(TENSE MUSIC) Obesity is an epidemic that kills millions of people each year. Not a single country has been able to reduce its obesity rates. And Kiwis are heavier than most. For the first time in history, children are facing shorter lives than their parents. But what if there was a silver-bullet solution? These New Zealand scientists think they might have found one, and it's all-natural. It's a theory that would end obesity as we know it. But their solution is not for the faint-hearted or the weak-stomached. I'm gonna go (LAUGHS) and do a poo. Their theory is that human faeces could contain the cure for obesity. It's the newest frontier in health research. There's no question about it. They're going to take fit people's poo and give it to obese people to see if it makes them lose weight. Effectively what we can do is we can manipulate their body. We can manipulate their metabolism. And when we do that, they lose weight. (RISING FESTIVE MUSIC) For the next six months, four overweight young women will see if this revolutionary treatment actually works. You are not eating half a cake. Try me. Oh! (LAUGHTER) Last night I had KFC. (LAUGHS) But it's all right. I had the coleslaw. There's no dieting, but the girls are going on trial. So it would be takeaways most days of the week? Yeah Wow. It's not like one cheat day a week; It's every day is a cheat day. When someone says, 'You're fat,' I don't really get offended. But If I hear something from my mum, I would take it more to heart. And the girls aren't the only ones on trial, because reputations are on the line, and this experiment will be closely followed around the world. I mean, this experiment is a bit of a mess, Thilini, right? It's game over. This is all turning a bit pear-shaped, you know? It might all go down the gurgler. How are you feeling now? I'm not crying. It's not gonna hold me back. I'm still gonna keep going. Because if their theory is right, this groundbreaking treatment could change the lives of every obese and overweight person on the planet. A free ride to Skinny Town. (LAUGHS) Welcome to the hidden world of human poo trials. Copyright Able 2018 (FUNKY MUSIC) The Liggins Institute ` Auckland University's elite medical research facility. Scientists here are taking major steps forward on a bold theory about the cause of obesity. This could turn out to be the biggest, most effective therapy for the treatment of obesity, ever. It's a multimillion-dollar gamble. But for it to work, the team needs 80 obese teens willing to ingest refined human faeces. When they explained that the capsules came from` virtually from fit people's poo, wasn't the best selling point. I want to do that push-up. I want to be able to move more. I want to not get a bit tired after climbing some stairs. I was like, 'Wow.' Like, 'If this actually works, this is crazy.' It sounds crazy, but it may be their last chance to change their lives. (CURIOUS MUSIC) Cos I've been overweight my whole life, (LAUGHS) and I'm willing to try anything This study is about gut-microbiome transfer to treat very overweight teenagers ` obese teenagers. The theory is that good bacteria in the gut of obese people have been killed or supressed. A gut-microbiome transfer replaces the bad bacteria with good bacteria from a donor. During the trial, researchers will take healthy poo and filter out everything until just the good bacteria is left. It goes in a capsule and is swallowed by our teens. We hope to see with treatment that the teenagers ` the overweight teenagers who take the gut-microbiome capsules become slimmer. But 'gut-microbiome capsules' is a real mouthful. So a 'faecal microbiotic transplant' is the scientific term, clearly. In fact, it describes what has happened. But they come in a number of other colourful names, depending on which route it goes into. You can have the 'trans-poo-sion', and that is when it goes up the... backside. And it can be the 'crapsule', which goes in the top end. It's a transplantation, of a foreign microbial community into your own microbial habitat. A repopulation, or as some people like to say, 're-poopulation'. Marker. Set. Yup. You see, even scientists can't resist a poo joke. (LAUGHS) But getting to the bottom of the science can be a bit messy. So we've rounded up the world's leading poo experts who actually talk shit for a living, and they'll be following the trial closely. There are more bugs in us than there are actually cells in us, which is a kind of icky thing to think about, but it is true. The human microbiome is basically... it's the collection of microbes, bacteria, fungi, other little creatures that live in a body, and their collection of genes. Undoubtedly if you actually take a fat person compared to a not-so-fat person and look at their microbiome, they are going to be different. Our drug companies, I think they've been missing the