Gut Health Naturopath & Nutritionist · Australia WideRoot-Cause Support For Women's Gut Health.

Low stomach acid (the missed root cause)

Most women I see in clinic with bloating, reflux, and upper-abdominal discomfort have low stomach acid, not high.

This is one of the most under-recognised root causes of digestive dysfunction in women over 35, and it sits at the very top of the digestive cascade, which means when it's not working, the entire cascade slows down.

Your stomach is meant to be extremely acidic, with a pH of 1.5 to 3.5.

That level of acidity does several jobs at once.

It breaks down protein by activating an enzyme called pepsin.

It kills bacteria, yeast, and parasites that come in with your food before they can reach your intestines.

It signals your pancreas to release digestive enzymes.

It signals your gallbladder to release bile.

And it's required for the absorption of iron, B12, calcium, zinc, selenium, folate, and vitamin C.

When stomach acid is low (a condition called hypochlorhydria), none of those steps happen the way they should.

The thing most women don't realise is that low stomach acid often produces the same symptoms as high stomach acid.

Bloating, burping, fullness after meals, and reflux.

The reason reflux is often a low-acid problem rather than a high-acid one comes down to a valve at the top of the stomach called the lower oesophageal sphincter, which needs adequate acidity to close properly.

When acid is too low, the valve doesn't seal, and the small amount of acid that's there can splash upward into the oesophagus where it burns.

The conventional treatment is antacids or proton pump inhibitors, which reduce acid further and over time make the underlying problem worse.

There's also a vicious cycle with zinc that comes up often in women who have been on the oral contraceptive pill, women who have been chronically stressed, and women who have been on long-term antacid medication.

Zinc is required for your body to produce stomach acid.

But zinc itself needs an acidic stomach to be absorbed.

So when stomach acid drops, zinc absorption drops, which then drops stomach acid further.

The deficiency feeds itself, often for years, before anyone connects the dots.

Most women with low stomach acid also have nutrient deficiencies showing up on bloods (low iron, low B12, low zinc) regardless of how well they eat, because the food is going in but the absorption isn't happening.

This is one of the first things I look at when someone presents with a long list of digestive symptoms and a longer list of supplements that haven't worked.

Bacterial imbalance (dysbiosis and bacterial overgrowth)

Your large intestine is home to roughly 38 trillion microorganisms, mostly bacteria.

They produce short-chain fatty acids that fuel the cells lining your gut wall.

They regulate how much oestrogen you reabsorb versus excrete.

They produce 90% of your serotonin, significant amounts of GABA, and precursors to dopamine.

They calibrate your immune system.

When the balance is right, your gut, your hormones, your mood, and your immune function all work the way they should.

When the balance is off, all four start to suffer at the same time.

Dysbiosis is the clinical term for an out-of-balance gut microbiome.

This can mean the wrong species are dominant, beneficial species have been depleted, or pathogenic bacteria and yeast (particularly Candida) have overgrown.

The most common causes I see in clinic are antibiotics (a single course of broad-spectrum antibiotics can disrupt the microbiome for up to 12 months), chronic stress (cortisol directly alters bacterial composition), a diet high in processed food and sugar, long-term medications including the oral contraceptive pill, NSAIDs, and proton pump inhibitors, alcohol, and low stomach acid (which lets pathogens survive into the intestines).

Bacterial overgrowth in the small intestine is a related concern.

Your small intestine is meant to be relatively low in bacteria compared to the large intestine, because that's where the majority of nutrient absorption happens and bacteria interfere with it.

When bacteria migrate up from the large intestine and colonise the small intestine in numbers they shouldn't, the symptoms are distinctive.

Bloating that comes on within an hour of eating (often within minutes), distension that visibly swells through the day, food intolerances that have multiplied over the years, and a feeling of fullness or pressure regardless of how much you've eaten.

This is one of the more under-recognised contributors to chronic IBS-type symptoms in women.

The estrobolome is another reason gut bacterial balance affects hormonal symptoms directly.

Your gut contains a specific group of bacteria that produce an enzyme called beta-glucuronidase, which determines whether oestrogen your liver has packaged for elimination is excreted in your stool or reactivated and reabsorbed back into circulation.

When the microbiome is balanced, oestrogen clears properly.

When it's out of balance, beta-glucuronidase activity increases, oestrogen recirculates, and the result is oestrogen dominance symptoms (heavy periods, breast tenderness, PMS, fluid retention).

This is why I see gut and hormone symptoms presenting together so often.

In clinic, dysbiosis rarely comes up on its own.

It's usually paired with low stomach acid above it (which let the bacteria survive into the intestines in the first place), gut wall compromise below it (because dysbiosis damages the gut lining), and stress threading through it (because cortisol disrupts bacterial composition directly).

The gut lining (permeability and inflammation)

Your gut wall is one cell thick.

A single layer of epithelial cells is the only barrier between the contents of your digestive tract and your bloodstream, and those cells are held together by protein complexes called tight junctions, which act like molecular zippers controlling what passes between them.

