L-carnitine supplementation has been shown to improve bowel function and lipid profiles in children undergoing ketogenic diet therapy (KDT) for drug-resistant epilepsy (DRE), according to a recent study. The research, published in Scientific Reports, assessed the impact of L-carnitine as an adjuvant therapy on gastric emptying and bowel function in pediatric DRE patients on KDT.
The study revealed that while L-carnitine supplementation did not improve seizure control, it significantly improved stool consistency and increased the frequency of defecation. Specifically, the frequency of defecation increased by 50% in the KDT with L-carnitine group compared to 33% in the KDT-only group.
Impact on Gastrointestinal Symptoms
The research indicated that L-carnitine supplementation led to a decrease in gastrointestinal (GI) symptom scores, suggesting clinical improvement in GI symptoms. Although these results did not reach statistical significance, the study demonstrated a notable increase in the median Bristol stool scale, indicating softer stools.
Murata and collaborators previously reported that serum carnitine levels were negatively correlated with the severity of constipation in patients with severe motor and intellectual disabilities. They attributed this to L-carnitine's role in mitochondrial transport of fatty acids, where its deficiency can affect smooth muscles in the gastrointestinal tract.
Correlation with Antral Length
The study also found a significant increase in antral length in patients receiving KDT with L-carnitine supplementation compared to those on KDT alone. A negative correlation was observed between antral length and GI symptom scores, suggesting that an increase in antral length is associated with clinical improvement of GI symptoms. According to Szurszewski, longitudinal smooth muscle contractions cause an increase in antral length, which improves gastric emptying and food mixing.
Furthermore, a positive correlation was demonstrated between antral length and the Bristol stool score, as well as the frequency of defecation, in the L-carnitine supplementation group. This indicates that an increase in antral length is associated with softer stool consistency and more frequent bowel movements.
Effects on Lipid Profile and Dietary Factors
The study revealed that L-carnitine supplementation had a positive effect on fasting lipid profiles, leading to a significant increase in HDL levels in pediatric patients on KDT. This is particularly important as KDT has been previously reported to increase total cholesterol and triglyceride concentrations in children.
Additionally, a significant positive correlation was found between fiber content in 24-hour dietary recall and antral length in the KDT with L-carnitine supplementation group. This suggests that increased fiber intake is associated with higher antral length, potentially improving gut function.
Anthropometric Measurements
Anthropometric measurements showed significant increases in weight z-score and height z-score after three months of KDT initiation, with no significant change in BMI z-score. These findings align with previous studies highlighting the importance of maintaining proper physical growth assessment during KDT.
Study Limitations
The authors noted several limitations, including the absence of comparisons with patients on traditional antiepileptic drugs (AEDs) or placebo, as well as the short follow-up duration. They recommend future large-scale, prospective clinical trials to further explore the benefits of L-carnitine supplementation in pediatric DRE patients on KDT.
Conclusion
While L-carnitine supplementation did not improve seizure control in pediatric DRE patients on KDT, it did improve stool consistency, increase the frequency of defecation, and positively affect fasting lipid profiles. The researchers suggest that L-carnitine supplementation may be a prudent addition to KDT for such patients, pending further research.
