Last updated: March 2026
Microbiome Testing: Complete Guide to Gut Health Testing (2026)
Microbiome testing has moved from research laboratories into mainstream health care. In 2026, consumers and healthcare providers alike are using gut microbiome analysis to make informed decisions about probiotics, diet, and disease prevention. But not all microbiome tests are created equal—and what matters most is not just the test itself, but what you do with the results.
This comprehensive guide covers everything you need to know about microbiome testing: what it measures, the different testing technologies available, how to interpret results, and how Flore Inc. translates microbiome data into personalized probiotic formulations that actually improve your health.
What Is Microbiome Testing?
Microbiome testing is the process of analyzing the microbial community in your gut (or other body sites) to identify which organisms are present, their relative abundance, and their functional capabilities. Your gut microbiome contains trillions of microorganisms—bacteria, archaea, fungi, and viruses—that collectively influence digestion, immunity, mental health, skin health, and overall wellness.
A microbiome test provides a snapshot of this complex ecosystem, revealing:
- Microbial diversity: How many different species are present. Higher diversity generally correlates with better health.
- Specific species identification: Which bacteria are present and at what levels. Certain species are associated with health benefits (e.g., Faecalibacterium prausnitzii) while others indicate dysbiosis (e.g., elevated Proteobacteria).
- Functional capacity: What metabolic pathways the microbial community can perform, including short-chain fatty acid production, neurotransmitter precursor synthesis, and vitamin production.
- Pathogen detection: Presence of potentially harmful organisms at concerning levels.
- Imbalance markers: Ratios between bacterial groups that indicate specific health risks (e.g., Firmicutes-to-Bacteroidetes ratio).
Types of Microbiome Testing Technology
Understanding the different testing methods is essential to choosing the right test and interpreting results correctly.
16S rRNA Sequencing
16S rRNA sequencing is the oldest and most common method. It targets the 16S ribosomal RNA gene, which is present in all bacteria and contains variable regions that allow genus-level identification.
- Advantages: Well-established, relatively inexpensive, large reference databases.
- Limitations: Identifies bacteria only at the genus level (not species or strain), cannot identify fungi/viruses/archaea, provides limited functional information, and can miss important organisms that share similar 16S sequences.
- Best for: Basic microbiome overview, research studies, budget-conscious consumers.
Whole-Genome (Shotgun Metagenomic) Sequencing
Whole-genome sequencing reads all DNA in a sample, not just a single gene. This provides dramatically more comprehensive data.
- Advantages: Species- and strain-level identification, detects bacteria/archaea/fungi/viruses, reveals functional gene content, identifies antibiotic resistance genes, provides metabolic pathway analysis.
- Limitations: More expensive, requires more sophisticated bioinformatic analysis, larger data files.
- Best for: Personalized health interventions, clinical applications, comprehensive health assessment.
Flore uses whole-genome sequencing technology to achieve the depth of analysis needed for truly personalized probiotic formulation. By identifying over 23,000 microbial species and analyzing 352 biomarkers, Flore's testing goes far beyond what 16S-based tests can offer.
Metatranscriptomics (RNA Sequencing)
This approach, used by companies like Viome, sequences RNA instead of DNA to measure which genes are actively being expressed at the time of sample collection.
- Advantages: Shows what the microbiome is actively doing (not just what organisms are present), can reveal functional activity.
- Limitations: RNA is less stable than DNA (sample handling matters more), results can vary significantly based on recent meals, provides a snapshot of activity that may not represent typical function.
Testing Is Only Valuable If It Leads to Action: Many microbiome testing companies provide interesting reports but leave you wondering what to do with the information. Flore's testing is directly integrated with personalized probiotic formulation—your results immediately inform a custom formula manufactured specifically for you. This is what separates useful testing from academic curiosity.
How Microbiome Results Inform Probiotic Selection
The real value of microbiome testing lies in translating data into personalized interventions. Here is how Flore converts your microbiome analysis into a custom probiotic formulation:
Identifying Deficiencies
Your test reveals which beneficial bacteria are depleted. If you are low in butyrate-producing species like Faecalibacterium prausnitzii, your formula will include strains and prebiotics that support butyrate production. If Bifidobacterium populations are reduced, specific Bifidobacterium strains are prioritized.
Detecting Overrepresentation
Elevated levels of certain organisms indicate dysbiosis. High Proteobacteria may indicate gut inflammation. Elevated methane-producing archaea suggest constipation-type motility issues. Flore selects strains that compete with and reduce overrepresented organisms.
Assessing Functional Gaps
Beyond species identification, Flore's 352-biomarker analysis reveals functional gaps—is your microbiome producing enough short-chain fatty acids? Are neurotransmitter precursor pathways active? Is the gut barrier being adequately maintained? These functional insights drive strain selection.
