Oral Prevotella Species and Their Connection to Events of Clinical Relevance in Gastrointestinal and Respiratory Tracts

Prevotella is recognized as one of the core anaerobic genera in the oral microbiome. In addition, members of this genus belong to microbial communities of the gastrointestinal and respiratory tracts. Several novel Prevotella species, most of them of oral origin, have been described, but limited knowledge is still available of their clinical relevance. Prevotella melaninogenica is among the anaerobic commensals on oral mucosae from early months of life onward, and other early colonizing Prevotella species in the oral cavity include Prevotella nigrescens and Prevotella pallens. Oral Prevotella species get constant access to the gastrointestinal tract via saliva swallowing and to lower airways via microaspiration. At these extra-oral sites, they play a role as commensals but also as potentially harmful agents on mucosal surfaces. The aim of this narrative review is to give an updated overview on the involvement of oral Prevotella species in gastrointestinal and respiratory health and disease.

Evaluation of efficacy of different tooth paste formulations in reducing the oral microbial load - An in vivo study

Introduction and Aim: Toothpastes are the most common preventive means in oral health care. Many commercially available dentifrices claim to have antimicrobial properties, but little research has been conducted to investigate these claims. Therefore, this study was conducted to evaluate the efficacy of different toothpaste formulations in reducing the oral microbial load. Methodology: A total of six types of tooth pastes-4 herbal and 2 non-herbal- were assigned to a group of 20 subjects each, who used it for a period of six weeks. During the course of the study, at the end of 1st, 3rd and 6th week, subgingival plaque samples collected were subjected to microbial analysis. Results: Microbial analysis identified colonies of organisms such as S. mitis, S. mutans, S. salivarius, Peptostreptococcus species, Prevotella species and Lactobacillus species. Colony forming units (cfu) calculated indicated a reduction in microbial load from 1st to 6th week of use of different tooth paste formulations. However statistical analysis of the results did not show significant differences between the groups (p>0.005). Conclusion: The selected tooth paste formulations were effective in controlling the microbial load and therefore contributing to maintain good oral hygiene. However, practicing appropriate oral hygiene measures & brushing technique is of utmost importance in maintaining good oral health than the effectiveness of various ingredients in the toothpastes used.

Identification of the Potential Role of the Rumen Microbiome in Milk Protein and Fat Synthesis in Dairy Cows Using Metagenomic Sequencing

The rumen contains abundant microorganisms that aid in the digestion of lignocellulosic feed and are associated with host phenotype traits. Cows with extremely high milk protein and fat percentages (HPF; n = 3) and low milk protein and fat percentages (LPF; n = 3) were selected from 4000 lactating Holstein cows under the same nutritional and management conditions. We found that the total concentration of volatile fatty acids, acetate, butyrate, and propionate in the rumen fluid was significantly higher in the HPF group than in the LPF group. Moreover, we identified 38 most abundant species displaying differential richness between the two groups, in which Prevotella accounted for 68.8% of the species, with the highest abundance in the HPF group. Functional annotation based on the Kyoto Encyclopedia of Gene and Genome (KEGG), evolutionary genealogy of genes: Non-supervised Orthologous Groups (eggNOG), and Carbohydrate-Active enzymes (CAZy) databases showed that the significantly more abundant species in the HPF group are enriched in carbohydrate, amino acid, pyruvate, insulin, and lipid metabolism and transportation. Furthermore, Spearman’s rank correlation analysis revealed that specific microbial taxa (mainly the Prevotella species and Neocallimastix californiae) are positively correlated with total volatile fatty acids (VFA). Collectively, we found that the HPF group was enriched with several Prevotella species related to the total VFA, acetate, and amino acid synthesis. Thereby, these fulfilled the host’s needs for energy, fat, and rumen microbial protein, which can be used for increased biosynthesis of milk fat and milk protein. Our findings provide novel information for elucidation of the regulatory mechanism of the rumen in the formation of milk composition.

