Oral and Gut Microbiota Dysbiosis is Associated with Mucositis Severity in Autologous Hematopoietic Stem Cell Transplantation: Evidence from an Asian PopulationOriginal paper
Karen Pendergrass is a microbiome researcher specializing in microbiome-targeted interventions (MBTIs). She systematically analyzes scientific literature to identify microbial patterns, develop hypotheses, and validate interventions. As the founder of the Microbiome Signatures Database, she bridges microbiome research with clinical practice. In 2012, based on her own investigative research, she became the first documented case of FMT for Celiac Disease, four years before the first published case study.
Read MoreWhat was studied?
This study asked how oral and gut microbiota changes relate to mucositis severity during autologous hematopoietic stem cell transplantation (HSCT) in an Asian population. It profiled both sites in one cohort. Mucositis was assessed daily. Blood, saliva, and fecal samples were collected before conditioning, on day 0, at 7 days, and at 6 months post-transplantation. Alpha and beta diversity were compared over time. Relative bacterial abundances were modeled with linear models, and combined effects on mucositis grade were measured with generalized estimating equations.
Who was studied?
The cohort was 96 adult recipients of autologous HSCT recruited from Hospital Ampang in Malaysia between April 2019 and December 2020. All were aged 18 years or older. Oral mucositis occurred in 58.3 percent and diarrhea, representing lower gastrointestinal mucositis, occurred in 95.8 percent. The study focused on a Southeast Asian population, addressing a gap where oral and gut microbiota had not been jointly studied in autologous HSCT in this region.
What were the most important findings?
Alpha and beta diversity differed significantly between sample types (p less than 0.001) and across time points. Diversity dropped, reaching significance at day 0 in feces and day plus 7 in saliva, then normalized by 6 months. Higher saliva Paludibacter, Leuconostoc, and Proteus were associated with worse oral mucositis grades. Higher fecal Rothia and Parabacteroides were associated with worse gastrointestinal mucositis. Protective associations appeared for saliva Lactococcus and Acidaminococcus and fecal Bifidobacterium. These links held independent of clinical and immunologic factors.
What are the greatest implications of this study?
The findings suggest oral and gut dysbiosis contribute to mucositis severity during autologous HSCT, offering a rationale to target the microbiota to reduce this debilitating complication. Specific taxa emerged as candidate markers of risk or protection, which could guide preventive or restorative strategies such as probiotics. Because microbiota composition varies by geography and ethnicity, this Southeast Asian evidence fills a regional gap. The associations are observational, so they do not prove that the bacteria cause mucositis.