Search Results (5,344)

Obesity is an increasingly important and modifiable driver of chronic kidney disease (CKD), with effects that extend well beyond its associations with type 2 diabetes, hypertension, and dyslipidemia. To synthesize the evidence that excess adiposity is a causal and modifiable determinant of kidney disease, and to examine how specific adipose depots injure the glomerulus and the tubulointerstitium, and then map these mechanisms onto established and emerging therapies. Throughout, obesity-related kidney disease (ORKD) denotes the full spectrum of diposity-driven renal injury, whereas obesity-related glomerulopathy (ORG) is reserved for the biopsy-defined glomerular lesion. Central, visceral, perirenal and renal-sinus adiposity act first through structural and haemodynamic mechanisms, promoting glomerular hyperfiltration, mechanical renal compression and activation of the adipose-derived renin–angiotensin–aldosterone system (RAAS). In parallel, these depots drive cellular and metabolic injury through lipotoxicity, adipokine imbalance, sterile inflammation, oxidative stress, gut dysbiosis, mitochondrial dysfunction, epigenetic remodelling and cellular senescence. Ectopic lipid accumulation within the renal parenchyma—fatty kidney—offers a unifying description of these changes and is most marked in type 2 diabetes mellitus. These interacting processes converge on podocyte stress, tubular metabolic failure, endothelial dysfunction and interstitial fibrosis, producing a phenotypic continuum that ranges from early albuminuria to obesity-related glomerulopathy and progressive CKD. Within the RAAS limb we highlight two comparatively underappreciated, adiposity-linked routes to injury: adipocyte-derived leptin directly upregulates adrenal aldosterone synthase (CYP11B2), and mast-cell chymase generates angiotensin II independently of angiotensin-converting enzyme, together reinforcing aldosterone- and angiotensin II–mediated damage that conventional RAAS blockade only partially interrupts. We further consider the counter-regulatory ghrelin–leptin axis, in which the suppression of ghrelin that accompanies obesity may withdraw an antioxidant, anti-inflammatory and podocyte-protective signal precisely as leptin-driven glomerular injury intensifies, positioning ghrelin as a plausible modulator and candidate biomarker of obesity-related kidney injury. We also examine how obesity complicates renal risk assessment, drug dosing, dialysis delivery and transplant access. Emerging, mechanism-matched therapies—SGLT2 inhibitors, GLP-1 receptor agonists, finerenone, structured lifestyle intervention, metabolic-bariatric surgery and, most recently, aldosterone synthase inhibitors that suppress the chymase- and leptin-driven aldosterone escaping receptor blockade—now enable a precision cardiovascular-kidney-metabolic framework that aligns adipose-depot biology, biomarkers, histology and treatment response to guide mechanism-based care in ORKD. Full article

Chronic kidney disease (CKD) is common in older cats, and nutritional management remains the intervention with the strongest clinical evidence. Interest has expanded from conventional control of phosphorus and uremic signs to the gut–kidney axis, in which renal dysfunction may alter the intestinal environment while microbial metabolism generates solutes that accumulate as kidney function declines. This PRISMA-ScR-guided scoping review and critical narrative synthesis evaluates feline evidence on CKD-associated dysbiosis, gut-derived uremic solutes, bile acid metabolism, and microbiome-directed nutrition. The original search covered January 2021 to April 2026, with inclusion of earlier studies and targeted source verification through July 2026. Eligibility was organized into two evidence strata: core feline evidence and contextual evidence. The final revised evidence map comprised 49 unique sources (28 empirical feline sources and 21 contextual sources spanning comparative, methodological, guideline, regulatory, or safety evidence); non-feline evidence was used only for mechanistic, methodological, safety, or translational interpretation and was not pooled with feline clinical outcomes. Cats with CKD have shown lower fecal microbial richness and diversity and higher circulating indoxyl sulfate in small cross-sectional cohorts, but causality remains unproven. Recent work also identified altered secondary bile acids and lower fecal ursodeoxycholic acid; however, Peptacetobacter hiranonis is principally linked to bai-mediated 7α-dehydroxylation, whereas ursodeoxycholic acid formation requires distinct hydroxysteroid dehydrogenase reactions. Complete therapeutic renal diets improve clinical outcomes, but their benefits reflect multiple simultaneous modifications and cannot yet be decomposed into a microbiome-specific effect. Evidence for isolated prebiotics, probiotics, postbiotics, synbiotics, fecal microbiota transplantation, and precision nutrition algorithms is preliminary or absent in feline CKD. The field is constrained by small cohorts, confounding, reliance on 16S rRNA sequencing, compositional data, and limited interlaboratory reproducibility. Current clinical practice should therefore prioritize a palatable complete renal diet, adequate energy and protein intake, muscle condition monitoring, hydration, and constipation management, while microbiome-directed products remain adjunctive or investigational. Full article

