You’ve decided to get a gut microbiome test to support your gut health. You’ve sent off your sample, received your results, only to find you don’t understand a word of what’s written. That’s perfectly normal. Depending on the type of microbiome test, interpreting the results can be confusing.

The results may contain charts, percentages, and unfamiliar bacterial names. Unless you know your Lactobacilli from your Clostridium, you’re likely to be left scratching your head.

Below, we cover what your gut microbiome test results mean, how to interpret them, and how they should guide your lifestyle or dietary improvements.

What a Gut Microbiome Test Actually Measures

A gut microbiome test usually refers to a stool microbiome analysis. The stool sample undergoes DNA sequencing to detect the presence and proportions of different gut bacteria.

The test typically measures:

• Bacterial diversity

• Beneficial vs harmful bacterial species

• Microbial balance

• Functional markers (sometimes)

But it’s not the only type of gut microbiome test. Your doctor might recommend SIBO testing, hydrogen sulphide testing, and more, which are all related to the gut microbiome. However, none of these tests provide a comprehensive assessment of the bacterial species or microbiome composition.

Understanding Microbial Diversity

Diversity is one of the most important metrics of your gut microbiome. It’s not just about what specific species live in your gut, but how many different ones there are. Studies show that higher diversity is linked to better metabolic health, stronger immune function, and resilience to disease.

Why? Well, each beneficial bacterial species provides a specific service. The more species you have, the more services you benefit from. Plus, with many different species, it prevents any one species from dominating.

In a stool microbiome analysis, it’s reported as an alpha diversity score or diversity index.

Unfortunately, poor diet, antibiotic use, stress, or illness can all harm your bacterial diversity. It can lower beneficial bacteria numbers, which may open the door for harmful species to take over.

Beneficial vs Potentially Harmful Bacteria

Diversity is only one metric. The next is the balance between different kinds of bacteria. Here, we start digging down into the specific species. Generally, we group bacteria into two categories:

1. Beneficial bacteria, such as Bifidobacterium and Lactobacillus, which support digestion, metabolic health, and other essential functions.

2. Opportunistic bacteria are fine in small numbers but become problematic when they overgrow.

There’s also a third category: pathogenic bacteria. They’re rarely present in healthy microbiomes but are responsible for certain diseases.

Relative Abundance: What the Percentages Mean?

Relative abundance is how common each group of bacteria is relative to others. It’s usually shown in charts or pie graphs. Think of it as the percentage of different bacterial groups in your sample.

For example, a report might show that certain groups make up 30% of your microbiome, while others account for smaller proportions.

Your report might compare your results with population averages or reference ranges. So, you’ll understand how your microbiome compares with others. It’s best not to take this part too seriously though, as everyone’s microbiome is unique.

Key Functional Markers in Some Reports

Advanced microbiome tests might go a step further, identifying bacteria and estimating how your gut microbes function metabolically. These tests might look at:

• Short-chain fatty acid production – Indicates how well your microbes produce beneficial compounds, such as butyrate which supports the gut lining.

• Fibre fermentation – Shows how effectively bacteria break down dietary fibre into useful metabolites.

• Inflammatory markers – Highlights microbial patterns sometimes linked to gut inflammation or imbalance.

• Bile acid metabolism – Reflects how gut bacteria help process bile acids involved in digestion.

Common Patterns Seen in Microbiome Results

Low Diversity

Low diversity means a few species or groups of bacteria dominate your gut. This is often linked to low fibre intake, repeated antibiotic use, or a diet high in ultra-processed foods.

High Opportunistic Bacteria

Opportunistic bacteria tend to proliferate due to poor diet, stress, or a gut imbalance. You may have noticed symptoms like bloating or constipation.

Low Beneficial Bacteria

Low levels of beneficial bacteria usually go hand in hand with high levels of opportunistic bacteria. It’s a common pattern seen in Western diets, where processed foods, not whole foods, dominate.

Using Your Results to Improve Your Gut Health

Bad results aren’t a moment to despair; it’s an opportunity to build a healthier gut. The Functional Gut Clinic provides personalised recommendations based on the gut microbiome results you receive from us to optimise your gut microbiome.

Often, our recommendations focus on:

• Fibre-rich foods

• Fermented foods

• Low-stress lifestyle changes

Learn more about how personalised microbiome testing can help you understand your gut health and take practical steps to improve it. And feel free to take a look at all we offer within our Microbiome Clinic.

You may find the following article interesting to read: How Your Gut Bacteria Can Influence Your Weight