SIBO

Some of the most common risk factors associated with SIBO are low stomach acid (including from PPI use), pancreatic insufficiency, irritable bowel syndrome (IBS) and Crohn’s, celiac diagnosis, and diabetes.

People suffering from SIBO often report a wide range of gastrointestinal (GI) symptoms, including

• Abdominal distension

• Bloating

• Flatulence

• Cramping

• Diarrhea

• Constipation

• Intestinal pain

As well as systemic symptoms (non-GI related) like brain fog, headaches, fatigue, skin conditions, and joint pain.

Any intervention strategy for SIBO would include looking at:

• Dysbiosis

• Low stomach acid

• A reduction of digestive enzymes

• Poor absorption of food leading to nutrient depletion

• Systemic inflammation

• Intestinal permeability (aka leaky gut)

A brief (but necessary) tour of the digestive process

After we have finished chewing our food, it goes down into the oesophagus (food pipe) and enters the stomach. A sufficiently acidic (pH 1-3) stomach environment will kill any pathogens carried on the food and can break down the food that we eat to release vital nutrients, such as iron and B12, but also zinc, copper, calcium and folic acid. When the digested food is ready to leave the stomach, it enters the small intestine as an acidic bolus called chyme.

The acid that travels with food from the stomach to the small intestine is one of the reasons why there are so few microbes living there compared to the colon.

And this is hugely important too because we need to be able to absorb the nutrients in the food we eat, and that absorption takes place in the small intestine, before the microbes get the leftovers in the colon.

The whole issue with SIBO is that these microbes have taken up residence in the small intestine, and they’re feeding on our food.

This is usually because the stomach either doesn’t have enough stomach acid, or the pH is above 5, which allows microbes to survive, and they end up competing for the available nutrients, especially iron and B12.

If they’re getting the iron and B12, that means you’re not, and a deficiency in these nutrients can lead to anaemia and brain fog.

Another offshoot of low stomach acid is the inability to produce pepsin, which is necessary for the breakdown of protein. Undigested protein fragments can ‘leak’ through the gut barrier and create a condition known as ‘leaky gut’. If large protein fragments enter the bloodstream, they can be seen as foreign invaders by the immune system, and so allergic or autoimmune responses can arise as a consequence. Even if undigested proteins don’t enter the blood, the fact that they haven’t been digested properly increases the likelihood that they’ll cause digestive distress.

Furthermore, low stomach acid (or low pH) can prevent the signal that should be sent to the pancreas to release the digestive enzymes necessary for the breakdown of carbohydrates. So, if we’re not digesting the short-chain carbohydrates in the small intestine, not only are we not getting any of the nutrients, but all that food is going to feed opportunistic microbes who have taken up residence in the small intestine. These microbes ferment the carbohydrates in the small intestine, creating gas (hydrogen, methane), bloating, abdominal pain or cramping. This excess gas can also cause something called intra-abdominal pressure (IAP) which can propel stomach acid back up the oesophagus from the stomach, causing heartburn.

You can see how there’s a vicious cycle here, because once someone regularly starts getting reflux, they might consider taking acid-suppressing drugs, which will prevent the proper digestion of carbs (because of the reduced pancreatic enzyme secretion).

These carbs will subsequently not be properly absorbed, which will make them available for microbes, who will ferment them and create huge amounts of gas (around 10 litres for every 30g of undigested carbs!) and this gas will create the intra-abdominal pressure that causes the acid reflux.

Acid-suppressing drugs are not the answer.

Anyway, I’ll flesh out the mechanism a little bit more before we can look at possible interventions for SIBO.

The gases created by microbes should ordinarily be created in the colon, where bacteria can ferment the leftover fibre of the carbohydrates we can’t digest. It’s not like we don’t want to feed these little microbes, we just want them to wait their turn, and we want them to specifically eat the leftovers because just as we have a difficult (or impossible) time digesting it, so too do the microbes, and the production of gas is much less compared to the fermentation of the short-chain carbs in the small intestine.

Sometimes SIBO can occur even if there is sufficient stomach acid. A diet very high in short-chain carbohydrates can tax our ability to digest and absorb it all, leaving the door open for our microbial friends to take up the slack.

It is very important that the food we eat is quickly spread throughout the small intestine and get absorbed, which is why as soon as we’re finished eating, the muscles and nerves in the gut contract and push the food down toward the colon. There needs to be a fairly swift clean-up operation so bacteria are not tempted to leave the colon.

I’ve said short-chain carbohydrates a couple of times, and what I mean is the carbohydrates are shorter and easier to break down and absorb. They are often called ‘simple’ carbohydrates, as opposed to ‘complex’ carbohydrates, which are more nutrient-rich, slower to digest and generally healthier.

Interventions

So, if SIBO is characterised by bacteria thriving in the small intestine, one of the best interventions is to starve them out of there. To do this, we have to take away the reason they’re there in the first place. They want to ferment the short-chain carbs, that’s why they’re thriving. Short-chain carbs are classified as fermentable oligosaccharides, disaccharides, monosaccharides and polyols (aka FODMAPS).

So, a popular SIBO protocol is the FODMAPS diet, which eliminates FODMAPS and starves the bacteria in the small intestine. It is important to note that some sugars are so rapidly absorbed by humans, that the bacteria don’t get a chance to grab it for themselves. Table sugar comes under that category, so too does glucose.

What is impossible for humans to digest and what bacteria in the small intestine just love to ferment is artificial sweeteners – sugar alcohols, such as sorbitol (in sugar free gum), sucralose, xylitol etc. These need to be eliminated from the diet in order to get rid of SIBO. Lactose too, so milk, cheese and yoghurt should be eliminated.

There are many websites outlining the FODMAP diet these days. A FODMAP diet can often seem counter-intuitive when you look at it from purely a health stand-point, because you’re limiting vegetables with a high content of non-digestible carbohydrates (aka fibre), such as broccoli, cauliflower, cabbage, and green leafy vegetables, and increasing simple carbs, such as rice, potatoes, and pasta. This is often contrary to regular health advice, which is why a FODMAP diet should only be implemented for the specific purpose of starving bacteria in the small intestine.

Other important foods to avoid are beans or legumes (which you already know create gas), including hummus, which is actually especially bad for people with SIBO. Numerous other healthy vegetables are available on this diet, however, such as peppers, tomatoes, cucumber, zucchini, squash, eggplant, peas, yams, beets, carrots, turnips.

It is important to allow sufficient time for the post meal clean-up operation to take place, so snacking is not advised. It is better to just eat three standard meals a day (with at least 4 hours between meals), or if you’re able to, you could consider doing intermittent fasting, which would improve the chances of properly cleaning out the small intestine before the next meal.

Anyway, if you have any of the symptoms of SIBO, feel free to schedule in an appointment with me and i’ll be happy to resolve this issue for you.

Kind regards,

Brady