Gut microbial composition during the acute phase of COVID-19 infection may help predict the occurrence of long COVID, according to study results presented at IDWeek 2023, held from October 11 to 15, in Boston, Massachusetts.
Approximately 65 million individuals worldwide are affected by long COVID. Data captured in previous studies suggest a potential link between the occurrence of long COVID and alterations within the gut microbiome.
To evaluate the relationship between the gut microbiome and long COVID, researchers at the Mayo Clinic in Rochester, Minnesota collected stool samples from patients (N=394) who tested positive for COVID-19 infection between November 2020 and September 2021. The samples were sequenced via shotgun metagenomics. Gut microbial composition was compared between patients with (n=84) and without (n=291) long COVID, defined as the persistence of symptoms for at least 4 weeks after infection onset. The researchers used Wilcoxon rank sum, x2, and Fisher exact testing to compare clinical characteristics between the groups.
Among patients with and without long COVID, the median ages were 57 (IQR, 45-66) and 57 (IQR, 50-69) years, 74% and 56% were women, 24% and 32% were fully vaccinated, and the median Charlson comorbidity index scores were 1 (IQR, 0-2) and 0 (IQR, 0-1; P =.001), respectively.
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Long COVID patients show distinct gut microbial composition during the acute phase of infection, suggesting a potential role in predicting long-term COVID health outcomes.
Further analysis between the groups showed that patients with long COVID were more likely to be symptomatic during acute infection (99% vs 89%; P =.006) and have moderate (30% vs 15%), severe (8% vs 1%), and critical (1% vs 0%) courses of index disease (P <.001).
Among patients with long COVID, the most frequently reported symptoms were fatigue (58%), dyspnea or increased respiratory effort (43%), cough (32%), headache (24%), cognitive impairment or “brain fog” (21%), postexertional malaise and/or poor endurance (21%), angina (21%), and lightheadedness (21%).
Results of a principal coordinate analysis of Bray Curtis dissimilarities indicated patients who developed long COVID had a distinct microbial composition relative to those without long COVID (R2, 0.005; P =.01).
Gut microbial composition in patients with long COVID also differed on the basis of number of symptoms (R2, 0.1; P =.007), which was primarily observed on analysis of the difference between patients with at least 3 vs 0 to 1 persistent symptoms (Bonferroni, P =.018).
A nonsignificant trend of decreased α-diversity was observed among patients who reported more than 3 long COVID symptoms (Shannon diversity, 2-way analysis of variance, P =.051).
According to the researchers, “Long COVID patients show distinct gut microbial composition during the acute phase of infection, suggesting a potential role in predicting long-term COVID health outcomes.”
This article originally appeared on Infectious Disease Advisor.
