FMT donor selection and screening protocol

 

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In Australia, to the best of my knowledge, Dr. Paul Froomes is the only gastroenterologist currently offering a donor screening service for individuals considering DIY FMT for mental health purposes. He is known for his extensive experience performing FMT across a range of conditions and may be willing to screen family members or friends as potential donors, even outside a clinical setting. While I’m unsure of the exact cost for this service, having a qualified gastroenterologist oversee the donor screening process is likely a desirable option for many. I believe it may even be possible for Dr. Froomes to coordinate testing for donors based in other states, though you would need to confirm this directly with his clinic. For those living outside of Australia, there are some microbiome testing companies that offer stool analysis for donor screening. However, a GP or other medical professional is still required to order the necessary blood tests to ensure a comprehensive screening.

 

Another option is to find a GP who is open to ordering the required tests (both blood and stool) for a potential donor. In our case, we were fortunate — our local GP had no issue when Alex requested screening to become a donor. However, this is not always the case. We’ve heard from others whose GPs refused to facilitate testing, especially when told it was for DIY FMT related to a mental health condition like bipolar disorder. This hesitation is understandable: FMT is not currently approved for treating bipolar disorder in Australia, and most GPs are likely unaware of the growing research linking the gut microbiome to mental health. If you do find a supportive GP willing to assist, it’s still important to carefully select your potential donor before reaching the testing stage. There are key factors to consider in choosing someone who may be suitable, which I outline elsewhere in this guide.

 

There is ongoing debate on DIY FMT forums about what qualifies as a “healthy” donor and what standards should define acceptable donor quality. One advantage of sourcing your own donor—rather than receiving FMT through a clinic—is the ability to set a much higher bar for donor health based on your own criteria. The trade-off, of course, is that you must take responsibility for both finding and screening the donor, as well as preparing the FMT material yourself. Clinic-based FMT can cost many thousands of dollars, while DIY FMT is significantly more affordable and involves far less financial risk if it turns out to be ineffective.

 

Many in the FMT community feel that current international clinical guidelines for donor selection are not stringent enough. Critics argue that they lack adequate exclusion criteria and fail to thoroughly assess lifestyle habits and medical history. For example, standard screening questionnaires often overlook critical factors such as long-term antibiotic use or poor dietary habits—both of which can negatively affect gut microbiome composition. Even more concerning, Australia’s Therapeutic Goods Administration (TGA)—our version of the FDA—does not explicitly exclude donors with a history of mental illness, despite growing anecdotal and research-based evidence that depression or anxiety may be transmissible via FMT. This oversight is deeply troubling. While online discussion about donor quality is valuable, it reflects a broader scientific uncertainty: even among microbiome researchers, there is no definitive consensus on what constitutes a “normal” or “healthy” gut microbiome. For those interested in exploring this topic further, I recommend the review article “What Defines a Healthy Gut Microbiome” published in Gut.

 

With all this in mind, what I can say—anecdotally—is that among the 20+ people I know who have experimented with FMT (either DIY or in a clinical setting), a “healthy enough” donor appears to be sufficient for achieving noticeable improvements in mental health symptoms such as depression, anxiety, and hypomania or mania. That said, the effectiveness seems to depend on whether the symptoms are actually influenced by the gut microbiome. For example, my own FMT experience did not resolve the anxiety related to my Complex PTSD, which I believe had a different root cause.

By “healthy enough,” I mean a donor who passes the international FMT donor screening criteria—on which the Australian TGA guidelines are based (link here).

 

That said, if I were starting my FMT journey today, with the knowledge I now have about the gut microbiome and health outcomes, I would set a significantly higher bar than what the TGA guidelines recommend. So while I believe that, at minimum, a donor should meet the TGA standards, I also have a personal “ideal donor wish list” that goes beyond them.

The truth, however, is that fewer than 5% of potential donors even meet the basic TGA criteria. So expecting someone to tick every box on a stricter wish list is a bit like searching for a unicorn. And even if you do find someone who qualifies, they might not be willing to donate stool—let alone do it regularly.

The logistics also complicate things. Your donor ideally needs to live nearby so they can donate fresh samples, or you may need to stay with them for a few weeks to complete your FMT course. If they’re particularly generous and committed, they might even prepare and freeze batches of FMT for you in advance. But in many cases, finding someone who is both eligible and willing is no small feat—it can be challenging, awkward, and sometimes downright impossible.

