Researchers reviewing 12 studies found that individuals with immune thrombocytopenia often show changes in their gut microbiome, though findings were inconsistent.
Immune thrombocytopenia (ITP) is an autoimmune disorder in which the body attacks its own platelets, leading to low platelet counts and increased bleeding risk. The review analyzed studies published from 1980 to July 2024, covering both adult and pediatric patients. Each study examined stool samples using sequencing methods to identify microbial patterns potentially linked to ITP.
Several studies reported an increase in the bacterial phylum Bacteroidetes among patients with ITP, while others found a decrease. Similar inconsistencies were observed for Firmicutes, Proteobacteria, and Actinobacteria. This suggests that while gut microbiome changes are common in ITP, no consistent pattern has been established.
Frequently elevated genera in ITP patients included Escherichia-Shigella, Streptococcus, Lactobacillus, and Phascolarctobacterium. In contrast, Eubacterium hallii, Ruminococcaceae, and Megamonas were often reduced compared to healthy controls.
The review also assessed microbial diversity. Alpha diversity, which measures the variety of species within a person, was reduced in three studies but unchanged or higher in others. Beta diversity, which compares microbial composition between individuals, showed notable differences between patients and controls in most studies.
“Microbial dysbiosis plays a role in ITP pathogenesis, though inconsistencies exist across studies, potentially due to population differences, dietary habits, or sample size variations,” the authors noted.
Geography may have contributed to the variation. Nine of the 12 studies were conducted in China, while three used large-scale genetic data from European populations. Differences in diet, genetics, and environment may affect gut microbiota and complicate comparisons.
The review also explored how the gut microbiome might influence ITP through microbial metabolites such as short-chain fatty acids (SCFAs) and trimethylamine N-oxide (TMAO). SCFAs, known for their anti-inflammatory effects, were found to be reduced in ITP patients. TMAO was associated with increased platelet activation, a potential contributor to disease severity.
ITP treatments may also alter the gut microbiome. Corticosteroids, commonly used as first-line therapy, can reduce beneficial bacteria and increase harmful species. Some studies found that the microbiota profile in steroid-resistant patients differed from that of responders.
Due to differences in study design, populations, and sequencing methods, the authors did not conduct a meta-analysis. They recommended larger, standardized studies to clarify the relationship between gut microbiota and ITP.
While the findings do not confirm a causal link, the review suggests a potential connection between gut health and autoimmune platelet disorders and highlights areas for future microbiome-based research.
The authors reported no conflicts of interest.
Source: Frontiers