pH and culture medium have been reported as two culture conditions that affect S. mutans MVs. First, the properties of S. mutans MVs are regulated by pH (Cao et al., 2020; Wen et al., 2021; Iwabuchi et al., 2021). In particular, the initial pH of the culture environment appears to play an important role in MV biogenesis. MVs prepared from S. mutans under different initial pH conditions exhibited different sizes. Although particles of 0–200 nm² dominated in MVs extracted from both pH 6.0 and pH 8.0 culture media, a higher proportion of MVs exceeding 1,000 nm² was found under alkaline conditions at pH 8.0 (Iwabuchi et al., 2021). Another study reported similar trends, where the diameter of S. mutans MVs at pH 7.5 was significantly larger than that at pH 5.5 (Cao et al., 2020). In addition, biofilm formation triggered by the treatment with different MVs from S. mutans under various initial pH conditions exhibited different results; these different MVs affected the structure and characteristics of the S. mutans biofilm (Iwabuchi et al., 2021). Although the specific mechanism may require further investigation, it is clear that MVs under different pH conditions are significantly different, not only in size but also in content. S. mutans produces larger MVs under neutral conditions (pH 7.5), despite harboring approximately 10-fold less protein content (standardized by bacterial colony-forming units) compared to acidic conditions (pH 5.5) (Cao et al., 2020).

In addition to pH, the culture medium also influences the characteristics of S. mutans MVs (Nagasawa et al., 2025). Brain heart infusion (BHI) is a complex medium that is commonly used for oral bacterial cultures, including S. mutans. Interestingly, the response of S. mutans to autologous SigX (alternative sigma factor)-inducing peptide (XIP) is restricted by this type of medium. In contrast, chemically defined medium (CDM) is a peptide-free culture medium that supports S. mutans growth and limits the function of self-generated competence-stimulating peptides (CSPs) (Son et al., 2012). Proteins within S. mutans MVs from the BHI medium and CDM were found to be quite different (Nagasawa et al., 2025). Moreover, S. mutans wild-type MVs isolated from BHI could induce the biofilm formation of S. mutans ΔgtfBC, a strain that lacks the corresponding coding products, glucosyltransferase B (GtfB) and glucosyltransferase C (GtfC), and could barely form biofilms (Nagasawa et al., 2025). In contrast, S. mutans wild-type MVs isolated from CDM have limited effects on the biofilm formation of S. mutans ΔgtfBC (Nagasawa et al., 2025).

In the autolysin-dependent process of S. mutans MV biogenesis, MV release occurs via a cell-to-cell communication system mediated by peptide signals, called the Com system (Nagasawa et al., 2025). The Com system consists of an upstream CSP-mediated ComDE pathway and a downstream XIP-involved ComRS pathway, which can regulate sigX to further control the autolysin-encoding gene lytF, the product of which is responsible for S. mutans MV release by targeting peptidoglycans (Khan et al., 2016; Nagasawa et al., 2025). Therefore, CSPs with 18 amino acids or XIP with seven amino acids may contribute to S. mutans MV biogenesis. As expected, the exogenous addition of CSP or XIP to BHI or CDM promoted S. mutans MV formation compared to the corresponding medium without peptide signals (Nagasawa et al., 2025). In addition, both CSP and XIP altered the protein contents of S. mutans MVs isolated from the corresponding medium (Nagasawa et al., 2025).

Different strains of S. mutans can produce different numbers of MVs (Wen et al., 2021). For instance, according to a quantitative analysis, S. mutans 27–3, a clinical strain isolated from a patient with active caries, can produce approximately 8-fold more MVs than S. mutans UA159 under the same conditions (Wen et al., 2021). Moreover, the above results are in line with qualitative observations from transmission electron microscopy (TEM), which revealed many more vesicular structures surrounding the cells of S. mutans 27–3 than S. mutans UA159 (Wen et al., 2021). The whole genome sequencing of S. mutans 27–3 revealed significant differences compared to S. mutans UA159, including the addition of 192 genes and the deletion of 275 genes. This may be related to the increase in MV yields (Wen et al., 2021). Evidence suggests that these genes are implicated in S. mutans MV biogenesis.

In addition to culture conditions, peptide signals, and bacterial strains, the properties of S. mutans MVs, including size, quantity, and content, are regulated by specific genes.

