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How Functional Medicine may Help with Small Intestinal Bacterial Overgrowth?

Have you been diagnosed with IBS but not sure of the cause? SIBO can often be a factor. Read below how Functional Medicine may be able to help you.

How Functional Medicine may help with Small Intestinal Bacterial Overgrowth?

Small Intestinal Bacterial Overgrowth, SIBO for short, develops when bacteria normally living in your large intestine migrate into your small intestine. These aren’t usually disease-causing bacteria, they’re simply bacteria in the wrong place. 1

Your small intestine is around three and a half times the length of your body, and it’s joined to your much shorter colon by a special valve. It’s where most of the nutrients from your food are absorbed. In your large intestine on the other hand water is removed, waste products are processed for excretion and bacteria ferment dietary fibre to liberate more vitamins.

It makes sense that the two very different environments in the small and large intestines should play host to different microbes. You may be aware of the enormous population of bacteria making your large intestine their home and living in symbiosis with you. In contrast, your small intestine naturally plays host to only a relatively small number of bacteria, and they’re significantly different types to those found in your large intestine. If the bacterial species found in the large intestine start to flourish in the small intestine, these bacteria may multiply out of control and SIBO is the result.

Symptoms of SIBO

The symptoms of SIBO typically occur soon after eating, and they’ll often disappear overnight and become worse as the day draws on.

  • Belching
  • Wind, gas
  • Bloating, feeling uncomfortably full after eating
  • Abdominal pain, cramping and indigestion
  • Diarrhoea or constipation
  • Nausea
  • Intolerance to histamine, causing hives, runny nose and sneezing
  • Brain fog, difficulties concentrating

SIBO is often a factor in IBS, and over time, can lead to chronic fatigue and a host of other health issues. Because the small intestine plays host to immune cells, bacterial imbalance can also lead to poor immune system function.

The errant bacteria in your small intestine break down substances needed to digest fats and may irritate your intestinal lining, resulting in decreased nutrient absorption. Bacteria may also produce acids acting as neurotoxins, in turn are causing brain fog.

Symptoms of SIBO tend to appear soon after eating foods containing certain types of fibre which can be fermented by migrant bacteria in your small intestine, producing gas. Foods containing this fibre are called high-FODMAP foods.

High-FODMAP foods include:

  • Beans, peas and lentils
  • Garlic and onions
  • Artichoke, asparagus, broccoli, brussels sprouts, cabbage, cauliflower, leeks and beetroot
  • Some fruits, especially apples, cherries, pears, apricots and peaches
  • Wheat, spelt, rye and barley
  • Dairy products containing lactose

Because the symptoms connected with SIBO are so similar to those coming under the umbrella of IBS symptoms, and they often fluctuate, many patients try for years to get to the bottom of their symptoms with little success.

Causes of SIBO

  • Low stomach acid, a side effect of some medications or nutrient deficiencies. A good level of stomach acid would normally neutralise any unwanted bacteria. Your stomach acid tends to reduce with age. Lowered production of digestive enzymes can have a similar effect. 2
  • Unbalanced gut bacteria in your large intestine, which can then access your small intestine.
  • Problems with the muscular contractions normally propelling food and bacteria onwards through your small intestine. This results in food moving slowly through your digestive system, providing an opportunity for bacteria to flourish.
  • Episodes of food poisoning, fungal infections and chronic stress can trigger SIBO, because of their effect on digestive secretions and intestinal transit time.
  • Problems with the ileocecal valve connecting your small intestine with your colon.
  • Insufficient chewing and eating too quickly.

Diagnosis of SIBO

A test looking at your breath can detect SIBO by checking for certain gases produced by the bacteria.

Conventional Treatment of SIBO

Antibiotics are often prescribed to eradicate the aberrant bacteria, and a low-FODMAP diet recommended to avoid the types of fibres the bacteria like to ferment for their food.

Functional Medicine and SIBO

The problem with the above methods of treatment is once antibiotics are stopped or a high-FODMAP food is eaten, symptoms invariably recur. This is because neither of these strategies corrects the root causes of the bacterial imbalance. While it’s important to reduce the overgrowth of bacteria in your small intestine, it’s also vital to pinpoint the causes of the imbalance and put these right too.

As well as a test to diagnose SIBO, functional tests will examine messenger molecules produced by your gut bacteria to establish the types of species predominant there, assess the health of your intestinal wall, and identify any nutritional deficiencies contributing to SIBO 3.

For a while at least, a diet excluding high-FODMAP foods may be necessary. But because many high-FODMAP foods provide valuable nutrients, the long term aim of therapy will be to heal your gut and restore the correct bacterial balance to allow you to eat a varied diet again. 4

Meanwhile, supplements may be recommended to restore your stomach acid and digestive enzyme levels if they’re low, and therapy will aim to support your liver and immune system.




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