Background: stroke remains a leading cause of global mortality and disability. Beyond established risk factors, modifiable dietary and metabolic pathways, particularly those involving gut microbiota, offer promising targets for prevention. The Dietary Index of Gut Microbiota (DI-GM) quantitatively assesses diets that support a beneficial gut ecosystem, providing a novel tool for clinical nutrition practice. Objectives: this study examined the associations of the Triglyceride-Glucose Index (TyG) and Dietary Index of Gut Microbiota (DI-GM) with stroke risk, with a focus on their interactions with conventional risk factors and implications for nutritional interventions. Methods: we conducted a cross-sectional analysis of 15,456 U.S. adults from NHANES (2007-2020). Multivariable logistic regression with propensity score weighting was used to examine associations. Results: a nonlinear relationship was observed between the TyG index and stroke risk. Conversely, a DI-GM score >= 7 was significantly associated with a 20.5 % lower stroke risk. This protective effect was driven specifically by the beneficial dietary components within the DI-GM, which were linked to a 13 % risk reduction per unit increase, independent of traditional cardiovascular risk factors. Subgroup analyses revealed that the TyG index's association with stroke risk was potentiated in individuals with hypertension or diabetes. Conclusions: both the TyG index and the DI-GM are significant and complementary predictors of stroke risk. The DI-GM provides a validated nutritional framework for stroke prevention, advocating for a diet rich in fiber, fermented foods, and plant-based polyphenols. These findings underscore the potential of integrating metabolic and gut-microbiota focused dietary strategies, such as those captured by the DI-GM, into personalized clinical nutrition plans for high-risk individuals.
Background: evidence supporting the effectiveness of vitamin supplementation on cognitive function in older adults with Alzheimer's disease (AD) is limited, and the reporting quality of existing research is often overlooked. Objectives: to a) evaluate the effectiveness of vitamin supplementation on cognitive function in older adults with AD; b) describe the characteristics of supplementation protocols; and c) assess the reporting quality of these interventions. Methods: a systematic search of seven databases was conducted for randomized controlled trials (RCTs) up to February 2026. Included studies involved vitamin supplementation for patients with AD and assessed cognitive outcomes. The risk of bias and reporting quality were evaluated. Results: seventeen RCTs (n = 2,478 participants) were included. While eight studies reported some cognitive improvements or stabilization with vitamin B3, D, E, folic acid or specialized multi-nutrient formulations, nine found no significant benefit. A high risk of bias was identified in seven studies, while only five were rated as low risk. The median TIDieR score of 10/12 indicates a good description of the vitamin supplementation protocols. Conclusions: the current evidence for vitamin supplementation in older adults with AD is inconclusive. While some protocols show potential for stabilizing or improving cognitive domains, results are compromised by methodological heterogeneity and a high risk of bias. Future research must focus on enhancing methodological quality and achieving greater homogeneity in vitamin supplementation prescription and dosing to ensure robust clinical evidence for patients with AD.
