Table 1 General characteristics and significant findings of ketogenic diet in association with gut microbiota and neurological diseases in cohort studies
First author, (Year) | Country | Study population | Sample size | Type of KD | Follow-up duration | Microbiota analysis method | Changes on microbiota | Clinical outcomes | Quality score |
|---|---|---|---|---|---|---|---|---|---|
Dahlin M., et al. (2022) [5] | Sweden | Children with drug-resistant epilepsy Mean age: 7.7 ± 4.6 yr Male:11 Female:17 | N = 28 | KD | Three months | rDNA sequencing | Increase in Gordonibacter, Eggerthella lentha, Lactococcus lactis, Bifidobacterium longum susp. longum | Decrease in seizures attacks (> 50%) | Poor |
Nagpal R., et al. (2020) [6] | United States | Mild cognitive impairment (MCI) and cognitively normal (CN) Mean age: 64.6 ± 6.4 yr Male: N.A Female: N.A | N = 17 | MMKD | Six weeks | Sequencing of the fungal rRNA ITS1 gene | Increase in Agaricus, Mrakia, decrease in Saccharomyces, Claviceps | Positive affect on cognitive health | Good |
Lee K., et al. (2020) [7] | South Korea | Children with epilepsy Mean age: 3.17 yr Male: 3 Female: 5 | N = 8 | KD | One month | 16S rDNA sequencing | Decrease in Enterococcis faecium, Bifidobacterium longum, Eggerthella lenta | Decrease in seizures attacks (> 50%) | Good |
Lindefeldt M., et al. (2019) [8] | Sweden | Children with drug-resistant epilepsy Mean age: 7.6 ± 4.5 yr Male:10 Female:14 | N = 24 | KD | Three months | rDNA sequencing | Decrease in Bifidobacteria E. rectale, Dialister, increased in E. coli | Decrease in seizures attacks (> 50%), improved cognition and motor functions | Good |
Mu C.,et al. (2019) [9] | United States | Children with ASD and TC Mean age in ASD: 9 ± 2.17 yr Mean age in TC: 11 ± 4.13 yr Male:24 Female:3 | N = 27 | Modified KD ( a gluten free diet incorporating MCT oil) | Threemonths | Gas Chromatography-Mass Spectrometry, H Nuclear Magnetic Resonance Spectroscopy, Inductively Coupled Plasma-Mass Spectrometry | Increase in gut microbe-derived trimethylamine N-oxide | Negative correlation between selenium and behaviour scores, negative correlation between ornithine and ADOS-2 Overall Score and Social Affect Score | Good |
Zhang Y., et al. (2018) [10] | China | Children with refractory epilepsy Mean age: 4.2 yr Male:14 Female:6 | N = 20 | KD | Six months | 16S rDNA sequencing | Decrease in Firmicutes, increase in Bacteroidetes | Decrease in seizures attacks (≥ 90%) in 3 patients, decrease in seizures attacks (50 to 89%) in 5 patients, decrease in seizures attacks (< 50%) in 10 patients, seizure free in 2 patients | Poor |
Spinelli E., et al. (2018) [11] | United States | Children with epilepsy Mean age: 4.2 yr Male:14 Female:6 | N = 20 | KD | Six months | 16S rDNA sequencing | Decrease in Firmicutes, Actinobacteria, increase in Bacteroides, increased in Clostridiales, Clostridia, Ruminococcaeceae, Lahnospiraceaea, Alistipes, Tikenellacase | Decrease in seizures attacks (≥ 50%) in responder patients | Poor |