Streptococcus salivarius K12 Alleviates Oral Mucositis in Patients Undergoing Radiotherapy for Malignant Head and Neck Tumors: A Randomized Controlled Trial

PURPOSE

Oral mucositis (OM) is a common debilitating toxicity associated with radiotherapy (RT) for malignant head and neck tumors. This prospective, randomized, double-blind, placebo-controlled trial aimed to evaluate the efficacy and safety of Streptococcus salivarius K12 (SsK12) in reducing the incidence, duration, and severity of severe OM (SOM).

METHODS

A total of 160 patients with malignant head and neck tumors undergoing definitive or postoperative adjuvant RT were randomly assigned (1:1) to receive SsK12 probiotic (n = 80) or placebo (n = 80) at West China Hospital, Sichuan University, Chengdu, China. Patients were instructed to suck SsK12 or placebo lozenges thrice daily from the initiation to the end of RT. OM was evaluated twice a week during RT and once a week thereafter for up to 8 weeks. The primary end point was the incidence of SOM. Adverse events were assessed according to the National Cancer Institute Common Terminology Criteria for Adverse Events, version 5.0.

RESULTS

Baseline patient characteristics were similar in the SsK12 and placebo groups. The incidence of SOM was significantly lower in the SsK12 group as compared with the placebo group (36.6% v 54.2%; P = .0351). The duration (median, 0.0 days v 7.0 days; mean, 8.9 days v 18.3 days; P = .0084) and time to develop SOM (median, not estimable v 42.0 days; hazard ratio, 0.55 [95% CI, 0.34 to 0.89]; log-rank test: P = .0123) were also improved in the case of the SsK12 group. Adverse events were similar between the groups, and mild or moderate gastrointestinal reactions (flatulence or dyspepsia) associated with the lozenges were observed in two patients in the SsK12 group. High-throughput sequencing results indicated that SsK12 inhibited opportunistic pathogens and enriched oral commensals during RT.

CONCLUSION

In this prospective, randomized clinical trial, SsK12 probiotic significantly reduced the incidence, onset, and duration of SOM with a good safety profile.

Mendelian randomization analysis reveals a causal effect of Streptococcus salivarius on diabetic retinopathy through regulating host fasting glucose

Diabetic retinopathy (DR) is one of leading causes of vision loss in adults with increasing prevalence worldwide. Increasing evidence has emphasized the importance of gut microbiome in the aetiology and development of DR. However, the causal relationship between gut microbes and DR remains largely unknown. To investigate the causal associations of DR with gut microbes and DR risk factors, we employed two-sample Mendelian Randomization (MR) analyses to estimate the causal effects of 207 gut microbes on DR outcomes. Inputs for MR included Genome-wide Association Study (GWAS) summary statistics of 207 taxa of gut microbes (the Dutch Microbiome Project) and 21 risk factors for DR. The GWAS summary statistics data of DR was from the FinnGen Research Project. Data analysis was performed in May 2023. We identified eight bacterial taxa that exhibited significant causal associations with DR (FDR < 0.05). Among them, genus Collinsella and species Collinsella aerofaciens were associated with increased risk of DR, while the species Bacteroides faecis, Burkholderiales bacterium_1_1_47, Ruminococcus torques, Streptococcus salivarius, genus Burkholderiales_noname and family Burkholderiales_noname showed protective effects against DR. Notably, we found that the causal effect of species Streptococcus salivarius on DR was mediated through the level of host fasting glucose, a well-established risk factor for DR. Our results reveal that specific gut microbes may be causally linked to DR via mediating host metabolic risk factors, highlighting potential novel therapeutic or preventive targets for DR.

