What can poo do for you?

This is a guest blog article written by Sarah Bailey.

Don't be put off by the title! Scientists often collect bodily fluids (or solids, in the case of poo) as they can provide very useful information about how the body works. In Life Study, a ground breaking new project aiming to follow 60,000 babies from birth into childhood, we use these waste products to answer questions about one of the most topical research questions around: how do microbes in our guts affect health throughout life?

What is Life Study?

 

The Life Study logo.Source and copyright: Life Study.

Life Study is a cohort study; it’s recruiting 60,000 babies (and their mothers and fathers) to follow them into childhood and try to find out how events that happen early in life might affect long-term health. The study is run by researchers at University College London and is divided into several parts. My own work focuses on infection and immunity, and I’m trying to discover how bugs such as bacteria and viruses influence the immune system in early life, and what the knock-on affects are as children grow up.

Since the 1980s, when Dr David Strachan came up with the hygiene hypothesis, we’ve shown a growing interest in microbes and how they shape our health throughout life. Our bodies are full of bugs, both on the surface of our skin and inside, especially in our digestive system. Life Study plans to investigate how the microbes that first appear in our guts might affect health later in life by collecting samples from babies, and their mothers, around the time of birth.

Right from the beginning, we’re collecting samples: eight of them; cord blood, placenta, a vaginal swab from mothers, saliva from babies, and urine and faeces from both mothers and babies. These samples will help us find out how babies get their microbes and how their immune system responds to infection around the time of birth. For me, the most interesting of these samples are the oh-so-glamorous poo samples. These are the ones that will tell us which microbes end up inside babies and are thought to have the biggest effect on health.

Mouse-over text: One of the Life Study lab technicians extracting DNA from a poo sample. Source: Sarah Bailey.

Why study microbes in poo?

It’s thought that around one trillion microbial cells (that’s a 1 with eighteen zeroes after it!), known collectively as the microbiota, inhabit the healthy human gut. That’s more bugs than all the cells in our bodies! Because of this, the microbiota, now thought of as a sort of organ, is becoming incredibly popular with scientists and the media. Films such as Microbirth and articles in the New York Times, Wired magazine and, more recently, BBC Focus Magazine along with probiotic foods such as Yakult, and the development of “poop pills” (or, to give them their posh name, faecal transplants), have got people talking about the wider role healthy microbes may have in human well-being. Feeding the discussion is the huge increases seen in eczema, asthma, and obesity over the last thirty years: more and faster than can be explained by evolution. Many studies have tried to find out why, and several have suggested that these conditions might be caused by imbalances in gut microbes, but no one has quite figured out how yet.

So what’s different about Life Study?

 

So far, studies that have looked at the microbes in poo haven't been able to answer a lot of the questions scientists have. Studies are frequently in adults, often don't include enough people, and tend to focus on looking at what bugs are there rather than any effects on health. Even if babies are the subjects, they're sometimes not followed for long enough to find out whether or not they get ill. Add all of this up, and it's been hard for scientists to get any clear answers. The difference with Life Study is numbers. We’ll have thousands of babies to get samples from, find out which microbes are there, and will follow them up long-term to see how many get ill. This means we can maybe even look at possible links with rare diseases. Then we’ll use all the data we collect to find out if there’s a link between microbes and health. For the first time, we're going to be able to find out how health is shaped from the very beginning of life, and that’s really exciting!

What will we find out?

 

To start with, we want to find out which microbes are present in babies' poo, and where they come from. Is it just from mum? We’ll also look whether there are any differences between babies born by caesarean or vaginally, and how being given antibiotics around the time of birth might affect the bugs that are present. But this is only the tip of the iceberg, and over the coming years as technology improves and the babies grow up, we hope to discover a lot more about how microbes, and infection, affect us.

And, more importantly, what’s the point?

 

Ultimately, we're aiming to find ways to improve health. Maybe we'll find out that giving antibiotics around the time of birth is really bad because it kills off certain other microbes, causing an increase in the chance of developing disease a few years later. Could we then find a way to replace the microbes that have been lost so that we could restore the microbiota and avoid disease? If we can prevent disease, then the potential impact of our research is huge, and that's exciting. Poo might be a taboo topic for many, but it's just possible that the future of improving health lies with the very small but very many bugs that live in our guts...

Sarah Bailey Author Bio:

 

Article author Sarah Bailey.

Sarah is a Research Associate at University College London’s Institute of Child Health. She studies how infections and microbes affect health from the moment a baby is born throughout life. She holds an MSc in Immunology of Infectious Diseases from the London School of Hygiene and Tropical Medicine and an MPhil in Epidemiology from the University of Cambridge. After working as a systematic reviewer producing National Institute for Health and Care Excellence (NICE) guidelines at the Royal College of Obstetricians and Gynaecologists (RCOG), she now works on the Infection and Immunity Enhancement to Life Study, a major new birth cohort following 60,000 babies from birth through into childhood and beyond.

For more reading about our microbiome, check our article.
You can visit the Life Study site here.