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If I were searching for a donor today, the first thing I’d do is look closely at my circle of friends and family and identify that person—the one who never seems to get sick, who’s always in a good mood, and who radiates good health. That would be my starting point. There’s now a substantial body of research linking lifestyle factors and medical history to the composition and functionality of the gut microbiome, as well as to long-term disease risk. While the ideal donor might be nearly impossible to find, I’ve included my personal donor “wishlist” below because I believe these factors are important to consider.

 

At a minimum, I would aim to find someone who meets the TGA’s official screening criteria. From there, my goal would be to find a donor who also ticks as many boxes on the wishlist as possible. That said, in reality, a person who simply meets the TGA guidelines may still be “healthy enough” for FMT to be effective. For those interested in exploring the topic further, I recommend this 2020 review: Fecal Microbiota Transplantation: Screening and Selection to Choose the Optimal Donor.

 

In addition to meeting the TGA’s official screening criteria (link provided at the end of this page), the ideal donor, in my view, is someone who:

 

• Has never experienced any form of mental illness or personality disorder. Personally, I would also exclude anyone with a family history of biologically-based mental illnesses such as bipolar disorder, schizophrenia, or major depressive disorder. That said, I would not disqualify someone solely because a family member has experienced situational depression or anxiety related to trauma or life circumstances—if I did, it would likely eliminate nearly everyone. A systematic review of gut microbiota composition in observational studies of major depressive disorder, bipolar disorder and schizophrenia 2022

• Ideally, a donor should be my age or younger, as there’s evidence that gut microbiome function tends to decline with age—even in people who appear healthy, pre-disease states may exist (see: The gut microbiome as a modulator of healthy ageing). For this reason, many clinics and countries set an upper age limit for donors, typically around 55–60 years. While a younger donor is preferable, I say this knowing that my own donor was my husband Alex, who is 18 years older than me—so age alone isn’t necessarily disqualifying. It’s just not ideal. Some people report success using children as donors, especially for conditions like C. difficile or IBS. However, this raises ethical questions around informed consent. Personally, I wouldn’t consider a child under the age of 3, as their gut microbiome hasn’t yet reached adult-like maturity. Children also tend to carry more viruses from school environments, and health issues such as allergies may not emerge until adolescence. While I haven’t personally heard of anyone using a child donor for mental health-related FMT, anecdotal reports exist for other conditions. I would also be cautious about a child receiving FMT from an adult donor.

• Limited lifelong antibiotic use. Repeated antibiotic use has been shown to reduce microbial diversity, gut microbiome resilience and functionality. I personally developed serious mental illness after multiple courses of antibiotics (~10 in a 2 year period) and know other people who had never experienced any mental illness symptoms until they were given antibiotics. (Alex had taken very few antibiotics in his life). "Antibiotics and the gut microbiome: Understanding the impact on human health"

• Consumes a healthy diet with a diversity of plant fibres, fermented foods and very little ultra-processed foods. Diet is the biggest driver of gut microbiome diversity. People who eat healthy diets with plenty of plant fibres have the best long-term physical and health outcomes. Zoe Blog: Why should you eat 30 plants a week? Also the donors diet seems to play a role in efficacy of FMT: Dietary Management for Faecal Microbiota Transplant: An International Survey of Clinical and Research Practice, Knowledge and Attitudes.

  • A key point around diet: If the recipient has allergies or sensitivities to certain foods then it is advisable that your donor avoids said foods to prevent the possibility of the recipient reacting adversely to the FMT.

• Regularly has stool type 3 or 4 on the Bristol stool chart: Get to know your poo: What your poo says about your bowel health , Stool consistency is strongly associated with gut microbiota richness and composition, enterotypes and bacterial growth rates

• Exercises regularly; people who exercise regularly promote beneficial microbes and a more diverse gut microbiome. Physical Exercise and the Gut Microbiome: A Bidirectional Relationship Influencing Health and Performance

• A non-smoker (smoking alters the gut microbiome) and preferably someone who avoids any recreational drugs. Cross-talks between gut microbiota and tobacco smoking: a two-sample Mendelian randomization study

• Little alcohol consumption (Alex drinks a glass of wine, G&T or whiskey here and there but he has only ever been ‘drunk’ less than a handful of times in his life). Alcohol negatively impacts the gut microbiome

