Microbial enterotypes, inferred by the prevotella-to-bacteroides ratio, remained stable during a 6-month randomized controlled diet intervention with the new nordic dietOriginal 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 whether human gut microbial enterotypes, defined by the ratio of Prevotella to Bacteroides abundance (P/B ratio), are a stable and biologically meaningful way to classify individuals. The researchers used quantitative PCR to measure the P/B ratio and 35 selected bacterial taxa. They then tested whether a 6-month controlled dietary intervention, comparing the new Nordic diet (NND) to the average Danish diet (ADD), could shift these microbial groupings or the underlying taxa.
Who was studied?
The study included 62 subjects between 18 and 65 years old who had central obesity and components of metabolic syndrome. Participants were grouped into two discrete clusters based on their P/B ratio, then followed through the randomized 6-month dietary intervention comparing NND and ADD.
What were the most important findings?
Subjects could be reliably divided into two discrete groups using only their P/B ratio, and this grouping remained stable across the 6-month diet intervention. Neither the P/B-based groups nor the broader cohort showed significant changes in the 35 quantified bacterial taxa when comparing the ADD and NND diets. Despite this microbial stability, the high-P/B group had higher total plasma cholesterol than the low-P/B group after the intervention.
What are the greatest implications of this study?
The findings suggest that P/B-based enterotyping identifies a stable, diet-resistant trait of the gut microbiota rather than a state that shifts readily with short-term dietary change. Because the high-P/B group showed higher plasma cholesterol after intervention, stratifying individuals by P/B ratio could help identify subgroups with differing metabolic or cardiovascular risk responses to diet. This supports using P/B ratio as a simple stratification tool for future studies assessing individualized responses to dietary interventions.