The lytF-encoding product, LytF, has been reported to induce cell death in a subpopulation of S. mutans and to promote eDNA production (Nagasawa et al., 2020). Interestingly, lytF-expressing S. mutans cells were abundant near the base of the biofilm, while all cells within the biofilm received the CSP signal, which could induce the expression of lytF (Nagasawa et al., 2020). S. mutans MV biogenesis has been reported to occur in an autolysin-dependent manner; the autolysin (LytF)-encoding gene lytF can undoubtedly affect S. mutans MVs. The S. mutans ΔlytF strain produced fewer MVs than its wild-type strain under CSP or XIP treatment. Moreover, the defect of the S. mutans ΔlytF strain in producing MVs was restored in a lytF-complemented strain. These results confirm the involvement of lytF in S. mutans MV biogenesis (Nagasawa et al., 2025).

GtfB and GtfC are encoded by gtfB and gtfC, respectively, and they are two of the most important glycosyltransferases involved in insoluble glucan synthesis in S. mutans. These two important cariogenic virulence factors are present in S. mutans MVs, as revealed by anti-GTF antiserum (Senpuku et al., 2019). These two GTF-encoding genes influence S. mutans MV biogenesis through multiple pathways. First, MVs isolated from strains deficient in gtfB and gtfC display markedly different effects on autologous and other oral microbial biofilm formation compared to those from the wild-type strain. The effects of S. mutans MVs were restricted significantly under S. mutans ΔgtfBC MV. For example, the remarkable enhancement effects of MVs from the wild-type strain on S. mutans UA 159 biofilm formation were not found in MVs from the S. mutans ΔgtfBC strain (Senpuku et al., 2019). The significant repression effects of MVs from wild-type S. mutans on the biofilm formation of Streptococcus gordonii (S. gordonii) and Streptococcus sanguinis (S. sanguinis) were lost when the MVs were replaced with the ones from the S. mutans ΔgtfBC strain (Cui et al., 2022). The protein content of MVs was decreased in S. mutans ΔgtfC and ΔgtfBC strains compared to MVs from the wild-type strain. In contrast, MVs from S. mutans ΔgtfB had a similar protein concentration compared to the wild-type strain. In addition, S. mutans and its ΔgtfB strain had larger MVs than ΔgtfC and ΔgtfBC strains (Nakamura et al., 2020). These results prove that GtfC, but not GtfB, influences the protein content and size of S. mutans MVs (Nakamura et al., 2020).

SMU_833, a putative glycosyltransferase encoded by smu_833, is recognized as an important virulence factor in S. mutans. The deficiency of smu_833 resulted in no changes in the overall biofilm biomass, but it caused changes in biofilm architecture, decreased acidogenesis in vitro, and reduced virulence in a rat caries model (Rainey et al., 2019). In addition, it can alter the interactions between eDNA and glucan, the two primary biofilm matrix constituents (Jakubovics and Burgess, 2015). The deficiency of smu_833 led to a reduction in glucan levels, which resulted from a decrease in Gtfs (GtfB and GtfC) and enhanced eDNA generation. Notably, the increase in eDNA was accompanied by improved release of MVs. The increase in eDNA and MVs as a result of the smu_833 deletion appears to compensate for the defects in Gtfs, making up for any biofilm biomass changes to some extent (Rainey et al., 2019).

Furthermore, SrtA, encoded by srtA, is a transpeptidase that covalently combines several surface-associated proteins with peptidoglycans within the cell wall and has been reported to play a role in MV biogenesis in S. mutans (Liao et al., 2014). The lack of srtA in S. mutans impairs the membrane localization and activity of the multifunctional adhesin P1 and other proteins, which subsequently affects bacterial adhesion and weakens biofilm formation. Therefore, SrtA is a significant protein that plays a role in biofilm formation (Liao et al., 2014). However, subsequent experiments showed that srtA deficiency did not disrupt the production of MVs significantly, as supported by transmission electron microscope observations (Liao et al., 2014). Quantitative analysis from another study suggested that the srtA deficiency strain had a higher MV particle concentration than the wild type (Morales-Aparicio et al., 2020). The protein profile of MVs was significantly altered by srtA deficiency (Liao et al., 2014; Morales-Aparicio et al., 2020). Detailed analysis using Western blotting revealed that MVs extracted from the S. mutans ΔsrtA strain produced lower levels of adhesin P1, glucan-binding proteins B (GbpB) and C (GbpC), and Gtfs compared to MVs released by the wild-type strain (Liao et al., 2014). In addition to differences in content, physical properties of ΔsrtA MVs, analyzed by nanoparticle tracking analysis, displayed a larger mean diameter than the wild-type MVs (Morales-Aparicio et al., 2020). Overall, srtA in S. mutans not only affects MV quantity but also the protein component and size (Liao et al., 2014; Morales-Aparicio et al., 2020).

