Is there a SIBO diet?

I was messaged

Ken, I read so much of your stuff, I have ZME 39 years. My granddaughter has POTS and now she was diagnosed with SIBO and fructose Intolerance. Could you point us to a diet for SIBO; She has not been given one nor can find it. I thought of you right away, Please help. Have a great weekend, holiday.

What has been actually studied

First, the reality of SIBO diagnosis. IMHO, it tends to be a little “hit and miss“.

Although abdominal bloating, gas, distension, and diarrhea are common symptoms, they do not predict positive diagnosis. Predisposing factors include proton-pump inhibitors, opioids, gastric bypass, colectomy, and dysmotility. Small bowel aspirate/culture with growth of 10-10 cfu/mL is generally accepted as the “best diagnostic method,” but it is invasive. Glucose or lactulose breath testing is noninvasive but an indirect method that requires further standardization and validation for SIBO. Treatment, usually with antibiotics, aims to provide symptom relief through eradication of bacteria in the small intestine. Limited numbers of controlled studies have shown systemic antibiotics (norfloxacin and metronidazole) to be efficacious. However, 15 studies have shown rifaximin, a nonsystemic antibiotic, to be effective against SIBO and well tolerated. Through improved awareness and scientific rigor, the SIBO landscape is poised for transformation.

Small Intestinal Bacterial Overgrowth: Clinical Features and Therapeutic Management [2010]

There are dozen of diets pushed by influencers for diverse reasons. I tend to be a “show me the clinical studies or reviews” type. What do we find is…

This narrative review suggested that there is a favorable association with monoprobiotics, fiber supplementation and mindful eating, and negative effects associated with low-FODMAP diets on the gut microbiome, especially in IBS patients. Applying these recommendations to the treatment of SIBO was inconclusive due to a lack of research including SIBO patients in the studies. 

Efficacy of an Irritable Bowel Syndrome Diet in the Treatment of Small Intestinal Bacterial Overgrowth: A Narrative Review [2022]

Our findings suggest preliminary evidence for a role of alternative therapies in the treatment of SIBO. However, robust clinical trials are generally lacking. Existing studies tend to be small and lack standardized formulations of treatment. Breath testing protocols and clinical symptom measurement greatly varied between studies. Large-scale, randomized, placebo-controlled trials are needed to further evaluate the best way to utilize alternative therapies in the treatment of SIBO.

Alternative Treatment Approaches to Small Intestinal Bacterial Overgrowth: A Systematic Review [2021]

Where do we go from here?

My inclination is to encourage a suitable microbiome test (OmbreLabs, Thorne or Biomesight.com [discount code: Micro] and use the Microbiome Prescription site. There is an apriori set of suggestions based on the bacteria reported from studies. It is interesting to note that rifampicin antibiotic is suggested which is closely related to rifaximin which is cited in the study above, suggesting that working from the microbiome data is a reasonable approach. Other diet related items computed are:

  • aspartame(sweetner)
  • bifidobacterium adolescentis,(probiotics) 12BCFU/day
  • carob
  • catecholamines(polyphenol)
  • e.coli probiotics (Mutaflor, Symbioflor-2)
  • dairy / lactose /lactulose
  • d-ribose 10gram/day
  • fat in diet
  • fluorine (i.e. in toothpaste!)
  • fruit/legume fibre
  • grape polyphenols
  • green-lipped mussel
  • iron 400mg/day
  • ku ding cha tea
  • mannooligosaccharide(prebiotic) 8gram/day
  • Miso
  • navy bean
  • non-starch polysaccharides
  • oligosaccharides(prebiotic)
  • proton-pump inhibitors(prescription) 60mg/day
  • Pulses
  • raffinose(sugar beet)
  • red alga Laurencia tristicha
  • red wine 250ml/day
  • rice bran
  • sodium butyrate
  • Sriracha sauce
  • ß-glucan 500mg/day, converting to foods:
    • Mushrooms, especially shiitake, maitake, reishi, shimeji and oyster varieties
    • Date fruit, a sweet and fiber-rich fruit native to the Middle East
    • Oats, a cereal grain that can help lower cholesterol levels
    • Barley, one of the highest-fiber grains
    • Seaweed, a marine algae that contains various nutrients and antioxidants
    • Rye bread, a type of bread made from rye flour [Sources of Beta-Glucan (weekand.com)]

Do just the items that you tolerate (physically, philosophically), there is not a need to do all.

Items to AVOID include:

  • cinnamon (oil.spice)
  • foeniculumvulgare,fennel
  • lactobacillus plantarum(probiotics)
  • oregano(origanum vulgare, oil) |
  • syzygiumaromaticum(clove)
  • thyme(thymol, thyme oil)
  • triphala

I would extend it to all lactobacillus probiotics because there are hostile to E.Coli probiotics.

Bottom Line

Working from an individual microbiome is the best way to proceed (IMHO). There are massive issues with both being sure of the SIBO diagnosis being correct AND no clinical evidence (except for antibiotics use) of any specific diet being useful.