Changes in the gut microbiome associated with liver stiffness improvement in nonalcoholic steatohepatitisOriginal 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 changes in the gut microbiome over time are linked to improvement in liver stiffness in people with nonalcoholic steatohepatitis (NASH). Researchers used 16S rRNA gene sequencing to profile gut microbial communities at baseline and again after 24 weeks of study participation. Liver stiffness was measured using magnetic resonance (MR) elastography, and the investigators compared microbial shifts in participants whose liver stiffness measurement (LSM) improved against those whose did not. They also looked at whether microbial changes tracked with secondary outcomes, including reduction in MRI-derived liver fat (MRI-PDFF) and regression of fibrosis on biopsy.
Who was studied?
The cohort consisted of 69 adults with biopsy-confirmed NASH and significant fibrosis (stages 2 to 3), enrolled in a multi-center randomized controlled trial evaluating the drug selonsertib alone or combined with simtuzumab. For comparison, fecal samples were also collected from 32 healthy adults. Genus-level multidimensional scaling was used to see whether microbial changes in the NASH participants who improved resembled the composition seen in this healthy comparison group.
What were the most important findings?
The abundance of 36 bacterial taxa shifted differently between participants with and without longitudinal improvement in liver stiffness. Lactobacillus showed a notably large decrease in participants with LSM improvement (log2 fold change of about -4.51, false discovery rate under 0.001), and Enterococcus was also among the taxa with altered abundance. These findings indicate that specific, identifiable shifts in gut bacterial composition accompany improvement in liver stiffness in NASH, rather than liver stiffness changing independently of the microbiome.
What are the greatest implications of this study?
By pairing longitudinal microbiome sampling with an objective, imaging-based measure of liver stiffness, this study strengthens the case for a mechanistic link between gut bacteria and NASH fibrosis trajectory. Identifying taxa such as Lactobacillus and Enterococcus as markers of improvement points toward candidate microbial signatures that could eventually help monitor or stratify NASH patients undergoing treatment. Because the design also compared shifts against a healthy reference cohort, the work lays groundwork for testing whether restoring a more typical gut microbial profile could be a therapeutic target in NASH, though this abstract does not itself establish causation.