The gut microbiome and the central nervous system are intricately connected through a bidirectional communication system that plays a vital role in maintaining gut homeostasis and overall health. Disr Show more
The gut microbiome and the central nervous system are intricately connected through a bidirectional communication system that plays a vital role in maintaining gut homeostasis and overall health. Disruptions in this interaction are linked to gastrointestinal and neuropsychiatric disorders, including anxiety. This review aims to provide a comprehensive analysis of the gut microbiota's role in anxiety and evaluate the therapeutic potential of prebiotics. This review synthesizes recent literature from databases including PubMed, Scopus, Web of Science, and Google Scholar, focusing on the gut microbiota's role in anxiety and the therapeutic potential of prebiotics. The microbiota-gut-brain axis communicates through multiple pathways, including the vagus nerve, immune signaling, microbial metabolites, and the hypothalamic-pituitary-adrenal (HPA) axis. Prebiotics modulate these pathways by enhancing beneficial microbial populations and influencing the production of neuroactive compounds. Key molecular targets implicated in this communication include brain-derived neurotrophic factor (BDNF), glucocorticoid receptors, and shortchain fatty acids, which modulate neurotransmitters such as GABA and serotonin, and influence neuroinflammatory pathways implicated in anxiety pathophysiology. The findings highlight the immunological, neurochemical, and endocrine mechanisms through which the gut microbiota interacts with neurophysiological systems. These mechanisms underscore the pharmacological potential of prebiotics in the management of psychiatric illnesses. The interplay between the gastrointestinal microbiota and neurophysiological systems provides key pharmacological insights into the potential of prebiotics as a therapeutic approach for managing psychiatric illnesses, detailing their mechanistic pathways and translational applications in clinical practice. Show less
Type 2 diabetes has been linked to oxidative stress, inflammation, and an imbalance in the gut microbiota, all of which contribute to neuroinflammation and cognitive decline. Gut microbiota influence Show more
Type 2 diabetes has been linked to oxidative stress, inflammation, and an imbalance in the gut microbiota, all of which contribute to neuroinflammation and cognitive decline. Gut microbiota influence inflammation and produce various substances, including butyrate, a short-chain fatty acid that promotes brain-derived neurotrophic factor (BDNF), which is essential for memory. This study investigated whether prebiotics, probiotics, or a combination of both (symbiotics) could improve memory in diabetic rats. Male Wistar rats were divided into five groups: control; diabetic and obese (induced by a high-fat diet and streptozotocin); diabetic and obese with prebiotics (inulin); diabetic and obese with probiotics (Lactobacillus acidophilus); and diabetic and obese with symbiotics (inulin + L. acidophilus). Treatments lasted 42 d. Memory performance was evaluated using the Morris water maze (spatial memory) and the Eight-arm radial maze (working memory). After testing, hippocampal tissue was analyzed for inflammatory markers (TNF-α, IL-10), BDNF, and butyric acid. Diabetes impaired memory and increased neuroinflammatory markers. All supplemented groups showed improved memory. The symbiotic group exhibited the most pronounced benefits, with higher levels of BDNF, IL-10, and butyric acid, and reduced TNF-α. Electrophysiological recordings revealed that diabetes reduced the firing frequency of CA1 pyramidal cells and decreased the synaptic strength in the hippocampus. Symbiotic supplementation preserved these neuronal and synaptic functions. Symbiotic treatment effectively countered diabetes-induced cognitive deficits by reducing neuroinflammation, increasing neurotrophic support, and maintaining synaptic plasticity. These results imply that altering the gut microbiota through symbiotic supplementation may be an effective approach to prevent or mitigate diabetes-associated cognitive decline. Show less