Hyposalivation but not Sjögren's syndrome associated with microbial dysbiosis in women

Oral Manifestations in Menopause-A Scoping Review

Background and Objectives: Menopause is a natural physiological process involving hormone production changes, affecting many functions and systems. This scoping review offers a contemporary outlook on oral issues related to menopause, such as saliva production, periodontal and alveolar bone issues, and changes in the microbiome, and it also investigates the effects of hormonal therapy. Materials and Methods: A literature search from 2019 to 2024 was conducted according to PRISMA-ScR guidelines. Articles investigating the oral effects of menopause were included. Results: A total of 30 studies were covered; 8 focused on salivary alterations, 5 on periodontal issues, 7 on bone, 3 on the microbiome, and 7 on multiple oral problems, showing that xerostomia and altered taste are the most common oral manifestations, followed by indirect causal effects on periodontitis. Many of these alterations can be contained through regular consultations and adequate hygiene. Some alveolar bone changes may occur after menopause and are associated with osteoporosis. Conclusions: Postmenopausal women experience notable reductions in salivary flow, pH levels, and taste sensitivity, which are associated with hormonal fluctuations as well as factors such as age, medication use, and treatments for climacteric symptoms. This population is at increased risk for periodontitis, tooth loss, altered taste, lichen planus, candidiasis, and decreased bone mineral density, which also affect the peri-implant area. Osteoporosis and hormonal changes can play a significant role in causing these increased risks. Maintaining proper oral hygiene and consistently monitoring bone health are essential. While changes in the oral microbiome are more heavily influenced by reductions in salivary flow than by menopause itself, hormone therapy may help improve periodontal health by reducing harmful bacteria and fostering a more balanced microbial environment. The intricate impact of hormones on oral health highlights the necessity for further research.

Association between oral microbiome dysbiosis and Sjogren Syndrome. A systematic review of clinical studies

OBJECTIVES

This systematic review investigates the association of oral microbiome dysbiosis with Sjogren Syndrome (SS).

MATERIALS AND METHODS

Indexed databases (PubMed/Medline, EMBASE, OVID, Web of Science, and Scopus) were independently searched for relevant manuscripts published until August 2024. Clinical studies on oral microbial flora count and diversity in SS patients were included. Risk of bias across individual studies was performed using the Risk of Bias in Nonrandomized Studies of Interventions tool.

RESULTS

Out of the initial 295 studies, 15 clinical studies met the selection criteria. The protocols were similar across the studies but varied in diagnostic criteria for SS, salivary flow estimation methods, dental and periodontal status findings, and the type of oral microbes observed. Out of 15 studies, 14 showed an alteration in the oral microbiome and differences in microbial diversity in SS patients. Higher oral microbial counts of Prevotella, Viellonella, and Firmicutes in SS were reported, whereas a higher prevalence of caries-associated bacteria Streptococcus, Lactobacillus, and Viellonella was found in SS patients. Overall, the studies had a low risk of bias.

CONCLUSIONS

The findings of the present review have shown the existence of significant oral microbial dysbiosis and differences in microbial diversity in SS patients compared to healthy subjects. Future well-designed longitudinal studies are needed to validate the results.

The Oral Microbiome: A Key Determinant of Oral Health

As the second largest reservoir of human microbes, the oral cavity is colonized by millions of tiny creatures collectively named as oral microbiome. Species detected in human mouth are diverse, including bacteria, fungi, viruses, and protozoa. Active bidirectional interaction exists between the oral microbiome and the host. Stresses from hosts shape the composition, distribution pattern, and the community behaviors of the oral microbiome, while any changes occurring on the oral microbiome may disrupt its symbiosis relationship with the host and ultimately lead to oral and systemic diseases that jeopardize the host's health. In this chapter, the latest understanding about the role of oral microbiome in common oral diseases, including dental caries, periodontal disease, oral candidiasis, and hyposalivation, is discussed.

Hormonal Environment Shapes the Oral Microbiome

Hormones are present in oral fluids and undergo dynamic changes throughout life. Hormonal changes can influence the interactions between the microbial community and the host. The oral microbiome is sensitive to changes in the oral environment, and hormonal fluctuations can create conditions that favour the growth of certain types of bacteria over others. Since the gingival niche harbours the resident microbial community in the biofilm form, while saliva has a transient microbiota in the planktonic form, both could modulate the host-microbial interaction under hormonal oscillations.The microbiome and hormones have a dynamic bidirectional interaction. Specific oral microorganisms can metabolize steroid hormones, disrupting their host regulation. Hormones can serve as host-microbial crosstalk related to health and disease. Hormonal imbalances are associated with systemic diseases such as polycystic ovary syndrome, endometriosis, cortisol-related conditions and oral cancer. Elucidating the complex relationship between steroid hormones and the oral microbiome offers valuable insights into the mechanisms of the disease and potential therapeutic avenues for maintaining oral and systemic health.

Balancing the Oral-Gut-Brain Axis with Diet

Background: The oral microbiota is the second largest microbial community in humans. It contributes considerably to microbial diversity and health effects, much like the gut microbiota. Despite physical and chemical barriers separating the oral cavity from the gastrointestinal tract, bidirectional microbial transmission occurs between the two regions, influencing overall host health. Method: This review explores the intricate interplay of the oral-gut-brain axis, highlighting the pivotal role of the oral microbiota in systemic health and ageing, and how it can be influenced by diet. Results: Recent research suggests a relationship between oral diseases, such as periodontitis, and gastrointestinal problems, highlighting the broader significance of the oral-gut axis in systemic diseases, as well as the oral-gut-brain axis in neurological disorders and mental health. Diet influences microbial diversity in the oral cavity and the gut. While certain diets/dietary components improve both gut and oral health, others, such as fermentable carbohydrates, can promote oral pathogens while boosting gut health. Conclusions: Understanding these dynamics is key for promoting a healthy oral-gut-brain axis through dietary interventions that support microbial diversity and mitigate age-related health risks.