The scarcity of robust models and therapeutic options for rare diseases continues to hamper their preclinical investigation. Traditional animal models and two-dimensional cell cultures are limited in their ability to replicate human heredity-associated traits and complex pathological features. Organoids-on-a-chip approaches open up new frontiers in rare-disease research via the integration of organ chips and organoid technology. This integrative strategy offers immense opportunities for the mimicry of disease-related traits, the clarification of the mechanisms underlying disease, and the prediction of treatment responses in a highly human-related manner. This forward-looking perspective suggests organoids on chips are transformative tools for parsing rare-disease pathogenesis, accelerating therapeutic discovery, and bridging the gap between basic research and precision medicine.

Progressive non‐alcoholic fatty liver disease (NAFLD) may culminate in severe complications, including fibrosis, cirrhosis and hepatocellular carcinoma, yet therapeutic breakthroughs remain elusive, necessitating novel pharmacological strategies. Semaglutide, a glucagon‐like peptide‐1 (GLP‐1) receptor agonist clinically approved for type 2 diabetes and obesity management, has demonstrated pleiotropic effects in preclinical NAFLD models. In this study, we investigated semaglutide's therapeutic efficacy and mechanisms in a human liver organoids (hLOs) model of NAFLD. Utilising microengineered array chips, human induced pluripotent stem cells (hiPSCs) were differentiated into hLOs with functional hepatic properties. NAFLD pathology was induced via free fatty acid (FFA) exposure, recapitulating disease hallmarks such as steatosis, inflammatory cytokine elevation and fibrogenic activation. Semaglutide treatment at 50 nM significantly attenuated lipid deposition caused by FFAs and reduced triglyceride levels by 8‐fold and cholesterol levels by 1.8‐fold. It also inhibited the expression of pro‐inflammatory markers (IL‐6, IL‐8, TNF‐α) by about 1.5–2 fold and increased the level of lipolytic genes by about 45%. These findings elucidate the therapeutic potential of semaglutide in attenuating key NAFLD‐associated pathologies and establish a robust in vitro platform for preclinical drug evaluation. The study provides critical insights into targeted NAFLD interventions and supports the translation of GLP‐1‐based therapies into clinical practice, addressing an unmet need in hepatology.

The growing global protein demand and environmental concerns from conventional animal agriculture have driven the exploration of sustainable alternative protein sources. Single-cell proteins (SCPs) from microbial fermentation offer a promising solution. This study comprehensively evaluated the nutritional value and safety profile of SCP produced from Ralstonia eutropha H16 through integrated in vitro and in vivo assessments. Nutritional analyses revealed a high crude protein content of 71.87 ± 5.05 g/100 g dry weight, with total amino acids of 53.67 ± 1.05 g/100 g. The essential amino acid content was 24.38 ± 0.51 g/100 g, accounting for 45% of the total amino acids. An essential amino acid index (EAAI) of 1.46 ± 0.04 and an amino acid score (AAS) of 0.83 ± 0.06 confirmed its classification as a high-quality protein source according to FAO/WHO standards. In vivo rat feeding trials demonstrated an adjusted protein efficiency ratio (PER) of 1.81, exceeding common plant proteins such as wheat (0.8–1.1). True digestibility (TD) reached 85.73%, with a biological value (BV) of 49.37%, net protein utilization (NPU) of 42.33%, and protein digestibility-corrected amino acid score (PDCAAS) of 0.71. Comprehensive safety assessments included chemical contaminant screening, acute oral toxicity studies in rats and mice, in vitro chromosome aberration tests, and erythrocyte micronucleus tests. Heavy metals and aflatoxin B₁ levels were below regulatory limits. Acute oral toxicity studies established LD₅₀ values exceeding 10,000 mg/kg body weight in both rodent species, classifying this protein source as practically non-toxic. The 28-day sub-acute toxicity study showed no significant adverse effects at low doses (6.25% protein replacement). Both genotoxicity assays (mammalian cell chromosome aberration assay and mammalian erythrocyte micronucleus test) returned negative results. These findings establish R. eutropha H16-derived SCP as a safe, nutritious, and sustainable protein source with considerable potential for feed and food applications, contributing to global food security and environmental sustainability.

Ralstonia eutropha H16, a metabolically versatile bacterium, has gained prominence as a microbial platform for sustainable bioproduction. While its capabilities in synthesizing single-cell proteins and biodegradable materials are well documented, comprehensive strain-level safety evaluations remain insufficient for food-grade applications. This study systematically assessed the safety of R. eutropha H16 through genomic, phenotypic, and toxicological analyzes. Genomic analyzes revealed the absence or minimal presence of virulence factors and antibiotic resistance genes, aligning with microbiological safety standards. Phenotypic investigations demonstrated a limited gastric fluid tolerance (pH 2.5, survival rate 25.70% after 3 h) and intestinal fluid persistence (pH 8, 44.67% viability after 3 h), coupled with an exceptional bile salt tolerance (0.2% w/v). Antioxidant assays confirmed the fermentation broth specifically scavenges DPPH free radicals (14.60 ± 1.24 μg Trolox/mL), whereas bacterial suspensions and cell-free supernatants exhibited a strong hydroxyl radical scavenging (>90 U/mL) and superoxide anion inhibition (>100 U/L). Acute toxicity testing indicated no mortality or histopathological abnormalities, with an LD₅₀ value exceeding 1 × 10¹¹ CFU/kg. Subacute toxicity studies (28-day, 1 × 10⁸–1 × 10¹⁰ CFU/kg) revealed no significant effects on growth, hematology, or organ function. Minor alterations in serum biochemistry might be attributed to physiological adaptation. Subacute exposure induced transient serum ALT fluctuations without hepatorenal dysfunction, while maintaining hematological parameters within physiological ranges. Collectively, these results substantiate the safety of R. eutropha H16 for food-related applications while underscoring the necessity of strain-specific risk assessments for industrial microbial platforms.