​Personalised Support for Small Intestinal Bacterial Overgrowth (SIBO)
SIBO . TESTING . RELAPSING SIBO . SIFO
At the Autoimmune Clinic, we specialise in small intestinal bacterial overgrowth (SIBO) through a functional medicine approach.
WE GO WAY BEYOND SYMPTOM MANAGEMENT TO UNCOVER AND SUPPORT POSSIBLE ROOT CAUSES OF YOUR SIBO, HELPING YOU REGAIN CONTROL OVER YOUR HEALTH AND WELLBEING.
SIBO stands for Small Intestinal Bacterial Overgrowth
IT IS A CONDITION CHARACTERISED BY AN EXCESSIVE GROWTH OF BACTERIA
This excessive growth in bacteria happens in the small intestine, where they shouldn't normally be present in large numbers. IBS is a chronic condition that can significantly impact a person's quality of life, causing physical discomfort and emotional distress.
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This overgrowth can lead to various digestive symptoms, such as bloating, abdominal pain, diarrhea, and malabsorption of nutrients.
SIBO, IBS & Autoimmunity
BOTH IBS AND SIBO HAVE BEEN ASSOCIATED WITH IMMUNE SYSTEM DYSREGULATION
Chronic inflammation in the gut, triggered by SIBO or other factors, can disrupt immune function and potentially contribute to the development or exacerbation of autoimmunity. This immune dysregulation may involve the production of autoantibodies and the attack on healthy tissues characteristic of autoimmune diseases. Additionally, SIBO can lead to increased intestinal permeability, or "leaky gut," allowing bacteria and other substances to enter the bloodstream and trigger the immune system, leading to chronic inflammation and potentially the development of autoimmune disease. ​
WE ALSO HAVE GROWING EVIDENCE ESTABLISHING A ROLE OF THE GUT MICROBIOME IN BOTH IBS AND AUTOIMMUNE DISORDERS
IBS is not a diagnosis but rather a symptom. Your bowel is irritated, and we must ask what is causing the irritation?
Changes in the composition of gut bacteria, known as dysbiosis, have been observed in these conditions. Dysbiosis can alter immune function, promote inflammation, and contribute to the pathogenesis of autoimmune diseases.
Shared risk factors, such as gastrointestinal motility disorders and anatomical abnormalities, may also contribute to the observed relationships among IBS, SIBO, and autoimmunity. Understanding the connections among IBS, SIBO, and autoimmunity could have significant implications for diagnosis and treatment. Targeting gut dysbiosis, restoring intestinal barrier function, and modulating immune responses may help manage these conditions and potentially reducing the risk of autoimmune disease development or progression in susceptible individuals.
Functional Medicine London | Functional Medicine Surrey | Functional Medicine Practitioner | Autoimmune Specialist | Autoimmune Practitioner | Autoimmune Nutritionist London | Autoimmune Clinic | Functional Medicine Clinic | MCAS Nutritionist | SIBO Nutritionist | IBS Nutritionist | Mast Cell Activation Syndrome
Testing for SIBO
FUNCTIONAL TESTING
Testing involves a breath test. This non-invasive test measures the levels of hydrogen and methane gases produced by bacteria in the small intestine. It helps to diagnose SIBO by identifying abnormal bacterial overgrowth in the small intestine. The breath test is usually performed after fasting and involves drinking a solution containing specific carbohydrates followed by breath samples at regular intervals. These samples are analysed to determine the presence and extent of SIBO.
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​Treatment for SIBO often involves a combination of dietary changes, antimicrobial therapy, and addressing underlying factors contributing to the overgrowth.
Why does my SIBO keep relapsing?
UNDERLYING CAUSES
If the underlying causes of SIBO are not addressed, such as impaired gut motility, structural abnormalities, or immune dysfunction, the overgrowth of bacteria in the small intestine may return.
INCOMPLETE TREATMENT
Failure to completely eradicate the bacterial overgrowth during treatment can result in a relapse. This can happen if the prescribed antibiotics or antimicrobial agents do not effectively target the specific bacteria causing the overgrowth.