boat. They should be looking in here. This is where all the great drugs have already been discovered by the microbes. Will the bugs from a thin person be able to make an obese person thin? That is the $64 million question. The researchers believe fit people have beneficial gut bacteria that might help obese people lose weight. But to get it in your system, you have to swallow capsules filled with human faeces. The study coordinators call themselves the 'Gut Bugs' team, and they've just started the task of finding volunteers. In terms of recipients, we're looking to 14-year-old to 18-year-old teenagers who clearly have a weight problem ` a major weight problem ` and in that group, we would expect to be able to achieve the greatest change, if you like, and potentially the greatest benefit. So how do you recruit patients for a trial like this? It was an ad on Facebook. I was just scrolling through, and it was Gut Bugs Trial. 'If you are 14 to 18 and worried about weight.' I went, 'Well, that's me.' So I just clicked on it and went, 'Well, nothing ever happens unless you actually try,' so I thought, 'Why not? I'll apply.' So, Maddie, this is the DEXA machine. OK. So what we're gonna do is have you lying on the machine with your head this end and your feet down that end. Yep. I was in year six at school. I was 11, and one of the girls in my class comes up to me and goes, 'You know, I've always wanted to know what it feels like to be fat,' and then proceeded to poke me in the stomach, so that really stuck with me, basically, since then. And when it gets to the end, we're going to get this report come out that will tell us how strong your bones are and also what your body is made of ` so how much is lean tissue, how much is fat, how much is bone. (CHUCKLES) It was a little confronting, cos in it I had my arms down by my side. When you see your skeleton and then the gap between where your ribs end, to where your arm begins, that was a little bit like, 'Uh-oh.' (LAUGHS) 'That's right.' There's quite a large layer in between. For women, a healthy body fat percentage is considered to be between 21% and 31%. An overweight woman might have 32% to 39% body fat. Anything over 40% body fat is considered obese. So let me just show you the scan. So, um, the first page is mostly about bone strength. You've got strong bones, and I don't think, long-term, osteoporosis and fractures is gonna be a worry for you. The other part that's interesting is this part, and this is talking about body composition ` so what your body is made of. Um, if we go across total then, um, we've got that you're about 115 kilos, and in there there's 63 kilos of fat and about 49 kilos of lean tissue. So then your percentage body fat is 56%. NZ does have a big obesity problem, not just in adult but in our children. One in three children in NZ are overweight or obese. Izzy! Be a good girl. Go. The big, big problem is obesity in kids. Because what then happens is ` we know that if you are obese as a kid, you are more likely to be obese as an adult. Type 2 diabetes used to be an adult disease, and kids are now getting it as young as 9 and 10 years old. Then you have a whole lifetime of actually being marinated in glucose. You know, that is not going to be great for you. Quick! Overweight parents tend to have overweight kids. But is the problem their gut or their genes? This is good exercise for us too. I mean, we've got a cholesterol problem in our family. We're all on cholesterol tablets. It's not so much cancer and stuff that gets to me; it's the fact that when you're big and your heart's struggling. Yeah. And you actually can't do some of the things that you'd like to do. You know? It's hard. I think that's fair. I definitely am hyper-aware of the fact that I'm big. Yeah. Dating (GIGGLES) is when I think about it the most. It's not something I had much experience in, partly because I'm, like, 'Well, I'm too fat. 'They won't like me.' And, yeah, if I do ever go out on dates, I'm very, very self-conscious. Constantly I'm like, 'What can I order what I actually like but doesn't seem too bad?' You know those beautiful dresses and everything you've got? Yeah. When you lose weight and put those on, there'll be a whole, completely different thing about it. Because when you stand in the mirror and you go, 'Oh my God,' that'll be just the thing you need. Cos this person will smile back at you, and you'll know that you look gorgeous. I mean, you're gorgeous anyway. (CHUCKLES) But you know what I'm saying. Yeah. My gran, especially, is really excited for me and wants me to go far in life. And she goes, 'Your weight's holding you back a bit, 'and you could go so much further if you were a bit thinner.' This isn't the first time Maddie has tried losing weight. She lost 15 kilos after dieting a few years ago. But the weight just came back. So it's not hard