The remarkable biological activities of oregano essential oils (EOs) have recently prompted a host of studies aimed at exploring their potential innovative applications in the food and pharmaceutical industries. The chemical composition and biological activities of EOs from two Origanum vulgare genotypes, widely cultivated in Sicily and not previously studied for their biological properties, were characterized. Plants of the two genotypes, belonging to the carvacrol (CAR) and thymol (THY) chemotypes and grown in different cultivation environments, were considered for this study. The chemical profiles, including the determination of enantiomeric distribution, of the EOs, obtained by hydrodistillation from dried leaves and flowers, were investigated by GC–MS. Biological activity was evaluated as antimicrobial properties against different pathogen indicator strains, while intestinal barrier integrity, reduction in pathogen adhesion and anti-inflammatory actions were assayed in the intestinal Caco-2 cell line. The chemical profile of the CAR genotype was less complex and characterized by higher levels of the most active compound, i.e., carvacrol, when compared to the THY genotype. The enantiomeric distribution of chiral constituents did not vary across genotypes, while being markedly different from that observed in Origanum vulgare genotypes from other geographical origins. In general, all EOs showed high antimicrobial activity, both in vitro and in a food matrix challenge test. Representative EOs from the two genotypes resulted not altering epithelial monolayer sealing only for concentrations lower than 0.02%, were able to reduce the adhesion of selected pathogens, but did not exert relevant anti-inflammatory effects. These results suggest their potential use as control agents against a wide spectrum of foodborne pathogens.

Antimicrobial resistance (AMR) is a global and increasing threat to human health. Several genetic determinants of AMR are found in environmental reservoirs, including bacteria naturally associated with widely consumed fermented foods. Through the food chain, these bacteria can reach the gut, where horizontal gene transfer (HGT) can occur within the complex and populated microbial environment. Numerous studies on this topic have been published over the past decades, but a conclusive picture of the potential impact of the non-pathogenic foodborne microbial reservoir on the spread of AMR to human pathogens has not yet emerged. This review critically evaluates a comprehensive list of recent experimental studies reporting the isolation of AMR bacteria associated with fermented foods, focusing on those reporting HGT events, which represent the main driver of AMR spread within and between different bacterial communities. Overall, our analysis points to the methodological heterogeneity as a major weakness impairing determination or a causal relation between the presence of AMR determinants within the foodborne microbial reservoir and their transmission to human pathogens. The aim is therefore to highlight the main gaps and needs to better standardize future studies addressing the potential role of non-pathogenic bacteria in the spread of AMR.

Nowadays, research on plant extracts has attracted increasing interest. The aim of this study was to compare phenolic profile, vitamin C, and carotenoid content, as well as the biological activities of five different rose species, including Rosa canina, R. corymbifera, R. micrantha, R. rubiginosa, and R. rugosa. These species had different morphological characteristics, with R. rugosa showing higher size of flower petals and higher weight of hips. The highest vitamin C content was found in hip extracts of R. rubiginosa and R. rugosa, which also showed the highest carotenoid amount. R. corymbifera showed the highest phenolic content. No significant antimicrobial activity of extracts containing phenolic compounds against different indicator strains could be detected. Cell monolayer integrity was not affected by treatments with the above-mentioned extracts of R. canina, R. micrantha, and R. rugosa at different concentrations for up to 24 h, while those of R. rubiginosa and R. corymbifera affected intestinal permeability at the highest concentration tested. The partial least squares regression analysis generated a predictive model correlating phenolic compounds with cell monolayer integrity, suggesting a relevant role for catechin, quercitrin, and p-coumaric acid. In conclusion, this study highlights how rose hips belonging to different species can have a diverse phenolic profile, differently influencing intestinal monolayer integrity.