DIET & LIFESTYLE FACTORS
Poor dietary choices, such as a high intake of fermentable carbohydrates or a diet low in fibre, can contribute to the recurrence of SIBO. Lifestyle factors like chronic stress, inadequate sleep, and lack of physical activity can also impact gut health and increase the risk of relapse.
UNDERLYING HEALTH CONDITIONS
Certain underlying health conditions, such as gastrointestinal disorders (e.g., Crohn's disease, celiac disease), immune system dysfunction, or hormonal imbalances, can predispose individuals to SIBO relapse.
To reduce the risk of SIBO relapse, it is essential to address the underlying causes, follow a customised treatment plan that includes appropriate antimicrobial therapy, and make dietary and lifestyle modifications. Regular follow-up with your practitioner can help monitor progress, identify any relapse signs early on, and make necessary adjustments to the treatment approach.
Underlying factors to SIBO
There are several underlying factors that can contribute to the development of Small Intestinal Bacterial Overgrowth (SIBO). Some common factors include:
IMPAIRED OR ALTERED GUT MOTILITY
Conditions that slow down the movement of food through the digestive tract, such as intestinal obstructions or conditions like gastroparesis, can create an environment for bacterial overgrowth in the small intestine. Conditions such as irritable bowel syndrome (IBS) or certain neurological disorders can disrupt the normal muscular contractions of the gut, leading to stagnant food and bacterial overgrowth.
STRUCTURAL ABNORMALITIES
Any anatomical or structural abnormalities in the gastrointestinal tract, such as strictures, diverticula, or surgical changes, can disrupt the normal flow of bacteria and promote SIBO.
DISRUPTED GUT FLORA BALANCE
Changes in the composition of the gut microbiota can allow certain bacteria to overgrow in the small intestine. This can occur due to factors like antibiotic use, low stomach acid, or a lack of beneficial bacteria.
IMPAIRED IMMUNE & DIGESTION FUNCTION
Weakened immune function can reduce the body's ability to keep bacterial populations in check, allowing overgrowth in the small intestine. Insufficient production of digestive enzymes or a decrease in bile acids can impair the breakdown and absorption of nutrients, creating an environment where bacteria can thrive.
IMPAIRED IMMUNE FUNCTION
Insufficient production of digestive enzymes or a decrease in bile acids can impair the breakdown and absorption of nutrients, creating an environment where bacteria can thrive.
SIBO & THYROID FUNCTION
There is a connection between thyroid function and SIBO (Small Intestinal Bacterial Overgrowth). Thyroid hormones play a crucial role in regulating the function of the gastrointestinal tract, including gut motility and the secretion of digestive enzymes. When thyroid function is disrupted, it can lead to changes in gut motility and digestion, increasing the risk of SIBO.
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Hypothyroidism, an under active thyroid condition, is commonly associated with SIBO. The slowed metabolism and reduced gut motility seen in hypothyroidism can contribute to bacterial overgrowth in the small intestine.
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On the other hand, SIBO itself can also affect thyroid function. Bacterial overgrowth in the small intestine can lead to impaired nutrient absorption, including key nutrients needed for thyroid hormone production and conversion. This can potentially impact thyroid function and exacerbate existing thyroid conditions.
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​It is important to address both thyroid function and SIBO when managing these conditions. Optimising thyroid function through appropriate medication, diet, and lifestyle interventions, along with treating SIBO through targeted therapies and dietary modifications, can help improve overall gut health and thyroid function. Working with a healthcare professional experienced in functional medicine can provide personalised guidance and support in addressing both conditions effectively.
Identifying and supporting these underlying factors is an important part of managing SIBO and preventing its recurrence, which is very common. A comprehensive approach that includes dietary modifications, lifestyle changes, and targeted treatments can help restore gut health and reduce the risk of SIBO.
SIBO and nutritional supplements
SUPPLEMENTS CAN BE USED AS PART OF A COMPREHENSIVE TREATMENT PLAN FOR SIBO
However, it's important to note that individual needs may vary, and it's best to consult with a healthcare professional before starting any new supplements. Here are a few examples of supplements that are commonly used in SIBO treatment:​
DIGESTIVE SUPPORT
Supplementing with betaine HCl and/or digestive enzymes can support the breakdown and absorption of nutrients, helping to improve digestion and alleviate symptoms associated with SIBO.
