Presence of Lactobacillus reuteri in saliva coincide with higher salivary IgA in young adults after intake of probiotic lozenges

Lactobacilli and Klebsiella: Two Opposites in the Fight for Human Health

The problem of antibiotic resistance is currently very acute. Numerous research and development of new antibacterial drugs are being carried out that could help cope with various infectious agents. One of the promising directions for the search for new antibacterial drugs is the search among the probiotic strains present in the human gastrointestinal tract. This review is devoted to characteristics of one of these probiotic strains that have been studied to date: Limosilactobacillus reuteri. The review discusses its properties, synthesis of various compounds, as well as role of this strain in modulating various systems of the human body. The review also examines key characteristics of one of the most harmful among the currently known pathogenic organisms, Klebsiella, which is significantly resistant to antibiotics existing in medical practice, and also poses a great threat of nosocomial infections. Discussion of characteristics of the two strains, which have opposite effects on human health, may help in creation of new effective antibacterial drugs without significant side effects.

Application of Lactobaillus salivarius WB21 to the Oral Care of Healthy Older Adults: A Randomized, Double-Blind, Placebo-Controlled Crossover Comparative Study

Objective: A randomized, double-blind, placebo-controlled crossover comparative study was conducted in a healthy older population to assess the usefulness of Lactobacillus salivarius WB21 (WB21) ingestion for oral self-care. Methods: The study population included 33 healthy older individuals who were randomly divided into two groups (A and B). Group A consumed WB21 tablets during the first two months and placebo tablets during the following two months. Group B consumed placebo tablets during the first two months and WB21 tablets during the following two months. Before and after ingestion, oral examination, mouth odor test, and saliva collection were performed a total of four times. In addition, health conditions were obtained from a questionnaire survey at the study’s midpoint. Results: Two people in group A and one person in group B dropped out of the study. Thus, 15 people in group A and 15 people in group B were included in the analysis. Over two months of WB21 ingestion, salivary secretory IgA increased significantly (p = 0.047) and tongue coating score decreased significantly (p = 0.013). The plaque index, bleeding on probing, and mouth odor levels (H₂S and CH₃SH concentrations) did not change. During the 6-month study period, no caries, deterioration of periodontitis, or changes in oral health or systemic subjective symptoms were observed. Conclusion: Continuous ingestion of WB21-containing tablets may promote self-care of the teeth and mouths of healthy older adults. Trial registration: R000028335 (UMIN-CTR).

Clinical efficacy and safety of NSCLC ancillary treatment with compound Kushen injection through immunocompetence regulation: A systematic review and meta-analysis

BACKGROUND

Compound Kushen injection (CKI) is a Chinese patented medicine that improves the immunity level of cancer patients and inhibits tumor cell proliferation and metastasis. Clinically, CKI is widely used in combination with platinum-based chemotherapy (PBC) for non-small cell lung cancer (NSCLC) treatment. This study attempted to systemically evaluate the efficacy and safety of a combination of CKI and PBC for NSCLC treatment by modulating the immune function.

PURPOSE

To evaluate the clinical efficacy and safety of CKI in combination with PBC for NSCLC.

MATERIALS AND METHODS

English and Chinese databases were retrieved for randomized controlled trials (RCTs) of NSCLC treatment using a combination of CKI and PBC, and the changes of peripheral blood T lymphocytes (such as CD3⁺ T cells, CD4⁺ T cells, CD8⁺ T cells), and CD4⁺/CD8⁺ T cell ratio among NSCLC patients were detected before and after treatment using CKI with PBC. The search deadline was set as November 2021. The systemic evaluation was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The methodology and quality of each study included in the systemic evaluation were assessed. Review Manager 5.4, Stata12.0, and trial sequential analysis (TSA) were used for data analysis. The outcome indicators were qualified using GRADEprofiler software.