Background/Objectives: Microsatellite-stable colorectal cancer (MSS CRC) accounts for the vast majority of CRC cases and remains largely resistant to immune checkpoint inhibitors. Emerging evidence suggests that the gut microbiome is an important regulator of antitumor immunity and may contribute to immunotherapy resistance through multiple mechanisms involving the tumor microenvironment. This review aims to summarize current knowledge of the microbiome–immunity–therapy axis in MSS CRC and to explore microbiome-based strategies to enhance immunotherapy responsiveness. Methods: A narrative review of the recent literature was conducted, focusing on studies published within the last five years that investigated gut microbiota composition, microbial metabolites, tumor immune regulation, immunotherapy response, and microbiome-targeted therapeutic interventions in CRC. Evidence from mechanistic studies, translational research, clinical investigations, and multi-omics analyses was integrated. Results: Current evidence indicates that gut dysbiosis contributes to immune resistance in MSS CRC through immune exclusion, myeloid-driven immunosuppression, T-cell dysfunction, chronic inflammation, and altered microbial metabolite signaling. Specific microorganisms, including Fusobacterium nucleatum, enterotoxigenic Bacteroides fragilis, pks-positive Escherichia coli, and other CRC-associated pathobionts, have been implicated in tumor progression and modulation of antitumor immunity. Microbial metabolites such as short-chain fatty acids, tryptophan-derived compounds, bile acids, succinate, and inosine represent key functional mediators linking microbial communities to host immune responses. Emerging microbiome-targeted interventions, including fecal microbiota transplantation, next-generation probiotics, postbiotics, selective microbial depletion, and engineered bacterial therapeutics, have shown promising results in preclinical models and early translational or clinical studies, although robust clinical evidence remains limited. In parallel, advances in metagenomics, metabolomics, spatial transcriptomics, and artificial intelligence are facilitating the development of precision immuno-microbiome oncology approaches. Conclusions: The gut microbiome functions as a critical regulator of immune resistance in MSS CRC through coordinated effects on microbial composition, metabolite production, and tumor immune remodeling. Microbiome-targeted interventions, combined with multi-omics-based patient stratification, may provide new opportunities to overcome immunotherapy resistance and expand the clinical benefits of immune checkpoint blockade in this traditionally refractory disease. Full article

Microbiota has emerged as a potential regulator of female reproductive health through immunological, metabolic, and endocrine networks. Growing evidence suggests that the composition and stability of the vaginal, uterine, and gut microbiota are associated with fertility outcomes. Disruptions in reproductive tract homeostasis have been linked to infertility, implantation failure, pregnancy loss, and diminished success in assisted reproductive technologies. Beyond local interactions, maternal gut microbiota may influence systemic immunity and metabolic pathways related to vaginal and endometrial microbiota. While these findings highlight the microbiome-based signatures’ potential as predictive and prognostic biomarkers, their clinical applicability remains unconfirmed. Evidence is limited by small cohort sizes, methodological and analytical heterogeneity, and lack of standardization, limiting clinical translation. This narrative review summarizes the current knowledge regarding the microbiome’s role in female reproductive health, highlighting its potential impact on pathophysiology, diagnostics, and therapeutic strategies. While this approach allows for a broad conceptual overview, we explicitly note that it is not systematic. As a result, this review is limited by the absence of a standardized search protocol, which may introduce selection bias. Finally, we review advances in microbial engineering and synthetic biology, highlighting engineered living biotherapeutics as promising strategies to improve microbiome-based reproductive medicine. Full article

