Small Intestine Bacterial overgrowth syndrome

Symptoms, Causes, and Treatments

What is Small Intestine Bacterial overgrowth syndrome?

Small Intestine Bacterial Overgrowth (SIBO) occurs when there is an excessive growth of bacteria in the small intestine, where normally only small amounts of bacteria live. This imbalance interferes with digestion and absorption, often causing bloating, abdominal pain, diarrhea, constipation, and nutrient deficiencies. While not life-threatening, SIBO can significantly affect daily comfort and overall health.

Common Symptoms Include

Abdominal bloating and distention
Excessive gas (burping or flatulence)
Abdominal pain or cramping
Diarrhea, constipation, or alternating between both
Nausea after eating
Unexplained weight loss in some cases
Fatigue and brain fog
Nutrient deficiencies (e.g., iron, vitamin B12, fat-soluble vitamins)
Symptoms that worsen after meals, especially those high in fermentable carbs

What causes it?

SIBO develops when normal protective mechanisms of the gut are disrupted. Common contributors include:

Impaired gut motility – food and bacteria don’t move properly through the small intestine.
Structural changes – scar tissue, adhesions, or diverticula that trap bacteria.
Low stomach acid – reducing the body’s ability to control bacterial growth.
Immune dysfunction – weakened defenses against microbial imbalance.
Dietary factors – diets high in fermentable carbs may worsen symptoms.
Previous infections or surgeries – which may disrupt the gut environment.

Possible contributors include:

Impaired gut motility (slow movement of food and bacteria)
Low stomach acid – reducing natural protection against bacterial growth
Structural changes in the gut – adhesions, scarring, or diverticula
Ileocecal valve dysfunction – allowing bacteria to move backward from the colon
Immune dysfunction – reduced ability to keep bacteria in balance
Previous infections (like food poisoning or gastroenteritis)
Abdominal surgeries that affect gut structure or motility
Dietary patterns – frequent high-carbohydrate or high-FODMAP meals
Chronic stress – disrupting the gut-brain axis and digestion

A Neuroplasticity-Based Approach

SIBO symptoms are not only caused by bacteria but also by how the gut-brain axis interprets signals from the digestive system. Sometimes, even after treatment, the nervous system remains hypersensitive, continuing to send pain, bloating, or urgency signals. A neuroplasticity-based approach helps retrain the brain and gut to communicate more calmly, reducing the intensity of symptoms and supporting recovery alongside medical care.

At Menda, we use therapies that help retrain the brain and calm the nervous system. Approaches such as Pain Reprocessing Therapy, Cognitive Behavioral Therapy, and Acceptance and Commitment Therapy can help reduce the brain’s fatigue signals and restore balance. By teaching the nervous system new, safer patterns, people can gradually rebuild their energy, resilience, and quality of life.

You don’t have to keep living with these symptoms. Explore Menda’s evidence-based therapies designed to rewire the brain and restore balance.

Key Neuroplasticity-Informed Strategies

Gut-directed relaxation: Breathing techniques, meditation, or guided imagery to calm the gut-brain connection.
Cognitive reframing: Reducing fear and stress related to food or symptoms to lower nervous system reactivity.
Gentle movement: Activities like walking, yoga, or stretching to improve motility and reduce stress.
Gradual reintroduction of foods: Supporting the nervous system in tolerating a broader diet over time.
Routine building: Steady sleep, hydration, and mealtime rhythms to promote digestive stability.

Why Neuroplasticity Works

The brain and gut are deeply interconnected. When the brain repeatedly receives distress signals from the gut, it can become “wired” to interpret normal digestion as painful or threatening. Neuroplasticity-based strategies retrain these patterns, helping the nervous system respond more accurately. Over time, this reduces bloating, pain, and urgency while restoring confidence in daily activities and eating.