This study explores the relationship between diet and the gut microbiome in patients with Parkinson’s disease (PD). Researchers analyzed the gut microbiome of 85 PD patients in central California using 16S rRNA gene sequencing and assessed diet quality using the Healthy Eating Index 2015 (HEI-2015). They found that higher HEI scores and fiber intake were associated with an increase in anti-inflammatory butyrate-producing bacteria, such as Butyricicoccus and Coprococcus 1, while higher added sugar intake was linked to an increase in pro-inflammatory bacteria like Klebsiella. Predictive metagenomics suggested that bacterial genes involved in lipopolysaccharide biosynthesis decreased with higher HEI scores, indicating less neuroinflammation. The study also found that a healthy diet, fiber, and added sugar intake affect the gut microbiome composition and its predicted metagenomic function in PD patients. These findings suggest that a healthy diet may support a gut microbiome that has a positive influence on PD risk and progression. The study highlights the importance of dietary habits in shaping the gut microbiome and their potential impact on PD development and progression. It also emphasizes the need for further research to understand the long-term effects of diet on the gut microbiome in PD patients.This study explores the relationship between diet and the gut microbiome in patients with Parkinson’s disease (PD). Researchers analyzed the gut microbiome of 85 PD patients in central California using 16S rRNA gene sequencing and assessed diet quality using the Healthy Eating Index 2015 (HEI-2015). They found that higher HEI scores and fiber intake were associated with an increase in anti-inflammatory butyrate-producing bacteria, such as Butyricicoccus and Coprococcus 1, while higher added sugar intake was linked to an increase in pro-inflammatory bacteria like Klebsiella. Predictive metagenomics suggested that bacterial genes involved in lipopolysaccharide biosynthesis decreased with higher HEI scores, indicating less neuroinflammation. The study also found that a healthy diet, fiber, and added sugar intake affect the gut microbiome composition and its predicted metagenomic function in PD patients. These findings suggest that a healthy diet may support a gut microbiome that has a positive influence on PD risk and progression. The study highlights the importance of dietary habits in shaping the gut microbiome and their potential impact on PD development and progression. It also emphasizes the need for further research to understand the long-term effects of diet on the gut microbiome in PD patients.