Application area · Obesity and metabolism

Metabolism and gut flora: what can be measured — and what we cannot promise about body weight

The market promises weight loss. The studies do not show this: microbiota transfer therapy (MTT) had no effect on body weight or on the body mass index. What there are data on is a few markers of metabolism — blood sugar, HbA1c, insulin level and HDL cholesterol — and even there the effect is small. This page says so before it asks anything of you.

Before we begin

What is happening in your body?

The gut flora has a say in metabolism. That does not mean that replacing it solves obesity.

If you have been struggling with your weight or your blood sugar for years, you have probably already heard that “the gut flora is to blame”. The picture is more nuanced than that — and that is precisely why it is worth reading this page through before you give anyone money for it.

There is no doubt that gut bacteria take part in metabolism. Some species extract more energy from the same food, they increase the permeability of the intestinal wall, and the bacterial cell-wall components that reach the bloodstream maintain a persistent, low-grade inflammation. Others — for example Akkermansia muciniphila — strengthen the gut barrier. And the short-chain fatty acids (acetate, propionate, butyrate) directly regulate fat metabolism.810

It is also true that gut flora from a lean donor temporarily improved insulin sensitivity in men with metabolic syndrome — this was the 2012 study from which the whole field started.194 The continuation, however, also showed the limit: the effect had disappeared by eighteen weeks, and it appeared only in those whose gut flora diversity was low to begin with.712

An important distinction. Whether the difference in the gut flora is a cause or a consequence of obesity is not decided by these studies. Diet shapes body weight and gut flora at the same time — so the two move together even without one causing the other.

The aim of MTT here is therefore not weight loss, but influencing a few measurable markers of metabolism, alongside the established treatment. What exactly was measured, what came out of it and how reliable it is, is discussed in the evidence section of this page and on the scientific background page — together with the numbers.

Seven questions

Is this for my case?

This is not a diagnosis and does not replace an internal medicine examination — but in one minute it shows whether it is worth getting in touch with us.

When this is not the next step

In the case of an active or previous eating disorder we do not start a course. A page that deals with body weight inevitably reaches readers whose relationship with their own body is damaged. If you are in such a situation, our service does not help, and it may even harm: please turn to a specialist experienced in eating disorder care. We are glad to help you find one.

In the same way, specialist care comes first in the case of unexplained, significant unintentional weight loss, recent or planned bariatric surgery, insulin-treated unstable diabetes without close supervision, severe immune deficiency or active oncological treatment, and in the case of pregnancy and breastfeeding.

Realistic expectations on timing

When to expect what

So that you know when things happen and where the decision points are.

Week 0

Pre-screening and baseline status

A free, 15-minute conversation, then registration. We record the baseline metabolic values measured by your treating physician: fasting blood sugar, HbA1c, insulin, blood lipids, waist circumference. Without these there will later be nothing to compare against.

Week 2

Exposome consultation and specialist assessment

We go through the diet, the physical activity, the sleep and the medication, and we clarify the goal. Decision: after the specialist examination it is decided whether starting is justified at all — and if it is not, we will say so.

Week 4

The course starts

UltraBiome capsule at the dose level and for the period determined by your treating physician. The established treatment — diet, exercise, medication — continues unchanged alongside it.

Weeks 12–16

Follow-up measurement and assessment

We repeat the same laboratory tests. Decision: has anything moved measurably. If not, we say so, and we do not recommend continuing. According to the studies the effect does not persist beyond twelve weeks anyway — this has to be known in advance.

How the process is built up

Your path step by step

The same order as on the timeline above. At every stage you will know what the next thing to do is.

Getting in touch and pre-screening

Fill in the form or ask for a call back. In a free, 15-minute conversation we clarify whether it makes sense to start in your case — including what you can realistically expect.

Registration and baseline measurement

We send a link by e-mail with which you can register as a patient. At that point you receive from us a unique identifier in the P0000000 format. We record the baseline laboratory values and the “Goals and expectations” questionnaire.

Exposome consultation

We go through the environmental and lifestyle exposures: diet, fibre intake, physical activity, sleep, medicines. Their effect on metabolism is orders of magnitude better documentedthan that of MTT — this is why we start here, not with the capsule. A DynaMAP microbiome baseline if you wish.

