The profile of intestinal microbiota in children affected by COVID-19 has been characterized for the first time and, thanks to peculiar anti-inflammatory properties, it seems to protect them from the severe forms of the disease. The identikit comes from the researchers of Bambino Gesù Children’s Hospital who carried out a study – the first at an international level – dedicated to the relationship between the microbiota and SARS-CoV-2 infection in pediatric age. The research, recently published in the scientific journal Frontiers in Cellular and Infection Microbiology, suggests possible therapeutic interventions on the microbiota to help control the disease.

The study on the composition and function of the intestinal microbiota in pediatric patients with COVID-19 was conducted by the Human Microbiome Research Unit, directed by Prof. Lorenza Putignani, in the framework of the project “CACTUS – Immunological studies in children affected by COVID and acute diseases” coordinated by prof. Paolo Palma. The survey included the clinical collaboration of specialists from various Departments of the Hospital.

The research included 88 patients with symptoms of suspected SARS-CoV-2 infection, hospitalized between March and September 2020 in the COVID Center of Bambino Gesù Palidoro and Gianicolo. Based on the results of the nasopharyngeal swabs, patients were divided into 2 groups: patients with COVID-19 (positive swab) and patients with other infections (negative swab).

The feces samples taken from each participant have been analyzed with metagenomic techniques (DNA sequencing of the entire intestinal microbial community) which allowed researchers to define the composition of microbiota. A comparison was made between the data from the two groups and those of a control group of healthy children. Furthermore, the study of microbiota function was also performed for the group with COVID-19.

The research found that, like in adulthood, the intestinal microbiota of children with COVID-19 is altered and poorly diversified compared to the microbiota of patients with other infections or healthy children. Specifically, this microbiota is rich in bacteria with a predominantly pro-inflammatory action (Bacteroidetes and Fusobacteria) and poor in some “good” microorganisms (Actinobacteria, Verrucomicrobia, Akkermansia, Blautia, Ruminococcus) which favor the maintenance of intestinal balance (homeostasis).

However, compared to the group of healthy people or with other infections, a significant increase of Faecalibacterium was also detected in children with COVID-19, a bacterium known for its beneficial and anti-inflammatory properties that supports the immune system in the defense of the human body. In adult patients with the most severe form of COVID-19, the absence of this bacterium is described precisely as a severity index. Furthermore, the functional study of the microbiota in the COVID group revealed an increase in some processes of microbial metabolism which also indirectly support an adequate immunological response.

Overall, the data collected by the researchers of Bambino Gesù highlight a potential link between the function of the intestinal microbiota and the clinical course of COVID-19 in pediatric age. The analyses performed by the research group support the hypothesis that – compared to adults – the microbiota in children, with its anti-inflammatory properties, contributes to reducing the severity of the infection. The study opens to the hypothesis of therapeutic interventions on microbiota to help control the evolution of important diseases, including COVID-19.