Search Results (418)

Background: Microbial communities of insects have distinct roles for their respective hosts. For the black fly (Diptera: Simuliidae), an important vector and ecological indicator, the representative microbiota from the different body regions are not known. Here, we investigated the microbial composition and diversity of the head, thorax, and abdomen of wild-caught Simulium vanluni. Methods: Adult Simulium vanluni were surface-sterilized and dissected into head, thorax, and abdomen. For each body region, 20 individuals were pooled into one sample with six replicates per region. DNA was extracted and sequenced using the 16S rRNA amplification method to assess for possible microbial diversity. Data were analyzed using MicrobiomeAnalyst, where we calculated alpha diversity, beta diversity, and tested compositional differences using PERMANOVA. Results: Across 17 pooled samples, three core genera, Wolbachia (78.33%), Rickettsia (9.74%), and Acinetobacter (9.20%), accounted for more than 97% of the 16S rRNA sequencing reads. Head communities were compositionally distinct compared to the thorax and abdomen (PERMANOVA, p < 0.05). Heads were nearly monodominated by Wolbachia (95–97%), exhibiting significantly lower diversity and evenness compared to other body regions. In contrast, the thoracic and abdominal communities were more even, where thoraces were enriched with Acinetobacter (19.16%) relative to Rickettsia (10.85%), while abdomens harbored higher Rickettsia (10.96%) than Acinetobacter (5.68%). Collectively, the near-monodominance of Wolbachia in heads and inverse abundances of Acinetobacter and Rickettsia in thoraces and abdomens suggest possible anatomical niche partitioning or competition exclusion of microbiota across body regions. Conclusions: Our findings reveal fine-scale anatomical niche partitioning in S. vanluni microbiota, with the heads being almost exclusively colonized by Wolbachia, while the thoracic and abdominal niche regions exhibit distinct enrichment patterns for Acinetobacter and Rickettsia. These spatially distinct microbial distributions suggest potential functional specialization across anatomical regions of S. vanluni. Full article

Researchers are increasingly focusing on understanding the microbiota’s influence on disease susceptibility and overall health. The vast number of microorganisms in our gastrointestinal tract and their extensive surface area underscore their undeniable impact on well-being. Viewing the gut microbiome as a distinct pool of microbial genetic information that interacts with the human genome highlights its pivotal role in genetically predisposed diseases. Investigating this complex crosstalk may lead to the development of novel therapeutic strategies—such as targeting dysbiosis—to complement conventional treatments and improve patient care. Parkinson’s disease (PD) is a multifactorial condition originating from a combination of genetic and environmental risk factors. Compelling evidence points to the enteric nervous system as an initial site of pathological processes that later extend to the brain—a pattern known as the ‘body-first’ model. Furthermore, most patients with PD exhibit both qualitative and quantitative alterations in the composition of the gut microbiota, including dysbiosis and small intestinal overgrowth. Nonetheless, the existing literature predominantly addresses fecal microbiota, while knowledge of upper intestinal sections, like the duodenum, remains scarce. Given the potential for microbiota modulation to impact both motor and gastrointestinal symptoms, further research exploring the therapeutic roles of balanced diets, probiotics, and fecal transplants in PD is warranted. Full article

The involvement of oral bacteria in the pathogenesis of distant organs, such as the heart, lungs, brain, liver, and intestine, has been shown. We analyzed the distribution of bacterial species in the resected aortic valve by 16S rRNA metagenomic analysis and directly compared their gene sequences with those in the oral cavity. Thirty-two patients with aortic stenosis or aortic regurgitation who underwent aortic valve replacement were enrolled in this study. Antibody titer against periodontal pathogenic bacteria in the patient’s serum was analyzed. The genetic background and distribution of bacterial species on subgingival plaque, the dorsal surface of the tongue, and the resected aortic valve were analyzed. Patients with aortic valve disease were shown to have more severe periodontal disease by the detection of antibodies against Socransky’s red-complex bacteria of periodontitis. Bacterial DNA was detected in the aortic valves of 12 out of 32 patients. The genomic sequences of the V3-V4 region of the 16S rRNA in some bacteria isolated from the aortic valves of six patients who underwent metagenomic analysis were identical to those found in the oral cavity. The findings indicate that bacteria detected in the aortic valve may be introduced through oral dysbiosis, a condition characterized by an imbalance in the oral microbiota that increases the risk of periodontal disease and dental caries. Oral dysbiosis and the resulting potential bacteremia are associated with the pathogenesis of aortic valve diseases. Full article

