Would you rather: stick someone else’s poop up your butt or swallow a liquid that used to be someone else’s poop?

Neither? Yeah, ok that is understandable.

But what if your life depended on it? That is what fecal microbiota transplants are. And as gross as they sound, they could save your life. throughout this video, their uses will get more and more surprising.

So without further a deuce, here’s what poo poo can do do for you. [intro music] If you associate fecal transplants with anything, it’s probably intestinal  stuff like ulcerative colitis, which I wish I were personally less familiar with. And they’re associated with that because they have a good track record of treating it! . But there are a lot of other uses for fecal transplants, and many of them have nothing to do with your gut.

So let’s start with an organ that’s nearby: the liver. If you don’t treat liver disease, it can kill you. And some liver disease is the direct result of drinking too much alcohol.

That’s because alcohol affects what’s called the gut-liver axis. You have veins that bring bacteria from your intestines to your liver and the antibodies and acids from your liver to your intestines. So whatever is in your liver, like a load of alcohol for example, will influence the community of microbes in your gut.

The balance of bacteria can get off kilter because the ones that are good at managing lots of alcohol dominate and you don’t end up with a diverse group of microbes. Essentially, alcohol use disorder can flood those lines so that your microbiome isn’t really able to focus on anything else. A study published in 2012 found that some people with that disorder had a significantly different microbiome than their peers who drank a maximum of three drinks in a sitting.

The gut bacteria more common among the group with alcohol use disorder were correlated with endotoxemia. And endotoxins sound bad because they are. They can lead to inflammation and all sorts of other problems.

So when researchers found significantly more endotoxins in the people with alcohol use disorder than in their peers, things weren’t looking good. But one thing that does seem to help is a fecal transplant! In fact, it can help repair your microbiome and might treat your liver disease better than other standard treatments like steroids and nutrition.

By replacing the pathogenic bacteria with good bacteria, these transplants helped participants in a 2018 study make fewer endotoxins so their bodies could focus on repairing the alcohol damage. And if you catch things early, fecal transplants can even prevent alcoholic liver disease! In a clinical trial, 10 patients with alcohol use disorder cirrhosis were given a fecal transplant and 10 were given a placebo enema.

If you were wondering how something like a fecal transplant could have a placebo. Now you know So then they identified the microorganisms in the guts of all participants. Microbial diversity increased among the transplant group but not the placebo group.

So the transplant worked as you would expect. But the truly remarkable thing was that 90% of the transplant group had significantly reduced alcohol cravings compared to 30% of the placebo group as well! So it’s kind of a two-for-one because it showed the transplant can treat liver disease and  the alcohol use disorder that caused it.

Which is, very weird Now, alcohol is literally poison. But fecal transplants can also treat your body’s dangerous response to more mundane stuff. Like allergies.

Allergies are an immune response. They’re basically your body treating something that shouldn’t kill you, like a peanut, as if it will. And parts of your immune system are controlled by the bacteria in your gut.

When you have a good variety of gut bacteria, it provides some protection against allergies. This isn’t just something we think might happen based on stuff scientists have seen under a microscope. It’s been studied in humans.

A lot. There’s plenty of research comparing the gut microbiomes of people, especially children, with and without allergies. And since your gut bacteria are also influenced by things like your diet and where you live, some of those studies focused on comparing twins.

One study showed that certain kinds of gut bacteria were lacking in allergic twins and present in much higher numbers in non-allergic twins. Basically, people with allergies don’t have diverse enough gut microbiomes. It could mean that you’re  missing a bacteria species that helps you break down starch from your diet or one that regulates your bile acid. you need a variety of bacteria in your gut to respond appropriately to all the things you come into contact with.

And you might have guessed where this is going. Because one way to introduce a wider variety of microbes into the gut is through … fecal transplants. In a 2019 study, mice were sensitized to cow’s milk, then divided into two groups.

One group was given fecal transplants from people with cow’s milk allergies, and the other group was given fecal transplants from people without that problem. The first group produced an  allergic response to cow’s milk, while the mice that got fecal transplants from people without allergies didn’t. And yes, not mice poop, people poop The two groups of mice had different microbiomes, with the non-allergic transplant mice having more bacteria that protect against allergic sensitivity.

They could also be distinguished  by their antibodies, which provided another confirmation that these transplants  influence the immune system. Although we are talking about mice here, it’s strong evidence that a fecal transplant from someone without allergies could potentially protect you against yours. And we are in the process of studying this in humans, too.

At least one clinical trial has been completed by a team at Boston Children’s Hospital. The results haven’t been published yet, but considering that the primary investigator has since started another clinical trial along the same lines, it looks promising. Someday soon, poop may make allergies a thing of the past.

And it could be helpful in treating other inflammatory diseases as well … including multiple sclerosis. But we’ll get to that, after the ad. MS is one of those all encompassing diagnoses that affects your neurological function and physical control of your body.

It’s what happens when your immune system starts attacking your brain cells and their connections with each other. The word “sclerosis” means “tissue that looks scarred,” and is referring to the damage left behind after these immune attacks. Fecal transplants might seem like an unlikely treatment for a disease of the nervous system.

But let me tell you about a thing called the microbiome-gut-brain axis. See, just because your brain is about as far removed from where your poop comes out as possible, that doesn’t mean they’re totally unrelated. The bacteria in your gut can activate certain cells in your brain.

