The Gut-Brain Axis: Neurotransmitters and SIBO – Part 2 with Dr Bradley Bush

In this episode Dr Nirala Jacobi continues the conversation with Dr Bradley Bush, with a focus on case presentations around chronic SIBO cases and inflammatory concepts.

Dr Bush received his Naturopathic Doctorate degree from the National College of Naturopathic Medicine.  He is co-owner and clinic director of Natural Medicine of Stillwater and its online consumer direct website for practitioners,

The Bush practice focuses on fatigue, insomnia, GI disorders, mood disorders, and lyme disease. Dr Bush has over 16 years of industry experience. He is the owner of Natural Health Insights, providing consulting services to the naturopathic products and laboratory testing industry.

Dr Bush speaks nationally and regularly publishes on the topics of neuroimmunology, brain-gut connections, neuroendocrinology, and lyme disease.  Dr Bush sits on two non profit boards, The Naturopathic Education and Research Consortium, and Compass Centre for Health.

The format of this episode is slightly different. In it Dr Bush discusses three different SIBO cases, diving into the variability and complexity of each presentation.


Case 1 – SIBO with associated fibromyalgia and chronic fatigue – 65 y/o female.

  • Incremental approaches with complex cases.
  • The gut being the epicentre of health, without which SIBO associated presentations will not rectify.
  • Polypharmacy approach and the compounding effect of this on the patient.
  • Analysis of basic chemistry.
  • Myeloperoxidase (MPO), the enzyme secreted by neutrophils, and the indications for testing and tracking this in treatments. (MPO elevation has associations with lipopolysaccharides (LPS), chronic infections, irritable bowel disease (IBD), and immune induced leaky gut)
  • The neurotransmitter imbalances that can be sustained by chronic inflammation (hint – upregulated indoleamine dioxygenase enzyme, precipitating downregulated synthesis of serotonin, among others)
  • Yeast association with SIBO.
  • Weaning off polypharmacy.
  • Metronidazol for rifaximin resistant SIBO, and C. diff.
  • An indication on how many rounds of rifaximin are required to attend to chronic versus acute SIBO.
  • Eating disorders prompted by therapeutic diets taken on for too long.
  • Botanicals vs conventional medicine for SIBO treatment, or a combination use approach?
  • Probiotic use as immunological modulators rather than massive impactors for floral diversity in the GI microbiome.
  • Botanicals that Dr Bush uses in SIBO treatment.
  • Mediherb gut flora complex – immune regulating capability, IBD modulation, mucosal affinity.
  • Dr Nirala Jacobi’s therapeutic recommendation – Mediherb Bacto-Cand GI.


Case 2 – SIBO with associated constipation, acne, halitosis – 20y/o male

  • Traumatic brain injury due to sporting event.
  • Tricyclic antidepressant therapy introduced in his recovery plan and his subsequent experience of anxiety and spacey feelings.
  • Naturopathic neurotransmitter production therapy alongside conventional antidepressant use.
  • Serotonin syndrome and the potential for it to be induced by dual therapy use.
  • Methane Protocol – rifaximin and neomycin combination for methane dominant SIBO treatment.
  • Anxiety caused by SIBO, key indications being:
    • Treatment resistant anxiety
    • Treatment resistant insomnia
  • Anxiety as a manifestation resultant of SIBO chemicals interrupting neurotransmitter signalling.


Case 3 – Lyme and SIBO – 25y/o female

  • Chronic fatigue, constipation, bloating, neuralgia, catatonic staring episodes.
  • Lyme testing.
  • The effectiveness of the paleo diet for symptomatic control, noting that the issue still exists, even though the bugs are simply not being fed and therefore symptoms abating.
  • SIBO as a concomitant condition with Lyme, and/or as a condition that can mimic the various presentations of Lyme.
  • The Lyme/SIBO overlap as discussed by Dr Farshid Rahbar at the 2017 SIBO Integrative Conference, and the methane association.
  • The clinically noted neuralgia and methane dominance link.
    • Methane endotoxins produced by SIBO bacteria theorised to contribute to neuralgia.
  • Constipation and methane dominance perpetuating each other.
  • Methane dominant SIBO moving from constipation to diarrhoea during treatment and why this can occur.



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