Obesity is a chronic metabolic disorder closely associated with dyslipidemia, insulin resistance, low-grade inflammation, and gut microbiota dysbiosis. Mulberry leaves are rich in bioactive proteins, but whether mulberry leaf albumin-type protein can improve diet-induced obesity remains unclear. In this study, ultrafiltered mulberry leaf albumin-type protein (UMP) was prepared and its anti-obesity effects were evaluated in high-fat diet (HFD)-fed C57BL/6J mice. UMP contained 87.12 ± 0.52 g/100 g protein, 2.52 ± 0.00 g/100 g polyphenols, and 8.21 ± 1.49 g/100 g polysaccharides, with two major albumin-type protein bands of approximately 14 and 52 kDa. Structural analysis showed that UMP was mainly composed of β-turns and α-helices. In HFD-fed mice, daily administration of UMP for 16 weeks reduced body weight gain by 3.85 g and 5.63 g in the low- and high-dose groups, respectively, without affecting food intake. Biochemical assays, glucose and insulin tolerance tests, and histological analysis showed that UMP improved insulin responsiveness, alleviated serum dyslipidemia, reduced hepatic lipid accumulation, and decreased circulating alanine aminotransferase, aspartate aminotransferase, and lipopolysaccharide levels. Histological analysis and nuclear magnetic resonance-based short-chain fatty acid quantification further showed that UMP protected colonic morphology and increased colonic short-chain fatty acid levels. Gut microbiota analysis showed that UMP restored microbial diversity, reduced the Firmicutes/Bacteroidota ratio, and enriched potentially beneficial genera, including Ileibacterium and norank_f_Muribaculaceae. Fecal biochemical assays suggested that UMP promoted fecal free fatty acid excretion and partially improved bile acid-related metabolic alterations. Untargeted serum metabolomics revealed that UMP reshaped metabolic pathways related to lipid turnover, bile acid signaling, glucose utilization, and glucuronidation. Correlation analysis linked UMP-enriched bacterial taxa with key metabolites involved in fatty acid and energy metabolism. Together, these findings indicate that UMP attenuates HFD-induced obesity through coordinated regulation of gut microbiota, intestinal metabolites, and systemic metabolic homeostasis. UMP may therefore represent a promising functional dietary protein for the prevention of obesity-related metabolic disorders. Full article

