Understanding What Drives Low Stomach Acid &
Why the Nervous System Matters
Low stomach acid is far more common than most people realise, especially in those with long-standing digestive symptoms.
Stomach acid is essential for breaking down protein, absorbing minerals, controlling bacteria and triggering the rest of the digestive process. When levels are low, digestion becomes inefficient and symptoms can appear throughout the gut.
Low stomach acid is not a diagnosis on its own, but a functional issue that often sits underneath reflux, bloating, food sensitivities, nutrient deficiencies, SIBO and dysbiosis.
What Low Stomach Acid Really Is
Healthy stomach acid production depends on adequate nutrients, good blood flow to the stomach, balanced nervous system signalling and intact stomach lining cells.
Levels commonly become low due to:
chronic stress and nervous system activation
long-term use of acid-suppressing medication
ageing
zinc, iron or B vitamin deficiencies
H. pylori infection
low protein intake
inflammatory gut conditions
disrupted sleep
eating while rushed or anxious
When acid is low, food is only partially broken down. This can lead to fermentation, gas, reflux-like symptoms, poor mineral absorption and increased risk of bacterial overgrowth.
The Gut–Brain Axis
Stomach acid secretion is directly regulated by the nervous system.
When the body is in fight, flight, freeze or shutdown, acid production is reduced as digestion becomes a low priority. Over time, this can create a persistent low-acid state.
Many people notice their symptoms began or worsened during periods of:
prolonged stress
burnout
emotional strain
irregular eating patterns
poor sleep
For some, low stomach acid reflects a digestive system that has been operating under stress for too long.
Whay Common Advice Falls Short
Reflux medication and antacids can reduce discomfort, but they often further suppress acid production and do not address why levels were low to begin with.
Without restoring healthy acid production, problems such as bloating, food reactions, SIBO and nutrient deficiencies often persist or worsen.
What Actually Helps Long Term
Supporting stomach acid involves improving the conditions required for the stomach to function properly.
This often includes:
Replenishing key nutrients
Such as zinc and B vitamins.
Treating infections
Such as H. pylori where present.
Supporting digestive signalling
Using timing, mindful eating and specific supplements where appropriate.
Balancing the microbiome
To reduce fermentation and pressure.
Reducing chronic stress
And improving nervous system regulation.
Reviewing medication use
Where possible and appropriate.
When these layers are supported together, digestion often becomes stronger, calmer and more efficient.
TLDR
What drives low stomach acid
Low stomach acid develops when stress physiology, nutrient status, infection, medication use and digestive signalling are disrupted.
The role of the nervous system
Stress states directly reduce acid production, impairing digestion and increasing the risk of bloating, reflux and microbial imbalance.
In short
Low stomach acid is rarely just a stomach issue. It is a digestive–microbiome–nervous system pattern. When these systems are supported together, many downstream symptoms improve.
This is the Mind–Body–Biome approach.