This study aims to investigate the response of surface bacterial communities in Trachinotus ovatus to Cryptocaryon irritans infection at different stages of a single infection cycle (0~168 h). These samples were analyzed using high-throughput 16S rRNA sequencing. Alpha diversity analysis showed a reduction in the richness and diversity of skin microbiota during infection, with partial recovery post-detachment. Beta diversity analysis revealed distinct structural shifts in skin microbiota at early (24 h) and post-detachment (168 h) stages compared to other phases, while gill microbiota remained stable except during detachment. At the phylum level, Proteobacteria, Actinobacteriota, Bacteroidetes, and Firmicutes were dominant on the skin at different stages, whereas the gill microbiota was predominantly Proteobacteria (>90%). At the genus level, opportunistic pathogens, such as Vibrio and Nautella, increased in relative abundance on the skin with the infection progression, while gill microbiota composition barely changed. The hepatic bacterial load continued to increase with infection duration. These findings indicate that C. irritans alters microbiota composition on skin, facilitating pathogen invasion, thereby elevating the risk of secondary bacterial infections in T. ovatus. Full article

In this study, the effects of enzymolysis on physicochemical properties, digestive characteristics, and flora regulation of the meal replacement powder (MRP) were investigated on the basis of the previously obtained compound MRP. The results showed that the color, water absorption index, and water solubility index of the MRP were obviously improved after enzymatic hydrolysis. The swelling power (1.43 ± 0.11 g/g, 25 °C) and water-holding capacity (4.66 ± 0.09 g/g) of the MRP (CE_1) were decreased, while the oil holding capacity (2.14 ± 0.13 g/g) was increased. In the microcosmic aspect, the samples treated by enzymolysis had different degree of degradation, the particle size decreased (D50 = 57.71 μm), and the specific surface area (679.2 cm²/g) increased. The MRP samples treated by enzymolysis had better antioxidant capacity and cholate adsorption capacity. All MRP samples belong to low glycemic index (GI) foods, and can improve gut microbiota (Megamonas, Bacteroides, Rocheella, Parasatre, Koalabacterium, and Prasus) and promote the production of short chain fatty acids such as acetic acid, propionic acid and butyric acid. Therefore, this study not only further expands the comprehensive utilization of Aronia melanocarpa, but also provides a reference for the diversification of low GI related products. Full article

Acne is a highly prevalent skin condition with multifactorial pathophysiology, where Cutibacterium acnes (C. acnes) overgrowths generate inflammation. C. acnes can grow and adhere, through the formation of biofilms, to almost any surface, which enables chronic infections. Acne treatment with antibiotics can induce topical antimicrobial resistance, impair microbiome biodiversity and cause cutaneous dysbiosis. In this study, we assess the effect of a standardized propolis extract (PE) from Greece against C. acnes, whilst maintaining skin’s microbiome biodiversity, and we investigate its effect against genes related to the attachment and colonization of C. acnes, as well as against biofilm formation. The extract has been chemically characterized by GC-MS and was additionally tested for its antioxidant properties by the Folin–Ciocalteu method and the 2,2-Diphenyl-1-Picrylhydrazyl (DPPH) assay and its regulatory activity on the expression of antimicrobial and anti-inflammatory genes in normal human epidermal keratinocytes (NHEKs). The suggested efficacy of PE in targeting pathogenic C. acnes biofilm, via downregulation of virulence genes, represents an alternative strategy to modulate the behavior of skin microbiota in acne, paving the way for next-generation acne-targeting products. Full article