to see why a magic weight-loss pill seems appealing, no matter what it's made of. Because I've been overweight my whole life. (LAUGHS) And I'm willing to try anything, because I'm fighting a losing battle. It's been five months since the Gut Bugs team started recruiting volunteers for their world-first medical trial to treat obesity. But Wayne and his team aren't just searching for obese teens to take the treatment; they're also hunting for people to donate the raw ingredients. We're after not just donors. We call them 'super donors', and that reflects the level of screening. I mean, they're going to be very rigorously assessed. In this study we have these super fit, healthy people who are our donors. and they are going to donate us some poo. We are then going to purify out the bacteria, clean them up and turn them into a treatment that we can give in capsules that will be swallowed by the recipients. It all sounds nice and clinical, but when push comes to shove, who are the people that want to poo on a plate for medical research? It's very interesting that my faeces could be used to help obese adolescents to lose weight. It's fascinating. It's bizarre; it's fascinating. So I thought, 'Hey, why not? I'll give it a go.' I would feel awesome if it changed someone's life, definitely, yeah. Cos I feel like everyone should have an equal chance to have a good and healthy life. Yeah, I mean my shit's going to waste, so why not use it to help other people? I'm not gonna do anything with it. (LAUGHS) These girls look lean enough, but scales alone can't tell us how much of their bodies is fat and how much is muscle. This is the DEXA scanner. This is the machine that can tell us how much of your body is lean tissue and how much is fat. Many people use a ratio of height and weight to gauge their fat levels. This is known as your 'body mass index', or BMI. BMI is useful, but it can be very misleading. Body mass index is a way of looking at someone's height and their weight and getting an idea about what that means about their body shape. But when you measure someone's height and weight, you don't actually know anything about what their body is made out of. A famous example is that most of the All Blacks are obese when you look at their BMIs, but, of course, they are mostly made up of muscle, and so they are metabolically really healthy. And conversely you can be someone who has got a BMI that is quite low but has a lot of body fat still, and so you could be relatively metabolically unhealthy and still have a normal BMI. The DEXA machine calculates body fat percentage, which is far more accurate than BMI. But it's raising some problems with the trial. The super donors need to be below 29% body fat. But so far, even though they look perfect, not a single volunteer has passed. Your overall percentage body fat is 34%. Now, that 34% is actually higher than our cut-off, which is a little bit surprising. OK, so your overall percentage body fat is 35%, and actually, that's too high for our study. So this is actually your skeleton that we can see, and what it tells us is that your body is 26.5% fat, which is quite low. Oh, OK. It's low enough to be a donor in our study, which is fantastic. Wow. Good. The gym's paid off. With just four weeks to go, Louise is the only donor to make the grade. It's really great to find someone who meets our DEXA requirements for the study. It's been harder than we thought it would be, so now we just have to show that she meets all other requirements, but hopefully we've got our first donor. So what does it take to get below 29% body fat? I currently exercise six days a week ` a mixture of cardio, weights and HIIT training. I quite enjoy it. I use to be a dancer back when I lived in Christchurch, and when I moved up to Auckland I couldn't find a dance school, so I chose exercise to fill that void, and it's been working, obviously. 'Cream crackers'. Not really. No, I'm not a big fan Six days a week is a lot of exercise. But the team now realise that is the key to finding the right super donors. Studies have shown a connection between regular exercise and a healthy mix of gut bacteria. So I train about six times a week. At the moment it's biking, but usually running and jumping and then some weights and stuff like that. The team found their second donor, Izzie, after they focused their advertising on people with an interest in fitness. By choosing people who are interested in exercise on Facebook, we're finding that around three-quarters of them are eligible for the study. If we look first overall at this total, you can see that your body is 25.6% fat. Mm-hm. And you know you weigh about 61 kilos. That means that your body fat percentage is low enough to be part of study, which is really awesome. Izzie now has the dubious privilege of pooing on to a paper plate for science. Do I think