Similar to SrtA, the 4′-phosphopantetheinyl transferase Sfp has been reported to affect MV biogenesis. Sfp deficiency by sfp mutation in other Gram-positive bacteria impairs the production of MVs and results in defects in biofilm formation (Brown et al., 2014). In S. mutans, the sfp homolog mubP (smu_1334c) is located within a prevalent large genomic island called TnSmu2 and affects MV biogenesis (Wu et al., 2010). In contrast to srtA, sfp deficiency results in lower MV particle concentration compared to its wild type (Morales-Aparicio et al., 2020). In addition, proteomic analyses have shown that sfp mutation also affects the protein composition of MVs (Morales-Aparicio et al., 2020; Wen et al., 2021). This indicates that protein transport from bacteria to MVs is selective and active, and multiple factors may affect this process during different delivery phases (Wen et al., 2021). In addition, the diameter of Δsfp MVs differed from that of wild-type strain MVs (Morales-Aparicio et al., 2020; Wen et al., 2021).

The OpuB transporter, encoded by opuB, was shown to play a critical role in the biogenesis of MVs and affected the composition of S. mutans MVs. For biogenesis, the opuB-deficient (Δ opuB) strain produced smaller and more MVs than S. mutans UA159 at pH 7.5 (Wang C. et al., 2025; Wang W. et al., 2025). However, there was no significant difference in MV quantity or size when the opuB-deficient strain was compared to the wild type at acidic pH 5.5 (Wang C. et al., 2025; Wang W. et al., 2025). When S. mutans MV composition was examined, the knockout of opuB impacted the lipid concentration and composition of MVs (Wang C. et al., 2025; Wang W. et al., 2025). In addition, 108 and 279 proteins in MVs were altered by more than 2-fold in the opuB-deficient strain under pH 7.5 and pH 5.5 conditions, respectively (Wang C. et al., 2025; Wang W. et al., 2025). Genes currently reported to affect S. mutans MVs are listed in Table 1.

In addition to the factors discussed above, other elements involved in S. mutans MV biogenesis need to be investigated. It is clear that components of S. mutans MV-related genes and their regulation play a role in S. mutans MV biosynthesis. Therefore, composition analysis and identification of S. mutans MVs may contribute to the control of MV biogenesis.

S. mutans MVs contain many proteins, and the MV protein content has been adopted as a measurement standard to quantify MVs (Cao et al., 2020). Proteomic analyses have identified proteins within MVs that are associated with several biological processes (Cao et al., 2020). A total of 509 proteins were detected in S. mutans MVs, comprising 351 proteins at pH 5.5 and 495 proteins at pH 7.5 (Cao et al., 2020). Although MVs with smaller sizes had significantly higher protein content (normalized by bacterial colony-forming units) under acidic conditions (pH 5.5) compared to pH 7.5, 344 proteins were detected at both pH 5.5 and pH 7.5. They included metabolic enzymes, membrane transporters, secretory proteins, signal peptidase, proteases, structural components of the ribosome, cell wall-associated hydrolases, and lysozymes (Cao et al., 2020). Notably, many virulence factors of S. mutans, such as Gtfs, surface protein antigen P1 (SpaP), glucan-binding proteins (Gbps), lactate dehydrogenase (LDH), and dextranase (DexA), have been identified in MVs using proteomic analysis (Cao et al., 2020).

In addition to the regulatory effects on the protein content due to pH changes, the deletion of some genes, such as srtA and spf, undoubtedly changes the protein composition and quantity of MVs, as mentioned above (Cao et al., 2020; Morales-Aparicio et al., 2020). It was reported that MVs from the S. mutans Δsfp strain shared 61.16% protein similarity with its wild-type strain MVs (Morales-Aparicio et al., 2020). The similarity in MV protein composition was 28.10% when the S. mutans ΔsrtA strain was compared to its wild-type strain (Morales-Aparicio et al., 2020). Comparatively, these two strains with gene mutations shared 28.51% similarity in MV protein composition (Morales-Aparicio et al., 2020). These results illustrate that the transport of proteins to S. mutans MVs is a selective process that is substantially influenced by the presence of SrtA, and to a lesser extent, by Sfp (Cao et al., 2020; Morales-Aparicio et al., 2020). All proteins reported under different conditions are listed in Table 2.

