Evaluation of the gastric microbiota based on body mass index using 16S rRNA gene sequencingOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study examined how the stomach lining's bacterial community relates to body mass index (BMI), independent of Helicobacter pylori. Researchers sequenced the 16S rRNA gene from gastric antral biopsies. They compared diversity, composition, and predicted metabolic functions across BMI categories. Functional pathways were inferred using PICRUSt2 metagenomic prediction.
Who was studied?
Participants were 30 adults undergoing health checkups at three medical centers in South Korea, aged 20 to 65 years. This was a cross-sectional human study using gastric mucosal tissue. They were split evenly into normal weight, overweight, and obese groups, 10 per group. People with H. pylori infection, atrophic gastritis, intestinal metaplasia, or recent antibiotics were excluded to isolate BMI effects. Four antral biopsies were taken per person.
What were the most important findings?
Evenness measured by the Gini-Simpson index was significantly lower in the combined overweight/obese group than in normal weight (p=0.049). Other alpha metrics did not differ significantly. Beta diversity separated the groups clearly: Bray-Curtis by ANOSIM (p=0.005) and unweighted UniFrac by PERMANOVA (p=0.004). Seventeen genera and 17 species differed by weight, with several species declining as BMI rose (Spearman Rho near -0.4). Predicted fatty acid, amino acid, vitamin, and carbohydrate pathways diverged by BMI.
What are the greatest implications of this study?
The results suggest the gastric microbiota, not just the intestine, may be linked to obesity and metabolic dysregulation. The stomach could become a target for microbiome-based interventions. Because the design is cross-sectional, it cannot say whether microbial shifts cause or follow weight gain. The sample was small (10 per group) and from one region of South Korea, so larger, more diverse studies are needed.