Do you have digestive issues when you eat? Have you heard of SIBO and wonder if this is the cause of your health issues? Are you looking for a SIBO clinic to help you? Then you are in the right place because this article will explain all about SIBO. Once you have a good understanding of this gastrointestinal disorder I will explain what to do next.
What is small intestine bacterial overgrowth?
SIBO is a chronic condition of the gastrointestinal tract, that is actually very common. Though unfortunately, it is not very well recognised by doctors. But is recognised by people like me who run a SIBO clinic.
Simply put, small intestine bacterial overgrowth is exactly what it says it is. Literally, an overgrowth of intestinal bacteria in the small intestine.
These are not 'bad' types of bacteria. Rather they are normal types of bacteria that are usually found in the human gut. But, instead of being in their usual place in the large intestine, they are now living in the small intestine.
Not only that, but this bacterial population is multiplying. To the point of being an overgrowth of bacteria! Which creates problems for you.
The small intestine
The small intestine and the large intestine are joined together. From the names, there may not seem a big difference. But, the small and large intestines are very different structures with different functions in the body.
The small intestine is the main organ responsible for the digestion of food and for the absorption of nutrients. It has a special lining that releases enzymes that break down food into nutrients. This part of the digestive tract has a very large surface area for absorbing those nutrients into the bloodstream.
Though bacteria are always found in the small intestine they do not usually grow or multiply there. Instead, bacteria usually flow through to the large intestine quite quickly, along with food.
As food moves through the small intestine, the body absorbs the digestible nutrients. The indigestible part of food, the fibre, is not absorbed and it moves through the gut and into the large intestine.
The large intestine
The large intestine contains trillions of bacteria. We used to think they had no importance. But now we know they are crucial for our health.
The contents of the large intestine are slow-moving. This creates the sort of environment that bacteria love. The bacteria in the large intestine ferment fibre and turn it into nutrients such as vitamins and other useful compounds.
Why bacteria multiply in the small intestine
The body has ways to protect us from having too many bacteria in the small intestine.
Stomach acid at adequate concentration kills almost all gut bacteria. So, having enough stomach acid can help to limit the number of bacteria in the small intestine.
However, a more important way is by keeping the small intestine contents moving. I hinted earlier at the importance of movement in the gut.
The small intestine cleans itself with a cleaning wave of motion that occurs between meals. Literally sweeping the bacteria and food through to the large intestine.
This wave is called the migrating motor complex (MMC). If the MMC slows or stops, the passage of food slows down or stops. This means that food and bacteria stagnate in the small intestine. If this happens the bacteria can begin to ferment the food or more specifically the carbohydrates. And, fermentation of carbohydrates creates gas.
What are the symptoms of SIBO?
If we have bacteria in the small intestine and they are producing gas, there is nowhere for that gas to easily go. So, the intestine expands and we have the sensation of bloating. This is really the main feature of SIBO.
With bloating we can also have abdominal pain. This pain is not just due to the intestines expanding. Certain bacteria break down bile into acids and these can make the intestines more sensitive to pain.
The liver makes bile to help us digest fat in our food. So if the bacteria break down the bile, we can have poor fat absorption or fat malabsorption. Having stools that float is a sign that you might have poor absorption of fats.
Diarrhoea or constipation?
People with bacterial overgrowth often have diarrhoea or constipation, or aspects of both. Whether someone has diarrhoea or constipation can depend a lot on the type of bacteria they have. and the gas they produce.
Most bacteria create the gas hydrogen. People with hydrogen gas tend to have diarrhoea.
Some bacteria create methane. In fact, these are not bacteria at all, they are archaea. Another name for them is methanogens. While an overgrowth of archaea might be known as a methanogen bloom. I will continue to describe all the microorganisms as bacteria for simplicity. But, just know that methane gas causes gut motility to slow down. And, of course, this just exacerbates the problem.
We have known about bacterial hydrogen and methane gas production for some time. Humans do not naturally produce either of these gases. So the presence of either or both of these gases in the small intestine indicates a problem.
More recently researchers found a third gas that some bacteria produce, hydrogen sulphide. This gas is produced by humans as well as by some probiotic organisms. So, hydrogen sulphide has some health benefits. However, you can have too much of a good thing. Having too much hydrogen sulphide is toxic, especially to the nervous system.
Diarrhoea and constipation
Like hydrogen, the hydrogen sulphide gas typically causes diarrhoea. It is also possible to have an even more complicated picture with two or more of these gases at the same time. Mixed symptoms are more likely to be due to the presence of several gases.