Global warming represents one of the most pressing environmental challenges to cold-water fish farming. Heat stress markedly alters the mucosal symbiotic microbiota and intestinal microbial metabolites in fish, posing substantial barriers to the healthy artificial breeding of rainbow trout (Oncorhynchus mykiss). However, the relationship between mucosal commensal microbiota, intestinal metabolites, and host environmental adaptability under heat stress remains poorly understood. In this study, rainbow trout reared at optimal temperature (16 °C) served as controls, while those exposed to maximum tolerated temperature (24 °C, 21 d) comprised the heat stress group. Using 16S rRNA amplicon sequencing and ultra-high-performance liquid chromatography–mass spectrometry (UHPLC-MS), we analysed the mucosal commensal microbiota—including gastrointestinal digesta, gastrointestinal mucosa, skin mucus, and gill mucosa—and intestinal metabolites of rainbow trout under heat stress conditions to explore adaptive and regulatory mechanisms. Analysis of microbial composition and diversity revealed that heat stress exerted the greatest impact on the diversity of gill and skin mucus microbiota, followed by gastrointestinal digesta, with relatively minor effects on the gastrointestinal mucosa. At the phylum level, Proteobacteria, Firmicutes, and Bacteroidetes were predominant in the stomach, intestine, and surface mucosa. At the genus level, Acinetobacter showed the greatest increase in abundance in skin and gill mucosa under heat stress, while Enterobacteriaceae exhibited the most pronounced increase in intestinal digesta, gastric digesta, and gastric mucosa. Differential metabolites in the intestinal digesta under heat stress were predominantly enriched in pathways associated with amino acid metabolism, particularly tryptophan metabolism. This study provides a comprehensive characterisation of microbiota and metabolic profile alterations in rainbow trout under heat stress condition, offering a theoretical foundation for understanding the response mechanisms of fish commensal microbiota to thermal stress. Full article

This study assessed the viable and culturable microbial diversity that remained on equipment surfaces after hygiene procedures in Brazilian poultry and fish slaughterhouses. Food-contact surface samples were collected using sterile swabs in poultry (n = 50) and fish (Oreochromis niloticus, n = 50) slaughterhouses. The swab samples were used to prepare culture plates to recover viable and culturable cells. The grown plates were washed, and the total DNA of the cell suspension was extracted with a commercial kit. Sequencing of the total DNA extracted from cultures was targeted at the V3 and V4 regions of the 16S rRNA. DNA reads were analyzed by QIIME2 software, with results expressed in relative frequency (%RF). Alpha and beta diversity indexes were analyzed considering the spots of sample collection, type of industry, surfaces (smooth or modular), and materials (polypropylene, stainless steel, or polyurethane). The results showed that in the poultry slaughterhouse, the most abundant genera were Acinetobacter (27.4%), Staphylococcus (7.7%), and Pseudomonas (5.3%), while for the fish slaughterhouse, there was a higher abundance of Staphylococcus (27.7%), Acinetobacter (17.2%), and Bacillus (12.5%). Surface characteristics influenced the microbial diversity, with Acinetobacter spp. dominating modular surfaces and Staphylococcus spp. prevailing on smooth surfaces. The results obtained indicate there is an important resident microbiota that persists even after hygiene processes, and surface-specific cleaning strategies should be developed. Full article

Serra da Estrela cheese (a raw ewe’s milk) ripened for 45 days was treated at 600 MPa for 6 min (P1) and at 450 MPa for 6 (P2) and 9 min (P3) and kept in refrigerated storage for 15 months. Lactobacillus and Lactococcus viable cell numbers were reduced in 3.2–3.6 and 2.7–3.6 log cycle units, respectively. Lower reductions were verified for total aerobic mesophilic and Enterococcus viable cell numbers in cheeses treated at 450 MPa (2.4–2.5 and 1.2 log reductions, respectively). In HPP cheeses, yeasts and moulds were below the enumeration limit up to 6 months of storage, but at 15 months 3.6–4.2 log cfu/g were quantified in all cheeses, while Enterobacteriaceae were inactivated to below the quantification limit. The increment of pressure treatment caused a greater impact on the microbiota’s viability than the increase in time under pressure. During storage, minor total colour differences were determined for HPP P3 cheese surface relative to control cheeses, Ch_C, at 45 days of ripening. HPP can thus be a good process to apply after cheese manufacture, since it offers a good potential to render raw-milk cheese microbiologically safer, with minimal changes in quality. Full article

