Small intestinal bacterial overgrowth (SIBO) is a widespread gastrointestinal condition that affects millions worldwide.1Archufusi T, Sharma A, Zamora EA, Manocha D. Small intestinal bacterial overgrowth: comprehensive review of diagnosis, prevention, and treatment methods. Cureus. 2020;12(6). https://doi.org/10.7759/cureus.8860 Despite being first identified by medical professionals more than 70 years ago, SIBO remains a frequently overlooked disorder, as misdiagnoses and challenges in understanding effective treatments continue to hinder care.2Leite G, Rezaie A, Mathur R, et al. Defining small intestinal bacterial overgrowth by culture and high throughput sequencing. CGH. 2024;22(2):259-270. https://www.cghjournal.org/article/S1542-3565(23)00452-4/fulltext
SIBO symptoms and diagnosis
Characterized by excessive harmful bacteria in the small intestine, SIBO causes numerous digestive symptoms that range from mild to severe. Chronic diarrhea, unintentional weight loss, malabsorption, and nutritional deficiencies are some of the most common.3Dukowicz AC, Lacy BE, Levine GM. Small intestinal bacterial overgrowth. CGH. 2007;3(2):112-122.
“Many of my patients have ongoing symptoms for years, sometimes overlooked by other providers who may not be as up to date regarding SIBO testing and treatment,” says Dr. Carrie Runde, a naturopathic physician with Charm City Natural Health in Baltimore, Maryland.
There are multiple SIBO risk factors, including age, weight, and co-existing conditions3Dukowicz AC, Lacy BE, Levine GM. Small intestinal bacterial overgrowth. CGH. 2007;3(2):112-122.:
- Older age
- Obesity
- Structural or anatomic issues with the small intestines or gastrointestinal system
- Motility disorders, such as Celiac disease
- Metabolic disorders, such as diabetes
- Low stomach acid
- Taking back-to-back antibiotics or gastric acid–suppressing medicines
- Organ system dysfunction (immunodeficiency, pancreatitis, Crohn’s disease)
- Chronic alcohol use and cirrhosis
- Irritable bowel syndrome (IBS)
Many common symptoms of SIBO mimic IBS—mainly bloating, cramping, abdominal pain, discomfort, and distention. Other symptoms include fatigue, weakness, diarrhea, indigestion, weight loss, and absorption-related nutrient deficiencies of fat-soluble vitamins, vitamin B12, and iron.3Dukowicz AC, Lacy BE, Levine GM. Small intestinal bacterial overgrowth. CGH. 2007;3(2):112-122.
Healthcare providers often begin by reviewing a patient’s medical history and discussing symptoms, but a breath test is typically used to confirm SIBO.1Archufusi T, Sharma A, Zamora EA, Manocha D. Small intestinal bacterial overgrowth: comprehensive review of diagnosis, prevention, and treatment methods. Cureus. 2020;12(6). https://doi.org/10.7759/cureus.8860
Treatment options
With SIBO, early diagnosis and care are crucial, as the condition can lead to severe malnourishment and intestinal failure.4Sorathia SJ, Chippa V, Rivas JM. Small intestinal bacterial overgrowth. StatPearls. 2023;Apr 17. https://www.ncbi.nlm.nih.gov/sites/books/NBK546634/?report=reader#_NBK546634_pubdet_
“SIBO can be difficult to treat because it has many causes,” says Dr. Runde. “Until the specific causes are identified and treated, a person suffering from SIBO symptoms may experience recurrence after [being] treated. Getting someone out of the ‘constantly stuck in SIBO phase’ usually involves detective work, and the path to healing is not always linear.”
Although mainstream medicine primarily relies on antibiotics to correct bacterial overgrowth, about 45 percent of patients who take antibiotics for SIBO will relapse. Recurrence rates are even higher among older adults.4Sorathia SJ, Chippa V, Rivas JM. Small intestinal bacterial overgrowth. StatPearls. 2023;Apr 17. https://www.ncbi.nlm.nih.gov/sites/books/NBK546634/?report=reader#_NBK546634_pubdet_ Consistent use of antibiotics can negatively interfere with gut health and affect immune regulation, metabolic activity, and overall health.5Patangia DV, Ryan CA, Dempsey E, et al. Impact of antibiotics on the human microbiome and consequences for host health. MicrobiologyOpen. 2022;11(1). https://doi.org/10.1002/mbo3.1260
If patients cannot tolerate antibiotics or symptoms recur after two rounds of antibiotics, food changes, e.g., an “elemental diet,” may help. Elemental diets are temporary and replace meals with liquids. However, many patients find the substitutes unpalatable, and the high cost of maintaining the diet, even for a short time, makes it less appealing.4Sorathia SJ, Chippa V, Rivas JM. Small intestinal bacterial overgrowth. StatPearls. 2023;Apr 17. https://www.ncbi.nlm.nih.gov/sites/books/NBK546634/?report=reader#_NBK546634_pubdet_
Correcting SIBO naturally
Some of Dr. Runde’s “go to” herbal antimicrobials include oregano, neem, berberine, and allicin. She typically pairs these herbs with a well-tolerated, SIBO–safe soluble fiber powder.
“Because some herbs are better at treating overgrowth of certain organisms, I treat with a combination of antimicrobial herbs that are chosen based on breath test results,” says Dr. Runde.” Treatment spans 45 days per round—a longer-than-average course.
“As a naturopathic physician, my SIBO treatment strategy and the tools I use may differ slightly from the conventional route,” she adds. “Because SIBO can be chronic and lengthy to treat, I lean heavily on natural treatments, [as] they expand my toolbox and help improve clinical outcomes.”