RESULTS

A total of 25 RCTs involving 2460 cases of patients were included. The results showed that the combination of CKI with PBC effectively increased the objective response rate (ORR) [relative risk (RR) = 1.31, 95% confidence interval (CI) (1.19, 1.44)] and disease control rate (DCR) [RR = 1.16, 95%CI (1.09,1.23)], regulated the expression of peripheral blood T lymphocytes (such as CD3⁺T cells, CD4⁺T cells, CD8⁺T cells, and CD4⁺/CD8⁺T cell ratio), upregulated the level of serum immunoglobulins (such as IgA, IgG, and IgM), and reduced the frequency of gastrointestinal reaction, marrow inhibition, hepatorenal toxicity, reduction of white blood cells and blood platelets, baldness, infection, neutrophilic granulocyte counts, diarrhea, or constipation. According to subgroup analysis results, chemotherapy cycles (1-2) had a more significant effect on DCR. A combination of CKI and GP regimens had better effects on improving CD3⁺T cell levels, and there were no significant changes among other chemotherapies regiments.

CONCLUSION

A combination of CKI and PBC had a marked effect in improving tumor response, priming immune function, and decreasing the frequency of adverse reactions, which was safe for NSCLC treatment.

The Effect of Oral Probiotics (Streptococcus Salivarius k12) on the Salivary Level of Secretory Immunoglobulin A, Salivation Rate, and Oral Biofilm: A Pilot Randomized Clinical Trial

We aimed to assess the effect of oral probiotics containing the Streptococcus salivarius K12 strain on the salivary level of secretory immunoglobulin A, salivation rate, and oral biofilm. Thirty-one consenting patients meeting the inclusion criteria were recruited in this double-blind, placebo-controlled, two-arm, parallel-group study and randomly divided into probiotic (n = 15) and placebo (n = 16) groups. Unstimulated salivation rate, concentration of salivary secretory immunoglobulin A, Turesky index, and Papillary-Marginal-Attached index were assessed after 4 weeks of intervention and 2 weeks of washout. Thirty patients completed the entire study protocol. We found no increase in salivary secretory immunoglobulin A levels and salivary flow rates in the probiotic group compared with placebo. Baseline and outcome salivary secretory immunoglobulin A concentrations (mg/L) were 226 ± 130 and 200 ± 113 for the probiotic group and 205 ± 92 and 191 ± 97 for the placebo group, respectively. A significant decrease in plaque accumulation was observed in the probiotic group at 4 and 6 weeks. Within the limitations of the present study, it may be concluded that probiotic intake (Streptococcus salivarius K12) does not affect salivation rates and secretory immunoglobulin A salivary levels but exhibits a positive effect on plaque accumulation. Trial registration NCT05039320. Funding: none.

Effect of postbiotic-toothpaste on salivary levels of IgA in 6- to 12-year-old children: Study protocol for a randomized triple-blind placebo-controlled trial

BACKGROUND

Children in mixed dentition are highly at risk for dental caries, which is a major health issue worldwide. Despite their effect in controlling dental caries, using probiotics can be challenging. Therefore, it has been advised to use their inanimate forms, called postbiotics. We hypothesize that postbiotics can enhance the oral immunity.

METHODS

The aim of this triple-blind, randomized, placebo-controlled trial is to investigate the effect of postbiotic-toothpaste (Bifidobacterium animalis subsp. animalis) on salivary levels of Immunoglobulin A (IgA) and pH in children. Using comparing two means formula to calculate the sample size, for this trial 80 healthy 6- to 12-year-old children during mixed dentition with no cavitated dental caries will be selected by convenience sampling method and randomly allocated to two groups, postbiotic-toothpaste or placebo-toothpaste. Saliva samples will be gathered at baseline and four weeks after the intervention. The level of salivary IgA will be determined by ELISA and salivary pH will be measured using a pH meter. Data will be compared within and between groups using independent t-test and paired t-test, in case of normality, with a p < 0.05 as statistically significant.

DISCUSSION

If postbiotics-toothpaste prove to be effective in improving the oral immunity, they can be used to prevent dental caries and other oral diseases. The result of this study can help researchers who are working on the immunomodulatory effects of postbiotics in children.

TRIAL REGISTRATION NUMBER

Iranian Registry of Clinical Trials (IRCT), IRCT20191016045128N2. Registered on 7 March 2022.

