In the recent years, the accelerating global demographic shift toward population aging has been accompanied by a marked increase in the prevalence of neurodegenerative disorders, notably Alzheimer’s disease, Parkinson’s disease, amyotrophic lateral sclerosis, and multiple sclerosis. Among emerging approaches, dietary interventions targeting the gut–brain axis have garnered considerable attention, owing to their potential to modulate key pathogenic pathways underlying neurodegenerative processes. This review synthesizes current concepts in precision nutrition and elucidates neurohumoral, immune, and metabolic regulatory mechanisms mediated by the gut microbiota, including the roles of the vagus nerve, cytokines, short-chain fatty acids, vitamins, polyphenols, and microbial metabolites. Emerging evidence underscores that dysbiotic alterations contribute to compromised barrier integrity, the initiation and perpetuation of neuroinflammatory responses, pathological protein aggregations, and the progressive course of neurodegenerative diseases. Collectively, these insights highlight the gut microbiota as a pivotal target for the development of precision-based dietary strategies in the prevention and mitigation of neurodegenerative disorders. Particular attention is devoted to key bioactive components such as prebiotics, probiotics, psychobiotics, dietary fiber, omega-3 fatty acids, and polyphenols that critically participate in regulating the gut–brain axis. Contemporary evidence on the contribution of the gut microbiota to the pathogenesis of Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis is systematically summarized. The review further discusses the prospects of applying nutrigenomics, chrononutrition, and metagenomic analysis to the development of personalized dietary strategies. The presented findings underscore the potential of integrating precision nutrition with targeted modulation of the gut–brain axis as a multifaceted approach to reducing the risk of neurodegenerative diseases and preserving cognitive health.

Metabolic syndrome is a cluster of cardiometabolic risk factors in which modifiable dietary factors play a substantial role. This structured narrative review summarizes evidence on biotechnological food reformulation, defined as the modification of the composition or functional properties of foods already present in the diet using enzymes, microorganisms, fermentation, and bioconversion. Approaches to reducing free sugar and sodium content, modifying lipid and protein components, and increasing micronutrient content and bioavailability are reviewed. The data were analyzed with a distinction between experimental systems (in vitro, animal, and human intervention and observational studies) and study populations (healthy individuals, individuals with risk factors, and patients with diagnosed metabolic diseases). Mechanistic and animal data support the biological plausibility of the effects of several reformulated products on individual cardiometabolic markers. However, human intervention studies are few and mostly short-term. They rely on surrogate markers and are often conducted in patients with established disorders; therefore, they do not allow conclusions to be drawn about preventive efficacy. Consumer acceptance, safety, regulatory status, and industrial scalability are discussed on the basis of limited and heterogeneous data and require separate assessment for each technology. Biotechnological reformulation may be considered a promising approach to improving the nutrient profile of mass-market foods. However, its impact on the risk of metabolic syndrome has not yet been established and should be evaluated in long-term randomized trials in individuals without diagnosed metabolic diseases.

The gut microbiome has been proposed as a contributor to Alzheimer’s disease (AD) pathogenesis via the microbiota–gut–brain axis, but findings across cohorts are inconsistent and scarce data exist from Central Asian populations. We used shotgun metagenomic sequencing to compare the gut microbiome of AD patients and cognitively healthy controls from Kazakhstan. In a cross-sectional case–control study (35 AD, 39 Control), we profiled taxonomic and functional (HUMAnN pathway) composition, and compared alpha/beta diversity, individual taxa and pathways, and their association with clinical and demographic variables (Mann–Whitney U test, PERMANOVA/PERMDISP, OLS regression, all BH-FDR corrected, sensitivity analysis using ANCOM-BC2), with sensitivity analyses adjusting for age and BMI and applying Bonferroni correction. Within the AD group, circulating adiponectin—measured only in this group—was examined for associations with microbiome features in an exploratory analysis. Alpha diversity was lower in AD (q < 0.05). Community composition also separated by group on PERMANOVA (R² = 8.6%, p = 0.001), and this separation held after adjusting for age and BMI. A total of 178 taxa differed significantly between groups (BH-FDR; 37 were also Bonferroni-significant), most prominently depletion of Faecalibacterium and enrichment of Eisenbergiella and Desulfovibrio in AD; 100 pathways differed significantly (20 Bonferroni-significant). Three clinical/demographic variables (total bilirubin, atherogenic index, BMI) were associated with specific taxa or pathways. Within the AD group, adiponectin correlated negatively with the pathway assimilatory sulfate reduction IV (rho = −0.60, q = 0.015). AD in this Central Asian cohort was associated with a less diverse, compositionally distinct gut microbiome, with depletion of butyrate-producing Firmicutes and enrichment of sulfate-reducing taxa, alongside other taxa whose direction of association differed from prior reports.

Ensuring the extended shelf life of fruit- and vegetable-based products while preserving their functional and sensory value remains one of the key challenges in modern food technology. Conventional thermal processing effectively ensures microbiological safety; however, it may lead to the degradation of heat-labile vitamins, polyphenols, and natural pigments, as well as to alterations in the structure of the food matrix. This review summarizes current evidence on the application of non-thermal technologies, including high-pressure processing (HPP), pulsed electric fields (PEF), high-pressure homogenization (HPH), ultrasound (US), cold plasma (CP), ultraviolet (UV) radiation, pulsed light (PL), and ionizing radiation (IOR), to the processing of liquid and semi-liquid fruit- and vegetable-based products. Particular attention is given not only to microbial inactivation and shelf-life extension but also to storage stability, residual endogenous enzyme activity, changes in color, rheological, and sensory properties, and modification of the plant matrix. The available evidence indicates that the efficacy of non-thermal processing is determined by the interplay of the mechanism of action, process intensity, product composition and structure, and storage conditions. Under optimized conditions (e.g., HPP at 400–600 MPa and near-ambient temperature; moderate-intensity PEF at 20–40 kV/cm; UV-C doses adjusted for product turbidity), combined with additional hurdles (mild heating to 40–60 °C, refrigerated storage, and low-oxygen-permeability packaging), these technologies can ensure microbiological stability, with vitamin C losses of approximately 5–10% for HPP and 2–10% for moderate-intensity PEF. In contrast, losses associated with US, CP, photochemical methods, and IOR are more variable and may be substantially higher. A comparative analysis of the reviewed studies shows that HPP yields the most consistent results across different matrix types, whereas surface and photochemical methods exhibit more pronounced matrix-dependent variability. Overall, a shift from assessing short-term chemical retention toward validating safety, stability, and functionality throughout the entire shelf life is a key prerequisite for the further development of non-thermally processed products for health-oriented nutrition.