Gut Bugs for Medicine
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Gut Bugs for Medicine Could changing our microbes improve our health? Gut Bugs for Medicine COULD CHANGING OUR MICROBES IMPROVE OUR HEALTH? Alistair Kwan, Suzanne Trask Wayne Cutfield, Justin O’Sullivan, Thilini Jayasinghe, and Jacquie Bay Liggins Institute First edition 2019 Liggins Institute University of Auckland Private Bag 92019 Victoria Street West Auckland 1142 New Zealand www.lenscience.auckland.ac.nz [email protected] © the authors 2019 © University of Auckland 2019 ISBN 978-0-473-50624-7 (print) ISBN 978-0-473-50625-4 (e-pub) ISBN 978-0-473-50626-1 (PDF) This booklet is part of a suite of learning and teaching resources whose production was generously funded by the Norman F.B. Barry Foundation. The photograph of Thilini Jayasinghe (page 12) is used with her permission. The photographs of Wayne Cutfield and Justin O’Sullivan (page 12) are used with permission from Greenstone Films. The engraving of a 19th-century microscope (page 5) is from Jabez Hogg, The microscope: its history, construction and application (London: Routledge, 1898), p. 94. Other images in this publication were drawn by the authors or are used under license from iStock or from the University of Auckland. 4 Contents Who and what live where? 6 Microbes on and in our bodies 8 Friends and foes 10 Mice on microbes 12 The Gut Bugs team 14 Gut Bugs—study design 16 Thilini’s work 17 Making capsules from poo 18 ...and poo-free placebos 19 Is it worth it? 20 What happened next? 21 Living better with our microbes 22 Glossary 25 A note for teachers 26 5 Who and what live where? Here are some people who live near a beach. What animals and plants would also live there, or might pass through? How about at night time, or at different times of year? Or in different weather? What different animals and plants would people see if they lived by a forest, or in the mountains? Anywhere people live, there are usually other people living, too. And there are always lots of other living things. VI TI T C Y Some living things come and go, like a lot of birds and flying Who and what live A insects do, and people who come to work during the day. Some around you? living things, like trees and worms and our pets and our neighbours, live there all the time. More than three hundred years ago,there was a man who bought and sold cloth for a living. He wanted a microscope to check the quality of his cloth but he couldn’t buy one that was powerful enough. So he made his own! This cloth seller looked closely at his cloth. Then he got curious and looked closely at other things, too. When he looked at other things, he was surprised to find tiny creatures moving around. He found them in water and dirt. He found them in plaque from his teeth and in his snot. He even found them in his poo. No one expected that these tiny creatures were there! Discovering them was the beginning of a new branch of science. Today, we call these creatures microbes. And they’re living all over us! Trillions of them! 6 microbe: a living thing so tiny that you need a microscope to see it VI TI T What you know about microbes already? Y C A Do you imagine things like in the picture on the left, or in the diagram below? Do you think microbes are good or bad? Clean or icky? Scary? Tasty? Useful? What do other people think? Ask around. PROTISTS VIRUSES e.g. amoeba, e.g. common cold virus, algae measles virus BACTERIA microbes e.g. Salmonella that MOULDS causes food poisoning, Lactobacillus that e.g. Penicillium on makes yoghurt bread, Rhizopus in FUNGI cheese YEASTS e.g. Tinea that causes athlete’s foot, Saccharomyces for making bread VI TI T C Y A You’ve probably heard of some of the microbes in the diagram above. What do you know about them already? What other microbes could you add? 7 Microbes on and in our bodies If you look on our skin, there are trillions of microbes to be found. WHAT AFFECTS MICROBES? Why do they live there? What do they do? How did they even get there? VI TI T C Y In one study, scientists asked volunteers A to rub cotton wool in their bellybuttons. The volunteers mailed the cotton wool to nutrients wetness the scientists. The scientists looked at the cotton wool to see what bacteria it had picked up. Some of their findings are below. What do you make of them? acidity light BACTERIA IN BELLYBUTTONS The scientists The scientists found received bellybutton swabs from 649 kinds 279 of bacteria in the warmth oxygen bellybutton swabs. volunteers. VI TI T C Y Think about some other enviroments A We have special inside your body. We have a lot in differences: they common: found How are they similar? 