Integrative multi-omics analysis reveals oral microbiome-metabolome signatures of obesity.

Obese participants showed altered oral microbial alpha and beta diversity compared to matched controls.

• Study analyzed 97 obese individuals and 95 matched controls from a prospective cohort of 628 Emirati adults.
• Multi-omics profiling included oral microbiome sequencing and metabolomics.
• Alterations in microbial diversity were observed at both the compositional (beta diversity) and richness/evenness (alpha diversity) levels.
• This represents what the authors describe as 'the most comprehensive oral microbiome analysis to date.'

Proinflammatory bacterial taxa Streptococcus parasanguinis, Actinomyces oris, and lactate-producing Oribacterium sinus were enriched in obese participants.

• These taxa were specifically identified as enriched in the obese group relative to matched controls.
• Oribacterium sinus is described as a lactate-producing organism, linking its enrichment to metabolic shifts.
• Streptococcus parasanguinis and Actinomyces oris are characterized as proinflammatory.
• These findings implicate specific oral microbial taxa in obesity-associated inflammation and metabolic dysregulation.

Pathways for carbohydrate metabolism and histidine degradation were upregulated in the oral microbiome of obese individuals.

• Functional analysis revealed upregulation of carbohydrate metabolism pathways in obese participants.
• Histidine degradation pathways were also upregulated in obesity.
• Pathways associated with obesogenic metabolite production were elevated.
• Conversely, B-vitamin biosynthesis and heme biosynthesis pathways were depleted in obese individuals.

Specific oral metabolites including lactate, histidine derivatives, choline, uridine, and uracil were elevated in obese participants and correlated with obesity-linked cardiometabolic markers.

• Elevated metabolites in obese individuals included lactate, histidine derivatives, choline, uridine, and uracil.
• These metabolites corresponded to the microbial functional pathway alterations identified in the same participants.
• The elevated metabolites were found to correlate with obesity-linked cardiometabolic markers.
• The metabolome data were generated alongside microbiome profiling as part of the integrated multi-omics approach.

B-vitamin and heme biosynthesis pathways were depleted in the oral microbiome of obese individuals.

• Depletion of B-vitamin biosynthesis was identified as a functional signature of the obese oral microbiome.
• Heme biosynthesis pathways were similarly reduced in obese participants.
• These depletions contrast with the upregulation of carbohydrate metabolism and histidine degradation observed in the same group.
• The findings suggest a broad functional reorganization of the oral microbiome in obesity.

The gut microbiome has been implicated in obesity, but the contribution of the oral microbiome as the body's second largest microbial ecosystem remains underexplored prior to this study.

• The authors identify the oral microbiome as 'the body's second largest microbial ecosystem.'
• Obesity is described as 'a leading global health challenge and risk factor for cardiometabolic disorders, driven in part by industrialization and low-fiber, ultra-processed diets.'
• Prior research has focused predominantly on the gut microbiome in relation to obesity.
• This study addresses the gap by providing what is described as 'the most comprehensive oral microbiome analysis to date' in the context of obesity.

The study cohort consisted of 628 Emirati adults, with multi-omics profiling conducted on 97 obese individuals and 95 matched controls.

• The study design was a prospective cohort of 628 Emirati adults.
• Multi-omics profiling was performed on a subset: 97 obese individuals and 95 matched controls.
• Matching of cases and controls was employed to reduce confounding.
• The population was drawn from the United Arab Emirates (UAE), providing a dataset from a Middle Eastern population where obesity prevalence is high.