Ketogenic Diets in Children With Intractable Epilepsy and its Effects on Gastrointestinal Function, Gut Microbiome, Inflammation, and Quality of Life.

OBJECTIVES: The ketogenic diet (KD) is a treatment for children with intractable epilepsy (IE), can cause gastrointestinal symptoms, and have an adverse effect on growth, nutrition and quality of life (QOL). This study investigated the extent of these side effects by comparing children with IE on KDs to their counterparts on normal diets. METHODS: Patients with IE were categorized into patients with KD or control groups. Gastrointestinal side effects and QOL were assessed using the PedsQL Gastrointestinal Symptoms Module. Cross sectional growth, gut microbiome compositions, and inflammation levels were also analyzed. RESULTS: Fourteen patients on the KD and 13 control patients were enrolled. Patients had been on KD for a median duration of 15 months (interquartile range: 9.8-60 months). The patients on the KD reported a trend to lower total gastrointestinal symptoms scores (more symptoms) compared to control patients, at 71.1 and 84.9, respectively ( P = 0.06, not significant). Patients on the KD had significantly lower QOL scores compared to control patients ( P = 0.01). Patients on the KD were found to have consistently lower median height/length, weight, and body mass index z scores compared to the controls although these were not statistically significant. Patients on the KD had a lower microbial diversity, Both groups had a normal level of S100A12, a marker of gut inflammation. CONCLUSIONS: Patients on the KD reported a trend to more gastrointestinal symptoms and more QOL concerns compared to controls. Although microbial differences were noted in patients on the KD, this did not result in detectable gut inflammation.

The role of the gut microbiome in paediatric irritable bowel syndrome.

Irritable bowel syndrome (IBS) is a common and disabling condition in children. The pathophysiology of IBS is thought to be multifactorial but remains incompletely understood. There is growing evidence implicating the gut microbiome in IBS. Intestinal dysbiosis has been demonstrated in paediatric IBS cohorts; however, no uniform or consistent pattern has been identified. The exact mechanisms by which this dysbiosis contributes to IBS symptoms remain unknown. Available evidence suggests the imbalance produces a functional dysbiosis, with altered production of gases and metabolites that interact with the intestinal wall to cause symptoms, and enrichment or depletion of certain metabolic pathways. Additional hypothesised mechanisms include increased intestinal permeability, visceral hypersensitivity and altered gastrointestinal motility; however, these remain speculative in paediatric patients, with studies limited to animal models and adult populations. Interaction between dietary components and intestinal microbiota, particularly with fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAPs), has drawn increasing attention. FODMAPs have been found to trigger and worsen IBS symptoms. This is thought to be related to products of their fermentation by a dysbiotic microbial population, although this remains to be proven. A low-FODMAP diet has shown promising success in ameliorating symptoms in some but not all patients. There remains much to be discovered about the role of the dysbiotic microbiome in paediatric IBS.