Optimal DX Protocols: SIBO

Small intestinal bacterial overgrowth (SIBO) is characterized by an overgrowth of bacteria in the small intestine. SIBO is diagnosed in someone who is symptomatic when a significant number of bacteria is present, as determined by small intestine culture or hydrogen breath testing with glucose or lactulose.

Common Culprits

Common SIBO culprits are gram-negative species, typically found in the colon, that convert fermentable carbohydrates into hydrogen gas. Hydrogen gas can also be converted to methane by microorganisms, and methane can be measured as well (Pimentel 2020). Besides colonic bacteria, oropharyngeal strains are also associated with SIBO. One study using small intestine culture revealed the most predominant strains retrieved included Streptococcus, Escherichia coli, Staphylococcus, Micrococcus, Klebsiella, Proteus for microaerophilic bacteria, and Lactobacillus, Bacteroides, Clostridium, Veillonella, Fusobacterium and Peptostreptococcus for anaerobic bacteria (Bouhnik 1999).

Risk factors

Risk factors for SIBO include proton pump inhibitor use, hypochlorhydria, chronic pancreatitis, cirrhosis, motility or GI anatomical disorders, diabetes, hypothyroidism, neuropathy, celiac disease, and immune disorders (Bushyhead 2021). Protective factors that may be compromised in SIBO include gastric acid, pancreatic enzymes, bile acids, secretory IgA, motility, and the migrating motor complex (Chedid 2014).

Symptoms

Symptoms of SIBO may be related to increased intestinal permeability, malabsorption, inflammation, and immune activation. They can include nausea, excess gas, bloating, abdominal pain, diarrhea, constipation (with methane-producing microbes), weight loss, anemia, nutrient deficiencies (Pimentel 2020).

SIBO can also increase the absorption of toxins and release of proinflammatory cytokines as it disrupts epithelial tight junctions and increases intestinal permeability. Additional manifestations of SIBO may include rosacea, arthralgias, interstitial cystitis, polyneuropathy, and fatty liver disease (Chedid 2014).

SIBO appears to be common in irritable bowel syndrome (IBS) and should be part of a comprehensive IBS workup. SIBO can also occur with disorders or medications that reduce motility and the natural movement of bacteria out of the small intestine. Although antibiotics have been routinely used to eradicate SIBO, potential consequences include adverse reactions, recurrence of infection, and growth of resistant or opportunistic bacteria. The presence of bile acids can enhance antimicrobial action (Bushyhead 2021).

SIBO can be common in diabetes, particularly if delayed gastric emptying and neuropathy are present. In one small study, SIBO was diagnosed in 43% of diabetic patients suffering from chronic diarrhea that improved significantly with antibiotic therapy (Salem 2014).

Symptoms of SIBO may be present in a number of conditions as well and should be investigated further. Disorders that increase the risk of concurrent SIBO include celiac, Crohn’s, IBS, short bowel syndrome, fatty liver disease, cirrhosis, pancreatic insufficiency, achlorhydria, fibromyalgia, connective tissue disorders, Parkinson’s, immune deficiency, and radiation enteritis. Nutrient deficiencies related to SIBO should be evaluated, including fat-soluble vitamins A, D, E, K, B1, B3, B12, and iron. Malabsorption of fat and protein may occur as well (Salem 2014). Invading bacteria are able to consume undigested food and even compete with the host for nutrients, further contributing to symptoms and deficiencies.

Brain fog may be seen with SIBO and includes difficulty concentrating, mental confusion, impaired judgment, and compromised short-term memory. This phenomenon may be associated with metabolic acidosis and elevated D-lactic acid, possibly due to the use of probiotics in some individuals (Rao 2018).

The use of probiotics for SIBO is debated as they may precipitate or exacerbate the condition. However, a meta-analysis of studies utilizing probiotics in SIBO found that probiotics alone effectively decontaminated the small intestine in 53.2-62.8% of SIBO cases, an effect enhanced by antibiotics, with the combination increasing decontamination to 85.8%. Probiotic species included Bifidobacterium, Bacillus clausii, Lactobacillus, S. boulardii, and mixed regimens. The analysis also found that probiotics were associated with improved abdominal pain and decreased hydrogen gas concentration, although they were ineffective in preventing SIBO (Zhong 2017). Probiotics may help prevent bacterial translocation and reduce bacterial endotoxins in the bloodstream as well (Twardowska 2022).