Streptococcus salivarius subsp. thermophilus CCFM1312 enhanced mice resilience to activity-based anorexia

Probiotic intervention, already showing promise in the treatment of various psychiatric disorders like depression, emerges as a potential therapy for anorexia nervosa (AN) with minimal side effects. In this study, we established an activity-based anorexia (ABA) model to probe the pathogenesis of AN and assess the impact of probiotics on ABA mice. ABA resulted in a compensatory increase in duodenal ghrelin levels, impairing the regulation of feeding and the brain reward system. Intervention with Streptococcus salivarius subsp. thermophilus CCFM1312 ameliorated these ABA-induced effects, and the activation of neurons in the nucleus tractus solitarius (NTS) was observed following probiotic administration, revealing the advantageous role of probiotics in AN through the vagus nerve. Furthermore, our metabolomics analysis of cecal contents unveiled that S. salivarius subsp. thermophilus CCFM1312 modulated gut microbiota metabolism and thereby regulated intestinal ghrelin levels.

Noniatrogenic Meningitis Caused by Streptococcus salivarius Associated with Early Esophageal Cancer and Early Gastric Cancer

Streptococcus salivarius is part of the normal oral cavity and gastrointestinal tract microflora and an unusual cause of acute bacterial meningitis. We herein report an 81-year-old man with S. salivarius meningitis, which led to a diagnosis of early esophageal cancer and early gastric cancer. S. salivarius infection may occur through the gastrointestinal mucosa when it is disrupted in association with early gastrointestinal cancer. To our knowledge, this is the first report describing S. salivarius meningitis associated with multiple early gastrointestinal cancers in the absence of other sources of infection.

Streptococcus salivarius Probiotics to Prevent Acute Otitis Media in Children: A Randomized Clinical Trial

Importance

New approaches for the prevention of acute otitis media (AOM), the most common reason for antibiotic use in children, are needed.

Objective

To assess the efficacy of the Streptococcus salivarius K12 oral probiotics in the primary prevention of AOM.

Design, Setting, and Participants

This double-blind, randomized placebo-controlled clinical trial was conducted from August 1, 2020, to May 31, 2021, at 50 day care centers in the Oulu region of Finland. A total of 827 children aged 1 to 6 years attending day care were included. The exclusion criteria consisted of ongoing antimicrobial prophylaxis or immunodeficiency. The follow-up time was 6 months and was completed on May 31, 2021. Data were analyzed from October 24, 2022, to September 16, 2023, based on intention to treat.

Intervention

Eligible participants were randomly allocated to receive 1 daily dose of a S salivarius K12 product or placebo every evening for 6 months. A daily dose was defined as 1 sachet of soluble oral powder for children younger than 3 years or 1 chewable tablet for children 3 years or older containing 1 × 109 colony-forming units of S salivarius K12.

Main Outcomes and Measures

The primary outcome was the proportion of children with at least 1 episode of AOM requiring antimicrobial therapy within 6 months of randomization. All physician visits and purchases of antimicrobial drugs were retrieved from the electronic national medical record and prescription register. The primary outcome was met if the legal guardian had purchased an antimicrobial prescription for AOM.

Results

A total of 827 children with a mean (SD) age of 4.1 (1.6) years (433 boys [52.4%]) were randomized to S salivarius K12 oral products (n = 413) or placebo (n = 414). Thirty-four children (8.2%) in the S salivarius group and 24 children (5.8%) in the placebo group experienced at least 1 episode of AOM requiring antimicrobial therapy during the 6-month follow-up period (relative risk, 1.42 [95% CI, 0.86-2.34]; proportion difference, -2.44% [95% CI, -5.94% to 1.09%]; P = .17). Time to first AOM episode did not differ between the groups (174 [95% CI, 171-177] days in the S salivarius group vs 176 [95% CI, 173-179] days in the placebo group; P = .18).

Conclusions and Relevance

In this randomized placebo-controlled clinical trial, the daily use of the S salivarius K12 products for 6 months did not reduce the occurrence of AOM. New approaches for primary prevention of AOM among children are needed.

Trial Registration

ClinicalTrialsRegister.eu Identifier: 2020-001076-14.

Antimicrobial activity of probiotic Streptococcus salivarius LAB813 on in vitro cariogenic biofilms

OBJECTIVE

To investigate the antimicrobial activity of a novel commensal strain of Streptococcus salivarius, LAB813, against Streptococcus mutans biofilms.

METHODS

The inhibitory activity of LAB813 towards S. mutans was tested using mono-, dual-, and multi-species cariogenic biofilms formed on three types of orthodontic appliances (metal, ceramic, aligner). The activity of the commercially available probiotic, BLIS M18™ was used as control.

