Fecal Transplant and Weight Loss: How Microbiota are Making You Obese

Studies are underway to see if FMT can encourage weight loss in overweight individuals.

If you are obese and having trouble losing weight, your microbiome might be to blame, but fear not – because a new weight loss treatment may soon be available. Researchers are now studying the benefits Fecal Microbiota Transplants (FMT) may have on obese individuals’ ability to shed pounds.

Fast fact: fecal transplantation is the insertion of stool from someone with a healthy system into the intestine of someone who is ill or unwell.

That’s right – putting someone else’s poop up your butt could make you slimmer! If you’re not sure that’s for you, there are also other methods of transplanting fecal matter, including poop pills. If you’re interested, but don’t really understand what this process looks like, we’ve got you covered with everything you need to know about FMT for weight loss, including:

Let’s get started by outlining how your microbiome and your weight are connected.

The gut microbiome and your weight

How could putting poop up my butt possibly help me lose weight? Well, it turns out certain bacteria in the gut microbiome can hinder our ability to lose weight, or make it easier – depending on which kind of bacteria you have. Doctors have discovered that there is a connection between gut bacteria and obesity.

Using FMT to manipulate the microbiome of those who are obese to more closely resemble the gut bacteria of lean individuals may encourage weight loss. Before we jump into anything further, let’s back up a bit and answer some of your questions about the microbiome.

What is the microbiome?

The microbiome, and specifically the gut microbiome, is the whole of the communities of bacteria, fungi, protozoa and viruses that live inside our gut. There are millions of them in the human body – even more than our own cells – and they play an important role in the regulation of key bodily functions such as digestion, immune response, and brain health (part of a function known as the gut brain axis). They are affected by many of our behaviours, including stress level, diet, geography, and even ancestral background.

close up of 3d microscopic blue bacteria

close up of 3d microscopic blue bacteria

What’s the association between the microbiome and obesity?

Researchers at the Mayo Clinic studied fecal samples of 26 overweight individuals undergoing an obesity treatment program, and measured their success against their microbial makeup. They noted that the subjects who had the most success losing weight had different gut bacteria than those who were unsuccessful. In the 26 person study, 9 of the participants experienced what researchers dubbed as successful results.

Within the group of people who were unsuccessful, researchers found a higher number of bacterial genes involved in the breakdown of carbohydrates, and a lower number in those who were successful. Other significant microbial differences were noted between the two groups, including higher levels of a bacteria known as Phascolarctobacterium in the success group. This means that an FMT could work as a gut bacteria obesity treatment.

How can you manipulate the microbiome with someone else’s poop?

Certain microbes in our guts determine our ability to become and/or stay lean or not;  by using FMT, we can manipulate our microbiome to look more like that of a thin person’s. By inserting the microbes more prominent in lean individuals’ guts into an obese gut, the microbes will encourage more effective weight loss. This science has been proven in studies, and the principle has been demonstrated with mice. The question now, is how that science translates and can be applied for safe human use.

Can fecal transplants help with weight loss?

Fecal Microbiota Transplants can help with weight loss, according to recent studies. As a practice, it has been around for a very long time, and has recently gained traction as a science to be studied. By manipulating the microbiomes in your gut, an FMT can help with weight loss – even obesity.

If you want more detail about the science behind this and exactly how it works, read on!

Fecal Transplant weight loss: poop to the rescue

FMT has been around for thousands of years, but in modern medicine it is most commonly used to treat the deadly gut infection, Clostridium Difficile (C. Diff for short). Fecal transplants involve the insertion of stool from a healthy individual into the gut of an ill patient to deliver healthy microbes into their gut. The idea is that the healthy bacteria will be able to stave off the bad bacteria living in the gut of someone who is sick.

Though it is mainly used for C. Diff, there are theories on a whole host of conditions that altered microbiome practices might treat, including: Autism, Parkinson’s Disease, Colitis, and now, obesity. Though all of these illnesses affect the human body in different ways, the gut connection is now being recognized as increasingly important when it comes to the most basic functions of the human body.

