Ketogenic diet does not reduce seizures or neuroinflammation in a virus‑induced epilepsy mouse model
In mice infected with Theiler's murine encephalomyelitis virus, a ketogenic diet achieved ketosis but failed to lower seizure incidence, burden, or severity, and did not attenuate overall neuroimmune cell infiltration, despite markedly reshaping gut microbiota.
Study and findings
The investigators fed adult mice either a high‑fat, low‑carbohydrate ketogenic diet or a standard chow before intracerebral inoculation with TMEV. Seizure activity was monitored by handling‑induced provocation from day 3 to 7 post‑infection. Flow cytometry quantified immune cell entry into the brain, and 16S rRNA sequencing characterized fecal microbial communities. Although blood β‑hydroxybutyrate levels confirmed ketosis, the ketogenic diet did not alter the proportion of mice experiencing seizures, nor did it change total seizure counts or severity scores compared with controls. Neuroimmune analysis showed no significant difference in overall leukocyte infiltration between diet groups. In contrast, the diet produced a pronounced shift in gut microbiota: alpha diversity declined, and taxa such as Akkermansia, Acetatifactor, Dorea and Flintibacter were enriched, while fiber‑associated genera like Bifidobacterium and Roseburia were depleted.
Clinical interpretation
These data suggest that the antiseizure benefit of ketogenic diets observed in many drug‑resistant epilepsy models does not extend to seizures driven by acute viral neuroinflammation. The lack of effect on global CNS immune cell infiltration indicates that metabolic ketosis alone may be insufficient to counteract inflammation‑mediated hyperexcitability. Although the diet markedly altered the intestinal microbiome, the specific microbial changes did not translate into seizure protection in this context, highlighting that microbiota‑dependent mechanisms may be contingent on the underlying seizure etiology.
Limitations and open questions
The study was limited to a single viral epilepsy model and a short observation window (days 3–7). It did not assess long‑term outcomes, specific cytokine profiles, or metabolic intermediates that could mediate neuroprotection. Moreover, only bulk immune cell infiltration was measured; finer phenotyping of microglial activation or peripheral immune subsets might reveal subtler effects. Future work should explore whether alternative dietary formulations, timing of initiation, or combination with anti‑inflammatory agents can modify infection‑related seizures, and clarify which microbiota‑derived metabolites, if any, are relevant in this setting.
Source
Meili CH et al., Epilepsia 2026; doi:10.1002/epi.70509.