Among patients with acute gastroenteritis (AGE) due to norovirus infection, no independent associations were observed between secretor status and the composition or diversity of the gut microbiome, according to study results published in Open Forum Infectious Diseases.

Data for this analysis were sourced from the SUPERNOVA study that enrolled patients from Veteran’s Affairs medical centers located in 4 states between 2016 and 2017. Patients with norovirus infection (n=51) and a control group of patients who were negative for norovirus infection (n=49) provided stool and saliva samples within 10 days of symptom onset or enrollment, respectively. Microbiome diversity was compared between cohorts on the basis of secretor status.

Among patients in the positive and negative norovirus groups, the mean age was 55.7 and 60.6 years, respectively. Of patients with norovirus infection, 94% had AGE symptoms, 88% were secretors, 39% were positive for GII.4 norovirus infection, and 24% were positive for other AGE pathogens. Among patients in the control group, 23 had AGE symptoms, of whom 70% had no pathogens detected on stool sample analysis.


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Compared with nonsecretors, α-diversity of the gut microbiome was decreased among patients who were secretors, with a mean of 224.6 amplicon sequence variants (ASVs) vs 247.7, respectively. Despite findings indicating substantial overlap of the microbiome composition via ordination using the most abundant genera, patients who were secretors had a slightly more disperse composition. The researchers found that α-diversity of the gut microbiome was similar between patients who were secretors, regardless of the presence of norovirus infection.

After stratification by AGE symptoms, patients with AGE had decreased α-diversity (mean ASV, 216.2) and a decreased Shannon index (mean, 3.773) compared with patients without AGE (mean ASV, 270.2; Shannon index, 4.096). In addition, patients with norovirus infection had decreased α-diversity compared with those in the control group without AGE (mean ASV, 227.5 vs 268.5) and increased α-diversity compared with patients who had AGE without norovirus infection (mean ASV, 200.3).

In the final model, after controlling for age and prescription drug use, no significant associations were detected.

This study was limited by the lack of serial preinfection stool samples, so it remains unclear what specific individual changes occurred after infection with norovirus or other AGE pathogens. In addition, the sample size was small and may not reflect the general population of the United States.

According to the researchers, “[although] findings suggest that there might not be a relationship between norovirus infection and the microbiome, longitudinal studies would be better suited to capture any causal effect of secretor status and norovirus infection [in] the microbiome.”

Reference

Johnson JA, Read RD, Petit RA III, et al. Association of secretor status and recent norovirus infection with gut microbiome diversity metrics in a Veterans Affairs population. Open Forum Infect Dis. 2022;ofac125. doi:10.1093/ofid/ofac125