Gut microbiome signatures of vegan, vegetarian and omnivore diets and associated health outcomes across 21,561 individualsOriginal 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 gut microbiome composition differs across three common diet patterns: omnivore, vegetarian, and vegan. The researchers built metagenomic profiles to determine whether diet pattern leaves a detectable, diet-specific signature in the gut microbiome. They also looked at whether these microbial signatures relate to host cardiometabolic health markers and whether diet-associated gut microbes overlap with microbes found in food itself, including dairy and soil sources.
Who was studied?
The analysis drew on 21,561 individuals pooled from five independent, multinational human cohorts. The abstract does not give further demographic detail (age, sex, or specific countries) for this pooled population. This scale and multinational scope let the researchers test whether diet-microbiome associations held consistently across different populations rather than in a single study group.
What were the most important findings?
Gut microbial profiles distinguished omnivore, vegetarian, and vegan diets with strong accuracy, achieving a mean AUC of 0.85. Red meat intake was a strong driver of the omnivore microbiome signature, with microbes such as Ruminococcus torques, Bilophila wadsworthia, and Alistipes putredinis enriched in omnivores and negatively correlated with cardiometabolic health. In contrast, vegan-associated signature microbes correlated with more favorable cardiometabolic markers and were also found enriched in omnivores who ate more plant-based foods. Diet-specific gut microbes partly overlapped with microbes found in food itself, such as the dairy organism Streptococcus thermophilus and typical soil microbes detected in vegans.
What are the greatest implications of this study?
These diet-associated microbial signatures, including the link between Bilophila wadsworthia and poorer cardiometabolic outcomes in omnivores, suggest gut microbiome profiling could help explain why plant-based diets are associated with better cardiometabolic health. The findings support using microbiome signatures as objective, diet-pattern-specific biomarkers rather than relying solely on self-reported dietary intake. The authors state that these signatures of common Western diet patterns can inform future nutritional interventions and epidemiological research.