# Gut Microbiome ### Summary AD's etiopathogenesis is not fully unerstood. Alterations in gut microbiome contribute to amyloid deposition. Gut microbiome of AD participants has decreased microbial diversity and compositionally distinct from control age and sex matched individuals. Some difference: decreased bifidobacterium, increased bacteroidetes, decreased firmicutes. Correlations between levels of abundant genera and CSF biomarkers of AD. ### Results APOE$$\epsilon$$4 genotype more prevelant in AD group. Sequencing V4 region of 16S rRNA generated 4.8 million reads. 972 OTUs - 95 genera, 46 families, 24 order, 17 classes, 9 phyla. AD is associated with changes in gut microbiome. Decrease in alpha diversity in AD group compared to control group. Compositional difference also present. Several taxa were less abundant in AD. Potential functional changes in gut microbiome of AD participants. (phosphorylation, metabolism etc). Abundant Genera are correlated with CSF Biomarkers of AD Pathology. Same trend between bacterial relative abundance and CSF biomarkers of AD Pathology. (More abundant in AD -> increase abundance means increase AD Pathlogy, same for less abundance in AD). Gut microbiome has decrease richness and diversity and distinct composition to control. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://tianyi0216.gitbook.io/blog/reading-notes/stats-other/gut-microbiome.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.