What should we expect after FMT?

What should we expect after FMT?So, you’ve completed your 10 day FMT programme.  What comes next?  How are you going to be feeling?  We are often asked this question and what people should expect in the days and weeks following FMT.

Everybody reacts very individually to FMT so it can be hard to predict how each person will respond.  Some people feel immediate benefits and report an increase in energy, feeling more clearheaded and are able to tolerate more foods than they were previously.  Patients who have been unable to keep weight on feel like they are absorbing more of their nutrients and are ‘filling out’ once more.  Appetite might increase, bowel movements normalize, and digestion starts to improve.  Many patients state that they feel like their old selves again – more like they were before they became unwell.

For other patients however, response to FMT may be slower and there can be some ups and downs along the way.  Some people feel a little worse before they begin to feel better, or old symptoms seem to reappear.

Some of the common symptoms for patients who fall into this category include fatigue, brain fog, increased gas, changes to bowel movements, flu-like symptoms, skin irritations, headaches, joint pains and changes to mood such as anxiety and depression.  These are normally transient symptoms which are generally short lived.

One explanation for why this type of response occurs might be that it’s due to the Herxheimer effect, otherwise known as “die off”.  The Herxheimer effect can occur when pathogens are killed off and release toxins into the bloodstream faster than the body can deal with them.  The symptoms can be very similar to ones that patients experience during or after FMT: nausea, headache, fatigue, joint pain, muscle pain, cold sweats, fever, chills.  Although unpleasant, a Herxheimer reaction may actually be a positive sign that toxins are being cleared from the body and healing is taking place.

Another explanation might be that people are experiencing a ‘healing crisis’.  Hering’s (1800 -1880) law of cure suggests that “All cure starts from within out, from the head down and in reverse order as the symptoms have appeared or been suppressed”.  Symptoms tend to disappear in reverse order to how they developed, taking approximately one month for each year of being unwell.  Symptoms move from the more vital organs to the less vital organs, from the inside of the body to the outside, and from the top of the body downwards.  Although we don’t necessarily see this specific pattern occurring in our patients, and Hering’s law was not scientifically tested and supported, it may go some way to help to explain some of the shifting symptoms or resurgence of old symptoms that some patients experience.

Thankfully, for most patients this period doesn’t seem to last long and by 3 months they are feeling much better.  Occasionally it can take a little longer than 3 months to settle and we have had patients come back to us at 6 months and say it took them a longer length of time to fully feel the benefits from the FMT.

Many of our patients fall into the categories above – they either respond quickly to the FMT or have a short period of ups and downs and a more gradual improvement in symptoms, but there are those who don’t seem to respond at all, or who experience a relapse in their symptoms at a later date.

We don’t know for sure why this is the case for those individuals.  It might depend on the type or severity of condition the patient has, how long they’ve been unwell, what other physical, psychological, environmental factors might be involved, and the patient’s own genetics.  Maybe the person has some heavy metal toxicity, or other toxic burdens in the body.  Perhaps they have a particularly virulent parasitic or yeast infection that is hampering their recovery, or maybe the gut bacteria just weren’t the underlying problem in the first place.

We are also very interested in the possible connection between dental health and gut health.  Could underlying issues in the mouth be perpetuating issues in the gut and thus preventing people from fully realising their health goals.  We hope this is an area we can explore more fully in the future as more research becomes available and we begin to forge working links with holistic dentists.

For some patients, it might simply be a matter of giving it a bit more time.  Others may just need further implants.  Professor Thomas Borody, a gastroenterologist in Sydney, recorded that from a group of 6 refractive (non-responsive) Ulcerative Colitis patients, eventually achieved remission for all of them after 2 years of intermittent FMT.

We hope that in our continuing work with FMT and through the research of others, that we will continue to develop our understanding of why different people respond in different ways.


Nina Mansell
Nutritional Therapist