You Are What You Eat: Red Algae Specimens Illustrate Odd Insights into Gut Health

For the first time ever, the National Herbarium of Victoria at Melbourne Gardens has loaned specimens from the State Botanical  Collection to Melbourne Museum to feature in their ‘The title is Gut Feelings: Your Mind. Your Microbes.’ The exhibition will explore the links between our mind, gut and microbes in a range of engaging and interactive demonstrations—one of which highlights an unusual instance of human gut microbes ‘borrowing’ DNA from marine microbes.

This example involves an enzyme produced by marine microbes that are able to break down the cell walls of red algae. These microbes are found on some of the seaweeds used to make sushi and, unsurprisingly, they cannot survive in the ecosystem of the human gut. Amazingly, a 2010 study found that the algae-busting enzyme produced by these marine microbes was present somewhere other than in the ocean, that is, in none other than the gut bacteria of Japanese people! This extraordinary situation is believed to be the result of lateral gene transfer between the marine microbes and human gut microbes. This groundbreaking study provided the first clear evidence that marine bacteria have been able to transfer genes to our own gut microbes.

Royal Botanic Gardens Victoria, Herbarium Collections Manager, Pina Milne, was asked to provide the exhibition with specimens of the red alga Porphyra to act as a visual aid to accompany the feature, allowing visitors to see exactly what the algae targeted by the enzymes looks like. As specimens can only be out of collection for three months at a time, three different specimens will be used over the course of the exhibition.

The plant specimens held in the National Herbarium of Victoria (some of which date back to the 1690s) offer a wealth of information that serves a wide range of purposes. They're used by researchers all around the world for research, helping us to better understand biodiversity, to assist with identifying new species, and to track rare and threatened species to inform conservation practices. The collections are an invaluable resource that can used to gather evidence of climate change, whilst also being a important source of work and inspiration for botanical artists. Moreover, the collections provide insight into family histories through the collection data attached to even the oldest specimens. The Herbarium specimen collection continues to be databased and digitised, an immense job involving a dedicated team, but those collections that have been processed can already be accessed via the Australasian Virtual Herbarium ( This massive database of plant specimen information can be freely used by researchers and the public alike.

What: Gut Feelings: Your Mind. Your Microbes.

Where: Melbourne Museum

When: 16 March 2019 - 2 February 2020

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