Small Intestinal Bacterial Overgrowth


Probiotics from supplements or food sources like yogurt, sauerkraut, kombucha, and kefir are popular for their beneficial bacteria content. In fact, according to BCC Research, the global market of probiotic ingredients, supplements and foods reached nearly $23.1 billion in 2012 and is expected to grow to $36.7 billion by 2018. These products help to improve your overall health when the live bacteria they contain proliferate in your large intestine. A healthy intestinal flora is related to decreased levels of cholesterol, less tooth decay, a reduction in upper respiratory infections, increased nutritional vitamin and mineral absorption and a host of other positive attributes.   Some people however just feel lousy when taking or eating these beneficial foods and supplements and can’t figure out why.

Gastrointestinal discomfort including belching, bloating and distension, GERD, diarrhea and/or constipation, pain in the abdominal area after eating or mucus in the stool are all symptoms of irritable bowel syndrome (IBS). There are no structural problems in the symptoms of those with IBS but research is now showing that 75% of those with IBS show an improvement of symptoms after eradication of bacteria in the small intestine.

But bacteria in the intestine is good right? Well, no, not necessarily. We have both a small and large intestine.   When beneficial bacteria inhabit the large intestine we see the health benefits. When too many bacteria inhabit the small intestine it’s a recipe of disaster. Bacteria use carbohydrates as their energy source and ferment them to gas, so small intestine bacteria consume food as it passes through and creates gas in an area not meant for it. Gas pressure causes abdominal bloating and stretches the intestinal lining. Once the intestinal lining is stretched, tiny proteins and the bacteria themselves can move from the digestive lining into the blood stream causing what is known as leaky gut. If food particles enter into the body the immune system can react increasing food sensitivities and causing allergies.   In addition, when bacteria enter the blood stream it strains the liver and can cause chronic fatigue, headaches, skin issues, anemia and body pain.

Treating SIBO requires a number of steps.   First one must decrease all sources of fermentable carbohydrates.   This cuts off the food supply to the bacteria.   This can be done in conjunction with antibiotics, and is the recommended strategy for those with chronic IBS symptoms, or can be done with antibacterial herbs, or through diet alone.   The second stage is to heal the damaged small intestinal lining.   Lastly you would need to prevent overgrowth from recurring through lifelong diet changes.

A low-carbohydrate diet can directly reduce symptoms by decreasing the food available to the bacteria, this decreases gas the bacteria produce. There are three popular low carbohydrate diets. These diets decrease polysaccharides, oligosaccharides, and disaccharides by eliminating all grains, starchy vegetables, lactose, sweeteners other than honey, and in the beginning, beans.

  • The Specific Carbohydrate Diet (SCD)
  • GAPS – Gut and Psychology syndrome
  • Low FODMAP

The basic advice of these diets is to decrease or completely eliminate all sources of fermentable carbohydrates.

Allowed on the diets:

  • meat, poultry, eggs and fish
  • lactose-free diary
  • cooked non-starchy vegetables
  • honey

Not allowed, Fermentable carbohydrates:

  • Starch and fiber: grains (whole and refined), legumes/beans, seeds and starchy vegetables
  • Sugar: Fruit and all sources of sugar
  • Prebiotics: beans, vegetables, roots/herbs, maple syrup, supplements