β‑Hydroxybutyrate mitigates intestinal acute GVHD in mice through microbiota‑bile acid remodeling and TLR4‑NF‑κB inhibition
In a murine model of acute graft‑versus‑host disease, administration of the ketone body β‑hydroxybutyrate reduced clinical severity and intestinal injury. The effect was associated with restoration of microbial balance, enrichment of Akkermansia muciniphila, normalization of bile‑acid profiles, and suppression of TLR4‑NF‑κB‑driven Th1/Th17 differentiation.
Study and findings
The authors first re‑examined publicly available transcriptomic and single‑cell RNA‑seq datasets from patients with intestinal acute graft‑versus‑host disease (aGVHD) and found down‑regulation of genes involved in ketone‑body metabolism and transport. In a murine aGVHD model, daily β‑hydroxybutyrate (BHB) treatment lowered clinical scores and ameliorated histopathological signs of intestinal injury, achieving a magnitude of effect comparable to methotrexate. Multi‑omics profiling revealed that BHB corrected dysbiosis, notably increasing the relative abundance of Akkermansia muciniphila, and restored bile‑acid metabolism. Flow cytometry and ELISA showed reduced intestinal T‑cell infiltration and diminished Th1 and Th17 differentiation both in vivo and in vitro. Transcriptomic analysis of intestinal tissue suggested that BHB suppresses the TLR4‑NF‑κB signaling pathway, providing a mechanistic link between microbial, metabolic, and immune modulation.
Clinical interpretation
These preclinical data indicate that BHB can modulate several axes implicated in aGVHD pathogenesis: microbial composition, bile‑acid signaling, and T‑cell‑driven inflammation. The enrichment of Akkermansia muciniphila, a mucin‑degrading bacterium linked to barrier integrity, may contribute to reduced intestinal permeability and downstream immune activation. By dampening TLR4‑NF‑κB signaling, BHB appears to limit the differentiation of pro‑inflammatory Th1 and Th17 cells, which are central effectors in aGVHD. While the murine findings cannot be directly extrapolated to patients, the study provides a mechanistic rationale for exploring ketone‑body supplementation as an adjunctive strategy in aGVHD management.
Limitations and open questions
The investigation was confined to a single mouse strain and a specific aGVHD induction protocol, limiting generalizability across genetic backgrounds and transplant settings. Dose‑response relationships and optimal timing of BHB administration were not explored. The study did not assess long‑term outcomes, such as graft‑versus‑leukemia effects or infection susceptibility. Moreover, while transcriptomic data implicate TLR4‑NF‑κB inhibition, causal proof (e.g., using pathway‑specific knockouts) is lacking. Future work should test BHB in clinically relevant transplantation models, evaluate safety in the context of immunosuppression, and determine whether the microbiota‑mediated effects are reproducible in human patients.
Source
Source: Tian R et al., Life Sci. 2026;124737.