DOK3 maintains intestinal homeostasis by suppressing JAK2/STAT3 signaling and S100a8/9 production in neutrophils

How pathogenesis of inflammatory bowel disease (IBD) depends on the complex interplay of host genetics, microbiome and the immune system is not fully understood. Here, we showed that Downstream of Kinase 3 (DOK3), an adapter protein involved in immune signaling, confers protection of mice from dextran sodium sulfate (DSS)-induced colitis. DOK3-deficiency promotes gut microbial dysbiosis and enhanced colitis susceptibility, which can be reversed by the transfer of normal microbiota from wild-type mice. Mechanistically, DOK3 exerts its protective effect by suppressing JAK2/STAT3 signaling in colonic neutrophils to limit their S100a8/9 production, thereby maintaining gut microbial ecology and colon homeostasis. Hence, our findings reveal that the immune system and microbiome function in a feed-forward manner, whereby DOK3 maintains colonic neutrophils in a quiescent state to establish a gut microbiome essential for intestinal homeostasis and protection from IBD.

Prospecting of anti-Candida bioactive in Origanum vulgare L. artisanal essential oil

Candida albicans is a yeast belonging to the normal microbiota of the human body, considered the most pathogenic species of the genus. It is the main microorganism related to candidiasis. Essential oils of Origanum vulgare have phenolic compounds, such as thymol and carvacrol, which have an effective antimycobacterial character at certain concentrations, but little is known about its biological activity in artisanal preparation. Thus, we evaluated the resistance of standard strains of opportunistic yeast C. albicans against in vitro antifungal activity of artisanal extract of O. vulgare. An inoculum of the challenger was subjected to different concentrations of the fungicidal agent in solidified Muller Hinton and broth followed by incubation at 35°C. The oil was prepared in a manner similar to a possible homemade procedure, and was further sterilized to ensure homogeneity of the indicator. The readings were performed in two days every 24 hours so that there were different possible moments of growth. The tests, which occurred in triplicate, showed that, under experimental conditions, the yeast was resistant to the essential oil compounds at all observed concentrations. Morphological variation was observed in both colonies and yeast cells. Based on analyzes, the artisanal essential oil is incorporated as a promising candidate for the development of antimycotics for clinical use, although in vivo tests are required.

Findings from the microbiota of tooth apical periodontitis and the search for pathogen forgranulomatous inflammation

BackgroundOrofacial granulomatosis (OFG) is a granulomatous inflammation (GI) disease in maxillofacial region, the underlying cause of it remains unknown. Our previous study demonstrated that tooth apical periodontitis (AP) plays a significant role in the pathogenesis of OFG, we aimed here to characterize the AP bacterial signatures of OFG patients, and identify bacteria that may be important pathogens capable of inducing OFG.ResultsThe composition of AP microbiota in OFG cases and common AP controls was compared using 16S rRNA gene sequencing, the results showed a specific AP microbiota signature in OFG patients, characterized by domination of phyla Firmicutes and Proteobacteria , notably members of Streptococcus, Lactobacillus and Neisseria. To assess the pathogenicity of the potential pathogens in OFG, we isolated and successfully in vitro cultured Streptococcus, Lactobacillus casei, Neisseria subflava, Veillonella parvula and Actinomyces from OFG patients, and injected the clinical isolates into mice respectively. Ultimately, foot pad injection with N. subflava elicited granulomatous inflammation, and the virulence of N. subflava was verified based on Koch’s postulates.ConclusionsOur findings confirmed the role of bacteria in OFG, and first suggested that the component of the host normal microbiota, N. subflava is likely a pathogen for GI.

