Gut Microbiome and Overall Health

Written By Petra Sander

The gut microbiome refers to the trillions of microorganisms living primarily in the large intestine. These microbes influence digestion, immunity, metabolism, brain health and even hormone balance.

When balanced (eubiosis), the microbiome supports vitality.
When disrupted (dysbiosis), it contributes to inflammation and chronic disease.

The gut microbiome refers to the trillions of microorganisms — bacteria, viruses, fungi and archaea — that live primarily in the large intestine.

An adult carries more microbial cells than human cells, and these organisms form a dynamic ecosystem that influences nearly every system of the body.

Key dominant beneficial species include:

  • Lactobacillus

  • Bifidobacterium

  • Akkermansia muciniphila

  • Faecalibacterium prausnitzii

When balanced (a state called eubiosis), the microbiome supports vitality and resilience.
When disrupted (dysbiosis), it contributes to inflammation and chronic disease.

Core Functions of the Gut Microbiome

1️⃣ Digestion & Nutrient Absorption

  • Ferments dietary fibre into short-chain fatty acids (SCFAs) such as butyrate

  • Enhances absorption of magnesium, calcium and iron

  • Produces vitamins B1, B2, B6, B12, folate and vitamin K

Butyrate is especially important — it fuels colon cells and reduces intestinal inflammation.

2️⃣ Immune System Regulation

Around 70–80% of immune cells reside in gut-associated lymphoid tissue (GALT).

A healthy microbiome:

  • Trains immune tolerance

  • Strengthens tight junctions (reducing intestinal permeability)

  • Reduces autoimmune activation

Dysbiosis has been linked to:

  • Allergies

  • Eczema

  • Autoimmune disease

  • Inflammatory bowel conditions

3️⃣ Brain & Mood (Gut–Brain Axis)

The gut produces:

  • ~90% of serotonin

  • GABA

  • Dopamine precursors

Communication occurs via:

  • Vagus nerve

  • Immune signalling

  • Microbial metabolites

Imbalances are associated with:

  • Anxiety

  • Depression

  • Brain fog

  • Neurodegenerative disorders

Emerging research links microbiome disruption to Parkinson’s disease, Alzheimer’s disease, and cognitive decline.

4️⃣ Metabolism & Weight Regulation

Gut bacteria influence:

  • Blood sugar regulation

  • Insulin sensitivity

  • Fat storage

  • Appetite hormones (GLP-1, leptin, ghrelin)

Reduced microbial diversity is strongly associated with:

  • Obesity

  • Type 2 diabetes

  • Metabolic syndrome

5️⃣ Oestrogen Balance (Estrobolome)

Certain bacteria regulate oestrogen recycling via beta-glucuronidase activity.

Imbalance may contribute to:

  • PMS

  • Endometriosis

  • Fibroids

  • Hormone-sensitive cancers

A healthy microbiome supports safe hormone detoxification.

What Disrupts the Gut Microbiome?

Common causes seen in clinical practice in NSW include:

  • Antibiotics

  • Highly processed foods

  • Low fibre intake

  • Chronic stress

  • Environmental toxins

  • Excess alcohol

  • Artificial sweeteners

How to Restore Gut Health Naturally

1. Increase Fibre Diversity

Aim for 30+ different plant foods per week
Include:

  • Leafy greens

  • Legumes

  • Garlic & onions

  • Berries

  • Nuts & seeds

2. Include Fermented Foods

  • Sauerkraut

  • Kefir

  • Natural yoghurt

  • Miso

3. Support With Targeted Probiotics

Strain-specific therapy may support:

  • IBS

  • Antibiotic recovery

  • Mood

  • Immune resilience

Clinical testing (stool microbiome analysis) allows personalised protocols.

4. Reduce Stress

Stress alters microbial diversity within days.
Support includes:

  • Breathing exercises

  • Nature exposure (especially here in the Blue Mountains 🌄)

  • Adequate sleep

5. Limit Toxins

Reduce exposure to:

  • Pesticides

  • Heavy metals

  • Ultra-processed foods

Home visits can be helpful in assessing environmental contributors to chronic inflammation.

Evidence Snapshot

  • SCFAs reduce colon cancer risk (PMID: 30654966)

  • Microbiome diversity linked to metabolic health (Nature, 2013)

  • Gut–brain axis influences depression (PMID: 31406558)

  • Dysbiosis associated with Parkinson’s disease (PMID: 28548957)

The Naturopathic Perspective

At Blue Mountains Wellness Clinic, we view the microbiome as a foundational pillar of health.

Initial consultations include:

  • Comprehensive medical and family history

  • Diet and medication review

  • Nutritional depletion assessment

  • Functional pathology options

Restoring gut balance often improves:

  • Energy

  • Mood

  • Skin

  • Hormonal balance

  • Immune resilience

Final Thoughts

The gut microbiome is not just about digestion — it is a central regulator of immune function, brain health, metabolism, and longevity.

When we nourish our microbes, we nourish ourselves.

Petra Sander
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