Young adults with metabolic syndrome or fatty liver show gut microbiota alterations, hinting at future cardiometabolic risk.
A large population-based study of young adults has shown that metabolic syndrome (MetS) and steatotic liver disease (SLD) are associated with distinct gut microbiota alterations, even before clinically apparent disease develops.
The findings from the Raine Study cohort in Western Australia were presented at the World Congress of Gastroenterology at Australian Gastroenterology Week 2025, held in Melbourne last week, and published in the Journal of Gastroenterology and Hepatology.
The results underscore the potential for gut microbial signatures to serve as early biomarkers of metabolic dysfunction and highlight links with future cardiometabolic risk, the researchers say.
The research, led by Yasmina Tashkent and colleagues at Flinders University, the South Australian Health and Medical Research Institute, and collaborating institutions across Adelaide and Perth, examined 558 participants from the Generation 2 Raine Study at age 27 years.
Hepatic steatosis was measured using a validated MRI-derived volumetric liver fat fraction (HepaFat) equation, with SLD defined as a liver fat fraction above 3.55%. MetS was classified using International Diabetes Federation criteria, and faecal microbiota composition was characterised via 16S rRNA gene amplicon sequencing.
In this cohort, 4.7% of participants met criteria for MetS and 17% had SLD. Notably, three-quarters of those with MetS also exhibited hepatic steatosis, reflecting the overlap of systemic and hepatic metabolic dysfunction at an early life stage.
Both MetS and SLD were independently associated with reduced gut microbial alpha diversity and significant shifts in overall community structure, with effects persisting after adjustment for sex and alcohol intake.
Related
These alterations were more pronounced in individuals with both conditions, who also exhibited microbiome features distinct from those with SLD alone.
Taxonomic analysis revealed enrichment of Lachnoclostridium in participants with either condition.
Distinct microbial signatures further differentiated the two phenotypes. MetS was characterised by increased abundance of Flavonifractor and Tyzzerella, taxa previously linked to adverse cardiometabolic profiles, while SLD was associated with higher relative abundance of Prevotella.
These findings align with earlier reports connecting specific microbial taxa to inflammation, metabolic dysfunction, and cardiovascular disease risk, the researchers said.
The authors suggested that microbiome features could ultimately be harnessed as biomarkers to improve early detection of metabolic risk, offering opportunities for preventative interventions at a stage where lifestyle or microbiome-targeted therapies may be most effective.
While causal relationships remain to be established, the findings lend support to the concept that gut microbiota play an active role in shaping metabolic health trajectories from early adulthood.
“Alterations in gut microbiome composition are evident in younger adults with MetS and SLD, even in the absence of clinically apparent disease,” the authors concluded.
“These microbiome features may represent early biomarkers of metabolic dysfunction and are consistent with microbial profiles associated with increased cardiovascular disease risk.”
The WCOG@AGW 2025 meeting was held in Melbourne, Australia from 19-22 September 2025. The confluence of World Congress of Gastroenterology and Australian Gastroenterology Week occurs once in a generation.
The scientific program covered all aspects of gastroenterology and hepatology, with more than 20 international speakers, each expert in their area of research.