When the wall is intact, nutrients are absorbed through controlled pathways and the rest stays where it belongs, in the gut.

The way I explain this in clinic is to picture millions of tiny doors lining your gut wall.

Every door has a lock.

Every nutrient you eat has a specific key for that lock.

When food has been broken down properly (by the stomach acid, enzymes, and bile we've been talking about), nutrients approach the lock, unlock the door, pass through into your bloodstream, and the door locks behind them.

Controlled, selective absorption.

Increased intestinal permeability, more commonly known as leaky gut, is what happens when those locks break.

The tight junctions stop sealing, the doors stay open, and the contents passing through aren't just nutrients anymore.

Undigested food particles, bacterial fragments (particularly one called lipopolysaccharide or LPS), yeast, toxins, and environmental chemicals start crossing into your bloodstream, where your immune system mounts a response because it has no choice.

The problem is that with the doors permanently open, the immune activation doesn't switch off.

This is chronic low-grade systemic inflammation, and it sits underneath a long list of women's health symptoms I see in clinic.

The causes connect directly to the previous two mechanisms.

Low butyrate production from inadequate fibre intake or depleted microbiome species, which means the cells lining your gut can't maintain the tight junctions.

Chronic stress, which activates mast cells in the gut wall that increase permeability directly.

Dysbiosis, which damages the wall through bacterial toxins and through Candida producing root-like structures that physically penetrate it.

Low stomach acid and enzyme insufficiency, which mean partially digested food fragments reach the lower gut and irritate the lining.

Plus NSAIDs, alcohol, gluten (which triggers a protein called zonulin that opens tight junctions, even in non-coeliac women), and nutritional deficiencies in zinc, vitamin A, and vitamin D.

When the gut lining is compromised, the symptoms are no longer contained to the gut.

Food intolerances multiply, skin flares without a clear external trigger, joints ache and stiffen without an injury, brain fog worsens after meals, mood and sleep deteriorate, allergies and sinus congestion get worse, infections recur, and autoimmune susceptibility increases because chronic exposure to foreign particles through the gut wall can trigger molecular mimicry, where the immune system confuses self-tissue with foreign protein fragments.

This is one of the reasons there is a strong clinical association between gut wall compromise and conditions like Hashimoto's thyroiditis, thyroid diseases, rheumatoid arthritis, and others.

The good news is the gut lining renews itself every three to five days, which means it responds to the right inputs faster than most other systems in the body.

The work is removing what's damaging it and supplying what it needs to repair, and most women see meaningful change within the first few weeks.

The gut-brain axis (why stress shuts down digestion)

The relationship between your gut and your brain is bidirectional, constant, and stronger than most women realise.

Your gut has its own nervous system called the enteric nervous system, made up of around 500 million neurons embedded in the wall of your digestive tract.

This nervous system communicates directly with your brain through the vagus nerve, and 80 to 90% of that communication runs from gut to brain, not the other way around.

Your gut is sending more information upward than your brain is sending down.

Your gut also produces approximately 90% of your body's serotonin (the neurotransmitter responsible for mood stability and sleep regulation), significant amounts of GABA (which calms your nervous system), and precursors to dopamine (which create motivation and reward).

When gut function is poor, neurotransmitter production drops, which is why low mood, anxiety, brain fog, and disrupted sleep often appear alongside gut symptoms.

This connection runs in the other direction too, and it is where stress shuts down every part of digestion at once.

When your nervous system is in a chronic stress state (sympathetic dominance, fight or flight), several things happen at once.

Stomach acid production drops, which disrupts the entire digestive cascade we covered in the first mechanism.

Pancreatic enzyme secretion drops, so food is not fully broken down.

Bile flow slows, so fats aren't digested and the antibacterial protection of bile in the small intestine is reduced.

Blood flow to the gut decreases because blood is being redirected to muscles for the perceived emergency.

Bowel motility either slows down (constipation) or speeds up (urgency and loose stools).

And mast cells in the gut wall are activated, which increases intestinal permeability directly.

The migrating motor complex (MMC) is another reason stress affects gut function.

The MMC is a series of cleansing waves that sweep through your small intestine between meals, clearing leftover food particles and bacteria from the upper gut.

The MMC only runs when you are in parasympathetic nervous system mode (rest and digest), which means if you're chronically stressed, eating constantly, or scrolling through your phone while you eat, the MMC isn't running properly.

This is one of the reasons bacterial overgrowth in the small intestine is so common in women under chronic stress.

In clinic, addressing gut symptoms without addressing the nervous system rarely produces lasting change.

The two systems are too intertwined.

This is why my plans always include practical nervous system support (vagus nerve work, breathwork, sleep regulation, eating in a calm state rather than at the desk or on the run) alongside the gut-specific protocol, because stomach acid, enzyme production, bile flow, gut motility, and gut wall integrity all depend on parasympathetic activation.