Specialist examination and decision

UltraBiome may be used only after a specialist examination, under medical supervision. This is where it is decided whether the treatment is justified, at what dose level and for how long. If it is not justified, this is where we stop.

UltraBiome course

The course runs at the determined dose level, under the direction of the treating physician. The established treatment is neither replaced nor modified. One packaging unit is 30 capsules.

Follow-up measurement, then tapering off

In weeks 12–16 we repeat the laboratory tests and compare them with the baseline values. If nothing has moved, we say so. The capsule is tapered off gradually, under medical direction.

Transparent pricing

What the procedure costs, and when you have to decide

You do not have to decide about the whole process at once. After every step you have the opportunity to assess the results achieved.

Before you look at the prices. The evidence above is not decoration on this page: for body weight the studies showed no effect, the measurable metabolic change is small, and it did not persist beyond twelve weeks. To anyone who would spend this sum on weight loss, we do not recommend this. If that is not acceptable to you, do not start.
StepWhat we providePriceMust you continue?
1. Call back and pre-screeningA 15-minute conversation, clarifying suitabilityfree of chargeno
2. Exposome consultationAssessment of environmental and lifestyle exposures, setting goals together (with a DynaMAP baseline if wanted)€185
the DynaMAP can be ordered separately: €325 (professional) or €575 (comprehensive)
no
3. UltraBiome 30(V) course
30 capsules / packaging unit
A high-density preparation, at the dose level and for the period determined at the specialist examination, under medical supervision€1,250 / unit
min. order 1 unit

What the price includes, and what it does not

ItemIncluded?
Call back and pre-screening (15-minute conversation)yes — free of charge
Exposome consultationseparate item: €185
DynaMAP microbiome profilecan be ordered separately: €325 (professional) or €575 (comprehensive)
Appearing in personis not necessary — the process is remote throughout
The capsules in the packaging unit orderedyes — at the price in the table above
Shipping costno — the delivery charge is separate
Follow-up during the courseyes
Joint closing assessment and tapering-off planyes
Examination by the treating physician, laboratory testsno — these take place at your own healthcare provider
The quantity needed is decided at the specialist examination. UltraBiome may be used only under medical supervision, after a specialist examination, and the dose level is also decided by the doctor. You will find the variants of the preparation and their prices on the UltraBiome data sheet.
The right treatment

Which capsule is for what?

Donor microbiota processed in a certified laboratory — in a metabolic indication it is the high-density preparation that comes into question.

High-density preparation

UltraBiome 30(V)

30 capsules
  • For the treatment of obesity, immune ageing and pathologically low physical performance
  • A high-density microbiota preparation from ultra-athlete donors
  • €1,250 / unit — minimum order 1 packaging unit (30 capsules)
  • Only under medical supervision, after a specialist examination
UltraBiome details →
Measurement, not treatment

DynaMAP microbiome profile

baseline and follow-up
  • Assessment of the composition of the gut flora before and after the course
  • It is not a diagnostic device and does not replace laboratory tests — it is for orientation and comparison
  • 325 € (professional) or 575 € (comprehensive)
  • Can be ordered with the exposome consultation
DynaMAP details →
Evidence

What we know today — in brief

The evidence situation for body weight and for the metabolic markers is not the same. This is the most important sentence to take away from this page. The most recent meta-analysis pools nine randomised trials, 303 patients in total — which is few, and on most of the endpoints it does not produce a significant result.821

Body weight and BMI: no effect. For body weight the difference was 2.72 kg compared with the control group, but with such wide uncertainty (95% CI −4.74 … +10.18) that it cannot be interpreted in any direction; for BMI the situation is the same.821 A 2025 analysis pooling eleven trials also found only a non-significant trend.809 We therefore do not promise weight loss, because there is nothing to base it on.

Metabolic markers: a small but measurable shift. Fasting blood sugar, HbA1c, insulin level and HDL cholesterol improved significantly — each of them to a small degree.821 The improvement in insulin sensitivity was also demonstrated by two earlier, well-documented studies.194, 712 One American study, by contrast, on these same endpoints found nothing, even though the transplanted flora did become established.804

Durability is the weakest point. In the follow-up beyond twelve weeks the meta-analysis found no difference on any endpoint between the two groups.821 In the 2017 mechanism study the improvement measured at six weeks had disappeared by eighteen weeks.712 One exception is known: in the four-year follow-up of a study in adolescents the body mass index did not differ, but the waist circumference, the body fat percentage and the inflammatory marker did.808

The accompanying treatment matters. Where fibre supplementation or a lifestyle intervention accompanied the MTT, there was a result; where it did not, often there was none.805, 806 This is the most important practical conclusion: the capsule does not make up for diet and exercise — at most it supplements them.