Some research reveals a reduction in SIBO GI symptoms with specific probiotics including Saccharomyces boulardii, a probiotic yeast (Nickles 2021). Small studies have found some benefits in SIBO with the use of Bacillus clausii, L. casei, L. acidophilus, and Bacillus coagulans (Chen 2014, Khalighi 2014). Earlier studies found L. plantarum 299v and Lactobacillus (rhamnosus) GG to be beneficial in children with SIBO, especially those with short bowel syndrome (Vanderhoof 2001). Ultimately, probiotic therapy should be individualized and discontinued if symptoms worsen.

SIBO may promote or exacerbate histamine intolerance due to increased histamine production by GI bacteria, or if less diamine oxidase (DAO) is available due to intestinal damage (Eade 2018, Schnedl 2021). Consuming supplemental DAO may reduce the histamine burden.

Dietary changes and herbal antimicrobials may be an alternative (or adjunct) to antibiotics for SIBO. Restriction of fermentable oligo-, di-, mono-saccharides, and polyol sugar alcohols (FODMAPs) may reduce symptoms and the amount of gas produced while SIBO is active (Pimentel 2020, Tuck 2018). An elemental diet is easily absorbed, can further restrict the “food” available to the problematic bacteria, and may be most beneficial in severe cases.

Natural anti-microbial are effective against SIBO. In a retrospective chart review of 104 symptomatic individuals with a positive lactulose breath test, herbal antimicrobials were not only as effective as the antibiotic rifaximin but normalized breath tests in some of the subjects who had failed rifaximin. Subjects had a choice of either Biotics Dysbiocide plus FC Cidal, Metagenics Candibactin-AR plus Candibactin-BR, or rifaximin (Chedid 2014).

Natural Antimicrobials for SIBO include (Kohlstadt 2012, Chedid 2014, Wright 2021, Nickles 2021, Brown 2016, Salem 2014):

• Berberine
• Black walnut (Juglans nigra)
• Caprylic acid
• Ginger
• Grapefruit/citrus seed extract
• Lemon balm
• Oregano oil
• Pau D’Arco
• Red thyme
• Sage leaf
• Wormwood (Artemesia anuua)
• Atranil (Quebracho, conker tree, and balsamea)
• Peppermint oil

Sample Protocol

Diet

Choose 1 plan from the options below or combine

These restricted diets are to be used short-term while SIBO is active and symptoms are present. Guidance from a nutrition professional is recommended.

• Low FODMAP Diet
• Low Histamine Diet
• Elemental Diet

Herbal Antimicrobials

Choose 1 of the options below. To be taken for four consecutive weeks, 30 minutes before a meal.

• Biotics FC Cidal and Dysbiocide: 2 capsules of each, twice daily
• Metagenics Candibactin-AR and Candibactin-BR, 2 capsules of each, twice daily
• Or customize the formula using individual ingredients and follow label directions:

• Berberine
• Black walnut (Juglans nigra)
• Caprylic acid
• Ginger
• Grapefruit/citrus seed extract
• Lemon balm
• Oregano oil
• Pau D’Arco
• Red thyme
• Sage leaf
• Wormwood (Artemesia anuua)
• Atranil (Quebracho, conker tree, and M. balsamea)

Digestive support

• Broad spectrum digestive enzymes with all meals and substantial snacks.
  • NOW foods Super Enzymes: 1 with each meal or snack
• Ox bile to support fat digestion and for its anti-microbial effects:
  • Seeking Health Ox Bile 125: 1 to 3 capsules as tolerated with meals if fat malabsorption is present or before bed on an empty stomach while SIBO is active.

Supplementation

• A high-potency multivitamin-mineral supplement is recommended if nutrient intake or absorption is suboptimal:
  • Life Extension Two per Day multivitamin-mineral capsules: 1 capsule, twice daily with a meal.
• Enteric-coated peppermint oil may be of some benefit as well.
• DAO supplements may be helpful if SIBO is associated with histamine intolerance:
  • Seeking Health Histamine Block 1 capsule 15 minutes before a histamine-containing meal or Seeking Health Histamine Block Plus 2 capsules 15 minutes before a histamine-containing meal or trigger food.
• Probiotics may or may not be tolerated, and supplementation should be individualized. Though research is limited, some probiotics may be tolerated with SIBO, including:
  • Saccharomyces boulardii, Bacillus clausii, Bacillus coagulans
    casei, L acidophilus, Bifidobacterium, Lactobacillus, L. plantarum, and Lactobacillus (rhamnosus) GG
  • Probiotics should be discontinued if symptoms worsen.

Protocols for SIBO should be used in the short term while SIBO is active, but they can be modified for maintenance as needed.

