Gut microbiota composition is associated with SARS-CoV-2 vaccine immunogenicity and adverse eventsOriginal 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 prospective, observational study examined whether gut microbiota composition is associated with immune responses and adverse events following COVID-19 vaccination. Researchers compared two vaccine types: the inactivated CoronaVac vaccine and the mRNA BNT162b2 vaccine. They performed shotgun metagenomic sequencing on stool samples collected at baseline and again one month after the second vaccine dose. Immune responses were assessed using a SARS-CoV-2 surrogate virus neutralisation test and a spike receptor-binding domain IgG ELISA.
Who was studied?
The study included 138 adult COVID-19 vaccine recipients, of whom 37 received CoronaVac and 101 received BNT162b2. Stool samples from these vaccinees were collected at two time points, baseline and one month post second dose, for shotgun metagenomic analysis. The abstract does not specify additional demographic details such as age range, sex distribution, or geographic location.
What were the most important findings?
Immune responses were significantly lower in CoronaVac recipients than in BNT162b2 recipients. Among CoronaVac vaccinees, higher persistent levels of Bifidobacterium adolescentis were associated with higher neutralising antibody responses, and their baseline gut microbiome was enriched in carbohydrate metabolism pathways. In BNT162b2 vaccinees, neutralising antibody levels correlated positively with the total abundance of flagellated and fimbriated bacteria, including Roseburia faecis. Prevotella copri and two Megamonas species were enriched in individuals who experienced fewer adverse events after vaccination.
What are the greatest implications of this study?
These findings suggest that baseline gut microbiota composition and function may help explain individual variation in vaccine immunogenicity and tolerability. Specific taxa, such as Bifidobacterium adolescentis, Roseburia faecis, Prevotella copri, and Megamonas species, and microbial functional features like carbohydrate metabolism pathways and flagellar or fimbrial machinery, appear linked to stronger antibody responses or fewer adverse events. This raises the possibility that gut microbiome profiling or modulation could eventually inform strategies to improve vaccine efficacy or reduce adverse events. Further research is needed to determine whether these associations are causal and generalizable across vaccine platforms and populations.