SIBO: Small Intestinal Bacterial Overgrowth

SIBO: Small Intestinal Bacterial Overgrowth 


SIBO, or small intestinal bacterial overgrowth, is the overabundance of bacteria in the intestines and bowel, which leads to many severe gut issues. SIBO is linked to many digestive issues like irritable bowel syndrome, Crohn’s disease, and even gastrointestinal cancers. The signs and symptoms of SIBO tend to mimic other stomach ailments, which is why proper diagnosis is difficult to reach. The issues caused from a SIBO infection can vary in severity from mild to extreme.  

SIBO directly affects the gut, causing uncomfortable and uncontrollable digestive issues. The symptoms of a small intestinal bacterial overgrowth include but are not limited to: 

  • Constipation 
  • Stomach pain 
  • Diarrhea 
  • Nausea 
  • Unintentional weight loss 
  • Malabsorption  
  • Bloating 
  • Severe abdominal pain 

The Causes of SIBO 

These types of bacterial overgrowth can happen when bacteria from the digestive tract travels to the smaller intestine, or when naturally occurring bacteria in the small intestine multiply too quickly. Some individuals may experience a SIBO infection due to these factors: 

  • the abnormally slow movement of the digestive system 
  • low levels of stomach acid 
  • physical abnormalities of the small intestine 
  • a weakened immune system 
  • damage to the GI tract from long-lasting infections 

Certain medical conditions tend to exacerbate SIBO infections. Many specialists consider SIBO a complication or side-effect of the following medical conditions: 

  • Cirrhosis 
  • Crohn’s disease 
  • Celiac disease 
  • Hypothyroidism 
  • HIV 
  • Diabetes 
  • IBS 
  • Scleroderma 
  • Fibromyalgia 

There are other risk factors for a small intestinal bacteria overgrowth, and they are: 

  • older age 
  • being female 
  • long-term use of proton pump inhibitors (PPIs), which are medications that reduce stomach acid production 
  • previous bowel surgery 
  • having recently completed a course of antibiotics 
  • drinking alcohol 

How is the SIBO Diagnosis Made 

Because SIBO tends to cause a host of symptoms with varying degrees of severity, it is difficult to officially diagnose. First, your doctor will take an appropriate medical history and list your symptoms. They may palpate your abdomen to feel for obstructions, inflammation or bloating. If they suspect you do have SIBO, they will prescribe a breath test.  

The breath test measures the concentrations of both hydrogen and methane in a person’s breath. The results of this test can tell the doctor the levels of severity and location of the bacterial growth in your gut. The breath test works because bacteria produce hydrogen and methane when they break down carbs in your digestive tract. These molecules then enter the bloodstream, travel to the lungs, and leave the body in the breath.  

The breath test is simple and is often done in the patient’s home. The patient must fast for twenty-four hours before doing the test, and then drink a sugar lactulose beverage before breathing into or beginning the test. Read the directions BEFORE you begin! After this test, the doctor may need samples of blood, urine or intestinal fluid for lab analysis if the breath test is not clear.  

What is the Treatment Options for SIBO 

There are different methods of therapy used to treat SIBO from holistic to antibiotic to dietary changes. Those patients who are suffering from malnutrition or become dehydrated due to SIBO will also need nutrients and fluids, which often come via IV drip. In some cases, broad spectrum antibiotics can stabilize the gut microbiota by reducing the number of intestinal bacteria. Addressing any underlying conditions is the only way to cure SIBO.  

Some doctors feel that dietary changes must happen hand-in-hand with other treatments, but there is no set evidence or proof of this fact. The role of diet is not fully understood as it works with a SIBO infection. That said, being healthy and eating a nutritious diet is a must with any SIBO infection. Those patients with underlying diabetes or Celiac disease may have extra difficulty with SIBO infections.  

Complications from a SIBO Infection  

When there are abnormally large populations of bacteria in the small intestine, it can have negative outcomes on the entire body. The overgrowth of bacteria makes it difficult for the body to absorb fats and carbs from food and it also leads to vitamin and mineral deficiency. Other complications that may arise are: 

  • a leaky gut 
  • malnutrition 
  • severe weight loss 
  • dehydration 
  • joint pain 
  • constipation 
  • hepatic encephalopathy, a decline in brain function due to severe liver disease 

Preventing SIBO Infections 

Prevention is a vital component of SIBO management, as many patients report SIBO symptoms months after completing antibiotic therapies. Patients usually develop SIBO as a result of an underlying condition or a physical defect in the small intestine. Dietary and lifestyle changes combined with medicinal therapy can help to keep the SIBO from returning. Eating plant-based foods and avoiding overly sugary and processed foods will allow good bacteria to grow and flourish in your gut.  

SIBO Outlook 

SIBO is often a complication of other digestive conditions like IBS, IBD, Crohn’s disease and Celiac disease. Treatment for SIBO aims to correct the balance of bacteria in the body. It should be known that SIBO is not yet fully understood by the medical community and current studies are helping to explore the human gut microbiome to advance treatment options.  

If you think you may be suffering from a small intestine bacterial overgrowth SIBO infection, do not wait to contact your doctor, as treatment takes weeks to months to complete.  



Resources Used: 

Reclaiming Intimacy  



Johns Hopkins  


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