Lactobacillus plantarum exhibits probiotic effects, including regulating the balance of the intestinal microbiota and enhancing immune function. However, this strain often experiences viability loss upon ingestion due to harsh conditions within the human digestive tract. This study aimed to evaluate the efficacy of metal–phenol networks (MPNs) fabricated via three polyphenols—tannic acid (TA), tea polyphenol (TP), and anthocyanin (ACN)—combined with Fe(III) coatings in protecting Lactobacillus plantarum during simulated digestion and storage. The results demonstrated that MPNs formed a protective film on the bacterial surface. While TA and ACN inhibited the growth of Lactobacillus plantarum YJ7, TP stimulated proliferation. Within the MPNs system, only Fe(III)-TA exhibited growth-inhibitory effects. Notably, ACN displayed the highest proliferation rate during the initial 2 h, followed by TP between 3 and 4 h. All MPN-coated groups maintained high bacterial viability at 25 °C and −20 °C, with TP-coated bacteria showing the highest viable cell count, followed by TA and ACN. In vitro digestion experiments further revealed that the Fe(III)-ACN group exhibited the strongest resistance to artificial gastric juice. In conclusion, tea polyphenol and anthocyanin demonstrate superior potential for probiotic encapsulation, offering both protective stability during digestion and enhanced viability under storage conditions. Full article

Background: Chronic intestinal failure (CIF), most commonly caused by short bowel syndrome (SBS), necessitates complex care. This review explores the gut microbiota’s role in intestinal adaptation in SBS, examining its potential as both a biomarker and therapeutic target. SBS results from extensive small bowel resection, leading to malabsorption and dependence on parenteral nutrition (PN). Post-resection, the gut microbiota undergoes significant alterations. While the small bowel microbiome typically comprises Streptococcus, Veillonella, and others, SBS patients often exhibit increased Gram-negative Proteobacteria. Dysbiosis is linked to adverse outcomes like liver disease and impaired growth, but beneficial effects such as energy salvage also occur. Intestinal adaptation, a process of increasing absorptive surface area in the remaining bowel, involves acute, remodeling, and maintenance phases. Preservation of ileum and stimulation with the oral diet are crucial. Biomarkers are needed to predict success, with gut microbiota composition emerging as a promising non-invasive option. The precise mechanisms driving adaptation remain incompletely understood. Conclusions: GLP-1 and GLP-2 analogues show promise in enhancing adaptation and reducing PN dependence. Surgical rehabilitation aims to maximize intestinal absorptive capacity, while transplantation remains a last resort due to high complication risks. Further research is needed to fully elucidate the microbiota’s role and harness its potential in managing SBS. Full article

The gastrointestinal tract has the largest surface area of the body and if it is subjected to continuous stress, it will activate the immune system. The intestinal barrier, the immune system, and the microbiota together form a line of defense against infection in order to maintain a healthy balance between the host and the microbiota. Nutritional strategies such as feed additives can be applied to maintain homeostasis in the gastrointestinal tract. When this equilibrium is disrupted, metabolic dysfunctions can occur. Postbiotics—the metabolic and/or structural compounds of microorganisms—can stimulate anti-inflammatory, antioxidant, immunomodulatory, and enzymatic effects, providing a safe alternative to establishing intestinal eubiosis. In addition, postbiotics can be used as an alternative to antibiotics in broiler diets by maintaining productive performance under challenging conditions. This review provides an overview of the postbiotic concept, mechanism of action and production, the evidence for the action in the gastrointestinal tract, and applications in poultry production. Full article

