Most patients have been suffering the very unpleasant symptoms of small intestinal bacterial overgrowth for years, without being correctly diagnosed.
They have been treated for the symptoms, rather than the underlying cause. Many of them have been prescribed lots of antibiotics in the past for various health issues and some of them have had their gut flora changed drastically after taking the oral contraceptive pill or hormone implants for contraception.
The small intestine connects the stomach with the colon. The job of the small intestine is to digest and absorb food into the body. It is a tube that is approximately 20 feet in length. The entire gastrointestinal tract, including the small intestine, normally contains bacteria, that aid the digestive process. The number of bacteria is greatest in the colon (at least 1,000,000,000 bacteria per ml of fluid) and much lower in the small intestine (less than 10,000 bacteria per ml of fluid). It is important to note that the types of bacteria normally found in the small intestine are different to the types of bacteria that live in the colon.
The normal (beneficial) bacteria 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 required for blood coagulation. The beneficial bacteria are also important for the muscular activity of the small intestine (the waves that drive the contents along). Without this bacteria, there is reduced muscular activity.
The small intestine contains an extensive immune system, which protects the intestine from disease-causing viruses, bacteria, and parasites. It’s rather like the home guard of the digestive system. The effects of the immune response have been experienced by anyone who has experienced gastroenteritis. The muscular activity or wave keeps the numbers of bacteria in the intestine at a low level. Mucus that is secreted into the intestine coats the intestinal lining and prevents the bacteria from touching the lining.
What is SIBO?
Small intestinal bacterial overgrowth (SIBO) refers to a condition, in which abnormally large numbers of bacteria (at least 100,000 bacteria per ml of fluid) are present in the small intestine and the types of bacteria in the small intestine resemble more the bacteria of the colon than the small intestine. This overgrowth also causes damage and inflammation to the gut wall.
What causes small intestinal bacterial overgrowth?
The gastrointestinal tract is a continuous muscular tube through which digesting food is transported on its way to the colon. The co-ordinated activity of the muscles of the stomach and small intestine propels the food from the stomach, through the small intestine, and into the colon. Even when there is no food in the small intestine, muscular activity sweeps through the small intestine from the stomach to the colon.
The muscular activity that sweeps through the small intestine is important for the digestion of food, but it also is important because it sweeps bacteria out of the small intestine and thereby limits the numbers of bacteria in the small intestine. Anything that interferes with the progression of normal muscular activity (the waves) through the small intestine can result in SIBO by allowing the bacteria to stay longer and multiply in the small intestine. The lack of muscular activity also may allow bacteria to spread backwards from the colon and into the small intestine, which is why types of bacteria normally found only in the colon, are found in the small intestine.
Nerve damage or muscular diseases can also alter the normal activity of the intestinal muscles, causing the waves to reduce in intensity. Diabetes mellitus damages the nerve supply to the intestinal muscles. Scleroderma damages the intestinal muscles directly. The effect of these diseases on the waves causes SIBO.
What are the symptoms of SIBO?
Symptoms may include:
Abdominal pain - 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. The increased amounts of gas are passed as flatus
Gas - Reduced digestion or absorption by the small intestine allows increased amounts of sugar and carbohydrate to reach the colon, where greater amounts of gas are produced. When bacteria digest food in the intestine, they produce gas.
Bloating - 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. The increased amounts of gas are passed as flatus
Diarrhoea - The bacteria also 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 diarrhoea by causing secretion of water into the intestine
Constipation - Some patients with SIBO have constipation rather than diarrhoea. There is some evidence that the bacterial production of methane causes constipation
Weight loss - When the bacterial overgrowth is severe, the bacteria may cause malabsorption of food and deficiencies of vitamins and minerals may develop, leading to weight loss
Aches – mostly in joints
Fatigue – sleep can be impaired; and a lack of good nutrition caused by malabsorption can result in constant tiredness.