Withania somnifera-Functionalized Selenium Nanoparticles Attenuate Glycerol-Induced Rhabdomyolysis-Associated Acute Renal Failure.

Functional bowel disorders (FBDs) encompass a spectrum of chronic gastrointestinal conditions characterized by abdominal pain, bloating, distension, and irregular bowel habits in the absence of structural abnormalities []. According to the Rome IV criteria, FBDs include irritable bowel syndrome (IBS), functional constipation (FC), functional diarrhea (FD), functional abdominal bloating (FAB), and functional abdominal distension (FAD) []. These disorders impose a substantial burden on quality of life and healthcare systems worldwide, affecting up to 40% of adults, depending on the diagnostic approach and region [,]. Despite their high prevalence, FBDs remain challenging to manage due to their multifactorial pathophysiology and heterogeneous clinical presentation. Emerging evidence indicates that FBDs arise from complex interactions involving altered gut motility, visceral hypersensitivity, intestinal barrier dysfunction, immune dysregulation, and gut microbiota imbalance [,]. In particular, low-grade inflammation and subtle immune activation, rather than overt mucosal damage, are increasingly recognized as key contributors to symptom generation []. Dysbiosis has been consistently reported in FBDs, with microbial alterations linked to changes in metabolic outputs that influence motility, epithelial integrity, and gut–brain signaling [,]. Reduced or atypical microbial diversity has also been associated with constipation and diarrhea [,,]. Consequently, microbiota-targeted interventions have attracted considerable interest as therapeutic strategies, although responses vary across individuals and microbial subtypes []. Probiotics—defined as live microorganisms that confer health benefits when administered in adequate amounts—have demonstrated modest but clinically meaningful effects in FBDs, particularly in alleviating abdominal pain, bloating, and bowel habit irregularities [,]. However, outcomes remain inconsistent across studies, largely due to strain-specific differences in biological activity, survivability in the gastrointestinal tract, and mechanistic engagement with host physiology []. This underscores the need for well-characterized probiotic strains supported by robust preclinical evidence before clinical evaluation.