If you ask the people who research the relationship between  your gut microbiome and MS, some will go so far as to say that drugs we currently use to treat the disease might be effective because they alter the gut microbiome. Gotta love someone who really believes in their work. That’s a big claim.

But we know a lot about how your microbiome regulates MS. And it works differently from allergies, even though they’re both immune problems. A 2022 study assessed the gut microbes of people with MS compared to people without the disease.

And they were significantly different. Especially when it comes to immune-related stuff. People with MS had more of the bacteria associated with inflammation, like Prevotella.

By now, you know that this is just the kind of problem that fecal transplants might be able to address. While research on this is still limited, there are several studies, so scientists are definitely barking up the transplant tree. One of those publications included three case studies of fecal transplant in MS patients, and they had almost miraculous results.

All three patients tried fecal transplant just to relieve the constipation symptoms that can come with MS. They ended up in remission for years, able to walk again after becoming wheelchair bound, got their catheters removed, and improved their neurological function, in some cases becoming asymptomatic! Those are results that scream “keep pursuing this!” And MS isn’t the only neurological condition that fecal transplants may be able to help with.

Poop might treat Parkinson’s, too! This is through yet another pathway from the gut to the brain. In contrast with MS, people with Parkinson’s Disease have less Prevotella bacteria in their guts.

But this time, the bacteria’s influence on dopamine is probably more important than the immune regulation. Because people who have fewer Prevotella often have less of the gut hormone ghrelin. Ghrelin does a few things, but one of them is regulating your body’s dopamine, which is impaired in Parkinson’s cases.

So people diagnosed with Parkinson’s have low Prevotella and dopamine, and researchers think those two things are related. But! Fecal transplants may help!

This is also very early days research. There aren’t many participants in the studies we have. And they started off with mild-to-moderate symptoms of Parkinson’s and were taking their other medicines while the study went on, so you need to take everything I’m about to say with a grain of salt.

But, that being said… Half of them had significantly improved symptoms after the transplant! And the biggest improvements were seen in patients with the worst starting symptoms. So a study that included participants at more severe starting points might show larger positive effects.

Of course, 50% is far from the magic brown bullet I promised at the beginning of the video. And one of the participants had a negative reaction. But when we’re talking about a condition that doesn’t have a reliable treatment as an alternative, this is a pretty exciting first step toward something that could be something.

Kind of like the last entry in the video. One of the most common symptoms of autism spectrum disorder is sensory processing differences. And some researchers think that comes from the system in your brain that tamps some stuff down and ramps other stuff up.

Your brain’s main tamper downer is a neurotransmitter called GABA. And according to a 2016 study, the link between GABA signaling and your ability to focus your visual attention is missing in people diagnosed with autism. Here’s where that idea came from: The authors of that study asked 20 autistic people and 21 people without that diagnosis to look into what were essentially binoculars.

But one eye saw one image and the other eye saw a different image. People in the non-autistic group processed the visual  information one eye at a time. Each side took turns shutting the other one down.

And they did more of the whole suppressing one image back and forth thing when they had more GABA in the visual center of their brains. But that’s not how it worked in the autistic group. The relationship between GABA and image suppression didn’t hold up for them.

Maybe it’s because of their GABA receptors or some other part of the GABA system t hat’s not set up the same way. But the researchers found that people who saw a mixture of the two images or were slow to switch between them could be reliably identified as also experiencing autism symptoms. So GABA might be an important neurotransmitter in creating the autistic experience.

But it’s not the only neurotransmitter that seems to be predictive of autism symptoms. A study from 2018 found that the higher your serotonin levels, the more symptoms you live with. Scientists have a few ideas about how and why this happens, but suffice it to say that serotonin and GABA both seem to be related to autism.

Just because they’re chemicals in your brain doesn’t mean they’re totally separate f rom the rest of your body, though. Thanks to the gut-brain axis, these neurotransmitters might work differently depending on your gut bacteria. Which means, if you’re looking to relieve some symptoms, fecal transplants might help!

I want to be clear that this is far from the controversial  idea of curing autism. At the end of these investigations, everyone was still autistic. Some of them were just able to communicate a bit more effectively or pass more comfortable bowel movements.

Since autism is a spectrum, the study I’m about to talk about i ncluded people across the entire thing. That being said, it was a small sample size. So just like the last condition, take these conclusions with a grain of salt.

In a 2021 publication, people on the autism spectrum had improved symptoms scores on a list that included mood, language use, and bowel movements after receiving fecal transplants. This was most true immediately, and kind of wore off as the weeks wore on. So transplants might have to be a continuing therapy rather than a one-off deal when it comes to autism.

But just like with Parkinson’s, the fact that it worked at all is pretty incredible. Whether they’re treating liver disease or allergies or neurological disorders, fecal transplants have a lot more to offer than people give them credit for. They seem like such a powerful tool, I am somewhat surprised that we don’t use them more often And I think part of the reason might just be because it’s kind of gross and also we’re not quite sure how to regulate it and also there’s not a ton of money to be made And ultimately we’re just beginning to explore the many uses for this weird new technology And hopefully this video will make their reputation a little less … crappy. [ OUTRO ]