Understanding What Drives SIBO &
Why Your Nervous System Matters

SIBO is a common digestive condition, yet one of the most misunderstood. It is not a single problem and it is rarely solved by one protocol. It is a pattern where bacteria build up in the small intestine, impacting digestion, motility, gut sensitivity, hormones and the gut–brain connection.

Many people are told SIBO is simply bacterial overgrowth or something that requires repeated antimicrobials. In reality, SIBO always has underlying drivers, and those drivers differ from person to person.

What SIBO Really Is

SIBO is not a disease on its own. It develops when the small intestine loses its normal rhythm and protective function.

For most people, this involves several factors happening together, such as low stomach acid, slow or disrupted motility, post-infectious changes, medication effects, stress-related digestive shutdown, structural tension in the diaphragm or abdomen, imbalances in the large intestine, and hormonal influences, particularly in women.

This is why no two people with SIBO look the same, and why personalised support matters.

Common SIBO Symptoms

SIBO can present in many ways. Common patterns include:

  • excessive or daily bloating

  • pain or cramping after meals

  • constipation, diarrhoea or mixed-type IBS symptoms

  • nausea or reflux

  • food reactions that shift over time

  • feeling full too quickly

  • brain fog or fatigue linked to digestion

Often, the pattern of symptoms tells you more than the label itself.

The Gut–Brain Axis: The Missing Link

The small intestine is highly sensitive to the nervous system.

When the body shifts into fight, flight, freeze or shutdown, digestion and motility slow significantly. This creates conditions where bacteria can accumulate and symptoms can flare.

Many people notice SIBO worsens during:

  • prolonged stress or overwhelm

  • emotional triggers

  • conflict or pressure

  • rushing or eating on the go

  • long-standing tension patterns

For many people, nervous system support becomes just as important as nutrition.

What Traditional SIBO Advice Misses

Antimicrobials can reduce bacterial overgrowth, but they rarely address why the environment allowed SIBO to develop.

Commonly overlooked contributors include:

  • low stomach acid

  • inadequate digestive enzymes or bile flow

  • sluggish gut motility or impaired MMC function

  • diaphragm tension

  • underlying dysbiosis in the large intestine

  • inflammation

  • hormonal influences

  • chronic stress physiology

Your SIBO is rarely “just bacteria”. It is usually a reflection of how digestion, the microbiome and the nervous system are functioning together.

What Actually Helps Long Term

True recovery involves restoring healthy function, not just suppressing bacteria.

This usually means supporting several layers at once:

Digestive strength
Improving stomach acid, enzyme output, bile flow and overall digestive capacity.

Microbiome balance
Reducing overgrowths while rebuilding beneficial species.

Nervous system regulation
Reducing reactivity, restoring safety and releasing chronic tension patterns.

Motility support
Re-establishing healthy MMC function and intestinal movement.

Food confidence
Understanding triggers, rebuilding trust with food and expanding the diet safely.

When your personal SIBO pattern becomes clear, the path forward often feels far more logical and achievable.

TLDR

What drives SIBO
SIBO develops when digestion, motility, hormones, stress physiology and the microbiome fall out of rhythm. It always has underlying drivers, and those drivers are unique to you.

The role of the nervous system
The small intestine relies on calm, regulated nervous system signalling for proper motility. Fight, flight, freeze or shutdown states slow digestion and make SIBO far more likely to persist.

In short
SIBO is not only bacterial. It is a digestive and nervous system pattern. When motility, digestion, the microbiome and the nervous system are supported together, symptoms begin to settle and recovery becomes possible.

Meaningful improvement comes from addressing the full picture. This is the Mind–Body–Biome approach.