## 7 Discussion  
In recent years, the importance of oral health for general well-being has been increasingly confirmed by scientific evidence, elucidating how oral infections and dysbiosis contribute to the triggering or worsening of various types of systemic diseases.  
In light of these findings, it has been shown that periodontal pathogenic bacteria as well as intestinal dysbiosis are also involved in the determinism of BMD loss, actively contributing to the onset and worsening of OP (Figure 1).  
This evidence has inspired research on the modulation of the microbiota to restore health by the use of prebiotics and probiotics. In particular, it has been shown that a number of host-indigestible food compounds (prebiotics such as galactooligosaccharide, inulin, and resistant starch) are involved in digestive processes by providing nourishment for healthy gut bacteria and thus promoting mineral absorption by enterocytes [59; 64]. Moreover, among the living microorganisms that have a positive effect on bone health by acting at the digestive level and known as \"probiotics\", _Lactobacillus_ sp. (mainly _L. reuteri_, _L. casei_, _L. rhamnus_ and _L. salivarius_) and _Bifidobacteria_, seem to significantly decrease osteoclastogenesis and stop bone resorption [59; 65].  
Promising results on the use of prebiotics and probiotics have also recently emerged for the restoration of oral dysbiosis [66; 67] and as adjunctive therapeutic agents to periodontal treatments [68]. Prebiotics promote the nourishment of beneficial bacteria, thus promoting the restoration of a balanced and healthy oral microbiota [69; 70]. For example, [PERSON] et al. [71] reported the effect of nitrate as prebiotic in modulating the composition of the oral microbiome by significantly reducing periodontitis such as _Porhyromonas_, _Fusobacterium_, _Leptotrichia_ and _Prevotella_. Other studies have also reported the benefits of using probiotics: from the use of _Lactobacillus_ sp. in addition to non-surgical periodontal therapy [72], to its adoption to improve the periodontal conditions [73], it results in a reduction of the need for antibiotics [74] and in safe and effective support to conventional mechanical therapies in the management of PD, with positive effects on both oral health and its systemic consequences [75; 76]. Another probiotic commensal widely investigated is Streptococcus sp. and the mechanisms by which it is able to mitigate the periodontalneqhogen activity of _Porhyromonas gingivalis_. [PERSON] et al. [77] addressed the competitive adhesiveness of _Streptococci_ sp. to oral epithelial cells as responsible for reducing the invasiveness of _Porhyromonas gingivalis_, while [PERSON] et al. [78], defined the ability of _Streptococcus gordoiii_ to mitigate and modulate the inflammatory signaling triggered by _Porhyromonas gingivalis_ and [PERSON] et al. [79] identified the ability of _Streptococcus cristatus_ to alter the expression of virulent genes of _Porhyromonas gingivalis_.  
On these bases, we can guide dentists to not underestimate the OP problem when facing a postmenopausal woman with or without signs and diagnosis of PD and encourage deeper study on oral dysbiosis and its rebalancing through the use of food products with appropriate and beneficial bacteria.  
Conceptualization, M.C., A.I. and R.S.; writing--original draft preparation, M.C., A.I., C.L.; writing--review and editing, M.C., G.G., R.S., and F.I. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
The authors declare no conflict of interest.