15 kinds 189 kinds of bacteria were of bacteria that How are they different? found in at least half were in no more than of the bellybuttons. one bellybutton. What adaptations do their microbes need? Different kinds of life need different things adaptation: something that makes it easier to live to live. What do you need to live? What do in an environment cats need? What do goldfish need? Different kinds of life get what they need from the environments where they live. skin in there. Bellybuttons are a little bit acidic, too. Microbes that live in bellybuttons are What is the environment like in our adapted to the bellybutton environment. bellybuttons? Our bellybuttons have a lot of oxygen, but not much water or nutrients unless Our bodies have other environments, too. Their you eat the little bit of sweat, skin oil and dead microbes have other adaptations to match. 8 Most of the time, many different kinds of SOME ENVIRONMENTS microbe end up living together. IN OUR BODIES Some microbes eat what’s around them, like sheep and goats eat plants that they find. conjunctival: around the eye Some microbes hunt and eat other microbes, like cats and wolves hunt other animals. buccal: in the mouth Some microbes work with other microbes, giving each other food or protection. nare: in the nostril These microbe communities are a lot like the animal and plant communities (ecosystems) skin that we know all around us. They are called microbiomes. stomach armpit What word do scientists use to describe VI TI T C Y different kinds of organism living A together? The body’s biggest microbiome is in the large intestine, or colon. Around a trillion microbes live there. They can weigh as much as two kilograms! Scientists are still counting them, but it seems that most people have around 500 different kinds of microbe in their gut. Our colon microbes get their nutrients and water from what we eat. The colon is a warm, dark, low-oxygen place for microbes to live. colon small intestine We get something from our microbes, too. Our (large intestine) microbes help us digest our food. microbiome: a community of many kinds of microbes Scientists have figured out that it’s VI TI T C Y possible to change the gut microbiome. A What could be some ways to do this? Why would some people want to change their gut microbiome? 9 Friends and foes Sometimes microbes make us sick. Microbes cause sicknesses like colds and ’flu and measles. Microbes can get into our cuts, eating us and poisoning us with their waste. It’s Anti-Biotic usually bacteria that do this. + Cure KILLS 99% Thousands of years ago, Egyptian doctors put OF BACTERIA mouldy bread onto infected cuts. The mouldy bread helped the infection to heal. Today, we understand that those infections were caused by bacteria, and bacteria are killed by antibiotics made by the bread mould. Antibiotic drugs now come in bottles. The first antibiotic drug was Penicillin. It came from the Penicillium fungus. It took until 1928 for scientists to make this antibiotic drug. Some science problems take a long, long time to solve! Sometimes bacteria in our guts make us sick. Thousands of years ago, Chinese and Arab They give us diarrhoea and make us vomit. doctors treated bad gut sicknesses by getting We could take antibiotics to kill them, but patients to drink a medicine made from poo. antibiotics would kill a lot of good bugs living We think it was basically a poo smoothie. They there, too. And some bad bacteria aren’t hurt by used both human poo and camel poo. antibiotics! VI TI T C Y A Poo is full of microbes. How could eating poo help a patient with an infected gut microbiome? Here is a healthy and diverse gut Here is an infected gut microbiome. How many kinds of What does “diverse” mean? How microbiome. How many kinds of microbe do you count there? is diversity important? microbe do you count here? For a long time, we thought that germs must be bad, and poo must be bad. But today, doctors are again using poo to treat bad gut infections that antibiotics cannot cure. How do you think that is done? 10 Recipe: A refreshing microbe drink—don’t try this at home! Today, there are medical clinics that specialise in treating the gut microbiome. The treament works like this. VI TI T C Y 1. Ask a healthy person (the Why does the poo need A donor) for a good poo.