet takes a personalized, thoughtful, and careful approach in order to truly eradicate the overgrowth AND prevent its reoccurrence. Taking a personalized approach with a thoughtful nutrition plan will only increase your chances of not only stopping all those irritating symptoms for good but also rediscovering your balance, wellbeing, and ultimately, yourself again.