The increasing interest in fermented foods stems from their health benefits, mediated by foodborne microorganisms. This study aimed to characterize the fermentative microbiota of Pecorino di Picinisco, a traditional Italian cheese made from ovine raw milk, and to evaluate the probiotic and technological potential of selected lactic acid bacteria strains. Three strains representative of the different species found (Lactococcus lactis, Lactiplantibacillus plantarum and Latilactobacillus curvatus) were chosen and analyzed. All three strains were able to adhere to human intestinal Caco-2 cells, were resistant to simulated in vitro digestion and significantly prolonged the lifespan of Caenorhabditis elegans, used as a simplified in vivo model, with respect to the commercial probiotic strain Lacticaseibacillus rhamnosus GG. The L. plantarum Pic37.4 strain was particularly promising; therefore, its cell-free supernatant was employed to evaluate the antimicrobial activity against indicator strains of foodborne and intestinal pathogens or spoilage bacteria. The results demonstrated the effectiveness of the supernatant against all strains tested, with the strongest effect on the intestinal pathogen enterotoxigenic Escherichia coli K88. In addition, the inhibitory effect on pathogen adhesion to intestinal mucosa was investigated on Caco-2 cells, resulting in a significant reduction in adhesion mediated by the L. plantarum Pic37.4 supernatant. The antimicrobial properties of the L. plantarum strain were confirmed in vivo in C. elegans. These promising results lay the ground for further investigations aimed at substantiating the probiotic and technological potential of the L. plantarum Pic37.4 investigated in this work.

Nowadays, the spread of foodborne diseases and the growing concerns about antibiotic resistance have shifted the focus of researchers towards the use of substances of natural origin. Phenyllactic acid (PLA), a naturally produced compound, has already demonstrated antimicrobial properties against pathogenic microorganisms and those responsible for food spoilage. This study examines the antibacterial and antibiofilm properties of PLA against foodborne pathogens such as Salmonella enterica Derby and Escherichia coli O26. The study showed that PLA effectively inhibited both biofilm formation and bacterial planktonic growth, with minimal inhibitory concentrations (MICs) ranging from 2 to 2.75 mg mL⁻¹. A dose-dependent inhibition of biofilm formation was observed, reaching approximately 90% for Salmonella strains and 50% for E. coli at 1.5 mg mL⁻¹. The cytotoxicity evaluation on Caco-2 cells showed that PLA was well-tolerated at concentrations up to 2 mg mL⁻¹. PLA’s effectiveness was also demonstrated in real food matrices, where its application in minced beef stored at 4 °C significantly reduced microbial populations, unlike in untreated samples where bacterial counts increased. PLA showed a good ability to inhibit biofilm formation and eradicate a mature biofilm, measuring the total bacterial biofilm biomass. Additionally, PLA was found to be biocompatible in Caco-2 cells, confirming that it poses no health risk at the tested concentrations. The study also observed that PLA reduced bacterial adhesion to intestinal cells, suggesting its potential in preventing intestinal bacterial colonization. These results highlight PLA as a promising natural antimicrobial agent for food preservation, with potential applications in sustainable packaging and controlling microbial contamination in food processing. Future studies should further explore PLA’s long-term stability and its interactions in complex food environments.

Coffee silverskin (CSS), the major by-product of coffee roasting, is reported to contain bioactive compounds, including xanthines and polyphenols, showing promising potential for food and nutraceutical applications. This study investigated the beneficial effects of CSS hydroalcoholic extracts, which were chemically characterized by Attenuated Total Reflectance–Fourier-Transform Infrared Spectroscopy and ElectroSpray Ionization tandem Mass Spectrometry, on Caenorhabditis elegans physiology. CSS supplementation improved healthspan-related parameters and delayed aging-associated functional decline, without significantly extending lifespan in wild-type nematodes. Treated worms exhibited a 57% reduction in reactive oxygen species (ROS) levels and upregulation of antioxidant genes (gst-4 and sod-3), suggesting that CSS mitigates oxidative stress through the DAF-2/DAF-16 pathway. Under high-glucose diet conditions, CSS reduced lipid droplet accumulation and modulated the expression of metabolic genes, including upregulation of nhr-49 which is a key regulator of fatty acid oxidation. CSS restored lipid homeostasis and rescued the shortened lifespan of obese nhr-49 mutant worms, suggesting enhanced β-oxidation. Moreover, CSS modulated serotonergic signaling by increasing tph-1 and ser-6 expression, linking its effects to serotonin-mediated regulation of fat metabolism. Finally, CSS promoted the growth of probiotic strains, suggesting potential prebiotic properties. Overall, these findings identify CSS as a metabolic modulator capable of alleviating oxidative and metabolic stress, supporting its sustainable application in the development of functional foods and nutraceuticals.