Production of Antifungal Gelatinase by Enterococcus durans S2C and Its Potential Role in the Biological Control

Probiotic bacteria are good sources for antimicrobial and are normal microbiota of the gastrointestinal tract of animals and humans. Enterococci are found everywhere in nature and have been utilized as probiotics in the food industry. In the present study, Enterococcus durans S2C strain was isolated from raw cow’s milk using the culture-dependent method and evaluated for antifungal properties. The strain S2C showed promising extracellular proteolytic activity and the extracellular peptide was an important source of antifungal activity. Besides, a low rate of antibiotic resistance and non-hemolytic activity was detected in E. durans S2C. Strong antifungal activity of E. durans against two plant pathogenic fungi namely Fusarium oxysporum and Rhizoctonia solani was also recorded. Antifungal activity evaluation showed that R. solani colony was the most inhibited fungus followed by F. oxysporum. Gelatinase enzyme having antifungal activity was also purified from E. durans S2C isolate. This study concludes that the environmental-derived E. durans S2C strain can be selected for technological application to control pathogenic fungi and to protect the economic value of the crops. © 2021 Friends Science Publishers

Comparative Study of Bacterial Isolates in Ovine Mandibular Osteomyelitis and Oral Microbiota of Healthy Sheep

Microorganisms involved in ovine mandibular osteomyelitis (OMO) have not yet been deeply studied. The aim of the present study is to elucidate the microorganisms involved in OMO, comparing them with the microorganisms found in the healthy oral cavity of sheep. Two hundred and five samples were taken from mandibular osteomyelitis lesions, and they were compared with the microbiological results of samples obtained from twelve periodontally healthy sheep. Sixty-four samples (32.98%) of OMO lesions showed pure growths, while 130 (67.01%) were mixed cultures. Microorganisms of the genus Streptococcus were the most frequently isolated (20.95%), followed by bacteria of the genus Pseudomonas (8.50%), Trueperella pyogenes (7.26%), Staphylococcus (6.63%) and Escherichia coli (6.22%). Ninety-one different isolates were obtained from healthy mouths, and again, microorganisms of the genus Streptococcus were the most frequent (16.48%), followed by bacteria of the genus Staphylococcus (13.18%), Pseudomonas (9.89%) and Moraxella (6.59%). Based on these and previous results, it could be concluded that the normal microbiota of the oral cavity could be involved in the development of OMO lesions when there is an injury of the gingiva that enables the entry of bacteria to the oral mucosa that eventually settle locally in bony tissues, causing mandibular osteomyelitis.

Toward understanding microbiota homeostasis in the plant kingdom

A diverse community of microorganisms inhabits various parts of a plant. Recent findings indicate that perturbations to the normal microbiota can be associated with positive and negative effects on plant health. In this review, we discuss these findings in the context of understanding how microbiota homeostasis is regulated in plants for promoting health and/or for preventing dysbiosis.

Exploring the Modulatory Effects of Gut Microbiota in Anti-Cancer Therapy

In the recent decade, gut microbiota has received growing interest due to its role in human health and disease. On the one hand, by utilizing the signaling pathways of the host and interacting with the immune system, the gut microbiota is able to maintain the homeostasis in human body. This important role is mainly modulated by the composition of microbiota, as a normal microbiota composition is responsible for maintaining the homeostasis of human body, while an altered microbiota profile could contribute to several pathogenic conditions and may further lead to oncogenesis and tumor progression. Moreover, recent insights have especially focused on the important role of gut microbiota in current anticancer therapies, including chemotherapy, radiotherapy, immunotherapy and surgery. Research findings have indicated a bidirectional interplay between gut microbiota and these therapeutic methods, in which the implementation of different therapeutic methods could lead to different alterations in gut microbiota, and the presence of gut microbiota could in turn contribute to different therapeutic responses. As a result, manipulating the gut microbiota to reduce the therapy-induced toxicity may provide an adjuvant therapy to achieve a better therapeutic outcome. Given the complex role of gut microbiota in cancer treatment, this review summarizes the interactions between gut microbiota and anticancer therapies, and demonstrates the current strategies for reshaping gut microbiota community, aiming to provide possibilities for finding an alternative approach to lower the damage and improve the efficacy of cancer therapy.

