Beneficial Effects of Nuts on Cardiovascular and Metabolic Health: An Insight into the Gut-Cardiometabolic Axis.

Cardiometabolic diseases (CMDs) are major contributors to global morbidity and mortality. Emerging evidence suggests that the gut microbiota plays a central role in the pathogenesis and progression of CMDs by regulating cardiometabolic endpoints, including lipid profiles, glucose homeostasis, immunity, inflammation, and oxidative stress. Nuts are nutrient-dense foods rich in unsaturated fatty acids, dietary fiber, polyphenols, vitamins, and minerals that interact with the gut microbiota. Additionally, nut intake has been associated with improved cardiometabolic health outcomes. This review examines current evidence on the effects of tree nut consumption on the gut-cardiometabolic axis, with an emphasis on clinical and mechanistic studies across different types of tree nuts. Clinical evidence of the capacity of nut consumption to affect CMDs is summarized. The bidirectional interaction between nut-derived microbial metabolites, including short-chain fatty acids, urolithins, phenolic acids, valerolactones, and gut microbiota, is highlighted. In addition, mechanisms by which changes in the nut-associated gut microbiome affect the CMDs via regulating lipids, glucose, energy homeostasis, and immunity modulation are discussed. The available evidence, although mostly associative, supports the potential favorable effects of nuts in modulating gut microbial composition and function in ways that may improve cardiometabolic health. However, future studies are needed to address limitations in current studies, including substantial heterogeneity across studies, the lack of established causal mechanisms, long-term clinical outcomes, and to investigate personalized responses to nut consumption given interindividual variability in gut microbiota.