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Many women panic when their waistlines start expanding and immediately turn to weight loss strategies. Usually, those include eating less and exercising more. But what if there’s a hidden imbalance causing both weight gain and bloating that no amount of exercise will fix? If you always feel a bit full and certain foods make it worse, your digestive health may be preventing you from reaching your goals. You may have something called small intestinal bacterial overgrowth or “SIBO.”   

What is SIBO? 

SIBO occurs when the gut bacteria and other microorganisms from the large intestine migrate into the small intestine. That can happen when there’s a dysfunction in the ileocecal valve that acts as a door between the two. It can also happen when built-up gases force that “door” to stay open.  

The small intestine should only have a small population of beneficial bacteria. That’s in contrast to the large intestine, which is rich in bacteria. The small intestine is the main place where nutrient absorption takes place. You don’t want a bunch of bacteria taking up residence there because it can affect absorption. An increase in bacteria can also irritate the gut lining, leading to leaky gut and autoimmune conditions. 

Bacteria that take over the small intestine consume carbohydrates as fuel. Fermentation of these carbohydrates then leads to gas production. The 3 main types of gases produced when this happens are hydrogen, methane, and hydrogen sulfide.  

The type of SIBO diagnosed derives its name from the primary gas produced. 

Types of SIBO 

So, you can have methane-dominant, hydrogen-dominant, or hydrogen sulfide-dominant SIBO. These are most often identified through a hydrogen breath test (HBT). 

Hydrogen-Dominant SIBO  

Hydrogen-dominant SIBO is the most common of the three types. The dominance of hydrogen-producing species can cause diarrhea, weight loss, and nutrient deficiencies. But… there are always exceptions. Some people don’t experience symptoms at all.  

Methane-Dominant SIBO  

The species that leads to methane-dominant SIBO is called Methanobrevibacter smithii. When the organisms are mostly methane-producing, it tends to lead to slow transit time and constipation. But again, not always — that’s why testing is necessary. Methane-dominant SIBO is now called Intestinal Methanogen Overgrowth (IMO). Methane-dominant SIBO is the type associated with weight gain. 

Hydrogen Sulfide-Dominant SIBO 

Hydrogen Sulfide bacterial overgrowth isn’t as well established or studied as the other two. An update on SIBO came out in 2016 describing hydrogen sulfide gas as another possible SIBO marker. The bacteria that produce hydrogen sulfide (H2S) tend to relax the smooth muscle lining of the gut, causing diarrhea. H2S can make your gas smell like rotten eggs. 

Symptoms of SIBO 

Common symptoms of SIBO include the following: 

  • Gas and bloating 
  • Abdominal pain or cramps 
  • Chronic feeling of fullness 
  • Nausea 
  • Heartburn or acid reflux 
  • Constipation, diarrhea, or both 
  • Incontinence 
  • Malabsorption symptoms like anemia or fatty stools 
  • Fatigue 
  • Food allergies 
  • Brain fog or memory issues 

SIBO can also cause seemingly unrelated symptoms, like joint pain, skin issues, depression or anxiety, and even asthma. Or it may not cause any symptoms at all. 

SIBO-Related Health Conditions 

Conditions associated with SIBO include: 

  • Irritable Bowel Syndrome (IBS)  
  • Increased gut permeability (“Leaky gut”) 
  • Autoimmune conditions 
  • Candida overgrowth 
  • Fibromyalgia 
  • Thyroid issues – especially hypothyroidism 
  • Obesity  

But there are many more. Check here for a full list of associated diseases along with scientific references to back it up.  

SIBO and Weight Gain  

While SIBO can lead to malnutrition and weight loss in some people, it can cause unwanted weight gain in others. The weight gain is usually tied to methane-dominant SIBO. This type of SIBO may lead to weight gain for several reasons:  


An invasion of microorganisms in the small intestine can irritate its lining, causing inflammation. When there’s a chronic inflammatory response, the body is in a type of emergency state. Most of the energy is directed toward quelling inflammation and not metabolism. Inflammation sets off all kinds of processes that may lead to weight gain.    

Archaea Microorganisms

This family of methane-producing organisms converts hydrogen produced by other bacteria into methane gas. These organisms increase the number of calories absorbed from food. They do this by helping the gut microbiota digest certain polysaccharides not digestible by humans. 

