Association between oral and fecal microbiome dysbiosis and treatment complications in pediatric patients undergoing allogeneic hematopoietic stem cell transplantation

• Published in: Scientific reports Vol. 14; no. 1; p. 6708
• Main Authors: Faraci, M., Bonaretti, C., Dell’Orso, G., Pierri, F., Giardino, S., Angiero, F., Blasi, S., Farronato, G., Di Marco, E., Trevisiol, A., Olcese, E., Rufino, L., Squillario, M., Biassoni, R.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 20-03-2024; Nature Publishing Group; Nature Portfolio
• Subjects: 631/326; 692/4028; 692/700/1720/3187; Aplasia; Bacteria; Child; Diarrhea; Dysbacteriosis; Dysbiosis - etiology; Feces; Fusobacteria; Graft versus host disease; Graft versus host disease (GvHD); Graft vs Host Disease; Graft-versus-host reaction; Gut microbiome; Hematopoietic stem cell transplant (HSCT); Hematopoietic Stem Cell Transplantation - adverse effects; Hematopoietic stem cells; Homeostasis; Humanities and Social Sciences; Humans; Immune response; Intestinal microflora; Microbiomes; Microbiota; Microorganisms; Mucositis; Mucositis - etiology; multidisciplinary; Oral microbiome; Patients; Pediatrics; Prevotella; Prospective Studies; Proteobacteria; Radiation therapy; Relative abundance; Science; Science (multidisciplinary); Stem cell transplantation; Stem cells; Transplants & implants; Mucositis; Graft versus host disease (G; HD; Gut microbiome; Oral microbiome; Hematopoietic stem cell transplant (HSCT); Graft versus host disease (GvHD)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-024-55690-6

The oral and gastrointestinal mucosae represent the main targets of the toxic effect of chemo and/or radiotherapy administered during the conditioning regimen before hematopoietic stem cell transplant (HSCT). These harmful consequences and the immunological complications that may occur after the transplant (such as Graft versus Host Disease, G
v
HD) are responsible for the clinical symptoms associated with mucositis during the aplasia phase, like pain, nausea, vomiting, and diarrhea. These toxicities could play a critical role in the oral and gastrointestinal microbiomes during the post-transplant phase, and the degree of microbial dysbiosis and dysregulation among different bacterial species could also be crucial in intestinal mucosa homeostasis, altering the host’s innate and adaptive immune responses and favoring abnormal immune responses responsible for the occurrence of G
v
HD. This prospective pediatric study aims to analyze longitudinally oral and gut microbiomes in 17 pediatric patients who received allogeneic HSCT for malignant and non-malignant diseases. The oral mucositis was mainly associated with an increased relative abundance of
Fusobacteria
, and
Prevotella
species, while
Streptococcus descendants
showed a negative correlation. The fecal microbiome of subjects affected by cutaneous acute G
v
HD (aG
v
HD) correlated with
Proteobacteria
. Oral mucosal microbiota undergoes changes after HSCT,
Fusobacteria,
and
Prevotella
represent bacterial species associated with mucositis and they could be the target for future therapeutic approaches, while fecal microbiome in patients with acute G
v
HD (aG
v
HD) revealed an increase of different class of
Proteobacteria
(
Alphaproteobacteria
and
Deltaproteobacteria
) and a negative correlation with the class of
Gammaproteobacteria
.