Blood biochemistry parameters are valuable tools for monitoring fish health. Their baseline values are still undefined for a multitude of farmed fish species. In this study, changes in the blood profile of rainbow trout females (Oncorhynchus mykiss) from three farms were investigated using different biomarkers during the summer season. In the given context, the main water physicochemical parameters were investigated and twelve biochemical parameters were measured from blood samples of rainbow trout reared in the Fiad, Șoimul de Jos, and Strâmba farms. We selected these farms because the genetic background of the rainbow trout is the same, with all studied specimens coming from the Fiad farm, which has an incubation station. Forty-five samples were collected monthly (May to August) throughout summer to observe the changes in the blood profile of rainbow trout. Principal component analysis showed a clear separation both among the studied farms and months. Furthermore, significant correlations (p < 0.05) between the majority of the biochemical parameters were found, indicating that the environmental parameters can influence several blood parameters at the same time. The present study provides several useful norms for assessing the welfare of rainbow trout, indicating that the relationships among different parameters are important factors in interpreting the blood biochemical profiles.

Smoking represents one of the oldest thermic processing methods of fish, and it was originally used to preserve fish for later meals, delaying spoiling. The objective of this study was to analyze the physicochemical and microbiological safety and quality of two traditionally smoked trout species (Oncorhynchus mykiss and Salvelinus fontinalis). We analyzed the effect of trout processed by traditional smoking, characterizing the samples according to the relationships existing between classical microbial analysis, physicochemical parameters, and the content of polycyclic aromatic hydrocarbons (PAHs). The microbial activity of the smoked fish was very low. Although traditional smoking implies high temperatures and direct exposure to the smoke, Benzo[a]pyrene, Benzo[b]fluoranthene, Benzo[k]fluoranthene, Dibenzo[a,h]anthracene, Benzo[g,h,i]perylene, and Indeno [1,2,3-cd]pyrene compounds had undetectable levels in the samples. The products obtained in this study did not exceed the maximum values imposed by EU legislation regarding the TVB-N values during the 30 days of the experiment. We conclude that traditionally smoked trout has many advantages in terms of quality and safety of the products. Thus, the obtained products are safe for consumption for at least 30 days after processing.

The structural integrity of the gastrointestinal tract is important because it dictates the functionality of this system. Regarding this, gut-associated lymphoid tissue (GALT) has a significant role in immunity. Most cancer research focuses on organized lymphoid structures and less on diffuse structures such as the lamina propria (LP). Therefore, this paper aims to investigate the link between the LP and cancer in humans. The interstitial matrix and loose connective tissue layer located directly under the epithelium is known as the LP. In this area, there are a lot of IgA+ plasma cells (PCs), T and B lymphocytes, macrophages, dendritic cells (DCs), and stromal cells (SCs). Antigens from the lumen are picked up by LP DCs and presented directly to B cells, which may cause IgA class switching and differentiation in the presence of T cells. In humans, the GALT of the mucosa has been proposed as the source of a unique malignancy known as “GALT carcinoma”, which is thought to represent the “third pathway of colorectal carcinogenesis”. However, present colorectal cancer classifications do not define GALT carcinoma as a separate histologic category.

The gut microbiome is central to immune, metabolic, and gastrointestinal health across species. Dysbiosis disrupts microbial communities and is linked to inflammatory bowel disease, celiac disease, and other immune-mediated gastrointestinal disorders. This review addresses the central question of how diet- and environment-driven gut dysbiosis in farm animals and fish is transmitted through the food chain to influence human gastrointestinal health within a One Health framework. This review synthesizes recent evidence within the One Health framework, focusing on how diet- and environment-induced dysbiosis in farm animals and fish can influence human gastrointestinal health via the food chain. We highlight mechanisms of immune modulation, alterations in food products, and the risks of pathogen transmission and antimicrobial resistance. An important limitation of the current body of evidence is the lack of studies that comprehensively trace the proposed axis from animal gut dysbiosis to human health outcomes. Emerging interventions, including precision nutrition, probiotics, and microbiota-targeted therapies, show potential for restoring microbial balance, though translating these findings into clinical practice remains challenging. By integrating human, veterinary, and environmental perspectives, this work proposes a novel cross-species microbiome–diet–immune framework to guide future research and interventions, advancing One Health strategies for disease prevention, antimicrobial resistance mitigation, and sustainable gastrointestinal health.

Fish smoking is one of the oldest preservation methods and has traditional forms in most parts of the world, each with distinct variables. The presence of PAHs in smoked fish is of great concern for producers and consumers alike, as PAHs have great negative effects on human health. This study aimed to determine the physicochemical characteristics and polycyclic aromatic hydrocarbons (PAHs) content level in smoked rainbow trout Oncorhynchus mykiss (Walbaum, 1792) processed using a commercial portable grilling and smoking oven. Sawdust of hardwood (beech, cherry, sour cherry, walnut, and plum) and softwood (fir, willow) were used to produce aromatic essences. The principal component analysis (PCA) revealed that different tree species tend to accumulate different PAHs in different concentrations. In the case of the generalized additive model (GAM) analyzing fish meat, fir tree reduced the concentration of PAHs in fish meat. When GAM analyzed fish skin, cherry, sour cherry, and willow trees significantly reduced the concentrations of PAHs in fish skin compared to beech trees. Furthermore, the results regarding the skin of the fish suggest that it acts as a protective barrier, trapping smoke particulates and reducing the penetration of PAHs into the meat. The present method clearly shows that, at least in the case of Benzo[a]pyrene, it is safer than traditional methods of smoking. This highlights the need for further research into the physicochemical properties of fish tissue and their impact on PAH accumulation.