Microbiome diversity in the report: what the value really tells you
The essentials at a glance
The diversity value describes two things at once: how many different bacterial groups the lab found in your sample and how evenly those groups are distributed within it. The number is a snapshot of your own gut microbiota. It is neither a grade nor a statement about your health.
This article takes the value apart: how it is calculated, why it can hardly be compared with other people’s values, what moves it up and down, and where its informative value ends.
If you have the report in front of you, start with Chapter 1. Chapter 2 explains the calculation behind it, Chapter 3 the comparison problem, and Chapter 5 brings together everything the number cannot tell you.
What to expect in this article
1. Where the number appears in the report and what is shown beside it
2. What the diversity value actually measures
3. Why your number is not someone else’s number
4. What moves the value up and down
5. What cannot be inferred from the value
6. Which test reports a diversity value
7. Is a second measurement worthwhile?
8. What you can do with the number
Frequently asked questions
Sources
Where the number appears in the report and what is shown beside it
A microbiome report consists of two very different parts. One is a long list of bacterial names with quantities, often spanning several pages. The other consists of a few summary metrics calculated from precisely that list. The diversity value belongs to the second part.
That explains why the number gets so much attention. It is usually near the top, often with a bar or color beside it, and it looks like a result. The species list below looks like an accessory. In fact, it is the other way around: the list is the measurement, and the diversity value is a summary of it.
A summary always loses information. Two people can have the same diversity value and carry completely different bacteria in their intestines. The value says something about the structure of the ecosystem, not about who lives in it.
Key message
The diversity value is not a measurement result, but a calculation based on the measurement result. It describes the structure of your gut microbiota, not its exact composition.
Four questions this article does not answer
A microbiome report raises several questions at once, and they require different answers. Four of them are deliberately left out here because they are answered in detail elsewhere.
The article Get your gut flora tested explains which test is right for your question and how to recognize a reputable provider. Your at-home gut test explains how collecting a sample at home works in practice. Building up your gut flora answers how long it takes for anything to change in the gut flora. And Understanding abdominal symptoms categorizes which abdominal symptom belongs where.
This section is concerned solely with the one number already shown on your report. In other words, not the selection or the setup, but the interpretation of an existing value.
What the diversity score actually measures
The score consists of two components that are usually combined into a single number in the report. The first is species richness: how many distinct bacterial groups were detected at all. The second is evenness: how the quantity found is distributed among these groups.
Imagine two gardens with twenty plant species each. In the first, roughly the same number of specimens of each species grow. In the second, a single grass species overgrows almost the entire area, while the remaining species stand as individual specimens at the edge. Both gardens have the same species richness. Only the first has high diversity.
That is precisely why the mere number of species is not sufficient as a metric. A report that only counts how many species were found overlooks the imbalance in the second garden. A diversity score that combines both components reflects it.
In the mybody®x gut encyclopedia (MYBODY Lab GmbH), bacterial diversity is listed under Metrics and Indices. The explanation there summarizes both components in one sentence: “Diversity shows how many different types of bacteria live in your gut and how evenly they are distributed.” (Gut Encyclopedia, accessed on August 27, 2026)
Diversity within a sample and diversity between two samples
In microbiological terminology, the value shown in your report has a more precise name. Alpha diversity describes diversity within a single sample—that is, exactly what species richness and evenness together represent. It is the measure that appears as your number.
Beta diversity is shown alongside it. It does not describe diversity within one sample, but the distance between two samples: how differently two gut microbiomes are composed. You need this second measure if you want to relate today's measurement to your measurement from a year ago.
The difference has a practical consequence. Two people can have almost the same level of alpha diversity and still have a large distance in beta diversity—their gut microbiomes are similarly broad in composition, but consist of different inhabitants. Anyone who reads only one number misses this difference.