Slowed Transit Time  

Slow transit time in the digestive tract can cause chronic constipation. This is associated with methane gas production and seems to cause weight gain. The slower transit time may provide a greater opportunity for calorie absorption. With excess calories comes weight gain. A study published in Gastroenterology & Hepatology found that participants who had tested positive for methane in the gut had a higher body mass index (BMI) than those who tested negative.  

Decreased Metabolism  

The small intestine produces several hormones that may impact metabolism and weight gain. These include leptin, glucagon-like peptide-1 (GLP-1), cholecystokinin (CKK), and peptide YY (PYY). If the small intestine is oversaturated with organisms that don’t belong there, it’s likely to affect how well these gut hormones work.  

“Fireman Doctors” and SIBO Treatment 

At The Wellness Way, we talk about the concept of the Fireman and the Carpenter. These two vocations help describe the difference between the traditional medical approach to health and The Wellness Way Approach.  

The “Fireman docs” have two tools in their toolbox: an axe and a hose. The axe represents cutting things out in a surgical procedure. The hose represents medications used to extinguish inflammation and symptoms. The Wellness Way doctors are like carpenters. They assess the damage and lay out a plan to rebuild with the right materials.  

“Fireman doctors” may not recognize SIBO as a condition –even though it’s mentioned in the scientific literature. If they do, they’ll typically use non-absorbable antibiotics called Rifaximin (Xifaxan) and Neomycin to treat SIBO. Occasionally, they’ll also use Metronidazole as an alternative to Neomycin.    

However, using antibiotics are likely only a temporary fix. Many people need repeat treatments.  

What to Do About SIBO 

If you think you may be dealing with SIBO, here’s what you can do:   

1. Get Tested

You don’t know what you don’t know. People with untreated SIBO usually have food allergies. If you don’t know your food allergies, get them tested as soon as possible. Eating foods that you’re allergic to contributes to chronic inflammation in the gut, dysbiosis, and an increased risk of weight gain. Gut health testing (with a stool sample) or specific SIBO testing (via breath test) can also help guide treatment. These tests can help differentiate between SIBO and other gut infections. Sometimes what looks like SIBO is SIFO (fungal overgrowth) or SIYO (yeast overgrowth). These types of infections may require a different supplement plan. 

2. Address the Bacterial Growth

It’s crucial to eradicate the bacteria (and archaea) that migrated into the small intestine. According to a multi-center study, including Johns Hopkins, herbs can work just as well as pharmaceutical drugs. The natural route uses herbs like Oregano oil, Oregon grape, Goldenseal, and others to balance the gut microbiome. Just like antibiotics, it’s important to find the right herb match, the right dose, and the right length of time. That’s where your Wellness Way practitioner comes in.  

3. Optimize Your Diet  

For many people, following a “Low FODMAP” diet helps alleviate many symptoms. FODMAP stands for Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols. These compounds are found in carbohydrate-rich foods, like wheat, beans, fruit, certain vegetables like onions and artichokes, and cow’s milk dairy. Bacteria that have colonized the small intestine have a hay day with these foods. As it says in the name, these foods are highly fermentable. The bacteria break them down and produce lots of gas, making SIBO symptoms worse. Avoiding them for a time is helpful in starving out the bacteria. However, this is alongside the herbal treatment.

In very extreme cases, a 2-week elemental diet may be considered. An elemental diet is usually based on a powdered food product like bone broth protein combined with vitamins, L-glutamine powder, and a powdered source of glucose. A non-GMO glucose source is tapioca maltodextrin or tapioca dextrose. Following an elemental diet for 14 days straight has been shown to normalize SIBO tests. It has an 80 to 84% success rate in eradicating SIBO.  

4. Support Digestion to Prevent a Reoccurrence

Addressing SIBO is not a “one-and-done” situation. It can certainly happen again. For that reason, you’ll want to improve your overall digestion. This may mean taking an HCL supplement for stomach acid support or digestive enzymes for absorption. Some people may need to improve motility (movement of food through the GI tract) with a “pro-kinetic” supplement like ginger. Consistent chiropractic care may also help with structural and motility issues.  

The Wellness Way Can Help! 

At The Wellness Way, we dig deeper to solve the health challenges others can’t. We know that weight issues aren’t always just about what you’re eating or not eating. Sometimes, it’s due to an imbalance in the body, whether that’s gut dysbiosis, hormone imbalance, or chronic inflammation. Often, it’s a combination rather than one single root cause. The only way to know for sure is to test! Reach out to a Wellness Way clinic today to get started on your health journey. Focus on your health, and weight loss will follow. We are here to help!  


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