Gut Microbiome Dysbiosis is Associated With Human T-Lymphotropic Virus Type 1 (HTLV-1) Infection and Disease Progression to HTLV-1-Associated Myelopathy/Tropical Spastic Paraparesis: A Cross-Sectional StudyOriginal 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 characterized the gut microbiome in the context of HTLV-1 infection and its clinical stages, including the neuroinflammatory disease HAM/TSP. Researchers analyzed fecal bacterial composition and diversity using Illumina MiSeq sequencing, drawing an analogy to the established gut-brain axis role seen in other neurological diseases like multiple sclerosis. Functional analysis was also performed to identify differentially enriched gene categories and KEGG metabolic modules. The overall aim was to determine whether gut microbiome alterations track with HTLV-1 infection and disease progression to HAM/TSP.
Who was studied?
The study included 112 Brazilian individuals in a cross-sectional design. This comprised 24 healthy controls and 88 HTLV-1-infected individuals, the latter group spanning different disease stages: 38 patients with HAM, 17 with intermediate syndromes, and 33 asymptomatic carriers. Fecal samples were collected from each participant for sequencing and functional analysis.
What were the most important findings?
HTLV-1-infected individuals showed significant gut dysbiosis compared to healthy controls, marked by reduced bacterial diversity and an inverted Firmicutes/Bacteroidetes ratio. Specific bacterial genera changed across disease stages, and functional KEGG modules were differentially enriched between groups. Notably, patients with HAM (the most advanced, symptomatic stage) exhibited decreased Faecalibacterium, a genus recognized for its anti-inflammatory, butyrate-producing commensal members, alongside increases in other bacteria.
What are the greatest implications of this study?
These findings suggest gut microbiome alterations, including loss of anti-inflammatory commensals like Faecalibacterium, may be linked to disease progression from asymptomatic HTLV-1 carriage to HAM/TSP. This supports extending the gut-brain axis framework, already established in diseases like multiple sclerosis, to HTLV-1-associated neuroinflammation. The results position the gut microbiome as a potential area for further investigation in understanding or monitoring HAM/TSP progression.