Nutritional Modulation of Immune and Central Nervous System Homeostasis: The Role of Diet in Development of Neuroinflammation and Neurological Disease

Abstract

The gut-microbiome-brain axis is now recognized as an essential part in the regulation of systemic metabolism and homeostasis. Accumulating evidence has demonstrated that dietary patterns can influence the development of metabolic alterations and inflammation through the effects of nutrients on a multitude of variables, including microbiome composition, release of microbial products, gastrointestinal signaling molecules, and neurotransmitters. These signaling molecules are, in turn, implicated in the regulation of the immune system, either promoting or inhibiting the production of pro-inflammatory cytokines and the expansion of specific leukocyte subpopulations, such as Th17 and Treg cells, which are relevant in the development of neuroinflammatory and neurodegenerative conditions. Metabolic diseases, like obesity and type 2 diabetes mellitus, are related to inadequate dietary patterns and promote variations in the aforementioned signaling pathways in patients with these conditions, which have been linked to alterations in neurological functions and mental health. Thus, maintenance of adequate dietary patterns should be an essential component of any strategy aiming to prevent neurological pathologies derived from systemic metabolic alterations. The present review summarizes current knowledge on the role of nutrition in the modulation of the immune system and its impact in the development of neuroinflammation and neurological disease.

The Potential Effects of Probiotics and ω-3 Fatty Acids on Chronic Low-Grade Inflammation

“…In adulthood, the composition of the intestinal microbiota is strongly dependent on factors such as long-term dietary patterns, antibiotic use, exercise, and psychological stress [5,10,24,25,34]. Because alterations in the intestinal microbiota have been linked to health and disease, many studies have examined ways to alter the microbiota composition through diet and supplementation [9].…”

“…For example, the probiotic bacteria Lactobacilli and Bifidobacteria, among other strains, have been widely studied and have been shown to improve intestinal barrier function and prevent hyperpermeability via a variety of mechanisms including Toll-like recptor-2 mediated-immune-modulating and anti-inflammatory effects, by promoting the production of compounds that support intestinal barrier function, such as butyrate, and by eliciting positive structural changes in Zo-1 and occludin as part of the tight junction protein complexes [35]. Thus, they may also decrease transfer of LPS [5,36]. In addition, previous research suggests that probiotic bacteria may have a role in forming certain neuroactive compounds.…”

“…In addition, chronic low-grade inflammation has been linked to an imbalance in the gut microbiota [2].The digestive system harbors the largest population of microorganisms in the body, where intestinal bacteria interact with one another and with epithelial and mucosal immune cells to maintain immunological homeostasis [4]. The microbiota is part of the body's communication system integrating the gastrointestinal, immune, and nervous systems, and its stability and adequate function are necessary for maintaining healthy levels of inflammation [5]. Commensal symbionts compete with possible pathobionts for available resources, and these interactions seem to help maintain a healthy equilibrium of the intestinal microbial population [6][7][8].…”

“…Moreover, certain nutritional factors are important to the immune system's functioning and could potentially impact inflammatory processes in a way that leads to either beneficial immune regulation and maintained health or, conversely, to the development of chronic disease [5]. In particular, probiotic bacteria, prebiotic fiber [10], and omega-3 (ω-3) fatty acids [24] have been suggested to serve as positive modulators of this nutrition-inflammation coalition.…”

The interaction between dietary marine components and intestinal flora

“…Intestinal flora imbalance caused by regularly consuming an unhealthful diet plays an important role in the occurrence and development of various diseases (Barrea et al 2018). Unhealthful eating habits can cause intestinal flora disorders, increasing intestinal permeability, forming chronic and low levels of inflammation, and further disrupting insulin signaling pathways, eventually leading to the onset of metabolic syndrome including insulin resistance, obesity, and diabetes (Avolio et al 2020;Dong et al 2019;Estrada and Contreras 2019;Saus et al 2019). Many studies have shown that marine dietary components can play a significant role in maintaining and promoting human health (Dong et al 2019).…”