Can FMT treat Parkinson's and MS: The Microbiome and Neurological Disease

June 6, 2023

It is becoming increasingly evident that the microbiome plays a role in a handful of neurological conditions, Parkinson’s and Multiple Sclerosis among them. GI issues have long been connected with neurological conditions, but more recent research has uncovered that microbial differences may be at the root.

These findings raise curiosity about how these conditions may be treated using bacterial therapies. Could FMT be used to treat both the GI and nervous system symptoms of Parkinson’s? We will explore this question in the following sections:

  • What defines a neurological condition?
  • GI symptoms in neurological conditions
  • Do Parkinson’s and MS originate in the gut?
  • Could FMT be a treatment for Parkinson’s and MS?
  • Studies on FMT and the brain

Let’s start out by breaking down what a neurological condition is and what effects they have on the body.

What defines a neurological condition?

Neurological conditions are diseases of the central nervous system, meaning they affect the brain, spinal cord, cranial nerves, nerve roots, peripheral nerves, autonomic nervous system and muscles. Epilepsy, Alzheimer's, Dementia, multiple sclerosis and Parkinson’s are all neurological conditions. They in turn affect the functions of such systems leading to symptoms that include loss of muscular control, loss of cognitive abilities and more.

Common symptoms

Symptoms of neurological condition vary, but generally they present as progressive diseases, with symptoms often worsening throughout one’s life. Symptoms include:

  • Muscle weakness
  • Poor cognitive abilities
  • Unexplained pain
  • Loss of alertness
  • Lack of balance
  • Slurred speech
  • Tremors

GI issues are also a common symptom in many with neurological conditions, scientists believe this is connected to dysbiosis in those living with these conditions. They now believe microbial alterations may have consequences beyond the GI tract and may be a key factor in how these diseases function.

GI symptoms in neurological conditions

GI symptoms are common to a number of brain related conditions. Those with Parkinson’s commonly report constipation as a symptom of their conditions and those with MS likewise commonly report GI problems. So, how are these two seemingly separate issues connected?

The gut-brain axis

The gut brain-axis is the bidirectional relationship between the brain and the gut. This connection is made up of pathways that include the enteric, vagal and spinal neural systems This connection is gaining more appreciation as researchers dig deeper in to the gut for the causation of diseases of the brain.

Do Parkinson’s and MS originate in the gut?

There is increasing evidence that a whole number of diseases that are located symptomatically in the brain actually stem from the gut. This has been confirmed by way of microbial differences in the guts of those with such conditions, compared to those without. The list of conditions affected by the microbiome spans from Autism, to depression to Parkinson’s, MS and other neurological conditions.

What is the microbiome?

The human microbiome is all of the bacteria, protozoa, viruses and fungi that live in and on the human body. The microbiome plays crucial roles in regulation of the immune system, digestion and cognitive functions. There are multiple microbiomes within the body, but the gut microbiome is perhaps the most influential.

Parkinson’s and the microbiome

In 2003 Heiko Braak and his colleagues, at the University of Ulm in Germany, proposed that Parkinson’s might actually begin in the gut., not the brain, which had been previously believed.  Since 2003 this idea has been gaining a lot of traction.

Research has uncovered that those with Parkinson’s have a unique microbiome composition.  And other studies have revealed that Parkinson’s prevalence is 28% higher in those with IBD.

There are a few proposals as to how the gut is affecting the brain in the way it does. It is possible Parkinson’s is triggered through the vagus nerve which connects the GI tract to the central nervous system. The inflamed gut may also be triggering elevated levels of alpha-synuclein, which has been associated with Parkinson’s.

MS and the microbiome

The bi-directional relationship between the neurological symptoms of MS and microbial alterations in the gut is undisputed. What has been up for question and is more recently becoming clear is in which direction this relationship is working. Recent studies suggest that it is the microbial alterations that affect neuroinflammation and not the other way around. Leaving open the potential of FMT and other bacteria focused therapies to treat the symptoms and perhaps the roots of Multiple Sclerosis.

Other neurological conditions and the microbiome

Though Parkinson’s and MS are our main focus in this article, there are other conditions that may be related to the microbiome and the gut-brain axis as well. Alzheimer’s and chronic seizures are among them.


A study out of the Wisconsin Alzheimer’s Disease Research Center studied the microbiome differences between those with Alzheimer's and their controlled counterparts. The study found that on the whole those with AD had a reduced level of bacterial richness in their guts. Specifically they had decreased amounts of Firmicutes and an increased level of Bacteroidetes. Although the study was focused on those with Alzheimer’s dementia patients, there is reason to believe that similar causation is at the core of other dementias.


Studies in both mice and children have shown that a ketogenic diet may be beneficial for the reduction of seizures in those with epilepsy. The diet alters gut microbiome composition, increasing Akkermansia muciniphila and Parabacteroides, which appear to protect against the onset of epileptic seizures. The benefits of a ketogenic diet provides strong evidence that the microbiome plays a role in epileptic seizures.

Could FMT be a treatment for neurological conditions?

Fecal transplants are under investigation as a treatment protocol for a wide variety of conditions believed to be influenced by the microbiome. Crohn’s sufferers to children with Autism spectrum disorder are seeing the benefits from FMT in studies across the globe. Could Parkinson’s and MS be treated with stool transplants as well?

What are fecal transplants?

Fecal microbiota transplants (FMT) are a medical treatment whereby stool from a healthy person is implanted into the gut of a sick person. The purpose of the treatment is to provide the sick person with healthy microbes, that they are otherwise lacking and perhaps are contributing to their condition.

Studies on FMT and the brain

As of yet there are no large scale trial results for the efficacy of treating Parkinson’s or Multiple Sclerosis with FMT. There has however been a reported case study on a woman who experienced relief from her MS symptoms after FMT. The case is summarized in the following section.

A case study on FMT and MS

A 61 year old woman with Remitting Relapsing Multiple Sclerosis, who had been suffering from the disease for 28 years, with increasingly worsening relapses contracted C difficile in 2005. The C diff was resistant to several treatments of antibiotics and was eventually treated with a single FMT in 2006. Her C diff was eradicated and her MS condition which had been consistently worsening over the course of nearly three decades suddenly stabilized without any other major treatment changes, except for the fecal transplant. Additionally, her symptoms saw minimal improvements in the years following the fecal transplant, again with no other significant changes to treatment, diet or lifestyle.

More research needed

So far it is too early to make any grand statements on FMT and neurological conditions, but early cases show there is potential for a gut focused treatment. There are plenty of clues that lead to the gut but it is a matter of finding the exact microbial culprits to target and that may take some time and certainly more research to figure out.