Background/Objectives: Metabolic dysfunction-associated steatotic liver disease (MASLD) is closely linked to Western dietary patterns. Yet, preclinical studies rely on continuous high-fat feeding, overlooking the intermittent nature of human eating. Whether dietary periodicity itself influences the gut–liver axis and MASLD pathogenesis remains unknown. We compared continuous and intermittent high-fat, high-cholesterol (HFHC) diets in guinea pigs, a model that mirrors human lipoprotein metabolism, hepatic cholesterol handling, and hindgut fermentation. Methods: Integrated multi-omics analyses (serum metabolomics, fecal 16S rRNA sequencing, and liver transcriptomics) were employed in a guinea pig model, stratified into normal diet (ND), intermittent HFHC diet (IHD), and IHD with flaxseed lignan supplementation, to compare the effects of dietary regimens and the therapeutic efficacy of lignan on hepatic pathology. Results: Both diets induced hallmark hepatic features of MASLD; however, the intermittent regimen provoked significantly more severe hepatic steatosis, inflammation, oxidative stress, and fibrosis. Hepatic transcriptomic analysis identified the PI3K-Akt signaling pathway as the most significantly enriched pathway in the IHD group. Mechanistically, this aggravated liver injury was linked to gut microbiota dysbiosis and a marked depletion of the microbial metabolite enterolactone. Fecal microbiota transplantation confirmed that the dysbiotic microbiota directly transmits the aggravated liver injury phenotype. Supplementation with flaxseed lignan, the dietary precursor of enterolactone, restored enterolactone production, corrected the dysregulated gut microbiota–enterolactone axis, and largely normalized the expression of PI3K-Akt downstream targets, thereby alleviating hepatic pathology. Conclusions: These findings suggest that alterations in the gut microbiota–enterolactone axis may contribute to diet-periodicity-driven liver injury and highlight its potential involvement in disease progression. Modulating this axis through dietary interventions, such as flaxseed lignan supplementation, may represent a promising nutritional strategy for mitigating MASLD associated with cyclical dietary exposure. Full article

Background/Objectives: Atopic dermatitis (AD) is a chronic inflammatory skin disease in which gut–skin axis dysregulation is increasingly implicated. We conducted a prospective pilot study to describe the clinical evolution of pediatric AD following individualized, stool-guided microbiota-targeted therapy and to explore whether baseline dysbiosis markers predict outcomes beyond baseline disease severity. Methods: Twenty-one children with AD and laboratory-confirmed gut dysbiosis were enrolled consecutively at a tertiary pediatric center in Romania in a single-arm prospective pilot study. Gut microbiota was assessed using targeted culture-based stool analysis, generating a Flora Index and a binary High Putrefaction Flora classification. Individualized treatment consisted of strain-specific probiotics, prebiotics, and antifungals when indicated. Disease severity was assessed using the Patient-Oriented Eczema Measure (POEM) and Scoring Atopic Dermatitis (SCORAD) at baseline, 30 days, and 90 days. Longitudinal changes were evaluated using repeated-measures ANOVA and hierarchical regression models. Results: High Putrefaction Flora was present in 71.4% of participants. Mean POEM decreased from 14.67 ± 5.22 at baseline to 7.10 ± 3.82 at 90 days, while mean SCORAD decreased from 41.66 ± 15.28 to 17.93 ± 11.68 (both p < 0.001). Approximately 76% of participants achieved a ≥50% reduction in POEM, and 71% achieved a ≥50% reduction in SCORAD. Individualized microbiota-targeted therapy was associated with substantial improvements in both clinical and patient-reported disease severity over the 90-day follow-up. Although children with High Putrefaction Flora exhibited higher disease severity scores in unadjusted analyses, baseline disease severity was the only significant predictor of 90-day outcomes. The Flora Index provided no independent explanatory value. Conclusions: In this exploratory single-arm pilot study, individualized microbiota-targeted therapy was associated with substantial and clinically meaningful improvement in AD severity over 90 days. Dysbiosis markers were associated with disease burden but did not independently predict outcomes, suggesting that they may function primarily as indicators of baseline severity rather than prognostic biomarkers. Because of the uncontrolled study design, causal inferences regarding treatment effects cannot be made, and these findings should be considered hypothesis-generating. Adequately powered randomized controlled trials are required to determine the efficacy of individualized microbiota-targeted interventions in pediatric atopic dermatitis. Full article

