The complete analysis of the gut microbiome
A microbiome test is a laboratory examination that maps all the bacteria and other micro-organisms populating your gut. From a simple stool sample, it identifies bacterial diversity, reveals imbalances (dysbiosis) and highlights certain functional markers.
At Kensington International Clinic, the examination is carried out with a specialised laboratory, then interpreted by our consultant gastroenterologists. The aim: to turn complex scientific data into actionable clinical insights.
What is a microbiome test and what does it measure?
A microbiome test relies on genetic analysis of the micro-organisms present in your digestive tract. Technically, it most often involves sequencing of the 16S rRNA gene, a universal bacterial marker that identifies and quantifies the species present in a sample.
This type of microbiome analysis measures several dimensions:
- The overall bacterial diversity, calculated through indices of richness and balance.
- The taxonomic composition: major families (Firmicutes, Bacteroidetes, Actinobacteria, Proteobacteria) and specific genera.
- The relative abundance of protective species (Akkermansia muciniphila, Faecalibacterium prausnitzii) and potentially pathogenic species.
- Functional markers: production of short-chain fatty acids, fermentation capacity, intestinal inflammatory markers.
Together, these parameters form a detailed picture of your intestinal ecosystem, far more precise than the classic culture-based tests.
How does microbiome testing work in the laboratory?
The process follows four technical steps, spread over around three weeks between collection and reporting.
- At-home collection: sterile kit with instructions. The sample is stored in a medium that stabilises the bacterial DNA.
- Extraction and preparation: in the laboratory, DNA is extracted, purified and quantified.
- High-throughput sequencing: DNA is amplified and sequenced. 16S rRNA sequencing is the most widely used method, although more in-depth metagenomic approaches also exist.
- Bioinformatic analysis: the sequences are compared to reference databases to identify species and calculate diversity indices.
The final report is then sent to the gastroenterologist for clinical interpretation.
What a microbiome test reveals: the key indicators
A properly conducted microbiome test delivers a structured report built around several indicators, interpreted as a whole by your doctor.
- Diversity indices (Shannon, observed richness) measuring the variety and balance of your flora. Low diversity is a recognised marker of dysbiosis.
- Firmicutes/Bacteroidetes ratio: the proportion between the two dominant families, associated with certain metabolic profiles.
- Abundance of key species: bacteria recognised as beneficial or potentially harmful.
- Functional markers: ability to produce short-chain fatty acids (butyrate, propionate, acetate), essential to mucosal health.
- Inflammatory markers: signals indicating inflammation of the digestive wall or an altered intestinal barrier.
The examination does not provide a direct clinical diagnosis: it offers a biological snapshot to be put into perspective with your symptoms and medical history.
Reliability and limits of a microbiome test
Reliability depends on several factors controlled in the laboratory: sample quality, storage conditions, DNA extraction protocol, sequencing depth, and robustness of the reference databases. In the UK, a rigorous microbiome test relies on standardised protocols and accredited laboratories.
A few limits to keep in mind:
- The gut microbiome naturally varies from one day to the next, influenced by diet, stress or ongoing treatments.
- Scientific literature evolves rapidly on the interpretation of ratios and species.
- The examination does not establish a diagnosis on its own: it is a complementary tool, to be combined with the clinical assessment.
This is precisely why interpretation by an experienced gastroenterologist is essential.
Preparing for sample collection for a microbiome test
As with any medical examination, the quality of results depends on following the preparation instructions:
- Antibiotics: wait 4 to 6 weeks after completing a course of treatment.
- Probiotics and prebiotics: stop 1 to 2 weeks before, unless otherwise advised medically.
- Diet: keep to your usual habits to obtain a representative baseline.
- No enema-type preparation is required: the sample is collected spontaneously.
- Storage: follow the kit instructions carefully for sending to the laboratory.
Detailed instructions are provided with the kit.
Our consultant gastroenterologists for microbiome test interpretation
At Kensington Clinic, the analysis is carried out by a team of consultant gastroenterologists with complementary expertise:
Our microbiome testing packages at Kensington Clinic
Two packages are available at Kensington Clinic, depending on the level of depth required.
Package | Fee | Includes |
Microbiome Analysis | £720 | Medical questionnaire + 45-minute initial consultation + Kit with stool analysis and urine analysis + Medical interpretation + 45-minute follow-up consultation + Personalised micronutrition plan |
Microbiome Analysis + Complete Blood tests | £960 | Full package 1 + Complete blood work-up for a cross-reading of metabolic and inflammatory markers |
A £70 prepayment is required at the time of booking; the balance is settled on the day of the appointment.
Cancellation: full refund more than 72 hours in advance; £70 prepayment retained between 72 and 48 hours; full charge less than 48 hours before.
FAQ
How to test your gut microbiome?
To test your gut microbiome, the reference method today is bacterial DNA sequencing, carried out from a stool sample.
The process comes down to four simple steps for the patient:
- Kit order and initial consultation at the clinic;
- At-home collection following the kit instructions;
- Dispatch to the partner laboratory for DNA analysis;
- Receipt of the report and interpretation consultation with a gastroenterologist.
Tests sold directly online do not include this medical interpretation step, which is nevertheless what determines the clinical value of the result.
What does a microbiome test show exactly?
Technically, the examination reveals the composition and diversity of your microbiome through DNA analysis:
- List of bacterial species present and their relative abundance;
- Diversity indices (Shannon, observed richness);
- Ratios between major bacterial families;
- Possible presence of pathogenic or over-represented species;
- Functional markers linked to fermentation and intestinal inflammation.
These data form a biological basis for guiding a nutritional or therapeutic strategy.
Are microbiome tests accurate?
Accuracy depends on three elements: the quality of the analysis laboratory, the standardisation of the sequencing protocol, and the qualification of the doctor who interprets the report.
A test carried out in an accredited laboratory, by 16S rRNA sequencing or a metagenomic approach, and interpreted by a consultant gastroenterologist, offers a high level of technical reliability.
The limits to bear in mind: natural variability of the microbiome over time, constant evolution of reference databases, absence of diagnostic value on its own.
The examination is a decision-support tool, not a verdict.
How much does a microbiome test cost?
At private clinics in the UK, fees vary according to the scope of analysis and the medical support included.
At Kensington Clinic, two packages are available:
- £720 for the analysis with full medical interpretation;
- £960 for the version complemented by a blood work-up.
These fees include the initial and follow-up consultations, which sets them apart from direct-to-consumer kits sold without clinical support.
Most private health insurance policies cover all or part of the examination; check your cover with your insurer before booking.
Kensington International Clinic: private medical care delivered by a French and international team of reference.
