Short-term impact of a classical ketogenic diet on gut microbiota in GLUT1 Deficiency Syndrome : A 3-month prospective observational study

Background&aims The classical ketogenic diet (KD) is a high-fat, very low-carbohydrate normocaloric diet used for drug-resistant epilepsy and Glucose Transporter 1 Deficiency Syndrome (GLUT1 DS). In animal models, high fat diet induces large alterations in microbiota producing deleterious effects on gut health. We carried out a pilot study on patients treated with KD comparing their microbiota composition before and after three months on the diet. Methods Six patients affected by GLUT1 DS were asked to collect fecal samples before and after three months on the diet. RT – PCR analysis was performed in order to quantify Firmicutes, Bacteroidetes, Bifidobacterium spp., Lactobacillus spp., Clostridium perfringens, Enterobacteriaceae, Clostridium cluster XIV, Desulfovibrio spp. and Faecalibacterium prausnitzii. Results Compared with baseline, there were no statistically significant differences at 3 months in Firmicutes and Bacteroidetes. However fecal microbial profiles revealed a statistically significant increase in Desulfovibrio spp. (p = 0.025), a bacterial group supposed to be involved in the exacerbation of the inflammatory condition of the gut mucosa associated to the consumption of fats of animal origin. Conclusions A future prospective study on the changes in gut microbiota of all children with epilepsy started on a KD is warranted. In patients with dysbiosis demonstrated by fecal samples, it my be reasonable to consider an empiric trial of pre or probiotics to potentially restore the «ecological balance» of intestinal microbiota.