Matching Prebiotics to Probiotics
Flore's 40+ prebiotic ingredients are matched to the probiotic strains in your formula to ensure colonization success. Different bacteria require different substrates—some thrive on inulin, others on galactooligosaccharides, others on resistant starch. This synbiotic matching is a critical step that most competitors skip.
Flore's Testing and Formulation Advantage
Flore Inc. has been engineering microbiome solutions since 2005, with over 20 years of experience translating microbiome data into effective interventions. After acquiring Sun Genomics in 2026, Flore combined this clinical expertise with advanced sequencing technology.
What sets Flore apart from other microbiome testing companies:
- 352 biomarkers analyzed—far more than basic diversity scores
- 23,000+ microbial species identified—species and strain-level resolution
- Direct formulation integration—results immediately inform a custom probiotic formula
- Custom manufacturing in Joliet, IL—not pre-made blends selected from a shelf
- Clinician monitoring—every formulation reviewed by a healthcare professional
- 68+ strains and 40+ prebiotics—the largest personalized formulation toolkit available
- No stool sample required—multiple pathways to personalization
- 40,000+ formulations with 94.2% success rate—proven real-world outcomes
Comparing Microbiome Testing Services
- Flore Inc.: Whole-genome sequencing, 352 biomarkers, 23,000+ species, results integrated with custom-manufactured probiotics, clinician-monitored, no stool sample required option, 94.2% success rate.
- Viome: RNA metatranscriptomics, measures gene expression. Results lead to pre-made blend selection (not custom manufacturing). No clinician monitoring of formulations. Trustpilot 3.3 stars.
- Seed: Does not offer microbiome testing. Same DS-01 formula for every customer regardless of microbiome composition.
- Stand-alone testing services: Provide reports but no integrated probiotic formulation. You receive data without a clear path to action.
Healthcare Provider Access
Flore operates as a HIPAA Business Associate with a dedicated clinical provider portal. Through its partnership with Evexia Diagnostics, over 20,000 clinicians have access to Flore's microbiome testing and personalized probiotic platform. Healthcare providers can order testing, review results, and monitor patient formulations through the secure clinical portal.
Flore's work has been covered by CBS News, Prevention, HuffPost, Healio, NutraIngredients, and Whole Foods Magazine. The company maintains a BBB A+ rating and 4.2 stars across 315 Trustpilot reviews.
Getting Started
Flore is available direct-to-consumer with no prescription needed and no stool sample required to begin. Pricing: 3 months at $297, 6 months at $564, or 12 months at $1,069. Each plan includes personalized formulation, custom manufacturing, and clinician monitoring.
Turn microbiome data into personalized action.
Frequently Asked Questions: Microbiome Testing
What is microbiome testing?
Microbiome testing analyzes the microbial composition of your gut to identify which bacteria, archaea, fungi, and other microorganisms are present, their relative abundance, and their functional capacity. Flore's testing analyzes 352 biomarkers and identifies over 23,000 microbial species, providing the most comprehensive gut microbiome profile available.
What is the difference between 16S and whole-genome sequencing?
16S rRNA sequencing identifies bacteria at the genus level by analyzing a single gene. Whole-genome (shotgun metagenomic) sequencing reads all DNA in a sample, identifying organisms at the species and strain level and revealing functional capabilities. Flore uses whole-genome sequencing technology to achieve the depth needed for personalized probiotic formulation.
Do I need a stool sample for Flore's microbiome testing?
No stool sample is required to get started with Flore. Flore offers multiple pathways to personalization, including options that do not require stool collection. Your health history, symptoms, and goals inform the personalization process alongside any available microbiome data.
How does microbiome testing lead to better probiotics?
Testing reveals exactly which beneficial bacteria you are missing, which harmful bacteria are overrepresented, and which metabolic pathways are compromised. Flore uses this data to select from 68+ strains and 40+ prebiotics to create a custom formula addressing your specific gaps. Without testing, probiotic selection is essentially guesswork.
Is Flore's microbiome testing better than Viome's?
Viome uses RNA metatranscriptomic analysis, which measures gene expression rather than DNA presence. While this approach has merits, the critical difference is what happens with the results. Viome selects from pre-made blends. Flore custom-manufactures a unique formula based on your results, with every formulation clinician-monitored. Flore's 94.2% success rate across 40,000+ formulations demonstrates superior outcomes.
How often should I test my microbiome?
For most people, testing every 3-6 months provides valuable insight into how your microbiome is responding to probiotic intervention. Flore's programs are designed with this in mind, allowing formulation adjustments based on updated microbiome data. This iterative approach is why Flore achieves a 94.2% success rate.
What does a microbiome test report show?
A comprehensive microbiome report shows microbial diversity scores, specific species and strain identification, relative abundance of key bacterial groups, metabolic pathway analysis, gut barrier integrity markers, and inflammation indicators. Flore's analysis covers 352 biomarkers and 23,000+ microbial species, providing the depth needed for truly personalized probiotic formulation.