There is no guideline recommendation. No professional guideline dealing with metabolic disease recommends MTT today in obesity or type 2 diabetes. We say this even though it speaks against our own service.

Scientific background →

What patients ask most often

Safety you can rely on

Donor screening

Every donor goes through our DSQ donor screening framework.

Batch identification

Every capsule we ship carries a LOT number (a manufacturing batch identifier), so it can be traced back to the donor at any time.

In the case of an eating disorder we do not start

We ask about it during the pre-screening. In the case of an active or previous eating disorder we do not begin a course, but refer you to specialist care. This is not a formality: this is where a service dealing with body weight can do the most harm.

The medication continues

The treatment of diabetes and of metabolic disease we neither touch nor replace. Only the treating physician may decide about stopping a medicine or changing a dose.

Assessment tied to measurements

We tie the assessment to a baseline and a follow-up laboratory test. In weeks 12–16 the numbers decide, not the impression. If nothing has moved, we say so.

Known side effects

In the studies only mild events occurred: a slight rise in temperature, headache, nausea, transient diarrhoea, abdominal pain. No serious side effect has been described. In an immunodeficient patient the risk requires individual assessment.

No two cases are the same

The detailed protocol of MTT therapy

The process breaks down into four stages, and at the end of each there is an exit point. We do not build on automatic continuation.

Step 1 — Pre-screening and baseline measurement. A free, 15-minute conversation, then registration. We record the baseline values measured by your treating physician: fasting blood sugar, HbA1c, insulin, blood lipids, waist circumference, body weight. Without these there will be nothing to compare with at the end of the course — and it is precisely this measurability that makes this page defensible at all.

Step 2 — Exposome consultation and DynaMAP (optional). We go through the diet, the fibre intake, the physical activity, the sleep and the medication. In the studies microbiota transfer produced a result where fibre supplementation or a lifestyle intervention accompanied it — which is why this step is not a formality. The consultation costs €185, and the DynaMAP can be ordered separately.

Step 3 — Specialist examination and UltraBiome course. UltraBiome may be used only after a specialist examination, under medical supervision; the dose level and the length of the course are decided by the doctor. One packaging unit is 30 capsules, at a price of €1,250. The established treatment continues unchanged throughout.

Step 4 — Follow-up measurement, gradual tapering off. In weeks 12–16 we repeat the same laboratory tests. If the values have measurably improved, we decide about continuing together with your treating physician; if not, the capsule is tapered off gradually, under medical direction.

What is worth paying attention to during the treatment:
  • Do not stop your diabetes and metabolic medicines, and do not change their dosage either — MTT does not replace them.
  • If you are treated with insulin, your blood sugar requires close monitoring during the course as well.
  • Avoid taking antibiotics and probiotics unless your treating physician advises otherwise.
  • Diet, fibre intake and physical activity affect metabolism in their own right — keep these up during the course as well.
  • Do not weigh yourself daily. The endpoint is not the scales but the laboratory test in weeks 12–16.
Common questions

