Paired samples from treatment-naïve gastric-cancer patients and controls showed substantially higher richness and diversity with mucosal brushing than biopsy. Brushing detected lower diversity and altered composition in cancer, whereas biopsy did not. Sampling method shapes microbiome signals, but causation and diagnostic utility are unproven.
Key findings
- Brushing versus biopsy yielded richness 60±46.5 vs 25.5±19.5, Shannon 3.45±0.71 vs 2.80±0.79 and Simpson 0.95±0.03 vs 0.92±0.06 (all p
Why this matters globally
Sampling standardization is a global microbiome challenge. The study shows how method sensitivity may explain inconsistent gastric-cancer findings and inform consortia.
Thai researcher contribution
Chulalongkorn University and King Chulalongkorn Memorial Hospital used paired Thai patient samples to separate disease from collection-method effects.
Limitations to consider
The abstract omits sample size and key confounders including diet, PPIs/antibiotics, H. pylori, tumour location and oral contamination. 16S has limited functional resolution, associations are non-causal, and beta-diversity R² is small.