Effect of fecal microbiota transplantation in patients with slow transit constipation and the relative mechanisms based on the protein digestion and absorption pathwayOriginal 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 fecal microbiota transplantation (FMT) improves slow transit constipation (STC) and investigated the underlying mechanism, with a focus on the protein digestion and absorption pathway. Researchers combined 16S rRNA microbiome sequencing with metabolomic analysis of feces and serum collected after each of three FMT treatments. The aim was to connect clinical outcomes with measurable shifts in gut bacteria and metabolites.
Who was studied?
Eight patients diagnosed with slow transit constipation were selected according to defined inclusion and exclusion criteria. Each patient received three rounds of FMT treatment. Feces and serum samples were collected from these same patients after each treatment for microbiome and metabolomic analysis.
What were the most important findings?
After the third FMT treatment, 62.5 percent of patients showed clinical improvement and 75 percent achieved clinical remission, with better scores on the Wexner constipation scale, the Gastrointestinal Quality-of-Life Index, and the Hamilton Depression Scale. Fecal microbiome alpha and beta diversity changed significantly following FMT. Bacteroidetes (Prevotella and Bacteroides) and certain Firmicutes (Roseburia and Blautia) decreased, while Actinobacteria (Bifidobacterium), Proteobacteria (Escherichia), and Lactobacillus (Firmicutes) increased. Metabolomic analysis showed FMT treated patients had relatively high levels of N-Acetyl-L-glutamate among other metabolite changes linked to the protein digestion and absorption pathway.
What are the greatest implications of this study?
The findings support FMT as an effective treatment for slow transit constipation, improving not only bowel symptoms but also quality of life and depressive symptoms. The paired shifts in specific bacterial taxa and metabolites such as N-Acetyl-L-glutamate suggest a mechanistic link between microbiome remodeling and the protein digestion and absorption pathway. This points toward specific bacterial and metabolic targets that could be explored to refine or monitor FMT based therapies for constipation.