Changes in the microbiome and metabolome in captive red kangaroos ( <i>Osphranter rufus</i> ) affected by macropod progressive periodontal disease

Macropod progressive periodontal disease (MPPD) is a severe oral condition frequently observed in captive macropods, particularly red kangaroos (Osphranter rufus), yet its underlying biological features remain poorly understood. In this exploratory descriptive study, we investigated oral and fecal microbiomes and metabolomic profiles in captive red kangaroos to characterise microbial and metabolic patterns associated with MPPD. Oral swabs, fecal samples and serum were collected from clinically healthy individuals and animals diagnosed with MPPD. Microbiome profiling was performed using 16S rRNA gene sequencing, and untargeted metabolomic analyses were conducted using GC-MS. All analyses were conducted in a descriptive manner to summarise observed patterns and trends rather than to support formal statistical inference. Descriptive comparisons suggested differences in the oral microbiome composition of animals with MPPD, including increased representation of several taxa previously associated with periodontal disease in other species. Oral metabolomic profiling indicated variation in multiple metabolites, including lower relative levels of guanosine higher relative levels of suberic acid and lower relative levels of L-octanoylcarnitine and adipic acid in affected animals. In contrast, fecal microbiome and serum metabolome profiles showed comparatively limited variation across groups. Although limited by small sample size, this study provides preliminary, descriptive observations on microbiome and metabolome features associated with MPPD in captive red kangaroos. These findings offer an initial framework to inform future hypothesis-driven investigations using larger cohorts.