How diversity differs from the neighboring metrics
In addition to diversity, the report includes other metrics calculated from the same species list that nevertheless describe something different. Anyone who confuses them draws reassurance from an unremarkable diversity value that it does not contain. The table places three of these metrics side by side according to the same criteria.
| Criterion | Bacterial diversity | Firmicutes-to-Bacteroidetes ratio | Butyrate production potential |
|---|---|---|---|
| What the metric describes | the number of species found and their distribution relative to one another | the basic distribution of two major bacterial phyla relative to each other | the calculated potential of the identified flora to produce butyric acid |
| What it arises from | from the complete species list, combining number and distribution | from the quantity ratio of two groups, regardless of the number of species | from the proportion of species to which this ability is attributed |
| What a high value suggests | a broadly structured ecosystem in this one sample | a shift in favor of one of the two phyla | a mathematically higher production potential, not a measured amount |
| Target value for individuals | No documented target value in the source material used | No documented target value in the source material used | No documented target value in the source material used |
| What it does not measure | says nothing about which species were found | says nothing about the diversity within the two phyla | does not replace a measurement of the amount actually produced |
The last line is the most important. Each of these metrics answers exactly one question and remains silent on all others. That is why anyone who wants to read the report as a whole reads them side by side, not one after another.
The fourth line is the most uncomfortable. For none of the three metrics does the source material used provide a target value that applies to an individual. This is not a gap in this article, but the current state of the evidence.
Why your number is not someone else’s number
The first instinct after receiving a result is to compare. Someone posts their value in a forum, someone else mentions theirs in conversation, and suddenly your own number is right beside it and seems too low or too high. This comparison delivers less than it promises.
On February 3, 2026, the German Federal Institute for Risk Assessment commented on bacterial additives in infant formula. The opinion addresses a different topic than your result, but it contains a statement about the baseline conditions that applies to every microbiome measurement.
Documented source
“Human studies indicate that there are large interindividual differences in the composition of the human fecal microbiota.”
German Federal Institute for Risk Assessment (BfR)
Opinion 005/2026 on “Probiotics” in infant formula, February 3, 2026
Interindividual means: from person to person. The differences between two healthy people are therefore large from the outset. A number that is below average for you may be significantly above average for another person with the same lifestyle, without either of them having a problem.
The BfR also states in the same opinion what these differences depend on. For early colonization, it cites, among other things, gestational age, mode of delivery, diet, antibiotic administration, and familial, geographical, and cultural influences (BfR, 2026). Some of these factors date back decades and can no longer be changed.
Key message
The most meaningful comparison value for your diversity score is your own value from an earlier measurement. Everything else compares two ecosystems that were not the same from the outset.
What comparison with a reference group provides
Many reports place your own value next to a reference group. This is useful as long as it is clear what is happening: Your number is compared with the numbers of other people who were tested using the same method in the same laboratory.
This leads to a practical rule. If you change the laboratory or the method, the reference value changes too. Placing two numbers from two facilities side by side and interpreting the difference is therefore not a comparison, but a calculation using two different scales.
The objection is understandable: Why have a reference group at all, then? Because it puts the scale into context. It tells you whether your score falls within the usual range for that group. It does not tell you whether it is good for you.
What Moves the Score Up and Down
The second common question after receiving a result is what can be changed about the number at all. Four factors come up repeatedly, and they differ greatly in how much they influence it and how quickly.
The first factor is diet. The Institute for Quality and Efficiency in Health Care describes the gut flora as billions of bacteria that live, among other things, on the indigestible components of food (IQWiG, 2026). Indigestible here means that what your small intestine does not absorb reaches the large intestine. Fibre is therefore not an accessory, but what some of these bacteria live on.
How much of this is intended can be quantified. The German Nutrition Society recommends at least 30 grams of dietary fibre per day for adults (DGE, 2021). This value applies equally to all adult age groups, from age 19 onward.
The score describes the day on which you took the sample.
The second factor is antibiotics. The BfR explicitly lists antibiotic treatment among the factors that influence bacterial colonization (BfR, 2026). Anyone who has undergone treatment shortly before sampling is therefore measuring an exceptional situation, not their normal state.
The third factor is the timing itself. The score describes the day on which you took the sample. A trip, an unusual week, an infection, or a holiday period with a different diet all affect the number without resulting in a lasting change.
Why Probiotics Move the Number Less Than Expected
The fourth factor is the one from which the most is expected. After a low diversity score, reaching for a bacterial preparation seems obvious because the logic appears so simple: little diversity, so add more bacteria.
In its statement from February 2026, the BfR describes a different observation. According to it, bacteria labelled as “probiotic” cause only temporary, non-significant changes in the overall structure and overall diversity of the stool microbiota (BfR, 2026). The assessment concerns infant formula, but it describes the effect on diversity itself.
This does not amount to a rejection of such products. It means that a diversity score is not the right measure of their success. Anyone who uses the number as a benchmark for a preparation is measuring in the wrong place.