Role of Probiotic Bacilli in Developing Synbiotic Food: Challenges and Opportunities

The human body is inhabited by a vast diversity of probiotic microorganisms that could positively affect human physiology. Besides, prebiotic food substances may induce symbiotic relationship among probiotic species through the successful establishment of commensal microbiota, whose connections with the host are multifaceted and multidirectional. As deliberated throughout this review, prebiotic and synbiotic foods contain the capability to stimulate numerous health characteristics in host organisms through various means. Predominantly, the normal microbiota fosters the digestion of food and may boost the innate and adaptive immune system’s functionalities. Therefore, live probiotic bacteria, for instance, probiotic Bacilli obtained together with prebiotic food, can help stimulate healthiness in humans. Thus, we discuss how certain dietary fibers may preserve the probiotic efficacy by serving as the scaffold for probiotic Bacilli to colonize them through forming symbiotic interactions. The fibers can essentially promote protection by encapsulating probiotic Bacilli against various environmental and physical stresses that might kill the free-living bacterial cells. Besides, these fibers would serve as prebiotic substances that would eventually be utilized for the proliferation of probiotic cells. It is believed that applying this conceptual idea will provide a novel platform toward developing probiotic and synbiotic foods, as discussed in this review.

Maintaining Digestive Health in Diabetes: The Role of the Gut Microbiome and the Challenge of Functional Foods

Over the last decades, the incidence of diabetes has increased in developed countries and beyond the genetic impact, environmental factors, which can trigger the activation of the gut immune system, seem to affect the induction of the disease process. Since the composition of the gut microbiome might disturb the normal interaction with the immune system and contribute to altered immune responses, the restoration of normal microbiota composition constitutes a new target for the prevention and treatment of diabetes. Thus, the interaction of gut microbiome and diabetes, focusing on mechanisms connecting gut microbiota with the occurrence of the disorder, is discussed in the present review. Finally, the challenge of functional food diet on maintaining intestinal health and microbial flora diversity and functionality, as a potential tool for the onset inhibition and management of the disease, is highlighted by reporting key animal studies and clinical trials. Early onset of the disease in the oral cavity is an important factor for the incorporation of a functional food diet in daily routine.

A Clinical Trial to Evaluate the Efficacy of α-Viniferin in Staphylococcus aureus – Specific Decolonization without Depleting the Normal Microbiota of Nares

Staphylococcus aureus is currently a significant multidrug-resistant bacterium, causing severe healthcare-associated and community-acquired infections worldwide. The current antibiotic regimen against this pathogen is becoming ineffective due to resistance, in addition, they disrupt the normal microbiota. It highlights the urgent need for a pathogen-specific drug with high antibacterial efficacy against S. aureus. α-Viniferin, a bioactive phytochemical compound, has been reported to have excellent anti-Staphylococcus efficacy as a topical agent. However, so far, there were no clinical trials that have been conducted to elucidate its efficacy. The present study aimed to investigate the antibacterial efficacy of α-viniferin against S. aureus in a ten-day clinical trial. Based on the results, α-viniferin showed 50% minimum inhibitory concentrations (MIC50 values) of 7.8 μg/ml in culture broth medium. α-Viniferin was administered in the nares three times a day for ten days using a sterile cotton swab stick. Nasal swab specimens were collected before (0 days) and after finishing the trial (10th day), and then analyzed. In the culture and RT-PCR-based analysis, S. ureus was reduced significantly: 0.01. In addition, 16S ribosomal RNA-based amplicon sequencing analysis showed that S. aureus reduced from 51.03% to 23.99% at the genus level. RNA-seq analysis was also done to gain insights into molecular mechanisms of α-viniferin against S. aureus, which revealed that some gene groups were reduced in 5-fold FC cutoff at two times MIC conditions. The study results demonstrate α-viniferin as a potential S. aureus-specific drug candidate.