RESULTS

LAB813 significantly inhibited S. mutans biofilms with cell killing approximating 99% for all materials. LAB813 showed effectiveness at inhibiting S. mutans in more complex multi-species biofilms with cell killing approximating 90% for all three materials. When comparing the killing kinetics of the probiotics, LAB813 had a faster rate of killing biofilms than M18. Experiments conducted with cell-free culture supernatant confirmed the presence of an inhibitory substance of proteinaceous nature. The addition of xylitol, a common sugar substitute used for human consumption, potentiated the inhibitory effects of LAB813 against S. mutans embedded in a more complex fungal-bacterial biofilm.

CONCLUSIONS

LAB813 possesses strong antimicrobial activity, potent anti-biofilm properties, and enhanced antimicrobial activity in the presence of xylitol. The identification and characterization of strain LAB813 exhibiting antimicrobial activity towards S. mutans hold exciting promise for this novel strain to be developed as an oral probiotic for use in the prevention of dental caries.

Oral Probiotics, Streptococcus salivarius K12 and M18, Suppress the Release of Volatile Sulfur Compounds and a Virulent Protease from Oral Bacteria: An In-Vitro Study

PURPOSE

To evaluate the inhibitory effects of Streptococcus salivarius K12 and M18 strains on the growth of six oral pathogens as well as their release of volatile sulfur compounds (VSCs), and whether these probiotics can inhibit the expression of arginine-specific gingipain A (RgpA), a protease secreted by Porphyromonas gingivalis.

MATERIALS AND METHODS

After six halitogenic oral pathogens (P. gingivalis, Treponema denticola, Tannerella forsythia, Fusobacterium nucleatum, Parvimonas micra, and Eikenella corrodens) were cultured with or without S. salivarius K12 and M18, the concentration of two VSCs was measured. Moreover, the antimicrobial activity of S. salivarius K12 and M18 against these pathogens and the suppressive effect on RgpA release by P. gingivalis were assessed.

RESULTS

In the co-culture of S. salivarius K12 or M18 with oral pathogenic bacteria, the growth of all six oral pathogens was significantly inhibited (p < 0.01). Additionally, S. salivarius K12 and M18 had an inhibitory effect on the production of the halitogenic substances H2S and CH3SH (p < 0.01) as well as the expression of P. gingivalis RgpA. Finally, we demonstrated that the addition of only culture supernatants of the two strains K12/M18 to oral pathogen cultures was sufficient to mimic the effects of K12/M18 co-cultures upon VSCs production and protease expression.

CONCLUSIONS

S. salivarius K12 and M18 inhibited VSC release by all six of the major oral pathogens that were assayed and reduced the expression of RgpA.

Anti-Inflammatory Efficacy of Human-Derived Streptococcus salivarius on Periodontopathogen-Induced Inflammation

Streptococcus salivarius is a beneficial bacterium in oral cavity, and some strains of this bacterium are known to be probiotics. The purpose of this study was to investigate the anti-inflammatory effect and mechanism of S. salivarius G7 lipoteichoic acid (LTA) on lipopolysaccharide (LPS) and LTA of periodontopathogens. The surface molecules of S. salivarius G7 was extracted, and single- or co-treated on human monocytic cells with LPS and LTA of periodontopathogens. The induction of cytokine expression was evaluated by real-time PCR and ELISA. After labeling fluorescence on LPS and LTA of periodontopathogens, it was co-treated with S. salivarius LTA to the cell. The bound LPS and LTA were measured by a flow cytometer. Also, the biding assay of the LPS and LTA to CD14 and LPS binding protein (LBP) was performed. The surface molecules of S. salivarius G7 did not induce the expression of inflammatory cytokines, and S. salivarius G7 LTA inhibited the inflammatory cytokines induced by LPS and LTA of periodontopathogens. S. salivarius G7 LTA inhibited the binding of its LPS and LTA to cells. Also, S. salivarius G7 LTA blocked the binding of its LPS and LTA to CD14 and LBP. S. salivarius G7 has an inhibitory effect on inflammation induced by LPS or LTA of periodontopathogens, and may be a candidate probiotics for prevention of periodontitis.

