II.6

Donor screening and the safety of the product

It is reassuring to know what stands behind your capsule: strict donor screening to international standards, blood testing done twice, an extensive pathogen panel and controlled manufacturing. Here you will get to know the full chain of safety.

Összefoglaló

It is natural that the question arises in you: is it safe to take another person's gut flora? The answer is that this is exactly why a long, strict chain of safety stands behind your capsule. We screen donors thoroughly, to international standards: blood testing done twice, an extensive pathogen panel and a careful health evaluation. We manufacture the finished product under controlled, documented conditions, and we give every batch a traceable identifier. In this chapter you will learn everything your capsule has been through by the time it reaches you.

The donor's journey — the strict screening

The contents of a DiffBiome capsule come from a healthy human donor^[G] — but for someone to become a donor, they must pass through a great many filters. The aim is twofold: on the one hand to ensure that the donor's flora is healthy, diverse and valuable, and on the other to exclude any risk that could deliver infections or other pathogens to the recipient^[G].

Donor screening^[G] is not a one-off test but a carefully constructed process that follows international professional standards. It begins with a detailed health and lifestyle questionnaire, which excludes a great deal: if someone has inflammatory bowel disease, for example, that is an outright exclusion criterion. We also pay attention to the donor's diet — they eat animal protein kept antibiotic-free, so that their flora is as clean as possible.

One cornerstone of the screening is that we carry out the blood test not once but twice, eight weeks apart. This matters because some infections have a "window period" during which they cannot yet be detected — the twofold, time-separated testing closes this gap. Only a donor who passes both rounds can proceed.

The safety of the product — from manufacturing to the capsule

From here, the screened donor's flora enters a controlled manufacturing process. We clear the raw material of pathogens, convert it into a living bacterial suspension, then dry it gently and fill it into capsules. The process is not industrial mass production but proceeds according to strict quality standards — so-called GMP, good manufacturing practice: we check every batch, among other things to ensure that it contains enough viable bacteria and nothing that it should not.

Every dose receives a traceable identifier, a so-called LOT number. This is like a birth certificate: it tells exactly which donor, when and from which batch your capsule was made. This is why it is important always to write the LOT number in your diary — if any question should arise, any dose can be traced this way. The LOT system also makes it possible to switch to another batch if needed.

The capsule contains not only living bacteria but also a few excipients that feed and stabilise the flora. These are all known, safe substances. The unopened bottle is best kept in a dark, cool place, standing upright — storage too has its own rules, so that the bacteria stay viable. This whole chain — from screening through manufacturing to storage — together provides the safety on which your course is built.

🩺 Klinikai blokk

Donor screening is carried out along EMA/WGO/EAGEN recommendations, as a multi-stage protocol. Serological testing twice, 8 weeks apart — HIV-1/2, Hepatitis A/B/C/E, Treponema pallidum (syphilis) and inflammatory markers — to cover the infectious window period. The donation is examined with a multiplex PCR pathogen panel: bacteria (Salmonella, Shigella, Yersinia, Campylobacter, pathogenic E. coli strains, Clostridioides spp., Vibrio, Plesiomonas), parasites (Cryptosporidium, Cyclospora, Entamoeba, Giardia), viruses (Adeno-, Astro-, Noro-, Rota-, Sapovirus, SARS-CoV-2), H. pylori, as well as multidrug-resistant pathogens (MRSA, MRSE, VRE, ESBL, CRE). The donor's diet contains antibiotic-free animal protein. Donor evaluation is done with a structured questionnaire and scoring (Donor Screening Questionnaire): structural/inflammatory GI diseases — IBD, coeliac disease, microscopic colitis — are absolute exclusion criteria, functional disorders (e.g. IBS) are handled with weighting, case by case; prior antibiotic exposure is a marker of flora quality (according to the curated evidence, donor antibiotic exposure worsens the FMT outcome — Grosen 2025 [2722] Lancet Microbe; Palleja 2018 [2721]; Dethlefsen & Relman 2011 [218]). Processing of the donation: pathogen clearance → bacterial suspension → lyophilisation → encapsulation.

🩺 Klinikai blokk

Manufacturing closes with GMP-level quality control: among the conditions for release are confirmation of an adequate colony count (the quantity of viable bacteria) and of the active-ingredient content, with LOT identification and full traceability. The excipients of the formulation: potato starch (Amylum solani), inulin (from chicory), vitamin B6 (pyridoxal 5-phosphate), vitamin B12 (cyanocobalamin) and vitamin B9 (folic acid) — they feed and stabilise the graft. Packaging in dark glass, with a tamper-evident (and, on request, child-resistant) closure; the label contains the patient's name, the capsule count, the LOT number, the expiry date and the storage condition. Safety profile: the most common side effects are mild and transient (GI discomfort, bloating, flatulence, transient diarrhoea/constipation); a rare, serious event (infection, allergic reaction) requires immediate medical evaluation; according to the randomised data, the serious adverse event rate is <0.5% (van Nood 2013 [7]). Heightened caution is needed in immunodeficient/immunosuppressed patients, and during pregnancy/breastfeeding limited data are available; within the framework of pharmacovigilance we report AEs to the EMA/FDA/local authority. According to the legal framework, the MicroBiome Bank provides a service, it does not sell a product — the graft is the donor's property until the recipient pays.