Lipids are vital structural constituents of bacterial cell membranes, including S. mutans, through which MVs are secreted (Morales-Aparicio et al., 2020). Hence, it is clear that outer membrane phospholipids are components of S. mutans MVs. Nevertheless, some lipids are found exclusively in MVs and not in the outer membrane of S. mutans (Morales-Aparicio et al., 2020). Lipids in MVs from S. mutans were analyzed using liquid chromatography-mass spectrometry, and approximately 30 individual lipids were identified in S. mutans MVs (Morales-Aparicio et al., 2020). The relative proportion of each lipid category varies between the cytomembrane and MVs. The analysis showed that cardiolipins and flavonoids are present in higher proportions in MVs compared to the cytomembrane (Morales-Aparicio et al., 2020). The lipid architecture plays an important role in environmental adaptation (Fozo and Quivey, 2004). The richness of monounsaturated long-chain fatty acids helps S. mutans improve its tolerance to the acidic environment generated during the fermentation of carbohydrates into organic acid end products (Morales-Aparicio et al., 2020). Interestingly, in MVs from S. mutans ΔsrtA and Δsfp strains, the level of monounsaturated long-chain fatty acids was significantly increased; this transformation may assist these strains to tolerate the acidic environment (Morales-Aparicio et al., 2020).

MVs from Gram-positive bacteria have been reported to harbor nucleic acids such as DNA and RNA, which can be delivered to other bacteria and facilitate horizontal gene transfer (HGT) (Schooling et al., 2009; Díaz-Garrido et al., 2021).

To identify whether S. mutans MVs can act as carriers for the release of eDNA, hydrolyzed MVs were used to detect eDNA existence. Unsurprisingly, the experiments confirmed the presence of eDNA in MVs (Liao et al., 2014). eDNA plays a crucial role in biofilm formation, including that of its own and several other bacteria (Senpuku et al., 2019; Wu et al., 2020). Several studies have also identified RNA in MVs, which are important for some physiological processes (Munhoz da Rocha et al., 2020). These RNAs include messenger RNA (mRNA), ribosomal RNA (rRNA), transfer RNA (tRNA), and long non-coding RNA (lncRNA) (Munhoz da Rocha et al., 2020). A recent study identified tRNA in S. mutans MVs that could facilitate cell proliferation together with the migration of the oral mucosa, support focal adhesion complex formation within organoids, and aid wound healing in a mouse model (Oh et al., 2025). RNA sequencing analysis identified “microRNA-like” molecules in S. mutans, suggesting that these RNAs may contribute to bacteria that are analogous to microRNAs within eukaryotes (Lee and Hong, 2012; Munhoz da Rocha et al., 2020).

In addition to the studies on MV components discussed above, further research on MV composition and its influencing factors is needed to further understand MVs and explore their potential functions and applications.

The self-regulatory effect of S. mutans MVs has been mainly observed in autologous biofilm formation. A previous study showed that MVs derived from S. mutans contribute to autologous biofilm formation (Senpuku et al., 2019). The extracellular biofilm matrix of S. mutans mainly consists of glucan polysaccharides, eDNA, and lipoteichoic acid (Klein et al., 2015). A significant part of this process is the glucan matrix, which facilitates S. mutans adherence to the tooth surface, maintains mechanical stability, protects microorganisms from environmental assaults, reserves energy sources, limits the diffusion of substances into and out of the biofilm, and helps concentrate metal ions and other physiological nutrients (Schilling and Bowen, 1992; Koo et al., 2009). The glucan matrix of S. mutans is synthesized and organized using extracellular Gtfs. Surprisingly, one of the most important components in MVs secreted from S. mutans is Gtfs, which is a key enzyme in dental caries development (Nakamura et al., 2020). Several studies have suggested that S. mutans secretes MVs harboring Gtfs that can augment sucrose metabolism and promote autologous biofilm formation. Compared to MVs from the S. mutans ΔgtfBC strain, the MVs from the wild-type strain significantly enhanced biofilm formation (Senpuku et al., 2019). Interestingly, GtfB largely adheres to the MV surface (Nakamura et al., 2020). In contrast, GtfC is primarily present within MVs and regulates MV size and aggregation and S. mutans biofilm formation (Nakamura et al., 2020). Another factor that plays an important role in the formation of S. mutans biofilms on tissues within the oral cavity is eDNA, which contributes to adhesion and the accumulation of S. mutans, as well as the architecture and stability of autologous biofilms (Castillo Pedraza et al., 2017; Kim et al., 2018). To investigate the function of eDNA and MVs in S. mutans biofilm formation, Senpuku et al. reported the extraction of a purified complex consisting of DNA and MVs with Gtfs from S. mutans and incubation with the S. mutans ΔgtfBC strain. Interestingly, the results suggested that this complex induced Gtfs-dependent S. mutans ΔgtfBC biofilm formation (Senpuku et al., 2019). Moreover, short DNA fragments associated with S. mutans MVs can significantly promote autologous biofilm formation (Senpuku et al., 2019). MVs that had eDNA removed showed a different effect on S. mutans ΔgtfBC biofilm formation compared to MVs at a relatively low concentration (Senpuku et al., 2019). Therefore, it is inferred that MVs can assist in autologous biofilm formation, further enhancing the cariogenicity of S. mutans and promoting dental caries.

