Holistic Approach to Wellness


What is small intestinal bacterial overgrowth (SIBO)?

Small intestinal bacterial overgrowth occurs when the bacteria in our “gut” get out of balance and overgrow. In this case, too much of a good thing can be a bad thing.

How do we get too much of some bacteria over others?

This can manifest in several different ways, and often occurs in those eating a diet high in sugar, alcohol and refined carbohydrates. Certain strains of bacteria feed off of refined carbohydrates and break them down into short-chain fatty acids, creating gas and causing bloating. Another strain of bacteria can break down bile salts before your body has a chance to use them. Bile salts are crucial for the breakdown of fats; without them, the end result is fat malabsorption or diarrhea. Finally, a third type of bacteria can produce toxins that damage the lining of the small intestine. This prevents your body from absorbing the nutrients you need, much like what we see with a leaky gut.

The entire gastrointestinal tract, including the small intestine, normally contains bacteria. The number of bacteria is greatest in the colon and much lower in the small intestine. Also, the types of bacteria within the small intestine are different to the types of bacteria within the colon. Small intestinal bacterial overgrowth (SIBO) refers to a condition in which abnormally large numbers of bacteria are present in the small intestine.
Small intestinal bacterial overgrowth (SIBO) is also known as small bowel bacterial overgrowth syndrome (SBBOS).

What causes the bacterial overgrowth?

Our gut relies on nerves, muscles, enzymes, and neurotransmitters to properly digest food. While enzymes mainly break down our food, the nerves, muscles and neurotransmitters physically move the food through our digestive tract from the stomach to the small intestine and to the colon. When this happens in a healthy gut, bacteria gets passed through the digestive tract along with the food to its final destination in the colon. Problems arise when something interferes with this process and effects the small intestine where digestion occurs.  Damage to the nerves or muscles in the gut can result in leftover bacteria in the small intestine, increasing your risk for SIBO. For example, diabetes mellitus and scleroderma can both affect the muscles in the gut, leaving room for SIBO to develop. Physical obstructions in the gut, like scarring from surgeries or Crohn’s disease, can also cause an abnormal buildup of bacteria in the small intestine. Diverticuli, which are tiny pouches that can form in the wall of the small intestine, can also collect bacteria instead of passing it on to the colon, where it belongs.

There are also medications that influence or disrupt the normal gut flora, such as antibiotics, acid-blocking drugs, and steroids but the most common cause is a diet high in sugar, refined carbohydrates and alcohol. Our SAD (Standard American Diet) is to be blamed for a lot of GI disorders.

10 Signs Of Small Intestinal Bacterial Overgrowth (SIBO)

1. Gas
2. Bloating
3. Diarrhea
4. Abdominal pain or cramping
5. Constipation (much less common than diarrhea)
6. Diagnosis of irritable bowel syndrome or inflammatory bowel disease
7. Food intolerances such as gluten, casein, lactose, fructose and more
8. Chronic illnesses such as fibromyalgia, chronic fatigue syndrome, diabetes, neuromuscular disorders and autoimmune diseases.
9. B12 deficiency as well as other vitamins and minerals
10. Fat malabsorption

What is the normal relationship between bacteria and the small intestine?

At birth, there is no bacteria present in the gastrointestinal tract. During birth, however, bacteria from the mother’s colon and vagina are swallowed by the baby and within a few weeks or months, they populate the baby’s gastrointestinal tract. Nature knows what she’s doing with natural child birth. The relationship between normal intestinal bacteria and the human body is complex. Each benefits from the other. The bacteria benefit from the warm, moist environment of the small intestine that is ideal for growing as well as the constant flow of food passing down the gastrointestinal tract.

The human body benefits in several ways from normal bacteria:

They stimulate the growth of the intestinal lining and the immune system of the intestine.
They prevent the growth of disease-causing bacteria within the intestine.
They produce vitamin K, which is absorbed and used by the host.
They improve the muscular activity of the small intestine.
The gastrointestinal tract, particularly the small intestine, contains an extensive immune system. The immune system protects the intestine from disease-causing viruses, bacteria and parasites. Somehow, the intestine only attacks harmful bacteria. It appears to become tolerant of the normal bacteria and does not mount an attack against them.

