The gut microbiome is one of the most discussed topics in nutrition in recent years. But what is it in practice, what affects it and what can we do through our everyday diet? In this guide you will find the basics, 6 simple dietary habits and when a microbiome analysis makes sense.
What the gut microbiome is
The gut microbiome (or gut microflora) is the name we give to all the microorganisms that live in our gut. They number tens of trillions, roughly as many as the cells of our own body, and weigh about 200 grams in total.
- It includes more than 1,500 species of microorganisms.
- About one third is common to most people.
- Two thirds are different for each person, like a personal «fingerprint».
Most gut bacteria are our allies: they help break down food and keep harmful microorganisms under control.
What the microbiome does for the body
Science has linked the gut microbiome to many functions, such as:
- regulating immune function,
- producing enzymes for the digestion and absorption of food,
- producing short-chain fatty acids (SCFA), which are the main source of energy for the cells of the colon,
- synthesising vitamins, such as vitamin K and B vitamins,
- metabolising dietary substances and medicines.
Research is evolving fast. Much of what we read online is still hypothesis, so it is wise to treat «miracle» promises with caution.
What affects the gut microbiome
| Factor | What we know |
|---|---|
| Nutrition | It is one of the most important factors. The composition of the microbiome is directly linked to what we eat. |
| Dietary fibre | They are «food» for many bacteria of the colon, which ferment them and produce SCFA. |
| Antibiotics | They can temporarily change the composition of the microbiome. They are always taken only on prescription. |
| Age | The microbiome changes throughout life. |
| Lifestyle | Sleep, stress and exercise are being studied as factors that probably affect it. |
6 dietary habits for a diverse microbiome
1. Variety in plant foods
In the large American Gut study, those who ate more than 30 different plant foods a week had a more diverse microbiome than those who ate fewer than 10. Vegetables, fruit, pulses, grains, nuts, seeds and herbs all count.
2. Enough fibre
The European Food Safety Authority (EFSA) considers 25 grams of fibre a day an adequate intake for adults. Many of us eat less.
3. Fermented foods
In a Stanford University study (2021), a diet rich in fermented foods such as yoghurt, kefir and sauerkraut increased microbiome diversity within 10 weeks.
4. Pulses and wholegrains
Lentils, chickpeas, beans, oats and wholegrain bread are easy ways to increase fibre, even in the weekly menu of a busy family.
5. Fewer ultra-processed foods
When the diet is based on ready-made, highly processed products, it usually lacks the fibre and variety the gut needs.
6. Gradual changes and enough water
If you currently eat little fibre, increase it gradually and drink enough water. A sudden change can bring bloating and discomfort.
Fibre from a supplement: when it has a place
The first choice is always food. But when the diet does not cover fibre needs, the dietitian may also suggest a supplement:
| Product | What it contains |
|---|---|
| Active Woman Xtra Fibre & Prebiotics | A fibre complex in capsules. Sugar beet fibre contributes to an increase in faecal bulk. |
| Active Woman My Fibre Plus | Fibre powder, 180 g. |
| Active Woman Slim Probiotics | 6 bacterial strains and inulin, 10.2 billion CFU per capsule. |
Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle.
Gut microbiome analysis: what it shows
With the The BioArte Gut Test gut microbiome analysis, the laboratory isolates the bacterial DNA from a small stool sample that you take yourself at home with the kit. The results are compared with a reference group of healthy people.
| Section | What is tested |
|---|---|
| Biodiversity | How diverse the microbiome is (Simpson index) |
| Main bacterial phyla | Distribution of the main phyla and Firmicutes / Bacteroidetes ratio |
| Species of interest | Probiotic, opportunistic and pathogenic bacterial species |
| Metabolic functions | Markers such as producers of vitamins and histamine |
| Recommendations | Personalised dietary advice and prebiotic / probiotic suggestions |
The analysis is carried out by the laboratory The BioArte Ltd (Malta, ISO 9001:2015 certified). The results are available about 3–4 weeks after the sample is received, and you can then book an appointment to have them interpreted.
When to see a doctor first
Microbiome analysis is not a medical diagnosis and does not detect infections. If you have symptoms such as blood in the stool, unexplained weight loss, fever or persistent abdominal pain, see a doctor first.
Frequently asked questions
How long does it take for the microbiome to change with diet?
The microbiome responds to dietary changes, but a stable result needs habits that are maintained over time, not a «diet of a few days».
Is it the same as the nutrition DNA test?
No. The nutrition DNA test examines your own DNA, which does not change. The microbiome analysis examines the DNA of your gut bacteria, which changes with diet and lifestyle.
How much does the gut microbiome analysis cost?
The BioArte Gut Test costs €390.
How is the sample taken?
At home, with the kit and the instructions that come with it. You also complete an online questionnaire about your medical and dietary history.
Does it detect infections?
No. The test detects bacterial DNA, not living microorganisms. If high levels of pathogens are flagged, further investigation by a doctor is needed.
Can I have the interpretation online?
Yes. You can book an online appointment by video call.
Sources
- McDonald D. et al. American Gut: an Open Platform for Citizen Science Microbiome Research. mSystems, 2018.
- Wastyk H.C. et al. Gut-microbiota-targeted diets modulate human immune status. Cell, 2021.
- EFSA. Scientific Opinion on Dietary Reference Values for carbohydrates and dietary fibre. EFSA Journal, 2010.
This article is for information purposes and is not a medical diagnosis, nor does it replace a doctor’s advice.