Exacerbation of allergic rhinitis by the commensal bacterium Streptococcus salivarius

Allergic rhinitis (AR)-commonly called hay fever-is a widespread condition that affects the quality of life of millions of people. The pathophysiology of AR remains incompletely understood. In particular, it is unclear whether members of the colonizing nasal microbiota contribute to AR. Here, using 16S ribosomal RNA sequencing, we show that the nasal microbiome of patients with AR (n = 55) shows distinct differences compared with that from healthy individuals (n = 105), including decreased heterogeneity and the increased abundance of one species, Streptococcus salivarius. Using ex vivo and in vivo models of AR, we demonstrate that this commensal bacterium contributes to AR development, promoting inflammatory cytokine release and morphological changes in the nasal epithelium that are characteristic of AR. Our data indicate that this is due to the ability of S. salivarius to adhere to the nasal epithelium under AR conditions. Our study indicates the potential of targeted antibacterial approaches for AR therapy.

Use of Streptococcus salivarius K12 in supporting the mucosal immune function of active young subjects: A randomised double-blind study

Introduction

Upper respiratory tract infections (URTI) are the most common illnesses affecting athletes, causing absences from training and competition. Salivary immunoglobulin A (sIgA) is the main immune factor in saliva, and a consistent association between low concentrations of sIgA and an increased incidence of URTIs has been reported. The oral probiotic Streptococcus salivarius K12 has been suggested to have the potential to improve oral diseases and mucosal barrier function. However, the effects of this probiotic on active young subjects performing a high-intensity training (HIT) program have not been investigated.

Methods

Active young students were randomised into a treated group (S. salivarius K12) and a control (placebo) group and asked to take the product daily for 30 days. After this period, participants performed a graded exercise test and five HIT sessions, all within 3 days. They were also asked to complete the Wisconsin Upper Respiratory Symptom Survey daily to monitor URTI's presence. Before and after the 30 days, and at 0h, 24h and 72h after the last training session, saliva samples were collected to quantify sIgA level, secretion rate, and flow. The effect of S. salivarius K12 intake on these parameters was tested using an ANOVA for repeated measures.

Results

Twenty (M = 14, F = 6) young subjects (23.5 ± 2.3 years old) participated in the study. The total accumulated training load (sRPE) in the supplementation period was similar in the two groups (treated: 4345 ± 3441 AU; control: 4969 ± 4165 AU; p > 0.05). Considering both sIgA level and secretion rate, significant time (F_(4,15) = 3.38; p = 0.037; F_(4,15) = 6.00; p = 0.004) and time×group interactions (F_(4,15) = 2.49; p = 0.049; F_(4,15) = 5.01; p = 0.009) were reported, with the treated group showing higher sIgA levels at 72h post-exercise and increased secretion rate both at 0h and 72h. The number of URTI episodes was similar in the treated and control groups (χ² = 1.83; p > 0.05).

Conclusion

This study demonstrates that relatively short-term S. salivarius K12 supplementation increased sIgA level and secretion in healthy subjects performing a demanding exercise-training programme composed of HIT sessions.

Exploiting the Acidic Extracellular pH: Evaluation of Streptococcus salivarius M18 Postbiotics to Target Cancer Cells

Previously, we showed that the growth, antibiotic resistance, and biofilm formation properties of the pathogens Pseudomonas aeruginosa and Klebsiella pneumonia were tremendously inhibited by the cell-free supernatant of the oral probiotic Streptococcus salivarius M18. These anti-pathogenic activities of the supernatant were more efficient under acidic conditions. The present approach takes advantage of the acidic nature of the tumor microenvironment to evaluate the effect of the S. salivarius M18 postbiotics on colon cancer cells. In both two-dimensional (2D) and three-dimensional (3D) cell culture models, S. salivarius M18 cell-free supernatant showed anti-cancer actions in the pH conditions mimicking the acidity of the tumor. The inhibitory effect was more prominent when the colon cancer cells have been treated with the cell-free supernatant obtained from the inulin incubated S. salivarius M18. The results of this study point out the potential of the S. salivarius M18 functional probiotic products to be used for targeting low pH environments including the unique acidic microenvironment of tumors.