What cannot be inferred from the value
A microbiome finding is not a diagnosis. It describes a sample, not a disease. This boundary may sound like fine print, but it is actually the most important reading guide for the entire document.
This is clearest with irritable bowel syndrome, because it is often mentioned in the same breath as the gut flora. IQWiG assesses the evidence cautiously: It is suspected, among other things, that hypersensitive intestinal nerves, disturbances of the intestinal muscles, changes in the gut flora, and inflammation of the intestinal wall could play a role (IQWiG, 2023). Suspected and could are the key words here.
The same source shows how common these symptoms are: Estimates suggest that around 10 to 20 out of 100 people have irritable bowel syndrome, women about twice as often as men, and it usually first occurs between the ages of 20 and 30 (IQWiG, 2023). A diversity score cannot infer any of this. It can neither confirm nor rule out that someone is affected.
Three conclusions the value cannot support
The first is the disease conclusion. A low value does not indicate a disease, and a high value does not indicate health. The value describes a structure, and structures are not findings about the person who carries them.
The second is the cause conclusion. Anyone who has symptoms and sees a low value at the same time almost automatically connects the two. But temporal proximity does not prove a connection. It could also have been the infection that explains both.
The third is the treatment conclusion. No dietary plan or treatment follows from a single metric. A finding gives you a starting point for your own decisions and for a conversation—nothing more.
And one boundary must be stated clearly: persistent or newly occurring symptoms should be evaluated in a medical practice, regardless of what the report says. IQWiG names significant weight loss, blood in the stool, fever, or pallor as signs that are more likely to indicate another intestinal disease (IQWiG, 2023). In such cases, a self-test is no substitute for an appointment; at most, it can help you prepare for one.
Chapter at a glance
A diversity score describes a sample, not a disease. It does not establish a diagnosis, a cause, or a treatment. IQWiG lists changes in the gut flora in irritable bowel syndrome as one suspected factor among several, not as a confirmed cause (IQWiG, 2023). Persistent or new symptoms should be evaluated in a medical practice regardless of the findings.
Which test reports a diversity value
For a report to contain a diversity metric at all, the method must be able to distinguish between species. An analysis that determines only a few selected indicator microbes cannot represent a distribution across many groups. Methods based on DNA sequencing can.
At mybody®x, the Microbiome Gut Test | Complete this section. The product page describes the analysis as DNA sequencing from a stool sample and explicitly lists biodiversity as one of the reported values (information from the product page, accessed August 27, 2026).
Gut test from a stool sample
Microbiome Gut Test | Complete
DNA sequencing of the gut microbiota, reporting biodiversity and other metrics such as the Firmicutes-to-Bacteroidetes ratio and butyrate production potential. What the test does not do: It does not provide a diagnosis, identify the cause of symptoms, or provide a target value you would need to achieve.
Laboratory evaluation 5–10 business days after sample receipt
Information from the product page, accessed August 27, 2026
One piece of information is deliberately omitted here, and the reason is part of the explanation: The number of species distinguished by the method is described on our own pages using different figures. Until this has been clarified, this article does not state a number for it. An unchecked figure would be the worse mistake.
What the individual bacteria and metrics in the report mean is explained entry by entry in the Gut Lexicon. This is where you look up a name that appears in the results and that you have never seen before.
Is a second measurement worthwhile?
Chapter 3 leads to a practical conclusion: If your own previous result is the best benchmark, then a single finding only becomes truly meaningful when compared with a second one. The only question is when that is worthwhile and when it is not.
Useful for you if …
you have noticeably changed your diet and want to know whether anything has changed in the same measurement.
the first report was produced shortly after antibiotic treatment or an infection and you need a reading without this exceptional circumstance.
you are planning a longer-term change and want a baseline against which you can measure later.
Probably not if …
you are hoping for a diagnosis or a cause for your symptoms. The score cannot provide either.
only a few weeks have passed since the first sample and nothing has changed in your daily life.
you have significant symptoms. These should first be addressed at a doctor’s office, not through a second self-measurement.
What matters here is that the two measurements are comparable. The same laboratory, the same method, and, if possible, similar circumstances when the samples were taken. Two measurements from two different providers give you two snapshots, but no direction of change.
If you see yourself in the right-hand column, this is not a rejection of the topic, only of the timing. Observing costs nothing, and a report does not expire.
