Tracking bacteria as they trek from gut to gut

Research Lives: Dr Hilary Browne, senior lecturer, School of Microbiology and APC Microbiome Ireland, University College Cork

What kind of research do you do?

I am interested in how beneficial gut bacteria transmit between people. Our mothers give us a microbial starter kit when we are born, some of these species can stay with us pretty much for life.

Then we acquire other bacteria from the people around us, including other family members. A diverse gut microbiome is health-associated, so it’s important to understand how bacteria spread from person to person.

How do we share gut microbes with others?

It’s mainly through the faecal-oral route. It probably happens when someone doesn’t wash their hands thoroughly after using the toilet and then they touch a surface. The bacteria sit on that surface and transfer from there on to to your hand, and you put your hand to your mouth.

Blocking faecal-oral transmission is central to preventing infection by harmful gut bacteria, but beneficial gut bacteria also move from gut to gut this way. It highlights how much we still have to learn about our gut microbiome and, yes, you still need to wash your hands.


What do you look at in these bacteria?

I’m interested in how the microbes survive that journey from gut to gut. The bacteria that live in our intestines are mostly anaerobic, which means they die when exposed to oxygen. But some can protect themselves during transfer by forming spores, which can sit dormant for months in some cases and then spring back to life when they get back into the gut. I have a new European Research Council (ERC) funded project called SYNergize to understand these processes better.

How did you develop an interest in microbes?

I always had an interest in biology. I grew up on a farm in Cork, and I studied agriculture initially and then biotechnology. I moved to the Wellcome Sanger Institute near Cambridge in England and worked on pathogen genomes, including the disease-causing bacteria Clostridium difficile, which can form spores.

The ERC project is widening that work to beneficial bacteria too. We want to understand how spore-forming bacteria can be used to help protect against disease-causing bacteria.

ERC funding is difficult to secure, what’s your secret?

I have been very lucky to be trained by some of the leading researchers in the field, they have been really encouraging and they have challenged me to push forward. I have just moved back to Cork to the School of Microbiology and APC Microbiome Ireland, and again I am surrounded by microbiome experts.

What do you wish people knew about the microbiome?

Studying gut microbiomes is complicated! To get strong signals about the microbes associated with health and disease, we need to look at the microbiomes of hundreds or thousands of individuals. Also, most scientific research has focused very much on European and North American populations, so we lack a good understanding of microbiome evolution in other parts of the world.

And how do you take a break from research?

We have small kids and I still have a lot of relatives living around Cork, so I spend a lot of my time outside work with family.

Claire O'Connell

Claire O'Connell

Claire O'Connell is a contributor to The Irish Times who writes about health, science and innovation