↑ Actinobacteria, Lactobacillus ↓ Proteobacteria, Epsilonproteobacteria, Helicobacteraceae, and Deferribacteraceae ↑ Cognitive impairments ↑ Expression synapsin I and postsynaptic density protein 95 (PSD-5) levels. Here, SYN1 is linked to Cognitive impairment.