The pathophysiology of several psychiatric diseases may entail disturbances in the hypothalamic–pituitary–adrenal (HPA) axis and metabolic pathways. Variations in how these effects present themselves may be connected to individual variances in clinical symptoms and treatment responses, such as the observation that a significant fraction of participants do not respond to current antipsychotic drugs. A bidirectional signaling pathway between the central nervous system and the gastrointestinal tract is known as the microbiota–gut–brain axis. The large and small intestines contain more than 100 trillion microbial cells, contributing to the intestinal ecosystem’s incredible complexity. Interactions between the microbiota and intestinal epithelium can alter brain physiology and affect mood and behavior. There has recently been a focus on how these relationships impact mental health. According to evidence, intestinal microbiota may play a role in neurological and mental illnesses. Intestinal metabolites of microbial origin, such as short-chain fatty acids, tryptophan metabolites, and bacterial components that might stimulate the host’s immune system, are mentioned in this review. We aim to shed some on the growing role of gut microbiota in inducing/manipulating several psychiatric disorders, which may pave the way for novel microbiota-based therapies.

Agro-industrial byproducts are recognized as sustainable sources of bioactive compounds with potential applications in functional foods. Pomegranate peel and coarse powdered date seeds are among the most abundant fruit processing residues, yet remain underutilized despite their rich in polyphenols, organic acids and other phytochemicals composition. This study aimed to comparatively evaluate the antioxidant, cytoprotective, acetylcholinesterase inhibitory, and anti-arthritic activities of pomegranate peel powder (PPP) and coarse powdered date seeds (CPDS) using a panel of in vitro assays. Antioxidant capacity was assessed by DPPH radical scavenging and reducing power methods, while cytoprotective activity was evaluated using erythrocyte membrane stabilization and protective against oxidative DNA damage methods. Anti-arthritic potential was determined using protein denaturation and proteinase inhibition methods, and acetylcholinesterase inhibitory activity was also examined. PPP exhibited significantly higher activity compared to CPDS across most assays. PPP demonstrated stronger DPPH radical scavenging activity (IC₅₀ = 6.73 µg/mL) compared to CPDS (IC₅₀ = 19.18 µg/mL), along with enhanced anti-hemolytic activity (IC₅₀ = 155.14 ± 1.58 µg/mL vs. 287.02 ± 2.93 µg/mL for CPDS) and stronger protein denaturation inhibition (44.73% vs. 35.78%, p < 0.05). These findings suggest that the superior biological activity of PPP may be attributed to its higher phenolic content . This supports the idea of using chemicals from pomegranate peel in functional foods and nutraceutical formulas that aim to make cells stronger and lower the health risks associated with inflammation.