• Does not experience chronic stress as this negatively impacts the gut microbiome. How does chronic stress harm the gut? New clues emerge

• Does not take the following commonly prescribed medications: Metformin, Statins, PPIs, NSAIDs (can cause dysbiosis). Potential effects of the most prescribed drugs on the microbiota-gut-brain-axis: A review

• Was preferably born vaginally and was breastfed. C-section birth can lead to a less diverse and rich gut microbiome than vaginal deliveries. Formula feeding can disrupt the gut microbiome, while breastfeeding can help support the development of beneficial bacteria.  The Impact of Cesarean Section Delivery on Intestinal Microbiota: Mechanisms, Consequences, and Perspectives—A Systematic Review

• Had pets as a child: Exposure to household furry pets influences the gut microbiota of infants at 3–4 months following various birth scenarios

• Has good skin: Several dermatological conditions, such as acne, atopic dermatitis, psoriasis and rosacea are linked to intestinal dysbiosis. Impact of gut microbiome on skin health

• In some cases, it may be advisable to use a donor of the same sex as the recipient, as hormones can potentially be transferred via FMT. One example is a friend of mine who received FMT from Dr Paul Froomes for Bipolar I. She was trying to conceive and specifically requested only female donors to avoid any potential hormonal interference—such as exposure to testosterone. While the clinical relevance in humans is not fully understood, one study in rats found that male recipients of female donor transplants showed reduced plasma testosterone levels. Whether this has meaningful effects in humans remains unclear, but it’s a consideration worth noting, particularly in cases involving fertility or hormone-sensitive conditions.​ "The Effect of Cross-Sex Fecal Microbiota Transplantation on Metabolism and Hormonal Status in Adult Rats"

  • The following example is pretty interesting: A man gave himself poop transplants using his mom's feces to treat his debilitating Crohn's. Then he started experiencing her menopause symptoms.  

 

You might also be wondering whether it’s worth paying to have your donor’s stool analysed. My view is: if you can afford a few hundred dollars for a microbiome analysis, it’s definitely worth considering. This article—A Comprehensive Guide to Stool and Microbiome Testing—is a great resource if you want to explore that further. In Australia, companies like Microba (now called Co-Biome) offer metagenomic testing, which provides detailed insights into the diversity and health of a person’s gut microbiome. If you’re outside Australia, you’ll need to research which organisations offer metagenomic analysis in your region. Microba kits used to be available directly to consumers online, but the service is now only accessible via a healthcare provider. In combination with passing the standard TGA screening guidelines, a metagenomic test can give you a much deeper understanding of whether your donor’s microbiome is diverse and functioning well. That said, I don’t personally know anyone who has tested their donor’s microbiome before proceeding with FMT. My partner Alex and I couldn’t afford it back in 2016. My assumption has always been that someone who is consistently healthy, has no history of chronic illness, eats a nutrient-rich diet, and exercises regularly is likely to have a robust and diverse microbiome—but of course, testing provides more certainty.

 

There are still many unknowns when it comes to donor-recipient matching in FMT. For example, the enterotype—the predominant bacterial composition of the gut—may play a significant role in how well FMT works, and factors like blood type could also influence outcomes. The “super donor” phenomenon is well documented, yet researchers still don’t fully understand why some donors produce remarkable results while others, despite appearing perfectly healthy, do not.

Using multiple donors may increase the likelihood of success, and this is one advantage of receiving FMT in a clinical setting, where it’s common to be treated with stool from more than one donor. There are many reasons why FMT from one donor might be ineffective, while FMT from a different donor may lead to meaningful improvement. For this reason, if your first donor doesn’t bring significant relief, I urge you not to lose hope—finding another donor could make all the difference.

 

If you’re interested in a deeper dive into this topic, this excellent 2024 article offers a thorough overview of the factors that influence FMT success: Faecal (or intestinal) microbiota transplant: a tool for repairing the gut microbiome, & The interplay of gut microbiota between donors and recipients determines the efficacy of fecal microbiota transplantation

 

Finally below is a link to the TGA screening questionnaires and blood and stool tests.

These tests are the very minimum screening requirements for FMT.

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Under no circumstances should you use an untested donor for FMT—this can pose serious health risks.

 

Link to printable version of: Therapeutic Goods Administration selection and screening questionnaire of FMT donors plus blood and stool tests

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