SIBO stands for Small Intestine Bacterial Overgrowth. While bacteria in the digestive system are normal and necessary for the breakdown of foods and absorption of nutrients, the highest concentration is typically in the colon or large intestine, not the small intestine. When bacteria overpopulate the small intestine, the body cannot properly assimilate nutrients from food. This, in turn, can lead to the aggravation of existing chronic health conditions or other symptoms.

Gas and Bloating

Excessive trapped gas in the gut leads to bloating. While digestion and processing of certain foods, especially those high in fiber, can cause bloating, SIBO also produces this painful symptom. Bacteria in the gut consume carbohydrates from the food we eat and process them in a way that produces gas and other by-products. The gas from the bacteria builds up and causes gas and bloating.

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SIBO can cause diarrhea: frequent loose, sometimes liquid stools. The excess bacteria in the gut make by-products that draw water into the intestines. The excess water softens and liquifies the stool and this leads to diarrhea. It is vital to drink plenty of fluids when experiencing this symptom, as it is easy to become dehydrated from the increased loss of fluids.

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Abdominal Pain and Cramping

The excess bacteria in the small intestine produce more gas, which can be painful. The gas can build up to the point that it distends the intestines and causes a sensation of fullness and bloating. In some cases, this can cause periodic abdominal cramping and discomfort.

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While constipation is rare in cases of SIBO, some people experience it. Overpopulation of gut bacteria inhibits digestion, which causes some bodies to slow food processing. Excess gas and painful bloating may also hinder regular bowel movements. Drinking prune juice or using prescribed stool softeners can also help alleviate this symptom, as can eating more meals with smaller portions; keeping the gut working regularly could help move things along.

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Irritable Bowel Syndrome

Irritable bowel syndrome renders the gut overly sensitive. People with IBS may be at higher risk of developing SIBO and should speak to a doctor about preventing bacteria overgrowth. Antibiotics and probiotics may help prevent this and repopulate healthy bacteria. Because SIBO and IBS symptoms are so similar, it's important to determine the cause to ensure correct treatment.

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Food Intolerances

The overpopulation of bacteria in the small intestine can damage the intestinal lining and reduce its ability to act as a barrier. When the intestinal barrier is damaged, undigested food and other proteins and particles can cross it and enter the bloodstream. The body may identify these larger particles as invaders and activate the immune system to attack them as allergens. As such, many people with SIBO develop food intolerances, allergies, or sensitivities.

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Certain Chronic Illnesses

Several chronic health conditions can increase one's risk of developing SIBO. Leaky gut syndrome, structural abnormalities, Crohn's and celiac disease, and irritable bowel syndrome have all been linked with SIBO. Other chronic illnesses create conditions in the body where bacteria overpopulation is more likely. These include fibromyalgia, chronic fatigue syndrome, diabetes, neuromuscular disorders, and certain immune system abnormalities. Immune system reaction to bacteria can also cause chronic fatigue and body pain. Certain medications increase the risk of developing SIBO, including antibiotics, narcotics, acid-suppressing medications, and some drugs used to treat the symptoms of irritable bowel syndrome.

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Vitamin B12 Deficiency

Bacteria overgrowth in the small intestine can cause malnutrition because nutrients the body needs are consumed by the bacteria instead of nourishing the body. Vitamin B12 is one favorite of gut bacteria. B12 deficiency leads to a host of complications including numbness or tingling in fingers or toes, anemia, jaundice, a decline in cognitive function, fatigue, weakness, and even hallucinations.

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Fat Malabsorption

An increase in gut bacteria also affects the amount of bile produced by the liver. Deconjugating bile by bacteria in the small intestine causes fat malabsorption in the digestive system, which can lead to vitamin A and D deficiencies and fatty stool. Dietary fats are necessary for brain function and for the body to absorb all the nutrients it needs. Some vitamins are fat-soluble; that is, they need fat to be absorbed. SIBO disrupts this balance, leading to malnutrition. This issue can affect the absorption of vitamins A, D, E, and K.

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When SIBO Becomes Serious

When SIBO is left untreated, or if the bacteria population grows out of control, malnutrition and aggravation of several health conditions and vitamin deficiencies can occur. The bacteria also secrete acids that may cause brain fog and fatigue.

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