Viable and Heat-Killed Probiotic Strains Improve Oral Immunity by Elevating the IgA Concentration in the Oral Mucosa

Oral-nasal mucosal immunity plays a crucial role in protecting the body against bacterial and viral invasion. Safe probiotic products have been used to enhance human immunity and oral health. In this study, we verified the beneficial effects of mixed viable probiotic tablets, consisting of Lactobacillus salivarius subsp. salicinius AP-32, Bifidobacterium animalis subsp. lactis CP-9, and Lactobacillus paracasei ET-66, and heat-killed probiotic tablets, consisting of L. salivarius subsp. salicinius AP-32 and L. paracasei ET-66, on oral immunity among 45 healthy participants. Participants were randomly divided into viable probiotic, heat-killed probiotic, and placebo groups. The administration of treatment lasted for 4 weeks. Saliva samples were collected at Weeks 0, 2, 4, and 6, and Lactobacillus, Bifidobacterium and Streptococcus mutans populations and IgA concentration were measured. IgA concentrations, levels of TGF-beta and IL-10 in PBMCs cells were quantified by ELISA method. Results showed that salivary IgA levels were significantly increased on administration of both the viable (119.30 ± 12.63%, ***P < 0.001) and heat-killed (116.78 ± 12.28%, ***P < 0.001) probiotics for 4 weeks. Among three probiotic strains, AP-32 would effectively increase the levels of TGF-beta and IL-10 in PBMCs. The oral pathogen Streptococcus mutans was significantly reduced on viable probiotic tablet administration (49.60 ± 31.01%, ***P < 0.001). The in vitro antibacterial test confirmed that viable probiotics effectively limited the survival rate of oral pathogens. Thus, this clinical pilot study demonstrated that oral probiotic tablets both in viable form or heat-killed form could exert beneficial effects on oral immunity via IL-10, TGB-beta mediated IgA secretion. The effective dosage of viable probiotic content in the oral tablet was 10⁹ CFUs/g and the heat-killed oral tablet was 1 × 10¹⁰ cells/g.

Pre and Probiotics Involved in the Modulation of Oral Bacterial Species: New Therapeutic Leads in Mental Disorders?

This systematic review aims to identify probiotics and prebiotics for modulating oral bacterial species associated with mental disorders. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guideline, we search the electronic MEDLINE database published till January 2021 to identify the studies on probiotics and/or prebiotics for preventing and treating major oral dysbiosis that provokes mental disorders. The outcome of the search produces 374 records. After excluding non-relevant studies, 38 papers were included in the present review. While many studies suggest the potential effects of the oral microbiota on the biochemical signalling events between the oral microbiota and central nervous system, our review highlights the limited development concerning the use of prebiotics and/or probiotics in modulating oral dysbiosis potentially involved in the development of mental disorders. However, the collected studies confirm prebiotics and/or probiotics interest for a global or targeted modulation of the oral microbiome in preventing or treating mental disorders. These outcomes also offer exciting prospects for improving the oral health of people with mental disorders in the future.

Effect of probiotics on gingival inflammation and oral microbiota: A meta-analysis

To evaluate the effect of probiotics on gingival inflammation and oral microbiota in patients suffering from plaque-induced gingivitis. PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), and EMBASE were electronically searched until December 2020. The quality of included studies was assessed with the Cochrane Collaboration's Risk of Bias tool. The differences were expressed as weighted mean differences (WMD) and 95% of confidence interval (95% CI). I² test was performed to evaluate the heterogeneity of the studies. All analyses were performed using Review Manager (version 5.3). Eleven randomized and controlled trials were included, enrolling 554 patients. All comparisons displayed that oral probiotics had no significant improvement in the Gingival Index (GI), Plaque Index (PI), and bleeding on probing (BOP) of patients with plaque-induced gingivitis. In terms of microecology, no significant difference in the volumes of gingival crevicular fluid (GCF), the concentration of IL-1β, and the counts of Aggregatibacter actinomycetemcomitans (Aa), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), and Fusobacterium nucleatum (Fn) were found between the probiotic group and the placebo group. There exists no clear evidence that oral probiotics have positive effect on gingival inflammation and oral microecological environment of patients with plaque-induced gingivitis.

