Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most prevalent neurodegenerative diseases, both without prevention or cure. The Mediterranean diet (MeDi) may be neuroprotective by modulating gut microbiota. We aimed to assess the effects of adherence to MeDi on the gut microbiota in relation to AD or PD risk. A search from inception to November 2020 was conducted in PubMed, CINAHL, EMBASE, Web of Science, Global Health, Biological Abstracts, and Grey Literature Report databases. Two searches were conducted: 1) (MeDi or Microbiota) and (PD or AD) and 2) MeDi and microbiota. Inclusion criteria for papers were specified prior to review. Of 4672 studies identified, 64 were eligible for inclusion. These studies were divided into five groups: MeDi and AD risk (n = 4), MeDi and PD risk (n = 2), MeDi and microbial composition or metabolomics (n = 21), AD and microbial composition or metabolomics (n = 7), and PD and microbial composition or metabolomics (n = 30). Adherence to the MeDi was associated with a lower risk of AD and PD development. Eight genera and two species of bacteria had an inverse relationship with MeDi and AD, and one family, eight genera and three species of bacteria had an inverse relationship with MeDi and PD. More studies are needed to investigate if MeDi, gut microbiota, and neurodegeneration are causally related.

Objective: The objective of this study was to assess clinical decision-making associated with the use of a multi-analyte blood biomarker (BBM) test among patients presenting with signs or symptoms of mild cognitive impairment or dementia. Methods: The Quality Improvement PrecivityAD2 (QUIP II) Clinician Survey (NCT06025877) study evaluated the clinical utility of the PrecivityAD2™ blood test in a prospective, single cohort of 203 patients presenting with symptoms of Alzheimer’s disease (AD) or other causes of cognitive decline across 12 memory specialists. The PrecivityAD2 blood test (C2N Diagnostics, St. Louis, MO) combines the plasma Aβ42/Aβ40 ratio and the p-tau217/np-tau217 ratio (%p-tau217) measurements in a statistical algorithm to yield an Amyloid Probability Score 2 (APS2) that informs on the likelihood of brain amyloid plaques. After receiving the BBM test results, clinicians completed surveys on management strategies for each patient. Results: Patients had a median age of 74, 53% were female, and 28% were traditionally under-represented in Black, Hispanic, and Asian groups. The composite primary endpoint, defined as a change in AD diagnostic certainty, drug therapy, or additional brain amyloid evaluation pre- and post-BBM testing, was 75% (p < 0.0001 versus the pre-specified threshold of 20% clinically meaningful change). Anti-AD medication orders decreased among negative APS2 patients and increased among positive APS2 patients (p < 0.0001). Additional brain amyloid testing decreased among negative APS2 patients (p < 0.0001). Conclusions: This blood biomarker test can help memory specialists guide patients to anti-AD therapies as well as rule out AD to allow for other diagnostic considerations.

Background/Objective: Genome-wide association studies (GWASs) demonstrate a complex genetic landscape for migraine risk. Migraine polygenic risk scores (PRSs) developed from GWAS data may have utility for predicting disease course. We analyzed the strength of association between an integrative migraine PRS and age at onset and chronification. Methods: In this retrospective clinical/genetic case–control study, PGS004799 was calculated for adults with European ancestry from two real-world community cohorts. In the DodoNA cohort, 1653 treated, deeply phenotyped migraine cases, diagnosed using International Classification of Headache Disorders 3rd edition criteria, were followed for a mean (range) of 2.3 (1–10) years and compared to 3460 controls (without migraine diagnosis). In the GHI cohort, 2443 cases were identified using the first migraine ICD code as a proxy for migraine onset and compared to 8576 controls (without migraine ICD codes). PRS associations with age at onset (DodoNA) or first migraine ICD code (GHI) and chronification (DodoNA) were evaluated. Results: In both cohorts, PRS was higher in cases (DodoNA mean (range) cases: 0.82 (0.07–1.76), controls: 0.78 (0.04–1.56); t (5111) = −6.1, p = 1.4 × 10⁻⁹, GHI: cases: 0.79 (0.003–1.68), controls: 0.75 (−0.06–1.53); t (11,017) = −7.69, p = 1.6 × 10⁻¹⁴), and a higher PRS was associated with earlier onset in females (HR [95% CI] DodoNA: 2.1 [1.6–2.6, p < 0.001; GHI: 1.8 [1.4–2.1], p < 0.001) and in males (DodoNA: 2.5 [1.3–4.7], p = 0.005; GHI: 1.6 [1.1–2.6], p = 0.027). PRS was not different in cases with or without chronification (t (1651) = −1.67, p = 0.094) and was not associated with earlier chronification (1.2 [0.8–1.6], p = 0.424). Conclusions: Higher genetic risk was associated with earlier onset and increased risk of migraine well into adulthood, but not with chronification. This suggests that the PRS quantifies genetic susceptibility that is distinct from factors influencing disease course.