References

Achufusi, Ted George O et al. “Small Intestinal Bacterial Overgrowth: Comprehensive Review of Diagnosis, Prevention, and Treatment Methods.” Cureus vol. 12,6 e8860. 27 Jun. 2020, doi:10.7759/cureus.8860

Bouhnik, Y et al. “Bacterial populations contaminating the upper gut in patients with small intestinal bacterial overgrowth syndrome.” The American journal of gastroenterology vol. 94,5 (1999): 1327-31. doi:10.1111/j.1572-0241.1999.01016.x

Bushyhead, Daniel, and Eamonn M Quigley. “Small Intestinal Bacterial Overgrowth.” Gastroenterology clinics of North America vol. 50,2 (2021): 463-474. doi:10.1016/j.gtc.2021.02.008

Brown, Kenneth et al. “Response of irritable bowel syndrome with constipation patients administered a combined quebracho/conker tree/M. balsamea Willd extract.” World journal of gastrointestinal pharmacology and therapeutics vol. 7,3 (2016): 463-8. doi:10.4292/wjgpt.v7.i3.463

Chedid, Victor, et al. "Herbal therapy is equivalent to rifaximin for the treatment of small intestinal bacterial overgrowth." Global advances in health and medicine 3.3 (2014): 16-24.

Eade, Georgia. "Histamine intolerance: Why freshness matters." Journal of Evolution and Health: A joint publication of the Ancestral Health Society and the Society for Evolutionary Medicine and Health 2.1 (2018).

Khalighi, A R et al. “Evaluating the efficacy of probiotic on treatment in patients with small intestinal bacterial overgrowth (SIBO)--a pilot study.” The Indian journal of medical research vol. 140,5 (2014): 604-8.

Kohlstadt, I. (2012). Advancing Medicine with Food and Nutrients, Second Edition. Hoboken: Taylor and Francis.

Nickles, Melissa A et al. “Alternative Treatment Approaches to Small Intestinal Bacterial Overgrowth: A Systematic Review.” Journal of alternative and complementary medicine (New York, N.Y.) vol. 27,2 (2021): 108-119. doi:10.1089/acm.2020.0275

O'Dwyer, Darla. “Homemade Elemental Diet to Treat Intestinal Methanogen Overgrowth: A Case Report.” Integrative medicine (Encinitas, Calif.) vol. 20,2 (2021): 32-41.

Pimentel, Mark et al. “ACG Clinical Guideline: Small Intestinal Bacterial Overgrowth.” The American journal of gastroenterology vol. 115,2 (2020): 165-178. doi:10.14309/ajg.0000000000000501

Rao, Satish S C et al. “Brain fogginess, gas and bloating: a link between SIBO, probiotics and metabolic acidosis.” Clinical and translational gastroenterology vol. 9,6 162. 19 Jun. 2018, doi:10.1038/s41424-018-0030-7

Ring, Melinda, and Sreela Namboodiri. "Clinical Roundup: Selected Treatment Options for Small Intestinal Bacterial Overgrowth." Alternative and Complementary Therapies 24.3 (2018): 140-141.

Salem, A., and B. C. Roland. "Small intestinal bacterial overgrowth (SIBO)." J Gastroint Dig Syst 4.225 (2014): 2.

Schnedl, Wolfgang J, and Dietmar Enko. “Histamine Intolerance Originates in the Gut.” Nutrients vol. 13,4 1262. 12 Apr. 2021, doi:10.3390/nu13041262

Tuck, C J, and S J Vanner. “Dietary therapies for functional bowel symptoms: Recent advances, challenges, and future directions.” Neurogastroenterology and motility : the official journal of the European Gastrointestinal Motility Society vol. 30,1 (2018): 10.1111/nmo.13238. doi:10.1111/nmo.13238

Twardowska, Agata et al. “Preventing Bacterial Translocation in Patients with Leaky Gut Syndrome: Nutrition and Pharmacological Treatment Options.” International journal of molecular sciences vol. 23,6 3204. 16 Mar. 2022, doi:10.3390/ijms23063204

Vanderhoof, J A. “Probiotics: future directions.” The American journal of clinical nutrition vol. 73,6 (2001): 1152S-1155S. doi:10.1093/ajcn/73.6.1152S

Wright, Ciara P., Melissa T. Dooley, and Heather Leeson. "Eradication of small intestinal bacterial overgrowth in irritable bowel syndrome using herbal therapy: A case report." International Journal of Functional Nutrition 2.5 (2021): 1-5.

Zhong, Changqing et al. “Probiotics for Preventing and Treating Small Intestinal Bacterial Overgrowth: A Meta-Analysis and Systematic Review of Current Evidence.” Journal of clinical gastroenterology vol. 51,4 (2017): 300-311. doi:10.1097/MCG.0000000000000814