Lameness is a major welfare and economic disorder in dairy production and a clinical sign with multiple causes. This review focuses on claw horn disruption lesions (CHDL), a major cause of periparturient lameness. Although hoof-centered prevention and treatment remain essential, preclinical systemic alterations, recurrence, and clustering with other transition-period disorders suggest that CHDL may sometimes represent the local expression of broader pathophysiology. We propose the Lameness Triad, in which three mechanisms converge: sustained endotoxemic pressure and TLR4-mediated innate immune activation, endothelial glycocalyx degradation and vascular dysfunction, and metabolic triage that reallocates resources from production toward defense. Their combined pathogenic pressure is proposed to produce clinical disease when it exceeds a cow-specific Susceptibility–Resilience Gate comprising mucosal barrier integrity, hepatic endotoxin clearance, immune calibration, redox reserve, hoof structural reserve, and prior damage. Ruminal dysbiosis, mammary involution, and postpartum uterine contamination may contribute to inflammatory and endotoxemic pressure, whereas the confined, continuously loaded digital corium may become a principal site of clinical expression. Longitudinal multi-omics studies identified inflammatory, urinary, and milk-metabolite alterations before diagnosis, with within-cohort serum and urine models discriminating cows that later became lame as early as eight weeks prepartum. These findings require prospective validation and do not establish the complete causal sequence. The framework extends, rather than replaces, established hoof-health programs and provides testable hypotheses for earlier detection, prevention, and selection for resilience. Full article

Persistent HIV-1 reservoirs remain a major barrier to a durable functional cure despite long-term suppressive antiretroviral therapy. Although resting memory CD4⁺ T cells constitute the best-characterized cellular reservoir, tissue microenvironments shape viral persistence and immune clearance. The rectal mucosa represents a specialized tissue niche containing HIV-susceptible target cells, antigen-presenting cells, microbial products, inflammatory cues, and local metabolic signals. Within this setting, myeloid-lineage cells, particularly tissue-resident macrophages and dendritic cells, may contribute to HIV-1 persistence through mechanisms distinct from classical T-cell latency. Here, we review how rectal mucosal macrophages may support HIV-1 persistence through longevity, resistance to apoptosis, metabolic adaptation, epigenetic regulation, and sequestration of virions within virus-containing compartments. We also discuss the dual role of mucosal dendritic cells as sentinels that capture and transfer HIV-1 to CD4⁺ T cells, while considering the limited evidence for inducible proviral persistence in selected anatomical and cellular contexts. Importantly, we further distinguish bona fide reservoir-bearing cells from reservoir-supportive mechanisms, including viral capture, trans-infection, immune suppression, and niche-mediated protection. We also highlight how mucosal dysbiosis, barrier disruption, microbial metabolites, chronic interferon signaling, and immunoregulatory myeloid programs may stabilize HIV-1 persistence in rectal tissues. Integrating intact proviral assays, functional measurements, single-cell profiling, multiplex imaging, and spatial transcriptomics will be critical for defining myeloid-associated persistence and guiding tissue-targeted HIV-1 cure strategies. Full article

Ulcerative colitis (UC) is a chronic inflammatory bowel disease marked by immune dysregulation, microbiota imbalance, and intestinal barrier damage. Unconjugated bilirubin (UCB) shows promise in treating UC due to its anti-inflammatory properties but is limited by poor solubility and potential toxicity. This study developed a chitosan-based controlled-release microsphere (CBMS) treatment to overcome these issues. CBMS utilizes the mucoadhesive properties of chitosan to achieve targeted, controlled UCB release in the colon, enhancing its stability and bioavailability. In a DSS-induced UC mouse model, CBMS alleviated clinical symptoms, reduced colon shortening, and improved histological outcomes, including reduced inflammation and enhanced mucosal repair. The mechanism involves CBMS retention in the intestinal lumen, UCB inactivation of digestive proteases, and restoration of microbiota balance, suppressing pro-inflammatory pathways. CBMS offers a promising new therapeutic strategy for UC and insights into polysaccharide-based drug delivery systems. Full article

