SIBO stands for Small Intestinal Bacterial Overgrowth. Our small intestine is more than 6m long! If the intestinal tube was laid out flat, the surface area would be about the size of a tennis court! This is where most of the absorption of nutrients occurs.
SIBO is where bacteria in the small intestine become out of balance and overgrown. Most of our good gut bacteria is supposed to be located in our large intestine. This is where they do their job of further breaking down food and synthesising vitamins, then eliminating waste.
Our small intestine should only have a small amount of good bacteria. When bacteria from other parts of the digestive system move house and colonise, or reside in the small intestine, this is when we see SIBO. Remember that these bacteria aren’t meant to be in the small intestine, but they continue to do their job regardless. So, if they are from the large intestine, they continue to do what they should do in the large intestine, but now in the small intestine. This throws everything out of balance and causes a number of issues.
These bacteria start feeding off the undigested food in the small intestine and they especially enjoy sugar, alcohol, carbohydrates and starches. This causes fermentation in the gut. The fermentation causes high levels of either hydrogen, methane or sometimes both in the digestive system.
There are two main types of SIBO, hydrogen dominant SIBO or methane dominant. If you suspect you have SIBO, you can go to your GP to get a referral for a breath test to measure the amount of these gases to determine the type of SIBO you have. If you are experiencing diarrhea more, then you are possibly more likely to have hydrogen dominant SIBO. If you are experiencing more constipation, you are possibly more likely to have methane dominant SIBO.
Other than constipation or diarrhea, some other symptoms you might notice include gas, bloating, abdominal pain, abdominal discomfort, abdominal cramping, IBS (Irritable Bowel Syndrome), food intolerances such as gluten, casein, lactose, fructose or histamine, IBD (Irritable Bowel Disease), vitamin or mineral deficiencies such as vitamin A, vitamin B12, vitamin D and vitamin E, fibromyalgia, chronic fatigue syndrome, diabetes, neuromuscular conditions, autoimmune conditions, fat malabsorption (a sign of this is pale, smelly, floating stools), rosacea or other skin rashes, dry patches of skin on your legs or other areas, poor digestion, leaky gut and restless legs. You can see that there are a huge range of symptoms that can be associated with SIBO.
If our gut health isn’t optimal or working the way it should, it then affects other body areas, and they aren’t able to work the way they should. Our gut health can be likened to the roots of a tree. A tree needs healthy foots to be able to flourish and grow. Our gut needs to be healthy so that it can absorb nutrients, break down food effectively, eliminate waste products and produce hormones effectively. If it isn’t, this causes many other problems in our body.
Some things that can particularly point to SIBO and increase your chances of having it include the following.
~ Stress
~ Previous abdominal surgery including Caesarean sections, hernia surgery, endometriosis surgery and any other abdominal surgeries
~ Eating a diet that is high in sugar, starches and carbohydrates
~ Drinking alcohol
~ Medications such as antibiotics, steroids, PPIs that block acid production that are used for reflux
~ Weak or poor function of the ileocecal valve that is located between the small and large intestine
~ Low thyroid function, this also slows gut function
~ Vagus nerve dysfunction, the vagus nerve regulates peristalsis which is the wave like movements that push food through the intestines and it also triggers the stomach to produce stomach acid
Looking more closely at these, when our stress levels are chronic, meaning ongoing, this affects our digestion. If we are in constant fight or flight mode, our body pumps blood away from the gut causing our digestion to slow down. Therefore the food that we eat is sitting for longer in the intestines. This causes fermentation and disrupts our microbiome or bacteria in our gut, leading to an imbalance.
Nerve or muscle damage from abdominal surgery can affect our digestion and the bacteria in our gut.
Eating a diet high in sugar, carbohydrates, starches and drinking alcohol feed the bacteria, keeping the growing and thriving. When the bacteria are in the wrong place in the digestive system, such as being in the small intestine rather than the large intestine, we don’t want to be feeding them. We don’t want them to be multiplying or flourishing there.
Slow thyroid function or hypothyroid causes slow or sluggish digestion. It also reduces the amount of hydrochloric acid produced by the stomach to break down food properly there. If this is an issue for you, you might notice reflux symptoms. If there is not enough stomach acid, food that isn’t digested properly can move into the small intestine. This then also feeds those bacteria and it sits there for longer and ferments.
Medications such as antibiotics, steroids, NSAIDs such as ibuprofen, anti-inflammatory medications and PPIs all disrupt the microbiome, leading to an imbalance in our gut bacteria.
Poor diet and the use of medications can cause inflammation, leading to leaky gut. As I mentioned earlier, there are many connections between SIBO and other conditions. There is a connection between SIBO and histamine intolerances. You might experience itching, fatigue, rashes, high blood pressure, hives or headaches.
There is a connection between SIBO and leaky gut. SIBO causes damage to the vili that line our digestive tract. Vili are finger type follicles that allow the absorption of nutrients into the bloodstream. This then damages the tight junctions that are like the gateway between our gut and our blood, allowing larger particles of food through. This then goes on to cause inflammation and sometimes also autoimmune conditions.
There is a SIBO and rosacea connection. People with rosacea are 9 x more likely to have SIBO. SIBO leads to leaky gut. Leaky gut leads to inflammation, including skin inflammation. Rosacea is where you have a flushed look all the time, or rosey cheeks.
There is a connection between SIBO and fatigue. The bacteria interfere with the absorption of nutrients, especially vitamin B12. We need this for many things, especially for red blood cell production. Our red blood cells transport oxygen around our body giving us energy. Low B12 can lead to fatigue, lack of energy and weakness.
So what can we do about SIBO?
Eating ~ stop feeding the bacteria. Reduce sugar, alcohol, carbohydrates, gluten, legumes, starches and fruit that is naturally high in sugar. Under the care of a Naturopath or other health practitioner, you might follow FODMAPs or a Specific Carbohydrate diet for up to about 6 weeks.
Weed the bacteria out ~ again, under the supervision and advice of a Naturopath or qualified health practitioner, using antimicrobial herbs such as thyme, oregano, garlic, rosemary. You should do this under supervision because if you go in too hard with these herbs, you will feel really yuck, headachey and lethargic because your body is trying to detox and get rid of all the bacteria.
Put back the good bacteria ~ using probiotics from either supplements or fermented foods. Again, I would recommend you work with a Naturopath or health care practitioner because depending on your symptoms will depend on what particular strains of probiotics are best for you. I go into this in more detail in my online program, Healthy Bellies. Often with SIBO, probiotic strains of Lactobacillus or Bifidobacterium are overgrown in the small intestine. Having more of these strains can make symptoms worse. If you have been previously supplementing with these strains of probiotics and you notice that your symptoms are worsening, not improving, this could be another indication of SIBO.
Increase your fibre ~ eat wholefoods and prebiotic foods such as onion, garlic, leek, asparagus to feed the probiotics.
Work with a practitioner to then slowly start to reintroduce foods that you have cut out, keeping a watch out for any return of symptoms.
If you are having symptoms of SIBO but you have had the breath test and it came back negative, you might have something known as SIFO, a fungal overgrowth in the small intestine. Or you might have another parasite in the gut or H. Pylori or a GI infection. To find out if you have these, you could have a CDSA stool analysis. Other causes of these symptoms could be food sensitivities causing inflammation, I use the hair analysis to work with this. Or it could be from other nutrient deficiencies or medication use.
There is a lot that can be done to support those with SIBO. Please get in contact with me if you would like further advice.