An Introduction to Small Intestinal Bacterial Overgrowth (SIBO)

July 27, 2021 Ashley Turner

The human digestive system is a mighty and miraculous yet delicately balanced realm. It doesn’t take much to disrupt the gut microbiome and create a tangle of uncomfortable and disruptive symptoms. Bacteria are a critical component to a healthy gut and small intestine, but when bacteria overgrow in the small intestine it can lead to leaky gut and a host of other gastrointestinal symptoms.

Many Americans experience intense and/or unspecified abdominal pain along with bloating and irregular bowel habits. Quite frequently the cause of these symptoms is a common but often misunderstood condition that can wreak havoc on your body: Small Intestinal Bacterial Overgrowth (SIBO).

The Small Intestine

Before we delve into SIBO, it is important to understand the role of the small intestine. The small intestine has a significant role in the body’s digestion and absorption of nutrients. Additionally, it is an important component of the immune system as it houses a complex organization of immune cells called lymphoid cells. Also known as the Gut-Associated Lymphoid Tissue (GALT), this facet of the immune system helps to fight infection and regulate the immune system. Because the small intestine has an essential role in overall health and well-being, it is crucial to understand what can go wrong in this part of the digestive tract.

What is SIBO?

SIBO occurs when there is an increase in the amount of bacteria or the types of bacteria found in the small intestine. In SIBO, bacteria normally found in the large intestine finds its way to the relatively sterile small intestine. Usually SIBO is not caused by just one type of bacteria, but an assortment of bacterial strains that would usually be found in the colon. The cause of SIBO is often quite complex and usually is a combination of issues such as decreased intestinal motility, low stomach acid, poor immune function, and dysfunction in the ileocecal valve.

Once the food you consume is broken down, nutrients are absorbed in the small intestine and waste products are formed and eliminated through the large intestine and colon. In a healthy digestive system, there is a high concentration of many bacterial strains in a large intestine. But sometimes that bacteria migrates backwards because of a malfunction in the ileocecal valve and into your small intestine initiating a microbial imbalance. The ileocecal valve is located between the ilium or terminal end of the small intestine and the cecum, which forms the first part of the large intestine.

When what you eat lingers for too long in the small intestine, trouble brews. This slow movement—often caused by reduced gastric motility or low gastric acid secretion—spawns the growth of bad bacteria. After some time, the good bacteria in your small intestine can’t hold the bad bacteria at bay, and once again, an imbalance is created and discomfort ensues.

In any of these scenarios, bacteria species (whether too much or the wrong types) in the small intestine can contribute to nutritional deficiencies because they hinder digestion and assimilation. In fact, these bacteria inhibit the absorption nutrients such as vitamin b12, vitamin A, vitamin D, vitamin K, iron, and some amino acids.

Who is at Risk?

People with weakened immune systems are especially susceptible to SIBO. Chronic conditions such as diabetes (type 1 and type 2), irritable bowel syndrome (IBS), celiac disease, Crohn’s disease, and lupus can also put you at risk for the condition. Low stomach acid can put someone at rick for SIBO as can abdominal scar tissue or a blockage in your GI tract. Medications such as antibiotics, proton pump inhibitors, antacids, and narcotics can also increase your chances of developing SIBO. Heavy alcohol consumption has been associated with SIBO. Even a bout of food poisoning can disrupt your system enough to trigger an overgrowth of small intestinal bacteria—which is exactly what happened to a few members of my own family in the past.

What are the Signs & Symptoms?

Symptoms of SIBO can be mild or easily (mistakenly) attributed to another condition, while others can be severe and impossible to ignore. This is why SIBO has been so difficult to diagnose. Any of the following may indicate SIBO:

Abdominal pain and discomfort
Bloating and abdominal distention
Gas and belching
Heartburn
Fatigue
Queasiness
Diarrhea or constipation
Irritable Bowel Syndrome (IBS)
Inflammatory Bowel Disease (IBD)
Weight loss
Anemia and other nutrient deficiencies
Brain fog and mood symptoms

Some experience systemic symptoms including headaches, fatigue, joint and muscle pain, and some dermatologic conditions.

What Happens Next?

The good news is that even though research on SIBO is ongoing and there’s still much to learn, there are ways to correctly diagnose and treat the condition. In the next post, we’ll cover in more depth how and where SIBO and IBS symptoms overlap, and the various tests available to determine whether you have SIBO.

If you think you might have SIBO and want relief from your symptoms, please feel free to reach out to our wellness center now for a consultation and testing!