Synbiotic Musa acuminata skin extract and Streptococcus salivarius K12 inhibit candida species biofilm formation

This study aimed to determine the effect of synbiotic Musa acuminata skin extract (MASE) and Streptococcus salivarius K12 (K12) on Candida species biofilm formation. Liquid chromatography quadrupole time-of-flight (LC-Q-TOF-MS) was conducted to characterize MASE. To determine the effect of synbiotic on Candida biofilm, 200 µL of RPMI-1640 containing Candida, K12, and MASE were pipetted into the same well and incubated at 37 °C for 72 h. A similar protocol was repeated with K12 or MASE to determine the probiotic and prebiotic effects, respectively. Dimorphism, biofilm biomass, and Candida total cell count (TCC) were determined. A total of 60 compounds were detected in MASE. C. albicans (ALT5) and Candida lusitaniae exhibited the highest reduction in biofilm biomass when co-cultured with prebiotic (77.70 ± 7.67%) and synbiotic (97.73 ± 0.28%), respectively. All Candida spp. had decreased TCC and hyphae when co-cultured with synbiotic. In conclusion, MASE and K12 inhibit Candida biofilm formation.

Streptococcus salivarius K12 inhibits Candida albicans aggregation, biofilm formation and dimorphism

Candida albicans causes candidiasis, particularly in immunocompromised patients. Streptococcus salivarius K12 (K12) is a probiotic isolated from a healthy oral cavity. The study aimed to determine the effect of K12 on C. albicans aggregation, biofilm formation and dimorphism. C. albicans ATCC MYA-4901, acquired immunodeficiency syndrome (AIDS) isolate (ALC2), and oral cancer isolate (ALC3) and K12 were used in the study. All C. albicans strains and K12 were grown in yeast peptone dextrose agar and brain heart infusion agar, respectively, prior to aggregation, biofilm and dimorphism assays. Auto-aggregation of C. albicans MYA-4901 and ALC2 was categorised as high, while the co-aggregation of the strains was low in the presence of K12. C. albicans total cell count decreased significantly when co-cultured with K12 compared with monocultured C. albicans biofilm (p < 0.05). Inhibition of yeast-to-hyphae transition was also observed when co-cultured with K12. In conclusion, K12 inhibits C. albicans aggregation, biofilm formation and dimorphism.

Impact Of Feeding Practice On Diversity Pattern Of The Gut Microbiome In Infants

BACKGROUND

The microbiome which is developed at the time of infancy remains predominant and influences the health in childhood and then throughout life through moderating different gut metabolic activities This study was designed to look for the impact of feeding practices on the diversity of gut microbiota in infants in a Pakistani cohort.

METHODS

A cross sectional study was carried out in 46 healthy infants [23breast-fed (BF) and 23 formula-fed (FF)], aged 0-4 months, enrolled from different centers and localities in Peshawar. Infants were screened to exclude any pathological or physiological condition that can vary the gut microbial flora such as gut surgeries and the use of antibiotics. Their stool samples were collected. DNA was extracted and subjected to next generation sequencing.

RESULTS

The results revealed that phylum Firmicutes was dominant in formula-fed infants (FF=25.4±22.7, BF=4.58±5.21), p=0.001. Similarly, Bacilli, Streptococcaceae, and Streptococcus were significantly higher in formula-fed infants. On the other hand, Selenomonadales and Streptococcus_salivarius were significantly higher in breast-fed infants with a p-value of 0.037 and 0.029 respectively when compared with formula fed infants.

CONCLUSIONS

The primary colonizer of the infant's gut is phylum Firmicutes, followed by Bacilli, Streptococcaceae, and Streptococcus in formula-fed infants and Selenomonadales and Streptococcus_salivarius in breast-fed infants.

Does Streptococcus Salivarius Strain M18 Assumption Make Black Stains Disappear in Children?

PURPOSE

This randomised controlled study evaluated the effectiveness of an oral probiotic, Streptococcus salivarius M18 (SsM18), in children with black stains (BSs) in order to counteract their reformation.

