Gastrointestinal Health, General Health

Ketogenic Diet Induced Shifts in the Gut Microbiome Associate with Changes to Inflammatory Cytokines and Brain-Related miRNAs in Children with Autism Spectrum Disorder

Autism Spectrum Disorder (ASD) affects over 1 in 100 children globally and is associated with immune system changes, inflammation, and gastrointestinal issues. Abnormal gut flora is linked to ASD symptom severity. The ketogenic diet has shown promise in ASD improving symptoms by raising blood ketone levels, which may have neuroprotective effects.

An interventional pilot study examined the effects of a modified ketogenic diet in seven children with ASD over four months. The diet was limited to 20-25 grams of net carbohydrate per day and included MCT oil supplementation. The study aimed to assess changes in microbiota, inflammation markers, and microRNAs.

Key findings after 4 months on the ketogenic diet:

• Decreased plasma levels of proinflammatory cytokines IL-12p70 and IL-1b
• Increase in gut microbiota diversity
• Increased expression of butyrate kinase in the gut
• Reduced brain-derived neurotrophic factor (BDNF) levels (The authors suggest this might be due to more BDNF being used in the brain, reducing its amount in the blood)
• Altered levels of brain-derived -associated microRNAs in plasma

These results suggest that the KD may improve outcomes for those with autism spectrum disorder by reducing inflammation, correcting gut microbial imbalances, and affecting the BDNF pathway involved in brain activity.

Larger studies are needed to look at how age and sex affect these changes, the duration of these changes, and how other gut chemicals like tryptophan and neurotransmitters impact brain activity and behavior.