Background/Objectives: Prebiotics, which are non-digestible compounds that selectively modulate gut microbiota, are recognized for their potential to promote host health. Although their bifidogenic effect is well documented, a systematic synthesis of how this microbial modulation translates into clinical gastrointestinal (GI) and metabolic outcomes across diverse populations is needed. This review aims to integrate mechanistic insights with clinical evidence to elucidate the pathway from prebiotic structures to tangible health benefits. Methods: This comprehensive narrative review details the structural properties of major prebiotics (e.g., inulin, FOS, and GOS) that govern their fermentation and the production of short-chain fatty acids (SCFAs). To evaluate clinical efficacy, an analysis of 22 randomized controlled trials from the past decade was conducted, focusing on human studies that utilized ISAPP-recognized prebiotics as the sole intervention. Results: The analysis confirms that prebiotic supplementation consistently increased the abundance of beneficial bacteria (e.g., Bifidobacterium and Lactobacillus) and SCFA production. These changes are associated with significant clinical improvements, including enhanced stool frequency and consistency, strengthened intestinal barrier function, and modulated immune responses. Benefits have been documented in healthy individuals, children, the elderly, and those with conditions such as constipation, metabolic syndrome, and antibiotic-associated dysbiosis. However, significant inter-individual variability in response was evident, and the study designs showed notable heterogeneity in prebiotic type, dosage, and duration. Conclusions: Prebiotics are effective modulators of gut health, driving clinical benefits through selective microbial fermentation and SCFA production. The documented heterogeneity and variability highlight the need for future research to focus on personalized nutritional strategies. Key priorities include standardizing intervention protocols, elucidating dose–response relationships, integrating multi-omics data to link taxonomy to function, and exploring novel applications such as synbiotic formulations and gut–brain axis modulation.

Ellagic acid (EA), a naturally occurring phenolic compound, has garnered significant interest as a potential antifungal agent owing to increasing fungal resistance and a scarce therapeutic pipeline. This review consolidates the evidence of the broad-spectrum activity of EA against critical priority pathogens, including Candida auris and Cryptococcus neoformans. We highlight its multi-target mechanisms of action, such as the impairment of cell wall integrity and plasma membrane disruption resulting from the inhibition of ergosterol biosynthesis, and inhibition of key enzymes, such as laccase. In addition to its direct growth-inhibitory effects, EA exhibits antivirulence properties, reducing biofilm formation and hyphal morphogenesis. Notably, it demonstrates synergistic potential with conventional antifungals, such as fluconazole, enhancing efficacy and potentially hindering the emergence of resistance. Although its poor solubility and bioavailability pose therapeutic challenges, advanced formulations such as liposomal systems show promise for improving its delivery. We conclude that EA is a promising candidate for developing new antifungal strategies, particularly as a synergistic agent or in nanoformulations, warranting further investigation to translate its potential into clinical practice.

Background/Objectives: The emergence of methicillin-resistant Staphylococcus aureus (MRSA) necessitates innovative strategies to overcome conventional resistance mechanisms. This study investigated the potential of the natural flavonolignan silibinin (SIL) as an antivirulence agent against S. aureus, with a particular emphasis on its putative multi-target antibacterial activity and its capacity to potentiate the effects of ciprofloxacin (CIP). Methods: The antibacterial and antivirulence properties of SIL were assessed using both in vitro and in silico approaches. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined, and its synergistic interaction with CIP was evaluated using checkerboard assays. Inhibition of biofilm formation, as well as disruption of established biofilms, was assessed using an MTT-based viability assay. Staphyloxanthin (STX) inhibition was examined through pigment extraction and spectrophotometric quantification of pathway intermediates. Molecular docking studies were conducted to predict the binding affinities of the compounds to key bacterial targets, while safety was evaluated through haemolytic and cytotoxicity assays. Results: SIL exhibited weak to moderate direct antibacterial activity (MICs of 256–512 µg/mL), which is characteristic of many natural product scaffolds. Notably, SIL potentiated the activity of CIP, reducing its MIC by up to fourfold against selected resistant strains of S. aureus. SIL significantly inhibited biofilm formation and disrupted established mature biofilms in a strain-dependent manner. In vitro metabolic profiling and in silico analyses provided mechanistic insights into the effects of SIL on STX biosynthesis. Precursor accumulation data suggest inhibition at the diapophytoene desaturase (CrtN) catalytic step, representing a potential mechanism not previously reported for flavonolignans. Molecular docking studies further predicted favourable binding affinities for CrtM and other key targets. Importantly, SIL exhibited no haemolytic activity and low cytotoxicity in macrophages at synergistic concentrations. Conclusions: This study provides evidence that SIL functions as a dual-action agent, potentiating ciprofloxacin efficacy while reducing STX production and inhibiting biofilm formation, thereby impairing key virulence mechanisms of S. aureus. These findings, together with its favourable safety profile, provide a strong rationale for the development of silibinin-based topical adjuvants to combat drug-resistant Staphylococcus infections in humans.