MVs are natural carriers of molecules that are protected by them, allowing long-distance delivery of these biological molecules and avoiding direct intercellular contact to safely reach their final destination (Gill et al., 2019). This characteristic endows S. mutans MVs with the function of interspecies communication by influencing biofilm formation in other species.

A recent study showed that MVs not only contribute to the biofilm formation of S. mutans but also influence the formation of other bacterial biofilms. S. sanguinis and S. gordonii are the initial colonizers of tooth surfaces. They compete with S. mutans for hydrogen peroxide (H₂O₂) and are countered by S. mutans through mutacin (Zhang et al., 2025). It has been reported that biofilm formation by S. gordonii and S. sanguinis is inhibited by S. mutans MVs, where the Gtfs in MVs play a role (Cui et al., 2022). When co-cultured with MVs from S. mutans, S. gordonii, and S. sanguinis, biofilm formation was significantly suppressed (Cui et al., 2022). In contrast, S. mutans ΔgtfBC MVs had no significant effect on the biofilm formation of these two species (Cui et al., 2022). In addition, S. mutans MVs suppressed the expression of their virulence genes, including GtfG (encoding glucosyltransferase in S. gordonii), GtfP (encoding glucosyltransferase in S. sanguinis), and SpxB (encoding pyruvate oxidase to produce H₂O₂) (Cui et al., 2022). Another study reported that biofilm formation by S. sanguinis, Streptococcus mitis, Streptococcus oralis, Actinomyces naeslundii, S. gordonii, and Actinomyces oris can be facilitated by S. mutans MVs (Senpuku et al., 2019). Further studies have shown that this facilitative action is GtfB- and GtfC-dependent, except in A. naeslundii, where MVs from S. mutans ΔgtfBC still display promotional effects (Senpuku et al., 2019). The differing effects of S. mutans MVs on S. gordonii and S. sanguinis biofilms observed in the two separate studies may have resulted from differences in culture conditions, bacterial strains, and experimental methods.

In addition to being involved in the communication between bacteria, S. mutans MVs also affect fungi, such as C. albicans, one of the most common colonizers within the oral cavity. MVs derived from S. mutans can augment the biofilm development of C. albicans and are Gtf-dependent (Wu et al., 2020). In addition, S. mutans MVs enhance the pathogenicity and carbohydrate metabolism of C. albicans. The enhanced pathogenicity of fungal biofilms was revealed in a bovine dentin demineralization experiment, where S. mutans MV-containing groups showed greater hardness loss, more exposure, and increased damage to dentin tubules (Wu et al., 2022). Promoted carbohydrate metabolism is mainly revealed by the increase in related metabolites and protein expression (Wu et al., 2022). In addition, when co-cultured with MVs, C. albicans biofilms have a three-dimensional structure with an abundant extracellular matrix, and C. albicans forms hyphal cells under biofilm-forming conditions (Wang C. et al., 2025; Wang W. et al., 2025).

Other potential functions of S. mutans MVs involved in interspecies communication include providing substrates for horizontal gene transfer (HGT) and regulating gene expression and protein translation, which are based on nucleic acid loading in MVs. HGT has recently been identified as an effective mechanism for microbiomes to interact, helping bacteria acquire new genetic traits in addition to plasmids (Arnold et al., 2022). The distribution of antimicrobial resistance genes is an example of this interaction and is considered a type of HGT (Yaron et al., 2000). S. mutans has been reported to release eDNA via MVs into developing biofilms; therefore, it is reasonable to infer that MVs from S. mutans also offer other competent bacteria an important source of transformation through this novel mechanism (Roberts and Kreth, 2014; Campoccia et al., 2021). In addition to eDNA, RNA is another type of nucleic acid found in MVs. As mentioned previously, multiple types of RNA can be delivered by S. mutans MVs (Munhoz da Rocha et al., 2020). It may contribute to bacterial communication by regulating gene expression via non-coding RNAs and protein translation via messenger RNAs (Munhoz da Rocha et al., 2020). The effects of RNA within S. mutans MVs have been demonstrated in microbe–host interactions (Tsatsaronis et al., 2018; Oh et al., 2025). However, whether nucleic acids within S. mutans MVs are involved in HGT, microbial interspecies regulation of gene expression, and protein translation requires further investigation.