Soluble fiber from fruits and vegetables or fiber supplements such as psyllium and inulin can also help curb SIBO symptoms.6Wielgosz-Grochowska JP, Domanski N, Drywien M. Efficacy of an irritable bowel syndrome diet in the treatment of small intestinal bacterial overgrowth: a narrative review. Nutrients. 2022;14(16):3382. https://doi.org/10.3390/nu14163382 Reducing fermentable carbohydrates may alleviate bloating, abdominal pain, and gas; however, SIBO–specific data on special diets like low FODMAP are limited.7Souza C, Rocha R, Cotrim H. Diet and intestinal bacterial overgrowth: is there evidence? World J Clin Cases. 2022;10(15):4713-4716. https://doi.org/10.12998/wjcc.v10.i15.4713 “With my patients, I’m mostly trying to help them expand their diet to better digest a wider range of plant foods,” says Dr. Runde. Taking digestive enzymes with meals may improve digestion and ease gas pain, bloating, and abdominal distention.8Martin-Biggers J. A multi-digestive enzyme and herbal dietary supplement reduces bloating in a single use in health adults: a randomized, placebo-controlled, cross over study. Nutrition and Diet Supp. 2024;16:51-57. https://doi.org/10.2147/NDS.S453377
Probiotics and prebiotics can improve gut health overall and may reduce SIBO symptoms. In an analysis of 18 studies, probiotics significantly reduced abdominal pain and bacterial overgrowth and lowered H2 breath test concentrations.9Zhong C, Qu C, Wang B, et al. Probiotics for preventing and treating small intestinal bacterial overgrowth: a meta-analysis and systemic review of current evidence. J Clin Gastroenterol. 2017;51(4):300-311. https://journals.lww.com/jcge/abstract/2017/04000/probiotics_for_preventing_and_treating_small.4.aspx
Supplementing antibiotic therapy with natural substances may improve treatment efficacy. A 2024 randomized clinical trial reported higher remission rates with combined antibiotics and herbs, probiotics, and prebiotics than with antibiotics alone.10Redondo-Cuevas L, Belloch L, Martin-Carbonell V, et al. Do herbal supplements and probiotics complement antibiotics and diet in the management of SIBO? A randomized clinical trial. Nutrients. 2024;16(7). https://doi.org/10.3390/nu16071083 Taking probiotics with prescription antibiotics can mitigate the damage these drugs may cause to the gut microbiome.11John D, Michael D, Dabcheva M, et al. A double-blind, randomized, placebo-controlled study assessing the impact of probiotic supplementation on antibiotic induced changes in the gut microbiome. Front Microbiomes. 2024;3. https://doi.org/10.3389/frmbi.2024.1359580
“When I treat SIBO, I address symptoms, but I am also trying to get to the root cause or causes,” says Dr. Runde. “I consider the entire gut microbiome. My goal is to assess and improve the health of the whole digestive tract using a comprehensive approach beyond symptom management.”
Footnotes
- 1Archufusi T, Sharma A, Zamora EA, Manocha D. Small intestinal bacterial overgrowth: comprehensive review of diagnosis, prevention, and treatment methods. Cureus. 2020;12(6). https://doi.org/10.7759/cureus.8860
- 2Leite G, Rezaie A, Mathur R, et al. Defining small intestinal bacterial overgrowth by culture and high throughput sequencing. CGH. 2024;22(2):259-270. https://www.cghjournal.org/article/S1542-3565(23)00452-4/fulltext
- 3Dukowicz AC, Lacy BE, Levine GM. Small intestinal bacterial overgrowth. CGH. 2007;3(2):112-122.
- 4Sorathia SJ, Chippa V, Rivas JM. Small intestinal bacterial overgrowth. StatPearls. 2023;Apr 17. https://www.ncbi.nlm.nih.gov/sites/books/NBK546634/?report=reader#_NBK546634_pubdet_
- 5Patangia DV, Ryan CA, Dempsey E, et al. Impact of antibiotics on the human microbiome and consequences for host health. MicrobiologyOpen. 2022;11(1). https://doi.org/10.1002/mbo3.1260
- 6Wielgosz-Grochowska JP, Domanski N, Drywien M. Efficacy of an irritable bowel syndrome diet in the treatment of small intestinal bacterial overgrowth: a narrative review. Nutrients. 2022;14(16):3382. https://doi.org/10.3390/nu14163382
- 7Souza C, Rocha R, Cotrim H. Diet and intestinal bacterial overgrowth: is there evidence? World J Clin Cases. 2022;10(15):4713-4716. https://doi.org/10.12998/wjcc.v10.i15.4713
- 8Martin-Biggers J. A multi-digestive enzyme and herbal dietary supplement reduces bloating in a single use in health adults: a randomized, placebo-controlled, cross over study. Nutrition and Diet Supp. 2024;16:51-57. https://doi.org/10.2147/NDS.S453377
- 9Zhong C, Qu C, Wang B, et al. Probiotics for preventing and treating small intestinal bacterial overgrowth: a meta-analysis and systemic review of current evidence. J Clin Gastroenterol. 2017;51(4):300-311. https://journals.lww.com/jcge/abstract/2017/04000/probiotics_for_preventing_and_treating_small.4.aspx
- 10Redondo-Cuevas L, Belloch L, Martin-Carbonell V, et al. Do herbal supplements and probiotics complement antibiotics and diet in the management of SIBO? A randomized clinical trial. Nutrients. 2024;16(7). https://doi.org/10.3390/nu16071083
- 11John D, Michael D, Dabcheva M, et al. A double-blind, randomized, placebo-controlled study assessing the impact of probiotic supplementation on antibiotic induced changes in the gut microbiome. Front Microbiomes. 2024;3. https://doi.org/10.3389/frmbi.2024.1359580
