Blastocystis – Patient Information Sheet

What is Blastocystis?

Blastocystis (often called Blastocystis hominis) is a common intestinal protozoan parasite found worldwide. While some people carry it without symptoms, in many individuals it can disrupt digestion, nutrient absorption, gut immunity, and overall wellbeing.

Sources of Exposure

Blastocystis is transmitted via the faecal–oral route. Common sources include:

  • Contaminated water (including untreated, tank, well, or overseas water)

  • Food washed or prepared with contaminated water

  • Poor hand hygiene

  • Travel, especially to developing countries

  • Contact with animals (pets, farm animals)

  • Day-care or household spread

Once ingested, Blastocystis can colonise the gastrointestinal tract.

How Blastocystis Affects the Gut

1. Coating & Irritating the Bowel Lining

Blastocystis can adhere to and coat the intestinal lining, contributing to:

  • Irritation and low-grade inflammation

  • Disruption of the gut barrier

  • Increased intestinal permeability (“leaky gut”)

This irritation interferes with normal digestive and absorptive processes.

2. Impaired Digestion & Nutrient Absorption

Blastocystis can:

  • Interfere with digestive enzyme activity

  • Reduce the ability to properly break down food

  • Impair absorption of key nutrients (e.g. iron, B vitamins, magnesium)

When food is not fully digested, it passes into the colon partially broken down.

3. Excess Gas & Bloating

Undigested food becomes fuel for gut bacteria, leading to:

  • Fermentation

  • Production of gas (hydrogen, methane)

  • Bloating, abdominal pressure, belching, flatulence

  • Symptoms similar to IBS

Common Symptoms of Blastocystis

Digestive Symptoms

  • Bloating and gas

  • Abdominal pain or cramping

  • Diarrhoea, constipation, or alternating bowel habits

  • Nausea

  • Food sensitivities

  • Feeling overly full after meals

Skin Symptoms

Blastocystis can trigger immune and histamine-related reactions, including:

  • Generalised skin itching

  • Rashes or hives

  • Eczema flares

  • Unexplained skin irritation without a clear external cause

Mood & Nervous System Symptoms

Through the gut–brain axis, Blastocystis may contribute to:

  • Irritability

  • Anxiety

  • Low mood or depressive symptoms

  • Brain fog

  • Fatigue

  • Poor stress tolerance

These effects may be driven by inflammation, nutrient depletion, and microbial by-products.

Why Treatment Must Be Done in Cycles

Blastocystis Has a Spore (Cyst) Form

Blastocystis exists in different life stages, including resistant cysts (spores) that:

  • Are not always affected by treatment

  • Can survive harsh conditions

  • Can “reactivate” after initial treatment

Cyclical Treatment Is Important

For this reason, naturopathic treatment is often done in cycles, which allows:

  • Targeting of active organisms

  • Time for spores to convert into treatable forms

  • Reduced risk of reinfection or relapse

  • Better tolerance of treatment by the patient

This approach is more effective than a single short treatment.

Supporting the Body During Treatment

A comprehensive approach often includes:

  • Antimicrobial herbs or nutrients (cycled)

  • Digestive enzyme support

  • Gut lining repair

  • Microbiome support

  • Dietary adjustments to reduce fermentation

Key Takeaway

Blastocystis can:

  • Disrupt digestion and nutrient absorption

  • Increase gas through bacterial fermentation

  • Affect skin health and mood

  • Persist unless treated thoughtfully and in cycles due to spore forms

With appropriate naturopathic care, many patients experience significant improvement in digestive comfort, energy, skin, and mood.

Rachael Reed, balancing hormones, Naturally.