Members of Prevotella Genus Distinctively Modulate Innate Immune and Barrier Functions in a Human Three-Dimensional Endometrial Epithelial Cell Model

Background Prevotella species are commonly isolated from the reproductive tract of women with obstetric/gynecologic health complications. However, contributions of this genus to changes in local microenvironment are not well characterized. Our objective was to evaluate species-specific effects of Prevotella on the human endometrial epithelium. Methods Thirteen Prevotella strains, originally isolated from the human oral cavity, amniotic fluid, endometrium, or vagina (including women with bacterial vaginosis), were obtained from BEI and ATCC resources. Bacteria were evaluated in silico and in vitro using human endometrial epithelial cells (EEC) grown as monolayers or a 3-dimensional (3D) model. Results Genomic characterization illustrated metabolic and phylogenetic diversity of Prevotella genus. Among tested species, P. disiens exhibited cytotoxicity. Scanning electron microscopy analysis of the 3D EEC model revealed species-specific colonization patterns and alterations of ultracellular structures. Infection with sialidase-producing P. timonensis resulted in elongated microvilli, and increased MUC3 and MUC4 expression. Infections with Prevotella species, including P. bivia, did not result in significant proinflammatory activation of EEC. Conclusions Collectively, findings indicate that Prevotella species are metabolically diverse and overall not cytotoxic or overtly inflammatory in EEC; however, these bacteria can form biofilms, alter barrier properties of the endometrial epithelium, and ultimately impact colonization of secondary colonizers.

STUDY OF ASSOCIATION OF INTESTINAL PREVOTELLA IN EARLY RHEUMATOID ARTHRITIS

BACKGROUND: - Despite being highly prevalent and highly studied autoimmune disease, the etiology for the autoimmunity in Rheumatoid arthritis is not known. One of the recent advances being the role of gut microbiota. The primary objective of this study is to explore the association of Prevotella copri species in the gut microbiota in untreated Rheumatoid arthritis patients. AIMS AND OBJECTIVES:-To study the association of Prevotella copri in the gut microbiota in untreated Rheumatoid Arthritis patients MATERIALAND METHODS: Stool samples were collected from controls and new onset, untreated Rheumatoid arthritis patients in reduced transport fluid (RTF) and were subjected to anaerobic culture in Kanamycin-Vancomycin blood agar to identify Prevotella species based on colony morphology and biochemical tests. Inoculated plates were incubated anaerobically by gas pak method for 72 hours. Also, broadband PCR was run on stool samples collected in RTF for detection of 16S RNA of Prevotella species and the samples which test positive were further subjected to specific PCR with another set of internal primers to detect 16S RNA of Prevotella copri. HiPurATM Stool DNA Purification Kit (#MB544 HIMEDIA) was used for extraction of bacterial genome. Separation of genomic DNAwas done using agarose gel electrophoresis. 2 sets of primers were used among which one is universal primer for bacterial species i.e., 16S rDNA to validate the sample or DNA for bacterial genomic study. Another primer mix specific to Prevotella copri was procured from Helini Biosciences along with positive control for Prevotella copri to identify samples positive for Prevotella copri. RESULTS:- Stool samples were collected from 30 cases and 25 healthy controls and were subjected to PCR and culture. Anaerobic culture showed no growth of Prevotella. PCR studies showed 19(63%) cases being positive for Prevotella copri nucleic acid whereas only 7(28%) samples were positive in controls. CONCLUSION: - Intestinal Prevotella copri was found in significant number of cases of Rheumatoid arthritis compared to controls (p value: 0.009) indicating the alteration in gut microbiota in cases, which could be the reason for priming of autoimmunity in Rheumatoid arthritis

Detection of Increased Relative Expression Units of Bacteroides and Prevotella, and Decreased Clostridium leptum in Stool Samples from Brazilian Rheumatoid Arthritis Patients: A Pilot Study

Interactions between gut microbes and disease modifying antirheumatic drugs (DMARDs) have been proposed. The aim of the present study was to evaluate the presence of some specific bacteria in stool samples from Brazilian RA patients receiving DMARDs and correlate these data with diet, clinical parameters, and cytokines. Stool samples were used for gut bacteria evalutation by qPCR. Serum samples were used to quantify IL-4 and IL-10 by flow cytometer. Statistics were performed by Pearson chi-square, Mann–Whitney U test, and Spearman’s correlation. The study included 20 RA patients and 30 healthy controls. There were no significant differences (P > 0.05) in dietary habits between RA patients and controls. Concerning gut bacteria, we observed an increase in relative expression units (REU) of Bacteroides and Prevotella species in stool samples from patients, and a decrease in REU of Clostridium leptum when compared with healthy controls. Positive correlation between Prevotella and rheumatoid factor was detected. The IL-4 and IL-10 concentrations were increased in patients when compared with controls. We concluded that gut bacteria are different between RA patients receiving DMARDs and healthy controls. Further studies are necessary to determine the real role of gut microbes and their metabolities in clinical response to different DMARDs in RA patients.