As the global population continues to age, cognitive decline has emerged as a major area of concern. Modifiable lifestyle factors, such as diet, have been associated with the trajectory of brain aging. Dietary patterns such as the Western diet (WD) have been linked to cognitive decline, whereas a Mediterranean diet (MeDi) promotes healthy brain aging. This study aimed to compare the effects of MeDi and WD on gut microbiota and cognitive health in middle-aged rats. Our hypothesis was that the MeDi, when introduced to middle-aged rats, would maintain cognitive health and produce a distinct gut microbiota composition relative to a WD. Twelve-month-old male Fischer344 rats were randomly assigned to MeDi, WD, or chow (n = 10/group). After 12 wk, fecal samples were collected for 16S rRNA gene sequencing to assess microbial composition. Animals completed the following neurobehavioral assessments, including Y-maze, Morris Water Maze, and Radial Arm Water Maze. At the end of the study, the hippocampus was analyzed for gene and protein expression related to barrier integrity, glial cell activity, and neuroplasticity. There were trending differences in cognitive function in MeDi rats relative to WD rats. Rats exhibited distinct diet-dependent microbial phenotypes with 28 differentially abundant bacteria, including Blautia, Clostridia UCG-014, Clostridium innocuum group, Faecalibacterium, and Bifidobacterium. This was accompanied by changes in hippocampal gene expression of glial cell activity, including glial fibrillary acidic protein, ionized calcium binding protein, and triggering receptor expressed on myeloid cells 2. Blood–brain barrier integrity and neuroplasticity were maintained during the short-term dietary intervention. A longer diet duration may be needed to elicit robust differences in cognitive function driven by the changes in microbiota and neurobiology. This study highlights that a short-term diet introduced in middle age has trending effects on cognitive performance but significantly impacts gut microbiota composition and gene expression of biomarkers of brain health.

With vast amounts of patients’ medical information, electronic health records (EHRs) are becoming one of the most important data sources in biomedical and health care research. Effectively integrating data from multiple clinical sites can help provide more generalized real-world evidence that is clinically meaningful. To analyze the clinical data from multiple sites, distributed algorithms are developed to protect patient privacy without sharing individual-level medical information. In this paper, we applied the One-shot Distributed Algorithm for Cox proportional hazard model (ODAC) to the longitudinal data from the OneFlorida Clinical Research Consortium to demonstrate the feasibility of implementing the distributed algorithms in large research networks. We studied the associations between the clinical risk factors and Alzheimer’s disease and related dementia (ADRD) onsets to advance clinical research on our understanding of the complex risk factors of ADRD and ultimately improve the care of ADRD patients.

Background/Objectives: Migraine is a common neurological disorder with highly variable characteristics. While genome-wide association studies have identified genetic risk factors that implicate underlying pathways, the influence of genetic susceptibility on disease characteristics or treatment response is incompletely understood. We examined the relationships between a previously developed standardized integrative migraine polygenic genetic risk score (PRS) and migraine characteristics in a real-world, treated patient cohort. Methods: This retrospective cohort study used covariate-adjusted regression to comprehensively evaluate associations between the PRS and clinical characteristics in 1653 treated migraine cases with European ancestry at baseline and, in 800 cases, after one year. Cases were deeply phenotyped by neurologists during extensive interviews, using structured clinical documentation tools to record ~200 discrete data elements. Results: In treated patients, higher standardized PRS showed associations with two common migraine symptoms: photophobia (odds ratio [confidence interval]: 1.33 [1.13–1.56], p = 0.001) and stabbing pain (1.21 [1.08–1.36], p = 0.001]; both retained significance at Q = 0.05. Associations with phonophobia, nausea, emesis, and unilateral headache had similar effect sizes but did not survive correction for multiple tests. In this population, the PRS was not associated with other symptoms of migraine attacks, objective measures of migraine disability, frequency, severity, average duration, time-to-peak intensity of migraine attacks, chronification, emergency department visits, triptan responsiveness, or changes at follow-up. Conclusions: In treated patients, genetic risk was associated with common migraine symptoms but not with the severity of migraine characteristics or treatment outcomes. This suggests that in treated patients, other genetic and non-genetic factors influence migraine symptom severity and disease course more strongly than genetic susceptibility.