there's a yuck factor? When you're here, a little bit. But, you know, your kind of shitting into a box. But in terms of what happens to that and from there, I wouldn't say there's a yuck factor at all. It's easy for Izzie to say. She's not the one up to her elbows in it for the foreseeable future. The first day I didn't eat at all, cos I always wanted to spit because it was very unpleasant, to be honest. So... But after some days, I got used to it. Thilini is at the centre of the research team. Yeah, this is the worst part, Because it starts to get smelly, really. (BLENDER WHIRRS) She's working on her PhD, and it's her job to turn this into a miracle pill. She's had a job that most people would say was a pretty shitty job, right? No pun intended ` or maybe it was, but, you know, a shitty job. Next I am going to filter this and remove all the rubbish. So it has all the fibres and undigested food particles. She has a really, really important part in this, and what she has done has been critical to what we're trying to do now. So this is the most precious part, which is the bacterial pellet. So I'm going to transfer this bacteria, using a syringe, into these capsules. Sure, it now just looks like runny poo, but it's been transformed to liquid gold. Each capsule is packed full of the lean donor's living bacteria. The biggest challenge we face with this study currently is the encapsulation process. Can we get the bacteria into the capsules without them dying? Gut bacteria need very specific conditions to live in. It starts dying as soon as it leaves the body. As long as the die-off is minimal, the pills should still work. But nobody knows how quickly the bacteria will die off. They're relying on Thilini to tell them the extent of the damage, and she can't. We need to understand whether the bacteria can survive the encapsulation process itself, and then beyond that, how long can we store them at minus-80? The longer we can store them, the better, because then we don't have to coordinate donors and recipients on the same day, which is complicated. Yeah. You said that 4% or 5% were dead at an hour` as Justin said, two hours ` and then over the week, we don't understand how quickly they die off. Just 7.3% That's better. So 7%? Yeah. Just after one hour freeze. Yes. But how many times have you done this now, this experiment? Just one. So you've only done this once? Yeah. We need a few more of those. I mean, this experiment's a bit of a mess, Thilini, right? So we're going to have to tidy this up. I thought you had done this at more time intervals. So immediately before you put them into capsules, how many are dead? Straight after encapsulation, before freezing, how many dead? One hour, how many dead? And then, I think, one, three, seven days. We've done that each time. Yeah, but the first time, I didn't see any difference between one hour frozen sample and the processed sample. So after that, I didn't check it. You can't do that. It's one thing to be able to make the capsules, and it's another thing to be able to do safety testing on them, but you have to know what is happening. If you don't, then you're wasting your time. So this experiment is forming part of your thesis, right, and, I mean, you've got to have this done suitable for publication and suitable for us to be confident in the results. It may sound harsh, but the team will face intense international scrutiny, and any loose ends could bring their results into question. So if we're going down that route and we're gonna do this, we have to do it properly, right? Yes. But there is more trouble to come. None of the people that we've brought through are gonna be able to be donors in the study, and unfortunately, all of the capsules that she's made aren't going to be usable, so it's pretty frustrating for her. (DIRE MUSIC) (PENSIVE MUSIC) There's just three weeks to go until the Gut Bugs team start treating obese teenagers. It's a multi-million dollar gamble to see if their revolutionary remedy can solve the global obesity epidemic. And the theory they're testing? If they give an obese person the bacteria from a fit person's poo, will they lose weight? So, these are all the capsules that I made from different donors. So, now we nearly have 600 capsules, including today's samples. But there's been a hitch ` a major one. We have really stringent criteria for what is required in order to be one of our super donors. You have to be really metabolically fit, and you have to prove that there's no risk that they have an infection they could pass on to other people. Unfortunately, we've now got all of the infection screen tests back and not one person has actually been able to get through all of our criteria. All of the donors tested have shown to be carrying some form of infection. None of them are physically affected, but the team cannot risk transferring bad