Ulcerative Colitis Seems to Imply Oral Microbiome Dysbiosis

Modulation of Gut Microbiota Composition and Microbial Phenolic Catabolism of Phenolic Compounds from Achillea millefolium L. and Origanum majorana L

The impact of the nonbioaccessible fraction of two phenolic-rich extracts from Achillea millefolium L. (yarrow) and Origanum majorana L. (marjoram) on the modulation of the human gut microbiota was investigated in vitro. Microbial metabolism of the phenolic compounds was also addressed. In general, phenolic acids or O-glycosidic flavones quickly disappeared, in contrast to methoxy- or C-glycosidic flavonoids. This colonic metabolism yielded phloroglucinol, 3,4-dimethoxyphenylacetic acid, 3-(4-hydroxyphenyl)-propionic acid, and 4-hydroxybenzoic acid as the main metabolites of the microbial catabolism of rosmarinic acid or caffeoylquinic acids, among others. The 16S rRNA gene sequencing showed that the most promising modulatory effect was related to the increase in Bifidobacterium spp., Collinsella spp., Romboutsia, and Akkermansia muciniphila for both plant extracts, along with Blautia spp. and Dialister for yarrow extract. This beneficial modulation was accompanied by the increase in butyric acid production, highlighting the potential prebiotic-like effect on the gut microbiota of these two previously unstudied edible plants.

Oral Microbiome Research in Biopsy Samples of Oral Potentially Malignant Disorders and Oral Squamous Cell Carcinoma and Its Challenges

This study aims to evaluate the potential benefits and challenges of integrating oral microbiome research into the clinical management of oral potentially malignant disorders (OPMD) and oral squamous cell carcinoma (OSCC). The oral microbiome has gained significant attention for its role in the pathogenesis and progression of these conditions, with emerging evidence suggesting its value as a diagnostic and prognostic tool. By critically analyzing current evidence and methodological considerations, this manuscript examines whether microbiome analysis in biopsy samples can aid in the early detection, prognosis, and management of OPMD and OSCC. The complexity and dynamic nature of the oral microbiome require a multifaceted approach to fully understand its clinical utility. Based on this review, we conclude that studying the oral microbiome in this context holds significant promise but also faces notable challenges, including methodological variability and the need for standardization. Ultimately, this manuscript addresses the question, “Should such research be undertaken, given the intricate interactions of various factors and the inherent obstacles involved?”, and also emphasizes the importance of further research to optimize clinical applications and improve patient outcomes.

Insights into respiratory microbiome composition and systemic inflammatory biomarkers of bronchiectasis patients

The human microbiomes, including the ones present in the respiratory tract, are described and characterized in an increasing number of studies. However, the composition and the impact of the healthy and/or impaired microbiome on pulmonary health and its interaction with the host tissues remain enigmatic. In chronic airway diseases, bronchiectasis stands out as a progressive condition characterized by microbial colonization and infection. In this study, we aimed to investigate the microbiome of the lower airways and lungs of bronchiectasis patients together with their serum cytokine and chemokine content, and gain novel insights into the pathogenesis of bronchiectasis. The microbiome of 47 patients was analyzed by sequencing of full-length 16S rRNA gene using amplicon sequencing Oxford Nanopore technologies. Their serum inflammatory mediators content was quantified in parallel. Several divergently composed microbiome groups were identified and characterized, the majority of patients displayed one dominant bacterial species, whereas others had a more diverse microbiome. The analysis of systemic immune biomarkers revealed two distinct inflammatory response groups, i.e., low and high response groups, each associated with a specific array of clinical symptoms, microbial composition, and diversity. Moreover, we have identified some microbiome compositions associated with high inflammatory response, i.e., high levels of pro- and anti-inflammatory cytokines, whereas other microbiomes were in correlation with low inflammatory responses. Although bronchiectasis pathogenetic mechanisms remain to be elucidated, it is clear that addressing microbiome composition in the airways is a valuable resource not only for diagnosis but also for personalized disease management.

IMPORTANCE

The population of microorganisms on/in the human body resides in distinct local microbiomes, including the respiratory microbiome. It remains unclear what defines a healthy and a diseased respiratory microbiome. We investigated the respiratory microbiome in chronic pulmonary infectious disease, i.e., bronchiectasis, and researched correlations between microbiome composition, systemic inflammatory biomarkers, and disease characteristics. The bronchoalveolar microbiome of 47 patients was sequenced, and their serum inflammatory mediators were quantified. The microbiomes were grouped based on their content and diversity. In addition, patients were also grouped into low- and high-response groups according to their inflammatory biomarkers' levels. Certain microbiome compositions, mainly single-species dominated, were associated with high levels of inflammatory cytokines, whereas others correlated with low inflammatory response and remained diverse. We conclude that respiratory microbiome composition is a valuable resource for the diagnostics and personalized management of bronchiectasis, which may include preserving microbiome diversity and introducing possible probiotics.

