SIBOis a complicated condition. It occurs when friendly bacteria, normally found in the large intestine, grow excessively in the small. Overgrowth can cause discomfort such as pain, bloating, and damage to the intestinal lining (known as leaky gut).

SIBO can cause some symptoms, including:

  • Appetite loss
  • Nausea and abdominal pain
  • After eating, you feel bloated and full afterwards.
  • malnutrition
  • unintentional weight loss

SIBO is associated with malabsorption, leading to weight loss instead of weight gain. SIBO is a condition that affects the digestive system and makes it difficult for people to absorb, use, or store nutrients from the food they eat 1,” states Victoria Hamilton, a nutritionist and specialist in autoimmune diseases.

If SIBO is a common symptom, then why does SIBO often cause weight gain? First, let’s look at SIBO. Victoria says that SIBO can be divided into hydrogen-producing or methane-producing. According to Victoria, the type of SIBO you have depends on the gas produced by your gut microbiome.

Hydrogen-dominant SIBO

The main sign of hydrogen-dominant SIBO is diarrhoea. This is often accompanied by dizziness, the urgency to go to the toilet, bloating, and fatigue. As a byproduct of fermentation, hydrogen gas is found in the large intestine. However, excesses of it can grow in the small intestine. This causes symptoms like diarrhoea. The gas tends to cause loose stool and rapid transit.

One of the most common causes of SIBO in hydrogen-dominant SIBO is food poisoning.

SIBO for Methane-dominant SIBO

Your SIBO methane dominant is likely to cause chronic constipation, bloating and burping immediately after eating. Other symptoms include headaches, fatigue, brain fog, and other non-digestive symptoms like headaches.

Because IMO means “things coming back up”, symptoms like acid reflux, burping, and nausea are all common. Research has shown that methane gas released into the small intestine causes a backward movement.

SIBO, weight gain

SIBO is often associated with weight loss because it impairs the body’s ability to absorb nutrients. However, SIBO can cause weight gain in large numbers of people. Recent studies show a link between SIBO and obesity. Victoria says that it is not clear which one came first. However, the likelihood is that obesity is the cause.

Is SIBO directly linked to weight gain? Victoria shares three reasons SIBO may cause weight gain.

Slower transit time

SIBO that produces methane has been proven to cause constipation. It may also cause slower transit times, meaning food stays in the stomach longer than it should 2. This can cause nausea, stomach pain, and weight gain.

Potentially higher caloric intake

Additionally, methane-producing SIBOs may get more calories from their food 3. Glycans are a fibre that you don’t absorb when you eat. However, high levels of methane can make it possible to absorb more calories from fibre-rich foods. This could lead to weight gain.

Reduce metabolism

SIBO patients might be more susceptible to decreased metabolism, the bodily process that converts food to energy. SIBO can also affect insulin and leptin, hormones that impact your weight 4.

The bottom line

The bottom line is that SIBO can lead to weight gain and may cause you to lose weight. If you have SIBO and have difficulty with your weight, consult your doctor before changing your diet.

What can a nutrition specialist do to help you?

Following a treatment plan and confirming by breath test that SIBO is absent, nutritional therapy can help you optimize your nutrition status. SIBO can lead to nutrient deficiencies caused by the rapid transit time in SIBO hydrogen-dominant SIBO. You can also experience high levels of bacteria in both SIBO types.

A nutrition professional can help you avoid foods that cause intestinal fermentation and aggravate SIBO. They can also help you manage your carbohydrate intake (the bacteria in SIBO feeds off the bacteria), identify foods that could contribute to weight gain, and provide healthy alternatives. They may also offer lifestyle recommendations to improve whole-body health.

Victoria Hamilton can help you connect with the support that you need. Or you can use the advanced search tool to locate a professional in your area trained to assist with SIBO.