bacteria to the recipients, so 600 capsules worth of poo goes in the bin. Everyone was a little bit surprised and disappointed. We found that finding the metabolically healthy group has been hard, and then getting through all these extra hurdles is really hard as well. Nobody has been hit harder than Thilini. You now see how much of time I spend to make capsules. It's, like, just handmade capsules. I do it one by one. But because when I knew it, I had to throw them, you know it's going to be useless, so I was very frustrated. The rug's been pulled out from under us a little bit with this news. I think this is gonna put us back at least a couple of weeks. The Gut Bugs team are back to square one with no poo pills and no super donors. It's a race against time now. There's less than a month to replace the supply, and the volunteers are already on standby to start treatment. OK, so how did you even get in to this? So, like, on Facebook, it kept constantly appearing, like, 'Gut Bugs Trial' constantly. It was always in my feed. I'm Ashlee, I'm 18 and I'm currently on a gap year, so basically what I'm doing is just working full-time before going to university. See, I like these, but I know it doesn't fit my body very well. I've always had body issues. The first time I remember thinking I was fat, I was watching the Sugababes on the TV, and I was like, I'm not that thin. I'm definitely not a small. It's not for a lack of trying. Ashlee weight has yo-yo'ed for years. My weight is 95.6kg, whereas as of early last year it was 63kg. It's a long time, but it's a short time to get such an amount of weight. OK, that's my favourite. The word fat is something that people use against women ` especially women. I never hear, 'What a fat man'. It's more, like, find your originality. Please, I've heard that plenty of times. It's not like it's going to hurt me. I used to go into clothes shops, go clothes shopping with my friends and I'd hate it. I'd think, 'Oh, they look so gorgeous. I look terrible because I'm fat.' You know, last time I went shopping, I cried. It was depressing. Why'd you cry? Because I was` I don't know. I think it was sad trying things on when I wasn't happy. How are you feeling now? I'm feeling better. Good. I mean, I'm not crying. But then I went out drinking afterwards to fix my problems. That's not the solution, Ashlee. Is it not? It is sometimes. I'm quite confident in myself. I'm quite` I love myself now. For a very long time, I hated myself. I don't want to be thin, I want to be healthier. Thin won't make happy. It didn't make me happy last time; it won't make me happy this time. Being healthier will make me happier. While the trial is about finding a cure for obesity, the team wants to know if there are any other health benefits, so regular blood tests will also show if the treatment reduces the risk of diabetes, heart disease and other obesity related illnesses. So, here is my DEXA scan. It basically tells me about my bone density, my body fat mass to my height, things such as that. So, I am 166.9cm and currently I am 95.6kg. And basically what it's telling me is that I have 48% that's body fat. I was expecting to be 40% body fat. When I found out I was 48, I was kind of like, 'Oh, that's something,' but, to be honest, it's something I can improve on, so I'm trying to take it more as a positive thing. This is seeing how I am and how I can improve hopefully over the months. (UPBEAT MUSIC) Looks good. Tomato and cheese croissant? Is that yours? Yep, that's mine. Thank you. Great. Ham, cheese and tomato. Enjoy. Thank you! Thanks. So, how did your appointment go today? What did you do there? So, I go in and do questionnaires, they take my measurements of, like, my hips and waist. All the fun stuff (!) Next year at uni, I'm gonna get bigger anyway. Why? Cos I'm gonna eat noodles all the time. I won't be able to afford anything. Isn't that how you students live? You can` Yeah, no, it's true. I've had conversations at dinner parties about this whole study, and the responses are interesting. Invariably they are, 'You've got to be kidding.' It's just... 'This is outrageous, really.' And when I start to explain some of the science, they think that's really amazing. And then towards the end of the conversation, I often get asked, 'Well, when it works, can I have some?' Ask yourself, could you get over the ick factor, if poo pills meant you could still eat pastry and not pile on the kilos? The first obese teens should have started this revolutionary new treatment four weeks ago, but the trial came to a grinding halt when the team suffered a major setback. The trial has had some issues, you know. The entire stock of poo pills was flushed down the drain when it was discovered none of the donors passed the infection screening. And so it actually did impact on Thilini, because she was making the capsules, and