How SIBO is Associated to Unexpected Weight Gain and Weight Loss Resistance

SIBO (small intestine bacterial overgrowth) is a medical condition that manifests differently in individuals. It occurs when an excessive amount of certain bacteria grow in the small intestine, creating an imbalance of the gut microbiome.

This imbalance is known as Dysbiosis which can either lead to increased gut motility and diarrhea or slowed motility and constipation.

Does SIBO Cause Weight Gain?

Scientists have linked an imbalance of bacteria in the gut to obesity and metabolic issues. Many people who visit a nutritionist are dealing with unexplained symptoms related to SIBO. Along with constipation or loose stools, clients often experience bloating, gas, and unexpected weight gain.

The presence of the bacterial imbalance in the gut can result in an excessive amount of gasses like methane and hydrogen.

Methane production has been associated with constipation, obesity, and irritable bowel syndrome. Researchers have found a link between the production of methane in the body and slow transit time. This means that food spends a much longer time in the gut, leading to several issues. One challenge is that since the transit time is longer, more calories are being absorbed, leading to weight gain. Due to this slow movement of food in the intestines, people who have SIBO with constipation tend to absorb more calories. The result is weight gain.

SIBO can also slow down metabolism, which affects the levels of insulin and leptin (hormones that control satiety and hunger) as well as thyroid hormones. Combine all these factors and no surprise that you may find it difficult to shed weight if you have SIBO!

How hormone imbalances slow down metabolism:

  1. Insulin – In a 2020 study, researchers found that patients who have type II diabetes and SIBO had increased insulin dysfunction lending to worse control of blood sugar than those who have type II diabetes with no SIBO.
  2. Thyroid Hormones – Studies have also linked SIBO with hypothyroidism. People with hypothyroidism tend to experience changes in their weight – in particular, weight gain.

Difficulty Losing Weight with SIBO

Weight loss resistance is when a person is unable to shed excess body fat despite eating an appropriate diet and following an exercise program.

Hormone and digestive imbalances are two common causes of weight loss resistance. Let’s discuss the connection between the bacteria in the gut and weight loss resistance for a moment.

Scientists have established a strong link between gut bacteria and weight loss resistance. According to recent studies, the bacteria in our gut affect fat storage in the body, hormones that regulate satiety and hunger, and how we control blood sugar levels. An imbalance of gut bacteria can increase our risk of developing obesity from the time we are born and an inability to lose weight.

Not being able to lose weight is undoubtedly frustrating. However, it is crucial to know that weight loss resistance is often a sign of an underlying issue. It is your body telling you that something is not right. Consider the resistance to losing weight as a tree branch. You have to find the root in order to bring about healthy change. Change won’t happen (that is, an imbalance will remain) if we only focus on the branches (symptoms) instead of the root.

Tips to Tackle SIBO-Related Weight Gain

1. Get Diagnosed 

It is crucial to see a trusted healthcare provider to know if you have the condition. Working with a gut health expert that understands your body and what you are dealing with will make a huge difference. SIBO is diagnosed with breath test, revealing if methane or hydrogen gasses are elevated.

2. Come Up With a Treatment Plan (Including a Diet Plan)

Diet and lifestyle changes are presently the first line of defense against SIBO.

3. Control stress

There is a correlation between stress and sibo. Finding ways to stay in the parasympathetic state as much as possible can greatly help. Try meditation, taking walks, massage, or any self care habit that appeals to you.

4. Get Good Sleep 

Sleep 7 to 9 hours each night. Not having adequate sleep over a long period of time is another source of chronic stress for the body, which can exacerbate your symptoms.

5. Gut-friendly Movement

For gut and overall health, it is important to regularly move your body in the ways you enjoy. Activities like walking, swimming, and yoga are excellent ways of incorporating movement into your day without stressing your body too much.


SIBO is a common condition these days and it can hamper your weight loss attempts as well as lead to unexpected weight gain. Proper diagnosis is a must to start the treatment in the right direction. Learning what foods trigger the condition can be immensely helpful to mitigate the uncomfortable symptoms.

To provide more robust support and dietary intervention to our SIBO patients, we have partnered with Dr. Aliza Cicerone, ND  with years of experience in treating gut health conditions. Dr. Cicerone is now seeing patients with BioIntelligent Wellness.

You can learn more about our SIBO program and Dr. Cicerone’s patient care by setting up a complimentary consultation here.

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