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 e 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 ¼ 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.