The long-term behavior of plant dietary fibers affects their usefulness in creating stable and sustainable functional ingredients. This study compared the structural and chemical features of Leucaena leucocephala seeds stored for 11 years under environmental conditions with freshly harvested seeds from the same plant. The anatomical parts, including the seed coat, cotyledons, and endosperm, were examined using physicochemical methods, as specified by the Association of Official Analytical Chemists (AOAC), as well as scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS). Stored seeds maintained surface integrity and had seed coat thickness similar to that of fresh seeds (p > 0.05), although fissures appeared due to tegument contraction. The elemental composition (C, N, Ca, K, S, Mg, and O) remained unchanged (p > 0.05), consistent with oxidative resistance and the preservation of lignocellulosic cell wall integrity, as inferred from the stability of dietary fiber and the seed coat microstructure. Chemical analysis showed higher levels of proteins (cotyledons and endosperm; p < 0.05) and ash (p < 0.001) in stored seeds, while fresh seeds contained more soluble carbohydrates (seed coat and endosperm; p < 0.001) and lipids in the endosperm (p = 0.004). The differences in composition reflect the combined effects of environmental exposure and physiological processes over time. Overall, L. leucocephala maintains its chemical and microstructural integrity during long-term natural aging, highlighting its potential as a durable, sustainable source of functional fibers for food science and plant biotechnology.

Background/Objectives: Plant-derived soluble fibers are being explored as sustainable prebiotic ingredients; however, tropical legumes such as Leucaena leucocephala remain understudied. This study evaluated soluble fibers from L. leucocephala seeds after simulated gastrointestinal digestion, focusing on rheological properties, microbial selectivity, metabolite production, and intestinal safety. Methods: The anatomical parts of the seed underwent INFOGEST 2.0 digestion. Soluble fibers were characterized by GC-MS monosaccharide profiling, viscosity, and SEM/EDS analyses, and were used as substrates for both probiotic and pathogenic bacteria. Fermentation supernatants were analyzed for short-chain fatty acids and lactate, and cytotoxicity was assessed using Caco-2 cells. Results: Endosperm polysaccharides exhibited high apparent viscosity (>300 cP) and pseudoplastic behavior. Monosaccharide profiles revealed the presence of galacto-oligosaccharides and arabinoxylo-oligosaccharides in the oligosaccharide fraction, and galactomannans, xylans, and arabinoxylans in the polysaccharide fraction. Polysaccharides selectively promoted the growth of Lacticaseibacillus rhamnosus GG and Bifidobacterium spp., comparable to or exceeding that of fructo-oligosaccharides (p < 0.05), while limiting pathogenic bacteria. Fermentation produced acetate and lactate concentrations of >4500 ppm and >1000 ppm, respectively. Caco-2 viability remained >90% across all treatments. Conclusions: Compartment-resolved analysis identified the endosperm as the principal source of digestion-resistant viscous fiber, selectively fermented by probiotic bacteria at levels matching or exceeding fructo-oligosaccharides. These findings position L. leucocephala endosperm fiber as a candidate prebiotic substrate, warranting further preclinical evaluation.