More sibo symptoms
Gas that builds up in the small intestine can try to escape upwards or downwards. Gas moving upwards creates a feeling of fullness in the stomach or stomach pain. There can also be belching. This backpressure disrupts normal functioning and can cause gastroesophageal reflux disease or GORD. Sometimes you might see this written as GERD. People with gastro-oesophageal reflux disease have symptoms of heartburn, or sometimes hoarseness or throat irritation.
Unfortunately, doctors often prescribe acid blockers or a proton pump inhibitor for reflux symptoms. And, as you now know, stopping stomach acid production could actually make SIBO worse.
Similarly, there can be nausea, from the sensation of fullness, and from stagnant food sitting in the stomach.
Not surprisingly, unintentional weight loss is a common symptom of SIBO. If your symptoms get worse when you eat, as in SIBO, people tend to eat less and can lose a lot of weight.
Gas can also travel downwards through the large intestine causing flatulence.
But perhaps one of the most worrisome aspects of gas in the intestine is that it directly damages the gut lining. As I explained before, the gut lining is important for digestion and absorption, including the absorption of carbohydrates. So damage to this important barrier creates all sorts of other digestive conditions.
When we don't absorb the nutrients from our food we can develop nutritional deficiencies of vitamins and minerals. So, you might have B12 deficiency. deficiency of fat-soluble vitamins such as vitamin D, or iron-deficiency anaemia.
These nutritional deficiencies can create their own symptoms too.
We produce several enzymes in the intestinal lining that help to break down carbohydrates in our diet. Damage to the brush border lining means we produce fewer enzymes. This increases the risk of food intolerance.
A common example is lactose intolerance. If we can't make the enzyme lactase, we can not digest lactose or milk sugar. So, we are unable to consume dairy products that contain lactose, without having digestive symptoms.
Breakdown of our first line of defence
But it is not just our food or our digestive enzymes that the bacteria break down. They also break down the mucous lining that covers the gut lining. This mucous layer serves as the first line of defence of our immune system. It can allow the passage of nutrients. But, it should prevent harmful waste products and toxins from entering the bloodstream.
Nutrients need to move across the barrier into the bloodstream. But, the damage the gases create, makes the barrier even more leaky. If the gut becomes too leaky we can have a situation where it is not just tiny nutrients moving across the barrier, but much larger molecules.
These large molecules should not be able to enter the bloodstream. In fact, the immune system monitors everything that crosses the gut barrier. If the immune system finds large molecules it does not recognise it can trigger an immune response. This creates an inflammatory situation. And, inflammation is an underlying cause of many health conditions.
Certain types of bacteria have compounds in their membranes called lipopolysaccharide or LPS. The immune system can recognise and react to these endotoxins. If the gut barrier becomes leaky, endotoxins can breach the barrier causing immune havoc.
Endotoxins in the general circulation have been linked with several symptoms. For instance, if you have a leaky gut, you will almost certainly also have a leaky brain. These bacterial products from the gut microbiota can cause headaches, foggy brain and anxiety. They may also cause joint pain, muscle pain like fibromyalgia and many more symptoms.
Lastly, alongside abdominal pain and bloating, perhaps one of the more common symptoms is fatigue. Again, after talking about all these other problems, perhaps it is no surprise that SIBO patients experience fatigue.
What are the causes of SIBO?
We don't know exactly what causes SIBO but there are certainly some common risk factors. I have already mentioned that not having enough stomach acid can promote SIBO. But, the most common underlying cause of SIBO is some sort of motility disorder. If the migrating motor complex is working well and things are moving smoothly and in good time, SIBO is much less likely.
A very common cause of reduced motility is infectious gastroenteritis, otherwise known as food poisoning. Pathogenic bacteria produce a toxin known as CDT (cytolethal distending toxin). To the immune system, CDT looks like a part of the nerve cells that stimulate the migrating motor complex. As the immune system reacts to CDT, it also damages our nerve cells, disrupting the MMC. And in my clinical experience, I have certainly seen that food poisoning can trigger the start of SIBO.
Another important factor in SIBO is intestinal obstruction. This could be anything that obstructs or impedes the smooth and timely flow through the small intestine. Typical examples are adhesions, scarring, areas of inflammation or tumours.