The role of S. mutans MVs in microbe–host interactions is mainly reflected in their immunity. On the one hand, S. mutans MVs can trigger an immune response and induce a pro-inflammatory effect. On the other hand, S. mutans MVs have emerged as promising tools for the development of vaccines and immunotherapeutic strategies against infectious and non-infectious diseases (Nakao et al., 2011; Long et al., 2022).

A recent study showed that S. mutans MVs could notably elevate the release of inflammatory cytokines and induce macrophage glycolysis. When cultured with S. mutans MVs, the expression of macrophage pro-inflammatory cytokines, such as interleukin-1β (IL-1β), interleukin-6, interleukin-8, and tumor necrosis factor α, was significantly increased (Song et al., 2024). Among these highly expressed cytokines, IL-1β was particularly prominent, and its increased production induced by S. mutans MVs could occur through the activation of the nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), absent in melanoma 2 (AIM2), apoptosis-associated speck-like protein containing CARD (ASC), and nucleotide-binding oligomerization domain-like receptor C4 (NLRC4) inflammasomes (Song et al., 2024). In addition, potassium ion efflux and adenosine triphosphate generation were involved in IL-1β production induced by S. mutans MVs (Song et al., 2024). Macrophage glycolysis is a crucial part of this pro-inflammatory process for classical activation (Song et al., 2024). In addition to these two main findings, S. mutans MVs promoted S. mutans colonization of oral epithelial cells and suppressed macrophage phagocytosis against S. mutans (Song et al., 2024).

In addition to their pro-inflammatory effects, S. mutans MVs can induce an immune response in the oral environment, making vaccine development feasible (Nakao et al., 2011; Long et al., 2022). GtfB and GtfC, which are closely associated with S. mutans MVs, are key cariogenic virulence factors that contribute to biofilm formation by themselves and through other microorganisms (Liao et al., 2014; Senpuku et al., 2019). Based on this evidence, S. mutans MVs are regarded as crucial virulence factors and targets for biofilm-associated disease control. It was reported that MVs from S. mutans wild-type, ΔgtfB, ΔgtfC, and ΔgtfBC strains produced anti-MV IgA and IgG antibodies after intranasal immunization of mice (Nakamura et al., 2020). Further investigation revealed that it is the antibodies induced by MVs from S. mutans wild-type and S. mutans ΔgtfB strains, rather than S. mutans ΔgtfC and S. mutans ΔgtfBC strains, that react with MV Gtfs (Nakamura et al., 2020). It is clear that S. mutans MVs harboring GtfC are operative mucosal immunogens that induce anti-Gtf antibody production (Nakamura et al., 2020). Using S. mutans MVs as antigens stimulated IgA and IgG antibody generation against to Gtfs successfully, which may be useful for future vaccine development. However, considering the extremely complex composition of S. mutans MVs, the potential side effects of this process require further investigation.

In addition to the two proven effects discussed above, S. mutans MVs have been shown to play a role in skin wound healing in mice (Oh et al., 2025). Specifically, S. mutans MVs not only promoted the proliferation of human oral organoids, assisted in the migration of oral epithelial cells, and enhanced the formation of focal adhesion complexes but also facilitated wound healing in the dorsal skin of mice (Oh et al., 2025). Further research has revealed that tRNA variants, the most abundant RNAs within S. mutans MVs, play a vital role in this process (Oh et al., 2025). Surprisingly, the tRNA mentioned above could take effect even when electroporated into Escherichia coli MVs, in addition to being packaged within S. mutans MVs (Oh et al., 2025). Further research revealed that the promotion of skin wound healing occurred through a Toll-like receptor 3-dependent mechanism (Oh et al., 2025). This study demonstrated that the use of S. mutans MVs and RNA cargo is a promising therapeutic strategy for skin wound rehabilitation (Oh et al., 2025).