Chronic diseases, like heart disease and diabetes, disproportionately affect Aboriginal and Torres Strait Islander peoples and are a leading cause of death in these communities.

These chronic disorders have been linked to Westernisation, particularly processed diets high in sugar, fats and additives.

In non-Indigenous communities, Western diets have been shown to reduce the diversity and composition of the gut microbiome – the trillions of micro-organisms that live in our digestive system which are essential for our health.

But in remote Indigenous communities, it remains unknown whether such changes are present in early life, are transmitted across generations, or are acquired throughout adulthood.

Study lead, Professor Leonard Harrison, said his team’s findings address this knowledge gap by showing Indigenous infants aren’t born with a gut microbiome associated with chronic disease.

“Indigenous infants start life as some of the healthiest Australians, but statistics show this drastically changes over time,” Prof Harrison said.

“The richer and more diverse a person’s gut microbiome is, the less chance they have of developing chronic diseases.

“Our team wants to learn how we can preserve the remarkable gut microbiome First Nations Australians are born with and protect them against developing chronic diseases later in life.

“Preserving this natural health advantage that we now know they are born with would be a major step in closing the health gap.”

The Doherty Institute and WEHI researchers worked closely with Elders and Indigenous health workers in remote Northern Territory to co-design the child gut health study that collected samples from 50 Indigenous infants.

These samples were then compared with data from non-Indigenous infants of the same age and sex, collected through the ENDIA study – a world-first longitudinal study tracking nearly 1500 children across Australia to understand what causes type 1 diabetes.

The Indigenous infants displayed markedly greater diversity and abundance of beneficial bacteria, viruses and fungi – some of which have now vanished from the gut microbiomes of non-Indigenous Australians.

The University of Melbourne’s Professor Beverley-Ann Biggs, Head of Global and Indigenous Health Group at the Doherty Institute, who spearheaded the field study, said the absence of these bacteria in non-Indigenous people shows how Western lifestyles have reshaped the gut microbiome over generations.

“Despite the mothers having access to Western foods, Indigenous infants retain a highly diverse gut microbiome, rich in fibre-degrading bacteria and balanced in ways that support strong early immune development,” Prof Biggs said.

“Our work provides an important window into how lifestyle, culture and environment shape biology from the very beginning of life.

“By reconnecting microbiome science with Indigenous perspectives and lived experiences, we have an opportunity to design nutrition, maternal-child health and chronic disease prevention programs that respect cultural strengths while addressing modern health challenges.”

Researchers hope to track the gut microbiomes of these study participants at varying time points in the future, to monitor how their gut microbiomes change and why.