Bile and gallbladder function

Bile is one of the most under-discussed parts of digestive function in women's health, even though it's doing six different jobs at once.

Your liver produces bile, your gallbladder stores and concentrates it, and when fat enters the first part of your small intestine, a hormone called cholecystokinin (CCK) signals your gallbladder to contract and release bile into the digestive tract.

Bile breaks fat into smaller droplets so the enzyme lipase can access and digest it.

Without enough bile, dietary fat is not fully broken down or absorbed, which means you also can't absorb the fat-soluble vitamins A, D, E, and K.

Bile also serves as the primary route your body uses to eliminate cholesterol.

It carries used hormones (oestrogen, cortisol, and others your liver has packaged for removal) out of the body via the gut.

It has antibacterial properties that help control bacterial growth in the small intestine.

And bile acids stimulate bowel motility, which is why low bile flow is one of the more common contributors to chronic constipation that nobody investigates.

Sluggish bile flow shows up clinically as nausea after fatty meals, pale or floating stools (because the fat hasn't been broken down and is passing through undigested), constipation, fat-soluble vitamin deficiencies on bloods, hormonal symptoms (because used oestrogen isn't being eliminated), and recurring small-intestinal bacterial overgrowth (because the antibacterial role of bile is reduced).

Women who have had their gallbladder removed often present with these symptoms long after the surgery, because the gallbladder's storage and concentration role is now missing, even though the liver continues to produce bile.

The most common reasons bile flow is sluggish are chronic stress (which slows bile production and release directly), low-fat diets followed for years (because bile is released in response to fat, so without dietary fat the gallbladder doesn't contract regularly and bile becomes thick and stagnant), nutrient deficiencies in choline and taurine (the building blocks of bile), high oestrogen states (oestrogen thickens bile, which is one reason gallbladder issues are more common in women, particularly during pregnancy, on the oral contraceptive pill, or in oestrogen dominance), and poor gut motility (which causes bile to get reabsorbed and recycled rather than eliminated).

Bile flow improves quickly when the right inputs are introduced, which is one of the reasons women often feel a noticeable shift in digestion within the first few weeks of working with me.

• EggsRich in choline
• BeetrootBetaine supports bile flow
• Bitter foods firstRocket, dandelion, endive, radicchio
• Extra virgin olive oilTriggers CCK at every meal
• Dandelion root teaA traditional cholagogue

Eggs (rich in choline), beetroot (containing betaine, which supports bile flow), bitter foods at the start of meals (rocket, dandelion, endive, radicchio), extra virgin olive oil triggering CCK and gallbladder contraction at every meal, and dandelion root tea as a traditional cholagogue (a substance that stimulates bile release) all support bile production and flow.

Food sensitivities vs true intolerances

Most women who walk into my clinic say some version of "I think I'm intolerant to gluten and dairy."

Sometimes that's accurate.

Often what's happening is more layered than that, and getting the distinction right shapes the treatment plan, because food intolerances, food sensitivities, and food allergies are three different mechanisms requiring three different clinical approaches.

A true food allergy is an IgE immune response (immediate, reproducible, sometimes severe) and includes things like peanut anaphylaxis or shellfish reactions.

These are clearly diagnosed and managed with strict avoidance and emergency protocols, and they sit outside the scope of what I do as a naturopath and nutritionist.

A true food intolerance is an enzyme deficiency.

Lactose intolerance is the clearest example, where the body doesn't produce enough lactase to digest the milk sugar lactose, and consuming dairy produces predictable bloating, gas, and loose stools.

Histamine intolerance is another, where the gut and liver can't clear histamine adequately and high-histamine foods (wine, aged cheese, leftovers) produce symptoms.

These have a clear physiological mechanism and are worth identifying because the management is specific.

Food sensitivities are the third category and where most women are sitting.

These are non-IgE immune reactions, often involving IgG antibodies, where the immune system is reacting to food particles that have crossed the gut wall through compromised tight junctions (which is exactly the mechanism we covered in the third H3 on the gut lining).

Symptoms are delayed (often 24 to 72 hours after eating the food), variable, and the list of reactive foods tends to grow over time rather than stay stable.

This is the presentation I see most often in women with chronic gut symptoms.

The clinical issue is that food sensitivities are a downstream sign of gut wall compromise rather than a root cause in themselves.

If a woman cuts out the foods she's reacting to but doesn't address the gut wall, the list of foods she reacts to keeps growing, because the underlying mechanism (intestinal permeability and immune activation) hasn't been touched.

This is why women on increasingly restrictive diets feel no better, sometimes feeling worse because their nutrition is getting narrower while their symptoms keep multiplying.

The clinical approach is to work on the gut wall, the microbiome, the digestive cascade, and the nervous system together, while temporarily reducing the foods that are triggering symptoms to give the system space to repair.

As the gut wall heals, most women find that the foods they were reacting to become tolerable again, and the long list shrinks rather than grows.

The goal is restoring tolerance, so women can eat more freely as the gut heals rather than less.