MATERIALS AND METHODS

Fifty-eight children (aged 4-10 years) presenting with BSs were enrolled. They were randomly divided into two groups: group A (n = 29) included children who were given the test product containing SsM18 once a day for 3 months; group B (n = 29) included children who did not receive any treatment. Before beginning the study, all the children underwent professional removal of BSs. The assessment of BSs was done after 3 months (T1) and after 6 months (T2).

RESULTS

Four patients (1 belonging to group A and 3 to group B) were excluded from the study because they started antibiotic therapy. After 3 months (T1), BSs were detected in 6 of the 28 children (21.2%) from group A and in 13 out of the 26 (50%) children from group B (p < 0.05). After 6 months (T2), BSs were detected in 9 out of the 28 (32.1%) children from group A and in 14 of the 26 (53.8%) children from group B (p > 0.05).

CONCLUSIONS

BSs formation in children could be prevented by administering S. salivarius M18.

Impact of Chlorhexidine Pretreatment Followed by Probiotic Streptococcus salivarius Strain K12 on Halitosis in Children: A Randomised Controlled Clinical Trial

PURPOSE

The aim of this study was to examine the effect of chlorhexidine disinfection, as a chemical method of oral hygiene practice, and subsequent use of probiotics on halitosis in children. The effects of mechanical and chemical oral hygiene practice methods on the severity of halitosis were also assessed.

MATERIALS AND METHODS

208 children with organoleptic test (OLT) scores of 2 or more were randomly assigned to four groups: A: conventional oral hygiene practices (COH) including toothbrushing and flossing; B: COH + tongue scraping (TS); C: COH + TS + chlorhexidine; D: COH + TS + chlorhexidine + probiotics. OLT was performed at 1-week and 3-month follow-ups.

RESULTS

A significant and stable number of participants showed major and moderate levels of improvement in OLT scores in group D (p < 0.001). The improvement of OLT scores in group C was also significant (p < 0.001), but not stable over the follow-ups (p = 0.44). Neither significant nor stable improvements in the OLT scores were detected in groups A and B through follow-ups (p > 0.05).

CONCLUSION

Probiotic therapy following oral disinfection with chlorhexidine may reduce the severity of halitosis over longer periods.

Effect of administration of Streptococcus salivarius K12 on the occurrence of streptococcal pharyngo-tonsillitis, scarlet fever and acute otitis media in 3 years old children

OBJECTIVE

Streptococcus salivarius K12 (BLIS K12) is a probiotic strain strongly antagonistic to the growth of Streptococcus pyogenes, the most important bacterial cause of pharyngeal infections in humans. Shown to colonize the oral cavity and to be safe for human use, BLIS K12 has previously been reported to reduce pharyngo-tonsillitis episodes in children or adults known to have experienced recurrent streptococcal infection. The present study was focussed upon evaluating the role of BLIS K12 in the control of streptococcal disease and acute otitis media in children attending the first year of kindergarten.

PATIENTS AND METHODS

By randomization, 222 enrolled children attending the first year of kindergarten were divided into a treated group (N = 111) receiving for 6 months a daily treatment with BLIS K12 (Bactoblis®) and a control group (N = 111) who were monitored as untreated controls. During the 6 months of treatment and 3 months of follow-up, the children were evaluated for treatment tolerance, and for episodes of streptococcal pharyngo-tonsillitis, scarlet fever and acute otitis media.

RESULTS

During the 6-month trial (N = 111 per group) the incidence of streptococcal pharyngo-tonsillitis, scarlet fever and acute otitis media was approximately 16%, 9% and 44% respectively in the treated group and 48%, 4% and 80% in the control group. During the 3-months follow-up (N = 29 per group) the corresponding rates of infection were 15%, 0% and 12% in the treated group and 26%, 6% and 36% in the controls. No apparent side effects were detected in the treated group either during treatment or follow-up. All of the enrolled children completed the study.

CONCLUSIONS

The daily administration of BLIS K12 to children attending their first year of kindergarten was associated with a significant reduction in episodes of streptococcal pharyngitis and acute otitis media. No protection against scarlet fever was detected.