What you can do with the number
At first, it seemed that the diversity score was the result and the species list below it was merely supplementary. The report becomes readable when you see the exact opposite: The list is the measurement, and the number is its summary. Reading it this way means expecting less from it—and getting more in return.
Two sentences are enough to remember. Differences between two people are substantial from the outset (BfR, 2026) – this removes the basis for comparing yourself with other people’s values. And the score describes the day the sample was taken, not your permanent state.
The conclusion is unremarkable. Write down the score, laboratory, and date somewhere you will be able to find them again in a year. Without these three details, a later second measurement is just another isolated number.
And something concrete for next week: Look at where fiber occurs in your day. Don’t count, just observe. The guideline of at least 30 grams per day (DGE, 2021) is difficult to achieve if two out of three meals contain none.
If you are unsure whether your report is even relevant to your question: The consultation is free, and it will not try to sell you anything.
Frequently asked questions
What does a low diversity score mean in a microbiome report?
It means that, in this particular sample, either only a few bacterial groups were found or the amount found was distributed very unevenly among them. No disease can be inferred from this. The BfR (2026) points out that differences between individuals are substantial from the outset.
Can I compare my value with someone else's?
Only to a limited extent. Two people have different starting points, and two laboratories calculate results against different reference groups. The value becomes meaningful when you compare it with your own previous value from the same method.
Does the diversity score show whether my gut is healthy?
No. The value describes the structure of a sample, not a person's state of health. There is no established target value for individuals for any of the three common metrics in the report. Anyone who wants to rule out or confirm a disease needs a medical evaluation.
How quickly does the value change?
Short-term influences such as travel, an infection, or antibiotic treatment show up immediately in a sample. Only a later measurement under the same conditions can show whether a change persists. Regarding the bacterial supplement, the BfR (2026) describes only temporary, non-significant changes in overall diversity.
When should a microbiome result be discussed with a doctor?
As soon as symptoms appear that do not subside. The IQWiG (2023) identifies significant weight loss, blood in the stool, fever, or paleness as signs that are more likely to indicate another intestinal disease. In these cases, seeing a doctor is the first step, and the result can at most serve as supporting material for the consultation.
Next step
If you want to track a diversity score that you can measure again later
The Gut Microbiome Test | Complete uses DNA sequencing from a stool sample and reports biodiversity as a separate value. The meaning of the individual metrics and bacterial names in the report is explained in the Gut Glossary.
To the Complete Gut Microbiome Test To the Gut GlossaryRead more
You might also be interested in
How to tell which testing method is right for your question.
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Every name and metric from your report, explained individually.
Sources
- Federal Institute for Risk Assessment (BfR): The health benefits of infant formula supplemented with “probiotics” have still not been scientifically proven, Statement 005/2026 (February 3, 2026) – bfr.bund.de
- Institute for Quality and Efficiency in Health Care (IQWiG): How does the intestine work? (as of 24.06.2026) – gesundheitsinformation.de
- Institute for Quality and Efficiency in Health Care (IQWiG): Irritable bowel syndrome (as of 22.02.2023) – gesundheitsinformation.de
- German Nutrition Society (DGE): Reference values for fiber (derived in 2021) – dge.de
The verbatim quote on interindividual differences, the list of factors influencing early bacterial colonization, and the assessment of bacterial supplements come from [1]; the statement addresses infant formula, and this context is disclosed in the text. The description of the gut flora and its nutrition comes from [2] and is reproduced with attribution because the original sentence begins with a reference word. The information on the frequency of irritable bowel syndrome, its distribution by sex, age at first onset, suspected factors, and warning signs comes from [3]. The guideline value of at least 30 grams of fiber per day comes from [4]. All four sources were accessed and checked live on 27.08.2026. Information on price, procedure, metrics, sample type, and laboratory comes from the mybody®x product page and Gut Lexicon, accessed on 27.08.2026; processing times follow the central specification for each test type. No species count is deliberately stated because the company's own pages give different orders of magnitude.
mybody®x Editorial & Expert Team
Microbiome and gut science Nutritional science Laboratory diagnostics
This article was created by the mybody®x editorial and expert team. The team combines microbiome and gut science, nutritional science, and laboratory diagnostics. Anyone who contributes to it is listed on the authors page.
Published on 27.08.2026 · Last updated on 27.08.2026
The content is for general information only and does not replace medical advice, diagnosis, or treatment. Reference ranges depend on the laboratory, method, and age; the information in your report is always authoritative.
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