Small Intestinal Bacterial Overgrowth (SIBO) is a common gut disorder. The problem is, many people are unaware of it and thus do not get diagnosed. New research shows SIBO can interfere with mental health, raising the risk of anxiety. Fixing the gut can lead to a calmer mood.

What is SIBO?

SIBO is defined as an increased number and/or abnormal types of bacteria in the small intestine. The condition encompasses yeast overgrowth such as Candida too, but excess bacteria is more common and a bigger problem.

There is not supposed to be a lot of bacteria in your small intestine. This part of your intestine is designed for nutrient digestion and absorption. Most of the bugs in your gut are supposed to live in your colon (large intestine).

Symptoms of SIBO

How would you know if you have SIBO? The majority of the symptoms are digestive, however, as you can see in this list, SIBO can adversely affect your head:

  • Bloating
  • Abdominal pain after eating
  • Nausea
  • Gas (burping or flatulence)
  • Constipation
  • Fatigue
  • Diarrhea
  • Muscle cramps, spasms or restless legs syndrome. Muscle cramps and spasms are usually caused by magnesium deficiency due to malabsorption. Iron deficiency and vitamin E deficiency are strongly correlated with restless legs syndrome as well.
  • Joint pain
  • Fibromyalgia
  • Fatigue
  • Multiple food sensitivities
  • Inflammation of the liver (raised liver enzymes)
  • Skin problems, including eczema, acne rosacea, rashes or itchy skin.
  • Strong sugar or carbohydrate cravings. The excess bacteria and yeast in the small intestine want to be fed. They need carbohydrate in order to survive, so you’re likely to have big cravings for these foods.
  • Anxiety
  • Brain fog

SIBO can cause leaky gut

The lining of the small intestine is fragile. It is not designed to tolerate large numbers of microbes. That means the cell lining of the small intestine can get damaged, leading to increased permeability of the intestinal barrier. This condition is known as leaky gut. Leaky gut can amplify SIBO symptoms and give rise to food allergies or sensitivities, autoimmune disease, inflammation and lowered immunity.

Why do people get SIBO?

How does the bacteria end up in your small intestine? It can either travel upwards from your colon, or downwards from your mouth. The far more common scenario is where the bugs travel up from your large intestine.

The bacteria present in SIBO are not necessarily bad bacteria, like the ones that cause gastroenteritis or food poisoning. The problem is, the bacteria are just in the wrong place. Having too much bacteria here can make you feel bloated and it can cause symptoms of irritable bowel syndrome such as abdominal cramps, gas, diarrhea or constipation. New research has shown that many cases of irritable bowel syndrome are actually caused by SIBO. BactoClear capsules are a natural herbal antimicrobial, designed to kill bacteria, yeast and fungi in the small intestine.

Most people with SIBO do not produce sufficient Digestive Enzymes or bile. This means food doesn’t get digested thoroughly and scraps are left behind, encouraging microbial growth. Digestive Enzymes and ox bile can be taken with meals to counteract this.

Can SIBO cause anxiety or depression?

Studies have shown that having an altered gut microbiome can be a cause of anxiety or depression. Specific research even suggests that certain strains of bacteria promote poor mental health when present in high numbers. Having an inflamed gut, or dysbiosis in the gut (imbalance between good and bad bugs) can lead to increased anxiety.


Clapp, M., Aurora, N., Herrera, L., Bhatia, M., Wilen, E., & Wakefield, S. (2017). Gut microbiota’s effect on mental health: the gut-brain axis. Clinics and practice, 7(4), 131-136.

Pimentel, M., Saad, R. J., Long, M. D., & Rao, S. S. (2020). ACG clinical guideline: small intestinal bacterial overgrowth. American Journal of Gastroenterology, 115(2), 165-178.

Quigley, E. M., Murray, J. A., & Pimentel, M. (2020). AGA clinical practice update on small intestinal bacterial overgrowth: expert review. Gastroenterology, 159(4), 1526-1532.

Leite, G., Morales, W., Weitsman, S., Celly, S., Parodi, G., Mathur, R., ... & Pimentel, M. (2020). The duodenal microbiome is altered in small intestinal bacterial overgrowth. PloS one, 15(7), e0234906.

The above statements have not been evaluated by the FDA and are not intended to diagnose, treat or cure any disease.