Blue poo: impact of gut transit time on the gut microbiome using a novel markerOriginal 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?
Researchers examined how gut transit time relates to gut microbiome composition and function in 863 healthy adults from the PREDICT 1 study. They also tested whether a simple blue dye method could reliably measure transit time.
How was it studied?
Participants swallowed a blue dye marker to measure gut transit time while providing stool samples for shotgun metagenomic sequencing. The study compared blue dye transit time against stool consistency and stool frequency as predictors of microbiome features, alongside cardiometabolic health and diet data.
What did they find?
Microbiome taxonomic composition discriminated between transit time classes with 0.82 area under the ROC curve. Longer transit time was linked to higher abundance of species including Akkermansia muciniphila, Bacteroides species, and Alistipes species (FDR-adjusted p<0.01). Blue dye transit time showed a stronger association with the microbiome than stool consistency or frequency did.
Why it matters
The blue dye method offers an inexpensive, scalable way to capture a microbiome-relevant marker that outperforms traditional stool-based proxies. This could improve future diet-microbiome-health research at large scale.