Histamine plays an essential role in gastrointestinal physiology and immune control, while its balance in the intestinal environment is largely maintained through degradation by diamine oxidase (DAO), a copper-dependent enzyme mainly produced by differentiated enterocytes. Impaired DAO activity reduces the intestinal barrier to luminal histamine, leading to increased local and systemic exposure and contributing to altered motility, permeability, visceral sensitivity, and immune activation. Accumulating research suggests that disturbances in diamine oxidase regulation contribute to the development of various gastrointestinal diseases, including histamine intolerance, inflammatory and functional bowel disorders, intestinal ischemia, and liver pathology. This review summarizes current knowledge on the biochemistry, localization, and regulation of DAO, as well as histamine signalling via H1–H4 receptors in the gastrointestinal tract. We highlight the interaction between epithelial injury, immune activation, dysbiosis, and histamine accumulation, and discuss the divergent interpretation of mucosal versus circulating DAO activity. Finally, we critically assess the diagnostic limitations of serum DAO and explore emerging therapeutic strategies targeting impaired histamine degradation. Although DAO represents a promising adjunctive biomarker and therapeutic target, its clinical utility requires standardized measurement methods and integrative diagnostic approaches. Full article

Gut microbiota dysbiosis has been associated with ischemic stroke (IS), myocardial infarction (MI), and aging, but whether these contexts share reproducible microbial features remains unclear. We conducted an exploratory and hypothesis-generating descriptive study of genus-level microbiota patterns across an internal IS cohort and publicly available external IS, MI, and age-stratified or longevity-associated datasets. Analyses were performed within predefined age strata and interpreted cautiously because of the small internal cohort, cross-cohort heterogeneity, and the absence of direct metabolite, intestinal barrier, inflammatory, or microbial activity measurements. No taxon in the internal cohort remained statistically significant after false-discovery-rate correction; therefore, all taxonomic observations were treated as descriptive. Candidate overlapping features included repeated detection of Escherichia-Shigella and Klebsiella and non-uniform patterns among genera previously associated with short-chain fatty acid metabolism, including Faecalibacterium, Blautia, and Roseburia. Lachnoclostridium and Bacteroides showed opposite abundance gradients in selected cross-dataset comparisons. These observations suggest possible ecological overlap across ischemic disease and age-associated microbiome contexts, but they do not establish causality, disease-specific biomarkers, or shared microbial function. The mechanistic models discussed in this manuscript are literature-informed hypotheses based on exploratory compositional data and require future validation in larger, harmonized longitudinal cohorts using metagenomic, metabolomic, clinical, and experimental measurements. Full article

Background/Objectives: Psoriatic disease (PsD) is a chronic, systemic inflammatory disorder characterized by a wide spectrum of clinical manifestations extending beyond skin and joint involvement. Increasing evidence suggests a relevant role of the gut microbiota in the pathogenesis of psoriatic arthritis (PsA), although a clear causal relationship remains to be fully established. The aim of this review is to summarize current evidence on the role of the gut microbiome in PsD, with a focus on immune modulation, disease pathogenesis and potential therapeutic implications. Methods: A narrative review of the literature was conducted, focusing on studies investigating gut microbiota composition, dysbiosis patterns, and microbiome-related mechanisms in PsD and PsA, as well as emerging microbiota-targeted interventions. Results: Recent advances in high-throughput sequencing technologies have identified distinct microbial signatures associated with PsA onset and progression. Dysbiosis appears to influence immune system regulation, contributing to systemic inflammation through mechanisms involving intestinal barrier dysfunction and immune activation. Patients with PsA exhibit specific alterations in gut microbial composition compared to healthy controls. Emerging therapeutic strategies targeting the microbiota—including dietary interventions, probiotics, and fecal microbiota transplantation—show potential as adjunctive approaches in disease management, although clinical evidence remains limited. Conclusions: The gut microbiome represents a promising area of research in PsD, offering novel insights into disease mechanisms and potential therapeutic targets. Further studies are needed to clarify causal relationships and to define the clinical applicability of microbiota-based interventions. Full article