Parvimonas micra can translocate from the subgingival sulcus of the human oral cavity to colorectal adenocarcinoma

Oral and intestinal samples from a cohort of 93 colorectal cancer (CRC) patients and 30 healthy controls (non-CRC) were collected for microbiome analysis. Saliva (28 non-CRC and 94 CRC), feces (30 non-CRC and 97 CRC), subgingival fluid (20 CRC), and tumor tissue samples (20 CRC) were used for 16S metabarcoding and/or RNA sequencing (RNAseq) approaches. A differential analysis of the abundance, performed with the ANCOM-BC package, adjusting the P-values by the Holm-Bonferroni method, revealed that Parvimonas was significantly over-represented in feces from CRC patients (P-value < 0.001) compared to healthy controls. A total of 11 Parvimonas micra isolates were obtained from the oral cavity and adenocarcinoma of CRC patients. Genome analysis identified a pair of isolates from the same patient that shared 99.2% identity, demonstrating that P. micra can translocate from the subgingival cavity to the gut. The data suggest that P. micra could migrate in a synergistic consortium with other periodontal bacteria. Metatranscriptomics confirmed that oral bacteria were more active in tumor than in non-neoplastic tissues. We suggest that P. micra could be considered as a CRC biomarker detected in non-invasive samples such as feces.

Ectopic colonization by oral bacteria as an emerging theme in health and disease

The number of research papers published on the involvement of the oral microbiota in systemic diseases has grown exponentially over the last 4 years clearly demonstrating the growing interest in this field. Indeed, accumulating evidence highlights the central role of ectopic colonization by oral bacteria in numerous noncommunicable diseases including inflammatory bowel diseases (IBDs), undernutrition, preterm birth, neurological diseases, liver diseases, lung diseases, heart diseases, or colonic cancer. There is thus much interest in understanding the molecular mechanisms that lead to the colonization and maintenance of ectopic oral bacteria. The aim of this review is to summarize and conceptualize the current knowledge about ectopic colonization by oral bacteria, highlight wherever possible the underlying molecular mechanisms and describe its implication in health and disease. The focus lies on the newly discovered molecular mechanisms, showcasing shared pathophysiological mechanisms across different body sites and syndromes and highlighting open questions in the field regarding the pathway from oral microbiota dysbiosis to noncommunicable diseases.

Unraveling the Impact of Gut and Oral Microbiome on Gut Health in Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD) is a complex disorder characterized by chronic inflammation of the gastrointestinal tract (GIT). IBD mainly includes two distinct diseases, namely Crohn's disease and ulcerative colitis. To date, the precise etiology of these conditions is not fully elucidated. Recent research has shed light on the significant role of the oral and gut microbiome in the development and progression of IBD and its collective influence on gut health. This review aims to investigate the connection between the oral and gut microbiome in the context of IBD, exploring the intricate interplay between these microbial communities and their impact on overall gut health. Recent advances in microbiome research have revealed a compelling link between the oral and gut microbiome, highlighting their pivotal role in maintaining overall health. The oral cavity and GIT are two interconnected ecosystems that harbor complex microbial communities implicated in IBD pathogenesis in several ways. Reduction in diversity and abundance of beneficial bacterial species with the colonization of opportunistic pathogens can induce gut inflammation. Some of these pathogens can arise from oral origin, especially in patients with oral diseases such as periodontitis. It is essential to discern the mechanisms of microbial transmission, the impact of oral health on the gut microbiome, and the potential role of dysbiosis in disease development. By elucidating this relationship, we can enhance our understanding of IBD pathogenesis and identify potential therapeutic avenues for managing the disease. Furthermore, innovative strategies for modulating the oral and gut microbiome can promote health and prevent disease occurrence and progression.

Potential Oral Microbial Markers for Differential Diagnosis of Crohn's Disease and Ulcerative Colitis Using Machine Learning Models

Although gut microbiome dysbiosis has been associated with inflammatory bowel disease (IBD), the relationship between the oral microbiota and IBD remains poorly understood. This study aimed to identify unique microbiome patterns in saliva from IBD patients and explore potential oral microbial markers for differentiating Crohn's disease (CD) and ulcerative colitis (UC). A prospective cohort study recruited IBD patients (UC: n = 175, CD: n = 127) and healthy controls (HC: n = 100) to analyze their oral microbiota using 16S rRNA gene sequencing. Machine learning models (sparse partial least squares discriminant analysis (sPLS-DA)) were trained with the sequencing data to classify CD and UC. Taxonomic classification resulted in 4041 phylotypes using Kraken2 and the SILVA reference database. After quality filtering, 398 samples (UC: n = 175, CD: n = 124, HC: n = 99) and 2711 phylotypes were included. Alpha diversity analysis revealed significantly reduced richness in the microbiome of IBD patients compared to healthy controls. The sPLS-DA model achieved high accuracy (mean accuracy: 0.908, and AUC: 0.966) in distinguishing IBD vs. HC, as well as good accuracy (0.846) and AUC (0.923) in differentiating CD vs. UC. These findings highlight distinct oral microbiome patterns in IBD and provide insights into potential diagnostic markers.