then that had an impact on Wayne and I, as we started to get, you know, a bit more stressed that, 'Hey, this is all turning a bit pear-shaped', you know? It might all go down the gurgler. So until they can find four new super donors who meet the criteria, the trial is on hold, so Justin has some time to visit a local school to do a talk on the power of poo. So clearly this is a normal mouse. This is a fat mouse. OK, that's pretty obvious, really, isn't it? Now, let's look at these mice. Now, with mice you can do these really cool experiments cos mice are what we call coprophages. Do you know what a coprophage is? So, a coprophage is an animal who eats poo. (ALL CHUCKLE) OK? As silly as it all sounds, the idea for this trial isn't one they've plucked out of thin air. So, what you can do with mice is real simple. This little mouse here ` you can take its microbiome, right, its personal bacteria and viruses, which it poos out out the back, and you can feed them. So, you can take it from this mouse ` the fat one ` and you can take his microbes and you can feed it to this mouse. What happens if we do that? Does anyone want to hazard a guess? Yeah, right up the back. It becomes fat. Yeah, exactly, it becomes fat. Oh, hang on that should work the other way, right? So, if we take this dude and we take his microbes ` his good happy microbes ` and we feed them to this guy, he becomes skinny. So, a fat mouse given the bacteria from a very lean mouse can lose up to a third of its body weight. That's dramatic. Now, I would be stunned if humans are exactly like mice, but there could be major weight loss achieved from taking these capsules. Yeah. If you eat another animal's poo, would that change the way of your body? Yeah, so that would give the microbes from the animal. I'm not saying that what you should do is go out and eat poo, OK. (CHILDREN CHUCKLE) That's not what I'm saying, all right? You've got to be very careful about this, it's not go home and feed poo to your brother or anything like that. That would be very bad. Don't do that. Putting the incredible shrinking mouse to one side, there's plenty of evidence that shows humans have actually tried this before. I recognise that it seems distasteful, but that's just our hang-up, you know, in today's modern world. This actually is an ancient practice. Faecal therapy, was undertaken by ancient Chinese physicians. There's documentation of this that goes back to 500AD. Those records show that 4th Century Chinese physicians used faecal therapy to treat food poisoning and severe diarrhea. It was also used in Ayurvedic medicine in India, and it was even used by German soldiers in WWII to cure dysentery. But using poo as a medical treatment isn't restricted to the history bin. Modern science has been using faecal therapy for a number of years now. The poster child for the effective use of faecal transplant is a particular disease called clostridium difficil colitis, or C. difficile or C. diff. C. diff is a disease that causes life threatening diarrhoea that's incredibly difficult to cure. what someone discovered was that if one takes a patient who has C. difficil colitis, now into this inflamed gut, you put someone else's microbial community, low and behold, it actually takes, it actually establishes itself, and resolves the infection. And there's one particular case study that's very interesting for us. There was a woman who had this terrible diarrhoea and the donor clearly didn't have the awful diarrhoea. It was her daughter. This woman had been lean all of her life. Her daughter had a weight problem. She was overweight ` obese. After the transfer, that woman became obese. So, that was an unintended effect. C diff patients receive their treatment by a tube inserted in the throat or the colon. Our team thinks swallowing the bacteria in pill form would be easier. Creating those capsules is far from simple. Thilini's work was set back when she couldn't tell the team how long the bacteria could survive in the freezer. But now, after extensive testing, the verdict is in. The numbers of non-viable cells that we can measure stabilizes at about 40%. But we're pretty confident that, in fact, the bacteria that remain an alive component still cover a very large percentage of the population. So, once we get the donors, we're happy that we have the capsule process ready and that we can encapsulate and we can go for transfer. At last, there's good news on that front too. So, we've have made really great progress with the trial now. We now have our four super donors selected. So what you can see first is that you're about 67 kilos. Of that, 52 kilos is lean tissue, and about 12.5 is fat, so that means that your body is about 19.7% fat, and that's really low. The fun part (!) Ok, here is, basically, the toilet seat, and what you just pop that down there and away you go. Too