Salmonella spp. is a pathogen detected in fish, although it is not part of its microbiota; the production and processing environment is the main source of contamination. Brazilian legislation recommends 5 ppm of free residual chlorine for fish washing, but Salmonella can still be present. The objective of this study was to evaluate flaws in the processing flowchart and propose adjustments to reduce Salmonella spp. on the fish surface. Ninety samples were analyzed in a fish processing plant in Mato Grosso, divided into three treatments: (1) conventional processing, (2) modified flowchart, and (3) modified flowchart adapted to the specific plant conditions. Treatment 2 completely eliminated Salmonella spp., while treatment 3 reduced contamination to 3.3%, compared to 56.7% in conventional processing. The success of the modified treatment was only possible due to the main changes implemented in the process, which included the separation of dirty areas (responsible for gill and scale removal) and clean areas (designated for the careful removal of viscera without rupture and for filleting). No statistical difference was found between treatments 2 and 3 (p = 1, CI 0.00000–39.00055), suggesting that the adjusted flowchart can be implemented on a large scale to ensure food safety (OR = ∞, CI = [7.655, ∞], p < 0.001). This study highlights the effectiveness of the adjusted flowchart in reducing Salmonella spp. contamination in fish, with treatment 2 resulting in a complete absence of contamination. Treatment 3 maintained low contamination levels, demonstrating practical applicability in meatpacking plants. Full article

Food spoilage caused by microbial contamination remains a global challenge, driving demand for sustainable antibacterial packaging. Conventional photocatalytic materials suffer from limited spectral response, rapid charge recombination, and insufficient reactive oxygen species (ROS) generation under visible light. Here, a Z-scheme heterojunction was constructed by coupling zeolitic imidazolate framework-8 (ZIF-8) with Ag₃PO₄, achieving dual-spectral absorption and spatial charge separation. The directional electron transfer from Ag₃PO₄’s conduction band to ZIF-8 effectively suppresses electron-hole recombination, prolonging carrier lifetimes and amplifying ROS production (·O₂⁻/·OH). Synergy with Ag⁺ release further enhances bactericidal efficacy. Incorporated into a cellulose acetate matrix (CAM), the ZIF-8/Ag₃PO₄/CAM film demonstrates 99.06% antibacterial efficiency against meat surface microbiota under simulated sunlight, alongside high transparency. This study proposes a Z-scheme heterojunction strategy to maximize ROS generation efficiency and demonstrates a scalable fabrication approach for active food packaging materials, effectively targeting microbial contamination control and shelf-life prolongation. Full article

Background: Hyperuricemia (HUA) is a widespread metabolic disorder that arises from disruptions in purine metabolism, impaired kidney function, or both conditions. FPAW (Phe-Pro-Ala-Trp) is a novel peptide identified from Trachinotus ovatus with great XOD (xanthine oxidase) inhibitory activity (IC₅₀ = 3.81 mM), which can be developed as a potential active ingredient to relieve hyperuricemia. However, it remains unclear whether FPAW alleviates HUA in vivo or not. Methods: In this study, potassium-oxonate-induced hyperuricemic mice were used to evaluate the in vivo anti-hyperuricemic activity of FPAW. Some physiological parameters, such as serum uric acid (SUA), serum creatinine (SCR), blood urea nitrogen (BUN), and the activity of XOD and ADA (adenosine deaminase) in the liver were determined to evaluate the effect of reduced uric acid. The modulations in the gut microbiota and its metabolites (SCFAs) were analyzed by sequencing the V3-V4 region of the 16S rRNA gene and GC-MS in different fecal samples. Molecular docking was used to predict the interactions between the enzymes and FPAW. Results: The results showed that FPAW reduced the levels of serum uric acid, serum creatinine, and blood urea nitrogen, while also suppressing the activity of XOD in the livers of HUA mice. Moreover, the FPAW treatment alleviated gut microbiota dysfunction and increased the production of short-chain fatty acids to protect normal intestinal function and health of the host. Molecular docking simulations revealed that FPAW inhibited XOD activity by entering the hydrophobic channel and interacting with amino acid residues on the surface via hydrogen bonding and hydrophobic interactions. Conclusions: This study provides new candidates for the development of hypouricemic drugs. FPAW exhibited great potential to relieve hyperuricemia of mice induced by diet in the animal experiment. Full article