Adhesions are surprisingly common. They are strands of scar tissue that the body makes as part of its healing process. The problem with adhesions is that they attach to the abdominal organs. Instead of organs freely moving or sliding around, adhesions stick organs together. Adhesions may occur between the small intestine and other organs such as the liver. Or there may be adhesions between or around loops of the intestine. Either way, this can obstruct smooth flow through the gut.
Adhesions can occur after abdominal surgery, or after an accident, blow or trauma to the abdomen.
As well as obvious obstructions, gastrointestinal conditions such as intestinal diverticulosis can create pockets of stagnation. Pouches or blind loop in the intestines where excess bacteria can multiply and overgrow.
Some other underlying conditions and causes include endometriosis, inflammatory bowel disease, Coeliac disease, Ehlers-Danlos Syndrome and medications such as opioid drugs or long-term antibiotics. In fact, in clinical practice, I often see more than one cause in the same person.
Things that make SIBO worse
In my experience, there are several things that make SIBO worse and should make you suspect SIBO:
- taking prebiotics (or probiotic supplements that contain prebiotics)
- taking fibre supplements, especially soluble fibre
- going gluten-free (GF alternatives are high in fermentable fibre)
- eating healthy foods, such as raw vegetables
- taking the polysaccharide-rich medicinal herbs (liquorice, marshmallow, Aloe vera, slippery elm)
How to find out if you have SIBO in the UK
It can be difficult to get a diagnosis of SIBO from your doctor. SIBO is a cause of irritable bowel syndrome and so small intestinal bacterial overgrowth is often diagnosed as IBS. Finding out if you have SIBO rather than IBS is important because it will help determine a solution.
Book a session at my SIBO clinic and I will explain how we can find out if SIBO is the cause of your health problems.
Of course, even though you might suspect bacterial overgrowth, it is helpful to have testing to confirm this. Testing is also helpful to track treatment progress. In my SIBO clinic, I recommend SIBO breath testing.
There are two types of SIBO breath test. The glucose and the lactulose breath tests. Both involve providing a series of breath samples, after drinking a test liquid. Each breath sample is analysed for the gases hydrogen and methane. Normal breath does not contain either of these gases.
It is important to take samples over a three hour period. Some labs only offer a two-hour test which can miss some cases of SIBO.
At the time of writing this article, we don't have a test for hydrogen sulphide in the UK, though this is available in some other countries.
Breath testing is a reliable, simple, and non-invasive test. The results are in the form of a graph that a clinician can interpret for the presence of SIBO.
You might be able to get a breath test on the NHS. For instance, your gastroenterologist may approve SIBO testing for you, after a referral from your GP. But this can be a long process on the NHS. Plus, the NHS SIBO test may only include hydrogen and as I have explained why it is important to know if methane is there too.
That is why I offer breath testing in my SIBO clinic. I offer the three-hour test for both hydrogen and methane as recommended by Dr Allison Siebecker. I have trained with Dr Siebecker and she has helped thousands of SIBO patients.
Other clinicians might suggest other tests such as the urine organic acids test. But, although this is a good test for other digestive tract problems, I don't recommend it for diagnosing SIBO. It can be a useful screen but it does not differentiate between overgrowth in the large and small intestines.
My approach in my SIBO clinic
If you have a diagnosis of SIBO there are three options. Antibiotics, herbal antibiotics and the elemental diet (a liquid diet). These can help to get your symptoms under control, but they don't necessarily address the underlying cause.
As a medical herbalist, I can offer herbal medicines. Medicinal herbs are just as effective as conventional antibiotics for SIBO, but they take longer to work. Some people prefer the natural approach that I offer at my SIBO clinic and choose to have herbs instead of drugs. Even so, it is important to realise this may mean they have a longer treatment time.
I also recommend a strict nutrition programme. Often this nutritional plan will be based around the low fodmap diet, but not always.
In some cases, bacterial overgrowth will resolve quickly, but usually, even with conventional antibiotics, multiple rounds of treatment are often needed to resolve gut symptoms. It can take a lot of patience and hard work, but at my SIBO clinic I provide lots of support to make it as easy as possible.
What to do now
If you suspect SIBO, you can waste a lot of time trying to fix it yourself. Why not ask an experienced practitioner to help with your healing journey. Contact me at my SIBO clinic to find out more.
If you would like to have a chat to discuss your gut health or want to know more, I offer a free no-obligation "hello call". This is a 15-minute chat about your symptoms and what my approach might be. This is your opportunity to see how we can work together. Find out if you have SIBO with the right testing. And, learn how in my SIBO clinic, herbs, diet and nutrition can help.