Dietary quality and the gut microbiome in early-stage Parkinson's disease patients.

Background: The prevalence of Parkinson's disease (PD) has increased steadily with the increase of the elderly population. PD may influence dietary intake and quality, and the gut microbiome composition. The present study examined differences in dietary intake and quality between PD patients and controls according to sex. In addition, we assessed the gut microbiome composition.

Methods: This cross-sectional study was conducted at A Medical Center, Seoul, South Korea. PD severity, swallowing function, olfactory function, and constipation status were examined by a skilled nurse. Dietary data were collected through a semi-quantitative food frequency questionnaire. Stool samples were subjected to microbiome analysis. To examine dietary quality, the Dietary Quality Index-International (DQI-I), Healthy Eating Index (HEI), Index of Nutritional Quality (INQ), Dietary Diversity Score (DDS), and Mediterranean Diet Score (MDS) were used. An independent t-test was used to determine differences between patients and controls. A chi-square test was used to examine frequency differences.

Results: Dietary intake did not differ between the PD patient and control groups. Regarding dietary quality, the patients consumed more saturated fat compared to controls. Overall, the dietary differences between the groups were minor. The composition of the gut microbiome differed between PD patients and controls. Lactobacillus and Bifidobacterium genus were most abundant in PD patients. Prevotella VZCB and other Faecalibacterium were most abundant in controls.

Conclusions: Our results indicated that PD patients may experience gut microbiome change even in the early stage, while nutritional needs can be met when a balanced diet including various food groups are consumed.