Microbiota composition may play a role in the development, prognosis, or post-infection of COVID-19. There are studies evaluating the microbiota composition at the time of diagnosis and during the course of COVID-19, especially in adults, while studies in children are limited and no study available in children with multisystem inflammatory syndrome in children (MIS-C). This study was planned to compare intestinal microbiota composition in children diagnosed with MIS-C and acute COVID-19 infection with healthy children. In this prospective multicenter study, 25 children diagnosed with MIS-C, 20 with COVID-19 infection, and 19 healthy children were included. Intestinal microbiota composition was evaluated by 16 s rRNA gene sequencing. We observed changes of diversity, richness, and composition of intestinal microbiota in MIS-C cases compared to COVID-19 cases and in the healthy controls. The Shannon index was higher in the MIS-C group than the healthy controls (
p
< 0.01). At phylum level, in the MIS-C group, a significantly higher relative abundance of Bacteroidetes and lower abundance of Firmicutes was found compared to the control group. Intestinal microbiota composition changed in MIS-C cases compared to COVID-19 and healthy controls, and
Faecalibacterium prausnitzii
decreased;
Bacteroides uniformis
,
Bacteroides plebeius
,
Clostridium ramosum
,
Eubacterium dolichum
,
Eggerthella lenta
,
Bacillus thermoamylovorans
,
Prevotella tannerae
, and
Bacteroides coprophilus
were dominant in children with MIS-C. At species level, we observed decreased
Faecalibacterium prausnitzii
,
and
increased
Eubacterium dolichum
,
Eggerthella lenta
, and
Bacillus thermoamylovorans in children
with MIS-C and increased
Bifidobacterium adolescentis
and
Dorea formicigenerasus
in the COVID-19 group. Our study is the first to evaluate the microbiota composition in MIS-C cases. There is a substantial change in the composition of the gut microbiota: (1) reduction of
F. prausnitzii
in children with MIS-C and COVID-19; (2) an increase of
Eggerthella lenta
which is related with autoimmunity; and (3) the predominance of
E. dolichum
is associated with metabolic dysfunctions and obesity in children with MIS-C.
Conclusions
: Alterations of the intestinal microbiota might be part of pathogenesis of predisposing factor for MIS-C. It would be beneficial to conduct more extensive studies on the cause-effect relationship of these changes in microbiota composition and their effects on long-term prognosis.
What is Known:
• Mi...