Gut Microbiome Signatures Linked to Obesity

Distinct patterns in the gut microbiome and circulating metabolites are associated with obesity, according to a multi-omics study. Researchers identified dozens of bacterial species and serum metabolites associated with body mass index (BMI), with several key microbial findings replicated in an independent population.

The study provides further evidence of complex interactions between the gut microbiome and host metabolism in obesity, while identifying specific bacterial species and metabolites that could provide targets for future mechanistic research.

Researchers Combine Microbiome and Metabolome Data

Researchers conducted a systematic multi-omics analysis using data from 495 men in the USA.

The analysis combined metagenomic profiles of the gut microbiome with several measures of the circulating metabolome, including untargeted serum metabolomics, lipidomics, and short-chain fatty acids (SCFAs).

Researchers then examined relationships between these molecular profiles and BMI to identify microbial and metabolic characteristics potentially associated with obesity.

Overall, single-omics analyses identified 52 gut bacterial species and 31 serum metabolites with potential associations with BMI.

Specific Gut Bacteria Associated With BMI

Several bacterial species showed particularly notable relationships with BMI.

Collinsella stercoris was negatively associated with BMI, meaning greater abundance was associated with lower BMI. In contrast, Bacteroides fragilis and Veillonella dispar were positively associated with BMI.

Importantly, these associations were subsequently validated using data from an independent Chinese cohort, providing evidence that some of the observed microbial signatures may be reproducible across geographically and ethnically distinct populations.

The findings add to growing research suggesting that obesity is accompanied by alterations in gut microbial composition, although the observational nature of the study means the results cannot establish whether these bacteria contribute to obesity or change in response to it.

Metabolites Reveal Links Between Microbes and Host Metabolism

The researchers also identified several circulating metabolites associated with the bacterial species highlighted in the analysis.

Gamma-glutamylglycine, asparagine, glycine, and serotonin were among the metabolites showing significant associations with the identified gut bacteria.

These relationships suggest potential connections between microbial composition and host metabolic processes. By analysing microbiome and metabolome data together, the researchers were able to identify patterns that would be difficult to detect when examining either biological system independently.

Such interactions could eventually help researchers understand how changes in the gut microbiome relate to metabolic health and body weight.

Multi-Omics Could Deepen Understanding of Obesity

The authors conclude that their findings provide a more systemic picture of microbiome–host metabolic interactions associated with obesity.

Rather than pointing to a single bacterial species or metabolite responsible for obesity, the results highlight a network of microbial and metabolic characteristics associated with BMI.

Further research will be required to determine the biological mechanisms underlying these relationships and establish whether the identified signatures have a causal role in obesity. Prospective and interventional studies could also help determine whether manipulating specific microbial or metabolic pathways might eventually contribute to obesity prevention or treatment.

Reference

Tian B et al. Multi-omics analysis identify novel microbiome-metabolome signatures associated with obesity. Journal of Applied Microbiology. 2026;137(7):172.