The intestine also has other ways to protect itself from both normal and harmful bacteria:

Muscular activity keeps the numbers of bacteria within the intestine at a low level.
Mucous that is secreted into the intestine coats the intestinal lining and prevents the bacteria from touching the lining.
The intestine secretes antibodies that can block, and sometimes kill, bacteria as well as substances that prevent the growth of bacteria.
The lining of the intestine can produce receptors for toxic substances produced by bacteria and can prevent the substances from having their toxic effects.

How does small intestinal bacterial overgrowth cause symptoms?

When bacteria digest food in the intestine, they produce gas. The gas can accumulate in the abdomen giving rise to abdominal bloating or distension. Distension can cause abdominal pain. This increased amount of gas causes wind or flatulence.
The bacteria are believed to convert food into substances that are irritating or toxic to the cells of the inner lining of the small intestine and colon. These irritating substances produce diarrhea. There is also some evidence that the production of methane gas by the bacteria may cause constipation.
Bacteria in the small intestine, when present in large numbers, can compete with the human body for the food that is eaten. This can lead to malnutrition with vitamin and mineral deficiencies. In advanced cases of SIBO, the bacteria use up enough food, that there are insufficient calories for the body, which leads to weight loss.

Is there a relationship between SIBO and irritable bowel syndrome (IBS)?

SIBO affects about 56 percent of patients with irritable bowel syndrome, but we do not know how common it is in the general population.
Irritable bowel syndrome (IBS) is a common gastrointestinal condition. Patients with irritable bowel syndrome typically complain of abdominal pain associated with bloating, wind and alterations in their bowel habit such as diarrhea or constipation. Irritable bowel syndrome is a chronic condition and symptoms can be continuous or vary over months, years or even decades.
There is no conclusive test for IBS and is a general diagnosis. The diagnosis is made on the basis of typical symptoms and tests that exclude other diseases that may cause symptoms such as ulcers, infections, tissue inflammation, cancers and obstruction of the intestine. Doctors have to rely heavily on their clinical judgment to make a diagnosis of irritable bowel syndrome.
There is a striking similarity between the symptoms of irritable bowel syndrome and SIBO. It has been suggested that SIBO may be responsible for the symptoms of at least some patients with irritable bowel syndrome. Support for the SIBO theory of IBS comes from the fact that many IBS patients are found to have an abnormal hydrogen breath test. Also, some IBS patients find symptoms improve after treatment for SIBO because you are addressing the cause.

How to test for SIBO

Breath Test: This simple, non-invasive, gastrointestinal test detects bacterial overgrowth in the small intestine, often referred to as BOSI or SIBO. Small intestine bacterial overgrowth (SIBO) is a common gastrointestinal disorder that often underlies chronic gastrointestinal symptoms of maldigestion and malabsorption, including bloating, gas, diarrhea, irregularity, and abdominal pain. Specimen Requirements: Six fasting breath samples, taken at Baseline, 40 minutes, 60 minutes, 90 minutes, and 120 minutes.

Organic acids test (urine): Organic acids are metabolic intermediates produced in pathways of central energy production, detoxification, neurotransmitter breakdown, and intestinal microbial activity.

Understanding your history: By listening to the patient’s history and symptoms, we are often able to make a diagnosis.

How is small intestinal bacterial overgrowth treated?

SIBO has been recognized for many years as a problem with severe disorders of intestinal muscles and intestinal obstruction. The treatment has been antibiotics, and they can be effective, however, the underlying cause is still unclear and symptoms frequently return when antibiotics are stopped. Antibiotics can cause symptoms of their own since they wipe out all bacteria including the good guys which is why it’s very important to balance with probiotics.

Natural Therapies for SIBO

Most physicians treat SIBO with antibiotics (primarily rifaximin), which can work but sometimes have adverse effects. Oregano oil, wild garlic and berberine (the active constituent of Oregon grape root and other plants used as GI remedies), which can help reduce the excess bacterial growth are commonly used. Treatment is very similar to treating Candida. There are anti-fungal nutraceuticals we use to treat bacteria overgrowth along with a personalize diet that addresses food intolerance.

Diet modification is essential to treatment but will not by itself cure SIBO. Consider a diet low in fructose and especially avoiding foods containing high fructose corn syrup.
For a list of Illegal vs. Legal foods to help clear SIBO visit Breaking The Vicous Cycle Specific Carbohydrate Diet. You can also view our Candida protocol which also addresses bacteria.
* It’s best to work with a professional to fine tune your dietary needs and address food intolerance.

Interested in the FODMAP Diet? See the FODMAP food list.


Sources: Web MD, Siboinfo.com, Mind Body Green