Small intestinal bacterial overgrowth (SIBO) is an undiagnosed condition caused by an excess of bacteria in the small intestine. The results of this bacteria overgrowth can be profound and lead to intestinal damage and nutritional deficiency. However, despite the far-reaching implications, many conventional practitioners miss the signs of SIBO. This is partly because the medical profession’s knowledge of the causes and treatment of SIBO is relatively new.
What Is Small Intestine Bacterial Overgrowth?
Bacteria play an important role in your large intestine, where they break down carbohydrates and help absorb nutrients. These processes produce a lot of gas, but the large intestine is designed to (mostly) accommodate gas production.
However, issues arise when gas-producing bacteria enter the small intestine, leading to bloating, diarrhea, and constipation – and sometimes, all three!
Generally speaking, there are three kinds of SIBO.
SIBO-D happens when bacteria produce hydrogen, leading to bloating and diarrhea.
SIBO-C is triggered by methane gas that slows down the transit time of waste products, leading to constipation.
Researchers are learning more about a third kind of SIBO, linked to excess levels of hydrogen sulfide, a gas you might recognize for its “rotten eggs” smell.
Many people experience a mix of the above, including alternating diarrhea and constipation.
Other symptoms of SIBO include:
- Excessive burping
- Acid reflux after meals
- Bad-smelling gas
- Gurgling noises in your stomach
- Cramping and other discomforts
SIBO can also trigger seemingly unrelated symptoms such as joint pain, mood issues, food sensitivities, memory problems, and weight gain.
The impact of SIBO on your health
The symptoms of SIBO aren’t just annoying and uncomfortable – they can also impact your overall well-being. Bacteria in the small intestine can damage the intestinal walls and interfere with nutrient absorption. People with SIBO-D are at risk of low levels of essential nutrients like vitamin B12 and iron. And SIBO-C is often associated with weight gain.
What Causes SIBO?
Digestion is a complex process, and when something goes wrong, the effects can multiply in unexpected ways. SIBO is often the result of multiple factors and it’s not always possible to pinpoint a specific trigger.
Many medical conditions create the conditions that lead to bacterial overgrowth in the small intestine, including
- Irritable bowel syndrome – by some estimates, almost 80% of people with IBS also have SIBO
- Lyme Disease
One of the most common triggers for SIBO is bacterial gastroenteritis, more commonly referred to as food poisoning. Your body’s response to food poisoning can slow digestive motility, and in effect the movement of bacteria.
Stress is also a common contributor to SIBO, in part because stress can also affect motility and trigger digestive upset.
Despite its complex possible causes, SIBO can be surprisingly easy to diagnose. The preferred diagnostic tool is a breath test that measures the hydrogen and methane gas in your breath. After following a specific diet or fasting for a day or two beforehand, you’ll drink a mix of glucose and water at regular intervals, breathing into tubes that measure gas levels after every drink.
Blood and stool tests to measure nutritional deficiencies and digestive function are sometimes also needed.
The best treatment for SIBO follows a three-pronged model designed to get to the root of the bacteria overgrowth and stop further growth. Be wary of any simple solution that merely masks the symptoms. Instead, focus on these steps.
1 – Start healing by reducing the symptoms through diet
To ease your symptoms and slow the continuing growth of bacteria, you want to eliminate the foods bacteria feed on: starches, sugars, and soluble fiber. Lean sources of protein and healthy fats can give your digestive tract a break. However, the best diet for SIBO patients can vary widely and depends on other factors such as food sensitivities and caloric needs, so it’s important to work with a healthcare practitioner.
2 – Reduce bacteria content in the small intestine
Again, this can vary a great deal by individual. Herbal antimicrobials can naturally reduce the bacteria without the side effects of antibiotics. Oil of oregano, berberine, and red thyme all have antimicrobial properties, but the exact treatment should be determined in consultation with a healthcare provider.
3 – Restore good bacteria
Our bodies require a certain amount of beneficial bacteria, so it’s important to repopulate! For many patients, this can be accomplished with probiotic supplements and a diet with plenty of fermented foods like sauerkraut and yogurt.
The symptoms of SIBO can be debilitating, but you don’t have to suffer. Because treatment is typically highly individual, it’s important to work closely with a healthcare practitioner. If you recognize the symptoms of SIBO and want to get started with treating it, call the nearest functional medicine doctor.
Ghoshal UC, Shukla R, Ghoshal U. Small Intestinal Bacterial Overgrowth and Irritable Bowel Syndrome: A Bridge between Functional Organic Dichotomy. Gut Liver. 2017 Mar 15;11(2):196-208. doi: 10.5009/gnl16126. PMID: 28274108; PMCID: PMC5347643.
Wang SX, Wu WC. Effects of psychological stress on small intestinal motility and bacteria and mucosa in mice. World J Gastroenterol. 2005 Apr 7;11(13):2016-21. doi: 10.3748/wjg.v11.i13.2016. PMID: 15800998; PMCID: PMC4305729.
Chedid V, Dhalla S, Clarke JO, Roland BC, Dunbar KB, Koh J, Justino E, Tomakin E, Mullin GE. Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth. Glob Adv Health Med. 2014 May;3(3):16-24. doi: 10.7453/gahmj.2014.019. PMID: 24891990; PMCID: PMC4030608.
Soifer LO, Peralta D, Dima G, Besasso H. Comparative clinical efficacy of a probiotic vs. an antibiotic in the treatment of patients with intestinal bacterial overgrowth and chronic abdominal functional distension: a pilot study. Acta Gastroenterol Latinoam. 2010 Dec;40(4):323-7. Spanish. PMID: 21381407.