Gut Microbiota, an Additional Hallmark of Human Aging and Neurodegeneration

Gut microbiota represents a diverse and dynamic population of microorganisms harbouring the gastrointestinal tract, which influences host health and disease. Bacterial colonization of the gastrointestinal tract begins at birth and changes throughout life, with age being one of the conditioning factors for its vitality. Aging is also a primary risk factor for most neurodegenerative diseases. Among them, Alzheimeŕs disease (AD) is probably the one where its association with a state of dysbiosis of the gut microbiota has been most studied. In particular, intestinal microbial-derived metabolites have been associated with β-amyloid formation and brain amyloid deposition, tau phosphorylation, as well as neuroinflammation in AD patients. Moreover, it has been suggested that some oral bacteria increase the risk of developing AD. However, the causal connections among microbiome, amyloid-tau interaction, and neurodegeneration need to be addressed. This paper summarizes the emerging evidence in the literature regarding the link between the oral and gut microbiome and neurodegeneration with a focus on AD. Taxonomic features of bacteria as well as microbial functional alterations associated with AD biomarkers are the main points reviewed. Data from clinical studies as well as the link between microbiome and clinical determinants of AD are particularly emphasized. Further, relationships between gut microbiota and age-dependent epigenetic changes and other neurological disorders are also described. Together, all this evidence suggests that, in some sense, gut microbiota can be seen as an additional hallmark of human aging and neurodegeneration.

Polyphenols and Ulcerative Colitis: An Exploratory Study of the Effects of Red Wine Consumption on Gut and Oral Microbiome in Active-Phase Patients

SCOPE

This paper explores the effects of moderate red wine consumption on the clinical status and symptomatology of patients with ulcerative colitis (UC), including the study of the oral and intestinal microbiome.

METHODS AND RESULTS

A case control intervention study in UC patients is designed. Intervention patients (n = 5) consume red wine (250 mL day-1 ) for 4 weeks whereas control patients (n = 5) do not. Moderate wine consumption significantly (p < 0.05) improves some clinical parameters related to serum iron, and alleviates intestinal symptoms as evaluated by the IBDQ-32 questionnaire. 16S rRNA gene sequencing indicate a non-significant (p > 0.05) increase in bacterial alpha diversity after wine intervention in both saliva and fecal microbiota. Additional comparison of taxonomic data between UC patients (n = 10) and healthy subjects (n = 8) confirm intestinal dysbiosis for the UC patients. Finally, analysis of fecal metabolites (i.e., phenolic acids and SCFAs) indicates a non-significant increase (p > 0.05) for the UC patients that consumed wine.

CONCLUSIONS

Moderate and regular red wine intake seems to improve the clinical status and symptoms of UC patients in the active phase of the disease. However, studies with a greater sample size are required to achieve conclusive results.

Oral manifestations serve as potential signs of ulcerative colitis: A review

As an immune dysregulation-related disease, although ulcerative colitis (UC) primarily affects the intestinal tract, extraintestinal manifestations of the disease are evident, particularly in the oral cavity. Herein, we have reviewed the various oral presentations, potential pathogenesis, and treatment of oral lesions related to UC. The oral manifestations of UC include specific and nonspecific manifestations, with the former including pyostomatitis vegetans and the latter encompassing recurrent aphthous ulcers, atrophic glossitis, burning mouth syndrome, angular cheilitis, dry mouth, taste change, halitosis, and periodontitis. Although the aetiology of UC has not been fully determined, the factors leading to its development include immune system dysregulation, dysbiosis, and malnutrition. The principle of treating oral lesions in UC is to relieve pain, accelerate the healing of lesions, and prevent secondary infection, and the primary procedure is to control intestinal diseases. Systemic corticosteroids are the preferred treatment options, besides, topical and systemic administration combined with dietary guidance can also be applied. Oral manifestations of UC might accompany or precede the diagnosis of UC, albeit with the absence of intestinal symptoms; therefore, oral lesions, especially pyostomatitis vegetans, recurrent aphthous ulcer and periodontitis, could be used as good mucocutaneous signs to judge the occurrence and severity of UC, thus facilitating the early diagnosis and treatment of UC and avoiding severe consequences, such as colon cancer.