What patients usually ask us

Will it make me lose weight?
No, and we do not promise it either. According to a pooled analysis of nine randomised trials there is no significant effect on body weight or on the body mass index. If someone promises you kilograms from a microbiota transfer, they are not quoting the literature. If your goal is weight loss, this service is not for you.
Then what is the point of it?
What there are data on is a small improvement in a few metabolic markers: fasting blood sugar, HbA1c, insulin level, HDL cholesterol. This can be considered alongside, not instead of, the established treatment — as a supplement to it. And since the effect is small and short-lived, the responsible position is to state this in advance, so that you decide in full knowledge of it.
How long does the effect last?
According to the current data, not for long. Beyond twelve weeks the meta-analysis found no difference on any endpoint between the treated and the control group, and in an earlier study the improvement measured at six weeks had disappeared by eighteen weeks. This is the field's most honest weakness, and we do not keep quiet about it.
Can I stop my diabetes medicines?
No. We neither touch nor replace the treatment of the metabolic disease. Only the treating physician may decide about stopping a medicine or changing a dose. If you are treated with insulin, your blood sugar requires close monitoring during the course.
Is a treating physician needed?
Yes. Without a treating physician — a general practitioner, an internist or a diabetologist — we do not start the protocol, and UltraBiome may be used only after a specialist examination, under medical supervision. If you do not have such a doctor, we will help you find the right specialist.
I have or have had an eating disorder. Is that an obstacle?
Yes, and we take this seriously. In the case of an active or previous eating disorder we do not start a course, but refer you to a specialist experienced in eating disorder care. In this situation a service dealing with body weight is not neutral: it can do harm. Please tell us during the pre-screening conversation.
What do we measure, and when will it become clear whether it has worked?
We tie the assessment to a baseline and a follow-up laboratory test: fasting blood sugar, HbA1c, insulin, blood lipids, waist circumference. The substantive assessment takes place in weeks 12–16, with the same tests. If there is no measurable change, we say so, and we do not recommend continuing.
Is this safe?
In the studies only mild, transient events occurred: a slight rise in temperature, headache, nausea, diarrhoea, abdominal pain. The meta-analysis described no serious side effect. In an immunodeficient patient, during active oncological treatment or in pregnancy the treatment is not recommended.
Where does the donor material come from and how is it screened?
Every donor goes through our DSQ donor screening framework covering bacteriological, virological, parasitological and serological testing, stool testing and detailed medical-history screening. After the donation the donor is followed by at least eight weeks of quarantine before we release the preparation — and we release it only after the results of the repeat tests have been received. Every capsule can be traced by its LOT number.
Why UltraBiome, and why does it cost this much?
UltraBiome is a high-density preparation from ultra-athlete donors; in a metabolic indication it is this variant that comes into question. One packaging unit is 30 capsules, at a price of €1,250. The price covers the donor screening, the certified laboratory processing and the traceability. Whether the treatment is justified and at what dose level is decided by the specialist examination — not by the order.
Would diet and exercise not be cheaper and better?
In terms of the evidence, yes. The effect of diet, fibre intake, physical activity and sleep on metabolism is orders of magnitude better documented than that of microbiota transfer, and it is cheaper too. That is why we start with the exposome consultation. MTT comes up only if these are already running and the patient asks for it, in full knowledge, as a supplement.
What is the legal and regulatory background?
In obesity and metabolic disease, microbiota transfer therapy is not a guideline recommendation, and in Hungary it is not an authorised medicinal product: we provide the service within individual care directed by a treating physician. We deliver the capsules under the “to the doctor's hand” system; the decision to use them rests in every case with the treating physician. This service is not a substitute for professional medical advice, diagnosis or treatment.

More questions

Documents

Downloadable materials

For treating physicians

If you are an internist, a diabetologist or a general practitioner, or the patient asks you for an opinion: treatment follows the MTT Clinical Protocol Guide v7.1 which sets out patient selection, dose determination, the rules of escalation and gradual tapering, donor screening requirements and the follow-up steps. Referring a patient requires no separate agreement: a single message is enough.

Clinical Protocol Guide v7.1Professional consultation →

The evidence in detail

The scientific background page works through, point by point and separately for body weight and for the metabolic markers, what the trials measured, what came out, where the uncertainty lies and what the alternative is. Beside every statement you will find the reference and its summary.

Scientific background →

Get in touch

Let us talk about your metabolic situation

Write briefly about what metabolic abnormality has been diagnosed in you, and what has been tried so far. We will review whether it makes sense to start in your case — and if we see that it does not, we will say so.

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MicroBiome Bank does not sell products; it connects donors and recipients by providing professional medical services: it organises the recruitment of donors and their screening in a certified laboratory, the stool tests, and the processing of the screened donation into capsule form. The contents of the capsules remain the property of the donor until the recipient has paid in full. The brand names of the services serve to make them easier to remember. We deliver the capsules “to the doctor's hand”, and they are to be used under the guidance of a treating physician. For detailed information, please contact us.

The MicroBiome Bank service is not a substitute for professional medical advice, diagnosis or treatment. The decision to use it rests in every case with the treating physician.