It is a substance many people take to achieve good gut health, commonly found in yoghurt and fermented vegetables like kimchi and sauerkraut.
But marine researchers think probiotics could help corals grown in aquaculture fight off disease and make them more resilient to stress once planted on the Great Barrier Reef.
A project investigating the possibility comes at a time when reef restoration efforts to address Great Barrier Reef challenges such as salinity, runoff, fishing, and climate change are in the spotlight.
In March, surveys of the Great Barrier Reef confirmed the World Heritage site had suffered a mass bleaching event during summer, the fourth event of its kind since 2016.
Townsville researchers are trying to develop corals that are more heat tolerant to plant in vulnerable areas.
But many do not make the journey due to disease.
Lone Høj, from the Australian Institute of Marine Science (AIMS), believed probiotics could be a game changer.
"It's about seeing if we can develop probiotics to help coral during an aquaculture production phase," Dr Høj said.
"If we are going to do this, we need to make sure that their health is supported through the aquaculture phase."
Probiotics are "good bacteria" commonly used to improve the gut microbiome.
The efficacy of probiotics in human health has been contested.
But Dr Høj said the right strain of bacteria would "perform antibacterial activities" when used on coral.
"They help fight off opportunistic pathogens that might take over if the coral is stressed," she said.
The AIMS study will test the efficacy of 85 different bacterial strains in search of the most successful.
In the meantime, researchers will monitor the success of probiotics that were used on coral during the annual spawning event in 2021.
Making waves in coral research
Probiotics have proven effective in fish and prawn aquaculture and is now a billion-dollar industry globally.
Townsville-based aquaculture Professor Dean Jerry said, in some cases, "good bacteria" increased survival rates by up to 60 per cent.
"Aquaculture animals live in an environment where they constantly ingest microbes in the water," he said.
"Sometimes those microbial communities in their stomachs can get out of sync and cause disease.
Professor Jerry said the use of probiotics on coral was new.
"But this whole idea of us being more aware in managing the microbiome, of any type of organism, is gaining traction," he said.
Dr Høj and her team were using probiotics on a small scale, but they soon hoped to upscale dramatically.
Restoration just 'buying time'
While research scientists believe reef restoration efforts have turned a corner by incorporating the use of probiotics, others warn projects of this scale will only buy time.
Professor Peter Harrison, the Director of the Marine Ecology Research Centre at Southern Cross University, said greater action on climate change was needed.
"Many research teams on the Great Barrier Reef and around the world are looking at different ways of trying to increase the rate at which we can put new coral onto these damaged reefs, which aren't naturally recovering," he said.
"We will not be successful at restoring parts of the Great Barrier Reef if the impacts of climate change are simply going to overwhelm the processes within coming decades."