HERBAL ANTIMICROBIALS
Herbal antimicrobial supplements, such as berberine, oregano oil, neem, or grapefruit seed extract, have shown effectiveness in reducing bacterial overgrowth in the small intestine. These should be used under the guidance of a knowledgeable practitioner.
GUT HEALING SUPPLEMENTS
Supplements like glutamine, short chain fatty acids, DGL aloe vera, and zinc carnosine can help support gut healing and reduce intestinal inflammation, which can be beneficial in SIBO management.
MOTILITY AGENTS
Certain supplements, such as prokinetics or motility agents like magnesium, ginger, or 5-HTP, can help improve gut motility and prevent bacterial overgrowth.
Please note: It's important to remember that addressing SIBO requires a comprehensive approach that includes dietary modifications, lifestyle changes, and potentially prescription medications. Working with us means that you are receiving a tailored treatment plan that suits your specific needs.
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Find out more about SIBO in our Blog
Read about 5 Common Mistakes Made When Treating SIBO (Small Intestinal Bacterial Overgrowth) in our blog post.
What is Small Intestinal Fungal Overgrowth (SIFO)?
Small Intestinal Fungal Overgrowth (SIFO) is a condition characterised by an excessive proliferation of fungi—most commonly Candida species—within the small intestine. While fungal organisms naturally exist in the gut microbiome, an imbalance can lead to a range of digestive symptoms and systemic effects.
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Unlike Small Intestinal Bacterial Overgrowth (SIBO), which involves an overgrowth of bacteria in the small intestine, SIFO is caused by fungal overgrowth, which can be more challenging to diagnose and treat effectively.
How Common is SIFO? Can You Have It With SIBO?
SIFO is increasingly recognised as a contributing factor to persistent gut symptoms, particularly in individuals who do not respond fully to conventional treatments for SIBO or irritable bowel syndrome (IBS).
Research suggests that up to 40% of individuals diagnosed with SIBO also have SIFO, meaning fungal overgrowth can coexist with bacterial overgrowth.
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However, SIFO can also occur independently, especially in individuals with risk factors such as:
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Chronic antibiotic use (which disrupts bacterial balance, allowing fungi to overgrow)
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Long-term proton pump inhibitor (PPI) use (which reduces stomach acid, creating an environment for fungal proliferation)
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Immunosuppression (due to conditions like diabetes, autoimmune diseases, or medication use)
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Gut motility disorders (such as gastroparesis or conditions that slow the movement of food through the intestines)
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A high-sugar, high-carbohydrate diet (which can fuel fungal overgrowth)
SIFO symptoms often overlap with those of SIBO, IBS, and other digestive disorders, making it difficult to identify. Key symptoms include:
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Persistent bloating and abdominal distension
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Excessive gas (flatulence and belching)
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Diarrhoea or constipation
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Nausea and indigestion
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Cramping or abdominal discomfort
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Food sensitivities, particularly to carbohydrates, sugars, and fermented foods
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Fatigue and brain fog (often linked to systemic fungal toxins)
Symptoms of SIFO to Watch Out For:
Because symptoms of SIFO mimic those of other gut imbalances, misdiagnosis or an incomplete diagnosis is common, leading to ineffective treatment approaches.
Is There a Reliable Test for SIFO?
Unlike SIBO, which can be diagnosed using a breath test, there is no universally accepted or highly accurate test for SIFO. The gold standard for diagnosis—obtaining a sample from the small intestine via endoscopy—is invasive and not widely available in clinical practice.
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However, functional medicine practitioners often use Organic Acid Testing (OAT) to assess fungal overgrowth indirectly. This urine test measures specific metabolites, such as D-arabinitol, a byproduct of Candida metabolism. Elevated levels of fungal markers can indicate an overgrowth in the gastrointestinal tract, supporting a clinical diagnosis of SIFO. While OAT does not provide a definitive diagnosis, it is a valuable tool in assessing underlying gut imbalances and guiding treatment strategies.
Meet Muriel & Claire,
your expert practitioners
Our practitioners are BANT registered nutritional therapists and functional medicine practitioners, with a real passion to help others achieve optimal health.
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You can read more about Muriel and Claire on our Meet the Team page.