Photo Credit: Zay Nyi Nyi

The following is a summary of “Potential changes in microorganisms and metabolites associated with oral cancer: a preliminary study,” published in the April 2025 issue of BMC Cancer by Wei et al.

Oral squamous cell carcinoma (OSCC) is a highly aggressive malignancy associated with substantial morbidity and mortality worldwide. Emerging evidence suggests a significant interplay between microbial dysbiosis and carcinogenesis within the oral cavity. This study was conducted to comprehensively characterize the alterations in oral microbiota and associated salivary metabolites in patients diagnosed with OSCC, with the goal of uncovering potential diagnostic biomarkers and mechanistic insights. A total of 79 saliva samples were analyzed, comprising 40 samples from patients with histologically confirmed oral cancer and 39 from healthy, age-matched control individuals. Microbial community composition was assessed using 16S rDNA gene sequencing, while metabolomic profiling was performed using liquid chromatography-mass spectrometry (LC-MS). 

Metabolite traceability was further explored using the Metorigin platform, and associations between microbial taxa and metabolite abundance were evaluated through Spearman correlation analysis. The microbial diversity analysis revealed significant differences in β-diversity between patients with OSCC and healthy controls, indicating distinct microbial community structures between the two groups, although α-diversity remained statistically comparable. At the phylum level, Deferribacterota was notably enriched, while Cyanobacteria was markedly reduced in the cancer group. On a more granular taxonomic scale, genera such as Vibrio and Lactococcus were significantly overrepresented in patients with OSCC, whereas beneficial genera, including Bifidobacterium and Faecalibacterium were significantly diminished. Metabolomic analysis identified 36 metabolites with differential abundance between groups. 

Notably, pro-resolving lipid mediators such as 13(S)-hydroxy-octadecatrienoic acid and 13-hydroxyoctadecadienoic acid (13-HODE) were significantly downregulated, while docosanamide—a long-chain fatty acid amide—was upregulated in patients with OSCC. Moreover, several bacterial-derived metabolites, including indole and its derivatives, showed marked reductions, suggesting a disruption in microbial metabolic activity. Among the most notable correlations, N-acetylneuraminic acid exhibited a strong inverse relationship (r < -0.4) with the abundance of Pseudoalteromonas and Vibrio, pointing toward a potential mechanistic link between microbial dysbiosis and altered metabolic signaling in the tumor microenvironment. Collectively, these findings underscore significant and multifaceted alterations in both microbial composition and salivary metabolite profiles in individuals with OSCC. The downregulation of key anti-inflammatory and bacterial-derived metabolites, combined with the overrepresentation of potentially pathogenic microbial taxa, supports a model in which microbial and metabolic shifts contribute to tumor progression and immune modulation. 

This study provides novel evidence for the utility of integrated microbiome-metabolome analysis in identifying potential biomarkers and therapeutic targets in oral squamous cell carcinoma, paving the way for improved diagnostic and personalized treatment strategies.

Source: bmccancer.biomedcentral.com/articles/10.1186/s12885-025-13680-5