easy. That's a lot of information, so I'm gonna go.. (CHUCKLES) and do a poo. With all four super donors on board, all that remains now is for the team to figure out the dosage. How much poo is too much? Great, so, there's a couple tests we've gotta do first. So, one's hold it in your mouth and see how long it takes to dissolve ` get a feel for that ` the second one is to hold it in their mouths, bite on them, and see how` whether or not they break easily, and then a third is to do the swallowing. WAYNE: Which is the 15? The capsules have been stored at -80 degrees. It should be crunchy if the contents are still frozen. Still crunchy. And they need to still be frozen when the girls take them. How's that one on the table doing? Ooh, it's really soft. That's too soft now, eh? And that's been at room temperature for five minutes. Well, we gotta start swallowing them soon, don't we? Just to be clear, these aren't actually poo capsules, they're capsules filled with saline and frozen to match the capsules the girls will be taking. Done. 40 seconds. One minute and 30` No, one minute and 40 seconds, yeah. The trial is a scientific first, and nobody knows how the girls will respond to swallowing the poo capsules. The risks for us on day one of treatment are that people start taking them and something goes wrong, and basically then they stop. Man, you must have a very wide throat to swallow them so fast. (CHUCKLES) They're designed and they're double encapsulated, so they should pass through the stomach and then dissolve as the pH changes when you go to small intestine. That's 3.10, man. That's fine. People have run marathons quicker. (ALL CHUCKLE) But, you know, things go wrong. Cos if we got a squishy one and someone's gagging and there is a bit of a taste or a smell or a reflux, then it's game over. They do need to swallow them straight away. We can't have them taste them and savour them. They'll come straight back up. Or you could have, you know, a farty burp. And that would be horrible and that would just put people off coming in. Really, it would. I mean, it would put me off coming back. Ideally, the teens take all the capsules in one sitting. So, what, are we going to try 30? Cos the question is whether we do 15 or 30, right? Yeah, OK, 15 more. Have we got 15 more? Yeah, but we know that you're not gonna swallow 30 in one day, though. We're gonna see if you can. Well, can you? I mean, I don't feel any` I can't feel anything. I feel stuck here. I feel them you know piled up down there. That was 15, was it? 30 is quite a lot. 30 is a large meal. There you go. Too much? My stomach's this big. Yeah, I think` 30 is too much. 30 is too much. That's it, then. After much deliberation, the teens will take the capsules over two days, and fingers crossed for no farty burps. Hi. Can please I have a large hot chocolate? The Gut Bugs Trial is just days away, and Maddie is ready for a big change. They say that New Zealand's one of the most obese countries in the world, and then me and my mum joke, we're like, 'Where are all the fat people?' Because we look around and we feel like the biggest people. I very much feel like eyes on me in any social situation. It's silly, cos I know people aren't looking at me. If you could look just behind my shoulder, like, above my shoulder. I'm currently studying nursing at Massey University, and giving presentations at university, I'm sitting there and I'm, like, OK, they're just going, 'What's that fat girl talking about nutrition for?' Its awkward when I've gotta be, like, 'OK this person needs to eat healthy and exercise regularly', and I feel very hypocritical trying to give that spiel. So I'm just gonna have a listen to your lungs. Just when I say, can you breathe in for me? Also with the nursing degree, we do a lot of labs and we have to bear all, which means generally stripping down to my bra, which is always a little bit uncomfortable, because I'm very much, like, well at least you get to see what it will be like on an obese person. Can you show me where your rib cage is? As a nursing student, Maddie understands the challenge of obesity more than most. There's a lot more to it than simply cutting out fatty food. I believe that obesity is to a greater level than just eating bad foods. There's gotta be something else, because people eat healthy and they're still fat. And they exercise and they are still fat. Are we fighting our biology in this current environment that we are in ` this current food environment? I think the answer is yes. Not everyone is fat so, why are there people that are fat and some people that are not, even in a situation when we get lots of food? Is it because some people are lazier than others? And I don't think so. I think what the genetics and biology now tells and shows us, is that some people feel slightly hungrier than others all of the time. 