Background/Objectives: Alcohol-associated liver disease (ALD) is driven by gut-liver axis dysfunction, including intestinal barrier disruption, dysbiosis, microbial translocation, inflammation, metabolic dysfunction, and malnutrition. Fermented dairy foods may modulate several of these domains, yet whether sheep yogurt, as an intact fermented dairy matrix, is relevant in ALD is unknown. This scoping review mapped evidence relevant to sheep yogurt, ALD, and gut-liver axis biology. Methods: A PRISMA-ScR-guided scoping review searched PubMed/MEDLINE, Web of Science, Scopus, and Google Scholar from January 2006 to February 2026. Eligible sources were charted using a prespecified framework classifying evidence as direct, indirect, or mechanistic inference. Mapped domains included ALD pathophysiology; intestinal barrier integrity; bacterial and fungal microbial ecology; bile acid and tryptophan-aryl hydrocarbon receptor signaling; nutritional vulnerability; fermented dairy interventions; and ovine dairy-matrix characteristics. Results: Of 1388 records identified, 121 sources were included after duplication and screening. No eligible study directly tested sheep yogurt or a defined sheep yogurt preparation in ALD-relevant experimental or clinical settings. Indirect evidence supported the relevance of gut-liver axis dysfunction to ALD and indicated that selected fermented dairy products, probiotics, postbiotics, and microbial preparations may influence intestinal permeability, inflammatory signaling, microbial ecology, oxidative stress, and liver-injury outcomes. Compositional data supported sheep yogurt as a distinct food matrix. However, findings from isolated components, probiotic-only interventions, and non-ALD models could not be interpreted as evidence of sheep yogurt efficacy in ALD. Conclusions: The current literature supports a hypothesis-driven research framework rather than any therapeutic claim for sheep yogurt in ALD. Any potential benefit of sheep yogurt in ALD remains hypothetical and cannot support clinical or dietary recommendations until validated experimentally. Future direct, comparator-controlled studies of intact sheep yogurt should assess liver injury, barrier integrity, microbial translocation, relevant metabolites, and nutrition-related outcomes. Full article

Background/Objectives: The skin microbiome maintains barrier integrity, immune homeostasis, and pathogen defense; dysbiosis contributes to acne vulgaris, dandruff, seborrheic dermatitis, atopic dermatitis, psoriasis, and alopecia. This scoping review critically appraised evidence on prebiotics, probiotics, synbiotics, postbiotics, and paraprobiotics in dermo-cosmetics for acne vulgaris and scalp disorders. Methods: A scoping search (2006–2026) covered SciELO, PubMed/PMC, Google Scholar, CAPES Portal, Scopus, Heliyon, Frontiers, Nature, Wiley, and MDPI, following PRISMA 2020 guidelines. Results: Of 1665 records, 66 were included. For acne, effective prebiotics included blackcurrant, grape seed, ginseng, trehalose, and glucomannan hydrolysate; effective probiotic strains included Streptococcus thermophilus, Bifidobacterium longum, Staphylococcus epidermidis, and Streptococcus salivarius. A synbiotic (B. breve BR03, Lacticaseibacillus casei LC03, Ligilactobacillus salivarius LS03) reduced inflammatory lesions by 56.67% in an 8-week RCT (n = 114). For scalp disorders, oral Lacticaseibacillus paracasei ST11 reduced dandruff by 70% vs. 23% (placebo); Lactiplantibacillus plantarum TCI999 increased hair root diameter (n = 50, 12 weeks); a Lacticaseibacillus rhamnosus plus Bifidobacterium longum mixture improved alopecia areata by 56% vs. 30% (n = 26, 24 weeks). Conclusions: Biotic dermo-cosmetics can modulate the cutaneous microbiome and attenuate inflammation in acne and scalp disorders, with strongest evidence for multi-strain/synbiotic formulations. Formulation stability, strain specificity, regulatory heterogeneity, and lack of standardized microbiological endpoints remain key challenges; larger standardized RCTs with active comparators are needed. Full article