Scientist making FMT at OpenBiome

Studies on FMT for weight loss: proof it really works

The legitimacy of this practice has been demonstrated in a proof of concept mice study, along with anecdotal cases being reported. There are a handful of human studies underway exploring the connection between gut microbiota and obesity, some of them are outlined below.

The Proof of Concept Mice Study

This 2013 study researched the use of FMT, and its effect on weight gain and loss in germ free mice.

Research Team: A team led by Jeffrey Gordon, at Washington University.
Completed: 2013
Results: The mice study showed that the manipulation of the gut microbiome affected weights in mice. In the study mice were given FMT from either lean or obese humans. The mice given the bacteria from the obese humans were found to gain weight and vice versa.
What’s Next: The study has been utilized now by researchers across the globe as a proof of concept for many current studies into the connection of obesity and the microbiome in human subjects.

The Gut Bug Trials

An ongoing study is using poop pills cultivated from fecal samples of lean individuals to help obese teens lose weight. Working off the 2013 proof of concept study on mice by Jeffrey Gordon, they are hoping that by administering the pills to overweight teenagers, they will be able to manipulate the microbiome in a way to encourage weight loss.

Research Team: Professor Wayne Cutfield, Dr Justin O’Sullivan and their team at the Liggins Institute at the University of Auckland in New Zealand
Time Frame: 2017-present
Hypothesis: “The basic idea behind our trial is that by introducing more kinds of gut bacteria to obese young people, it will enable their bodies to metabolise food better, potentially leading to weight loss and other health benefits.” says Dr O’Sullivan.

FMT and Insulin Resistance

A study currently underway at the University of Toronto is exploring the effect of FMT on metabolic syndrome, with a specific focus on insulin resistance.

Research Team: A University of Toronto research team, lead by Dr. Joann Allard.
Time Frame: 2017 – Present
Hypothesis: Determining whether FMT has an effect on insulin resistance in obese individuals. Other effects are also being noted in the study, including the effect on appetite, weight, and gut hormones. Subjects are randomized, either receiving their own feces, or the fecal transplant of a lean donor, and are then monitored over several months. The study is still in its early stages.

FMT as a weight loss program

If you are already close to a healthy weight based on your height and just want to shed a few pounds, this treatment is not for you. At this time, research is only being done into the implications of weight loss in those who are clinically obese (those with a BMI over 30), and are looking for alternatives to more invasive procedures like bariatric surgery. In addition, if you are close to a healthy weight, it is likely that you don’t have the bacteria that this treatment would target in the first place.

At this point in time, if you are considering FMT for the purpose of weight loss you would have to do so through a study. Different studies are exploring different ways of delivering FMT for weight loss. The University of Toronto study is performing a weight loss fecal transplant by way of colonoscopy, while the University of Auckland study is delivering the transplants in digestible capsules.There is no basis for how to treat obesity with FMT, the researchers performing these studies are at the forefront of the practice.  If you are interested and eligible, we highly encourage you to get involved in a study.

To DIY or not to DIY Fecal Microbiota Transplants

Many people have taken it upon themselves to try FMT at home to help with weight loss or cure other conditions. So, should you try it? At this stage, we would recommend not to. Results have only been released from the mice studies so far, and though they are promising, it doesn’t necessarily mean it will work for all humans.

There is some anecdotal evidence that an FMT procedure will help with weight loss, but the potential risks may outweigh the benefits in this case. The biggest concern is that it is very difficult to ensure a safe fecal donor without testing, which can only be done in a clinical setting. Our suggestion is to leave this one to the doctors – for now.

Think you could lose weight with FMT? Here’s what to do:

If you are a person who is interested in participating in a study of this sort, there are studies going on right now as mentioned above. With the continued rise in interest in FMT treatments, you can be sure there will be more studies popping up. Check out a nearby University or research institute to see if they have any studies you can participate in!