Curator Dr Johanna Simkin has built a dark and ethereal space, lit up by technicolour microbes that swim, crawl, scuttle and ooze across the walls.

"We wanted to do it like this because it does seem like magic – how does my gut do this to my brain? What are these little magical creatures controlling my behaviour and mood?” she says.

There are more microbes in your body than human cells. There are, in fact, more microbes in you than there are stars in the Milky Way.

"Every time you hear one of those factoids, it's like: what!," Dr Simkin says, as she walks deeper into the exhibit.

After spitting in the tube, visitors are invited to place their hand against a wall. Instantly, neon microbes appear, seeming to crawl from your hand up and into the exhibit.

It’s a visual demonstration that you are you, but you’re also microbes.

“We're trying to break through the stereotype about them being icky straight away: they are good, they are beautiful,” Dr Simkin says.

Inside the exhibit, a map traces the neural superhighway that runs between gut, the immune system, and the brain.

When gut bacteria digest food they like, they release chemicals which cut inflammation. But a diet full of foods they don’t like – junk food – could increase your chances of anxiety and depression.

There is a soft wall covered in rubbery 'fingers', so you can feel what your small intestine (which most of your microbes call home) feels like. And a video game where players compete to eat things your bacteria like (vegetables) and avoid things they hate (ice cream, antibiotics).

Just down the hall sits a fatberg: a giant and disgusting lump of congealed fat and disinfectant wipes that clogged up a sewer pipe somewhere in Melbourne; Yarra Valley Water had to cut it out.

Fat from our junk-food-filled diets, and bacteria-killing disinfectants. Both things that our gut bacteria hate, says Dr Simkin, shaking her head.

We come to the final room of the exhibit. “Did you notice how the pink walls are like the walls of the intestine?” asks Dr Simkin. “Well, this our conceptual anus. The poo room.”

The poo room is dedicated to the medical powers of poo, which seem near-miraculous.

Having a community of microbes that is out of balance can make us very sick. To fix that, scientists have recently pioneered poo transplants, replacing the unbalanced microbes with new, healthy ones.

The procedure already being used to treat a range of intestinal conditions such as ulcerative colitis. 'Crapsules', little tiny freeze-dried pieces of poo which can be swallowed, are hitting the market soon as well.

Finally, the exhibition ends with Dr Simkin's“Instagrammable moment” – a room filled with pictures of the foods your microbiome will love you for eating. Fruits, vegetables, yoghurt, kombucha and kefir.

The message is simple, says Dr Simkin. Love your bacteria, and they will love you back.