5% hungrier, you know a couple of percentage points hungrier. And so, because you feel hungrier you're gonna eat more. Imagine this over a lifetime. It's easy to not eat when you're not hungry, but it's very difficult to not eat when you are hungry, because we are designed to eat when we are hungry. With so much at stake, it's time to put this theory to the test. It's six weeks overdue, but at long last, it's launch day. This study has been planned for a long time ` more than a year, more than 18 months. But today we have our recipients. These are the people that we want to treat, and we wanna understand ` will this treatment make a difference? If the treatment is a success, it means the team's hard work won't go to waste. But the stakes are just as high for the teens. They could turn their lives around. Today I am taking the first pill for the Gut Bugs Trial. Over the next few days, the Gut Bugs team will treat the young women. It's the first wave of the trial, which will treat 80 teens in total, and the girls need to start with a blank slate. I had to take something called Glycoprep, which is like a laxative that they use to clear the colon and the bowels completely. And it worked! (CHUCKLES) They say that real change starts inside. And for the next six months, the girls will literally be changing what their gut is made of. You looking forward to it? Yeah, it should be good. I'm excited, but, yeah. First day. Very interesting. Yeah, I know. Something different. Saskia is the youngest of our volunteers. She's 17 and in her final year of high school. I dunno, I'm just hoping for the best, I just wanna get it underway. You want to make it success. She's focused on that success ` on those indicators. We're achieving steps along the way, and I think she's looking forward and she wants it now done. She knows it takes a bit of time, but at the same time, you know the youth of today if we can have it now it would be even better. But it gets there, it just takes time. One step at a time. Good step today. Alofa is 19 and in her first year at university. I don't feel too bad. Sort of excited, hopeful. So last night, I drank my glycol prep, and that was supposed to remove my bacteria from my stomach and then I'll be replacing it today with the capsules. And last but not least, 18-year-old Ashlee. So I believe it's 16 pills today and I have 30 minutes to drink the water and the pills. She's also had a successful response to the Glycoprep. (LAUGHS) Basically I was in the bathroom for about 20 minutes. I'm good to go! Now everyone's bowels should be clean as a whistle ` rid of the bacteria that may be adding to their weight problem, and ready for a helping of new, healthy bacteria. I'm really excited now. We've been plotting and planning and designing and anguishing and chasing funding for this study for a very long time, and it's happening. We've got donors and we've got recipients, and we're about to treat them, and, you know, this is like launching an Apollo rocket. We're right there, and we're about to hit the 'go' button. Open this up. These are the treatment capsules in little packets of four. So, I can do two at a time? If you want to. It hasn't been easy getting here, but now is the moment of reckoning. It's easier than I thought, to be honest. I thought they were gonna be bigger. We know that the capsules are tasteless, odourless, flavourless. The issue is if they break down a little too quickly on the way, could that result in some sort of funny after taste? Farty burps, basically. How many pills are there tomorrow? 12. Ah, OK. It's, like, you're sort of six weeks away from the first assessment of people where maybe we will start to see shifts. You're welcome to take a little break if you want to. (ALOFA CHUCKLES) I feel like I need to get it done as fast as I can. Cool. If all of a sudden, there's half a dozen people turn up and they have all lost sort of body weight then it starts to become very, very exciting. Sometimes I'm like, 'Wow, this could actually be amazing, ground breaking technology that will save lives,' because obesity does kill people. Obesity is one of the most risky and expensive health issues of our time. If this trial is a success, it could be the breakthrough that eliminates it permanently. Yeah, right now, I think everyone's kinda on the edge of their seat and just, sort of, like, excited. Next time... I really just want donuts. Will the girls' diet kill off their new bacteria? It's always takeaways. Cool, thank you! It's all the time. That funny girl is covering up a bit of a sad girl under there that's struggling with other issues. And the trial gets messier than expected. Could we have just given her an infection that causes diarrhoea? I'm not gonna be discouraged, like I am right now. I'm gonna be positive. And with the first weigh-in coming up, the girls are put to the test.