Day 19 – The foundation of trust

Today, make yourself aware that a strict chain of safety preceded your capsule. This can help you let go of worry, and continue the course with peace of mind.

Take the daily DiffBiome dose according to the usual routine
Check that the LOT number appears in your diary
Hydration: an extra glass after every looser stool
Diary: stool count, Bristol, bloating, bloody stool, fluids, LOT number, wellbeing

Day 20 – Correct storage

Today, pay attention to storage: your capsules stay viable if you keep them in the right place. This is your part of the chain of safety.

Take the daily DiffBiome dose
Check that the unopened bottle is in a cool, dark place, standing upright (follow the storage instruction on the label)
Open the bottle only to take the dose, then close it again
Diary: stool count, Bristol, bloating, fluids, wellbeing

Day 21 – After three weeks

Today, look back at the trend, and make yourself aware of how far you have come. The first phase is slowly turning into the longer engraftment stage.

Take the daily DiffBiome dose
Diary: review the stool-count and Bristol trend for days 19–21
If the complaints are not easing, let your treating physician know
In the event of any red flag (e.g. a sign suggesting infection or allergy) → see a doctor immediately

🍽️ Eating during these days

In these three days you come to know the product's chain of safety — donor screening, manufacturing and storage — while your diet continues to follow the gentle, firming line. Your tasks: take the daily dose according to the usual routine, drink an extra glass of water after every looser stool, and do not forget to write the LOT number in your diary, and to store the unopened bottle in a cool, dark place, standing upright.

For these days, the Plant Calendar recommends sources providing gentle, soluble fibre and resistant starch: on day 19 oats (the beta-glucan in them is a soluble fibre, gentle on the gut), on day 20 cooked carrot (soluble fibre, soothing in effect), and on day 21 cooked, cooled potato, in which resistant starch forms during the cooling. These fibres feed the good bacteria in the colon and support a firmer stool while your symptoms settle. Build the plant of the day into at least one meal, cooked or steamed; if you do not tolerate one of them well, leave it out and return to it later.

📊 Adat

In these days, record daily:

DiffBiome dose (capsules/day) and the LOT number;
daily stool count;
stool Bristol scale (1–7);
bloating (0–5);
bloody stool (yes/no);
fluid intake (litres);
wellbeing (1–5);
note: any unusual, possibly allergic reaction.
Movement: type + minutes, step count (target/actual)
Stress level (1–5) and mood (1–5)
Sleep (hours + quality 1–5)

Why does this matter?

If you know what strict screening and controlled manufacturing your capsule goes through, it is easier to continue the course with trust and calm. Logging the LOT number is your part in this chain of safety: with it, every dose stays traceable — which serves your safety.

[[REFERENCES]]

References

[7] van Nood E, Vrieze A, Nieuwdorp M et al. Duodenal infusion of donor feces for recurrent Clostridium difficile. N Engl J Med. 2013. Link

Open-label RCT in patients with recurrent C. difficile infection comparing duodenal donor faeces infusion (after short vancomycin + bowel lavage) with standard 14-day vancomycin, with or without bowel lavage. The primary endpoint was diarrhoea resolution without relapse at 10 weeks. The trial was stopped early at interim analysis: 13/16 patients (81\%) in the FMT arm achieved resolution after a single infusion, substantially exceeding both vancomycin arms. Establishes FMT as superior to antibiotic monotherapy for recurrent CDI and provides the landmark evidence base for FMT clinical translation.

[218] Dethlefsen L, Relman DA. Incomplete recovery and individualized responses of the human distal gut microbiota to repeated antibiotic perturbation. Proc Natl Acad Sci USA. 2011. Link

This longitudinal study examined the distal gut microbiota of three individuals over 10 months spanning two courses of ciprofloxacin, analyzing 1.7 million 16S rRNA sequences from 52-56 samples per subject. Interindividual variation dominated; baseline within-subject communities were stable over months. Ciprofloxacin profoundly reduced diversity and shifted composition within 3-4 days of initiation, with incomplete and individual-specific recovery. The findings characterize gut microbiota resilience and the durable disruption caused by repeated fluoroquinolone exposure.

[2721] Palleja A, Mikkelsen KH, Forslund SK et al. Recovery of gut microbiota of healthy adults following antibiotic exposure. Nature Microbiology. 2018. Link

Shotgun-metagenomic study of 12 healthy men: after a 4-day course of three last-resort antibiotics (meropenem, gentamicin, vancomycin) the gut microbiota largely but incompletely recovered over six months — several common species stayed missing and resistance genes were transiently enriched.

[2722] Grosen AK et al. Effects of clinical donor characteristics on the success of faecal microbiota transplantation for patients in Denmark with Clostridioides difficile infection: a single-centre, prospective cohort study. The Lancet Microbe. 2025. Link

Single-centre, prospective Danish cohort: clinical donor characteristics — including antibiotic exposure in the 12 months before donation and donation stool consistency — affect FMT success in recurrent C. difficile infection; donor antibiotic use worsens outcomes, supporting strict donor screening.