Currently, it is well established that the gut microbiota, besides providing protection for the host against pathogenic microorganisms, cooperates via neural, circulatory, hormonal, and immune systems to establish the normal function of diverse organs of the body. It is also becoming clear that gut dysbiosis favors the onset or worsening of several chronic abnormalities, including metabolic, cardiovascular, and neurodegenerative diseases. There is a growing body of evidence that the consumption of some functional food has beneficial effects in those disorders by mechanisms not yet completely elucidated. In this regard, ongoing translational and clinic research have provided evidence that the beneficial actions of many food ingredients or dietary supplements with probiotic, prebiotic, or both (synbiotic) properties are due in part to the decrease of the excessive production reactive oxygen species (ROS) which is a common characteristic of most of the chronic diseases, such as atherosclerosis, hypertension, diabetes, and neurodegenerative disorders. Moreover, other classical and new diets that can also provide antioxidative molecules could modulate the gut flora and contribute to the prevention and treatment of different chronic diseases. On the other hand, omics approaches can also be useful to determine how the microbiota affects the biology of the host and participate in the development of pathologies. For example, metabolomics studies, by means of new enzymatic and mass spectrometric methodology, are increasingly used to investigate the metabolite profiles related to the gut microbiota, thus increasing our knowledge of the impact of dietary factors on chronic and acute diseases. Also, metabolomic studies give important information on the contribution of gut microbiota in drug metabolism. Furthermore, lipidomics approaches are being used to know how gut microbiota may affect host energy and lipid metabolism in multiple organs.

In agreement with the present research scenario and with the scope of this journal, it is a timely opportunity for researchers to publish their most exciting findings on the beneficial effects of functional food in health and disease conditions. The submissions may preferentially report new approaches designed to evaluate the potential of functional food to fight diseases, mainly focusing on those characterized by local or systemic high levels of ROS. Also, studies that describe the interactions of the microbiome with the functional physiology of the host to evaluate its role in the development of diseases and its potential use for the discovery of new biomarkers are welcome.

Therefore, the editorial team of this special issue invites investigators in the field to submit their basic, translational, or clinical articles, as well as state-of-the-art reviews articles, which may be focused on the mechanisms of action of classic or new nutritional modulators of the gut microbiota and that in the near future could be used as coadjuvants on the prevention/treatment of ROS- or aging-related chronic diseases.

Potential topics include but are not limited to the following:

• Methodological approaches to assess the bidirectional interaction between gut microbiota and function of body organs
• Nonpharmacological therapies to prevent or minimize gut dysbiosis-related chronic metabolic (dyslipidemia and atherosclerosis) and cardiovascular disorders (cardiac dysfunction, endothelial dysfunction, and arterial hypertension)
• Approaches designed to evaluate the antioxidative effects of classical prebiotics, probiotics, and synbiotics and other functional food for prevention or coadjuvant treatment of chronic diseases
• Mechanisms of action of functional food in chronic diseases, including aging-dependent neurodegenerative disorders (dementia, Alzheimer, and Parkinson diseases)
• New omics approaches designed to reveal the active components of classical probiotics and to search for new compounds with antioxidant actions in prevalent chronic diseases
• Components of the Western diet that exhibit beneficial modulator effects on the gut microbiota and that could be promising coadjuvants of preventive and reparative therapy in the above chronic diseases related with oxidative stress and/or longevity