The efficacy of probiotics in management of recurrent aphthous stomatitis: a systematic review and meta-analysis

There is currently a lack of effective drugs to cure recurrent aphthous stomatitis. This study aimed to evaluate the efficacy of probiotics alone or as an adjunct in recurrent aphthous stomatitis (RAS) patients. Seven randomized controlled trials (RCTs) were included, of which three were included in quantitative analysis. Of five studies evaluating the efficacy of probiotics alone compared with placebo or Oracure gel, two reported no significant difference in relieving oral pain, while probiotics exhibited a higher capacity for decreasing oral pain in the other three. A significant decrease in ulcer severity was found in one, while no significant difference was found in the other four. The remaining two studies demonstrated that probiotics, as an adjunct to steroids or anaesthetic antiseptic gel, significantly reduced the ulcer severity and oral pain. The meta-analysis showed a significant decrease in oral pain (- 1.72, P = 0.0001) with probiotics compared with placebo. In conclusion, probiotics alone were capable of relieving oral pain but not effective in reducing ulcer severity. A combination of probiotics and steroids or anaesthetic antiseptic gel was more effective than steroids or anaesthetic antiseptic gel alone in RAS patients. Probiotics are promising for the treatment of recurrent aphthous stomatitis.

Evaluation of the effect of probiotic lozenges in the treatment of recurrent aphthous stomatitis: a randomized, controlled clinical trial

OBJECTIVES

The study aimed to explore the effectiveness of probiotics in the treatment of minor recurrent aphthous stomatitis (RAS).

MATERIALS AND METHODS

We performed a randomized, controlled clinical study. Sixty adult (group A) and 60 children patients (group B) with diagnosis of minor RAS were included. Both groups were divided into two subgroups; AI and BI (test subgroups) and AII and BII (control subgroups). For test subgroups, probiotic lozenges were consecutively administered twice daily, for 5 days. The size and pain level of ulcers were recorded on treatment days 0, 3, and 5. The outbreak frequency of RAS within 6 months was investigated for all subgroups.

RESULTS

Compared with baseline, an improvement was evident for all subgroups. However, for effectiveness in pain reduction, a statistically significant difference in favor of AI was observed for all evaluation periods when compared with control subgroup. Regarding effectiveness in ulcer size reduction, a statistically significant difference in favor of BI was observed at day 5 when compared with control subgroup. No significant difference was observed in the effectiveness index between subgroups AI and BI (test subgroups) except in effectiveness in pain reduction at day 3. The outbreak frequency decreased significantly in subgroup BI.

CONCLUSIONS

Topical application of probiotics decreased pain intensity and accelerates RAS healing. The effectiveness in pain reduction is more evident in adult patients while acceleration of healing is more evident in children.

CLINICAL RELEVANCE

Probiotics could be a well-tolerated, topical therapeutic agent in the treatment of minor RAS.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT04383236.

Effects of probiotics on salivary cytokines and immunoglobulines: a systematic review and meta-analysis on clinical trials

Findings on the effects of probiotics on salivary cytokines and immunoglobulines have been conflicting. We aimed to perform a systematic review and meta-analysis on clinical trials that examined the effects of oral intake and local administration of probiotics on salivary cytokines and immunoglobulines in adults. We searched PubMed, MEDLINE, SCOPUS, EMBASE, and Google Scholar up to April 2020 for all relevant published papers assessing probiotic intakes and salivary cytokines and immunoglobulines. We included all randomized clinical trials that investigated the effect of oral probiotic supplementation or lozenges tablets on inflammatory biomarkers in adults. Studies that reported their effect sizes as mean ± SD or mean ± SEM were included. After excluding non-relevant papers, 8 studies remained in this review. Combining findings from 3 studies with 4 effect sizes, we found no significant reduction in salivary IgA concentrations after oral probiotic supplementation [weighted mean difference (WMD): -0.26; 95% CI: (-0.86, 0.35)]. A significant increase in salivary IL-1β concentrations reached after local probiotic supplementation (WMD: 28.21; 95% CI: 18.42, 38.01); however, no significant changes in salivary IL-6 concentrations after local probiotic supplementation was found (WMD: 0.36; 95% CI: -0.85, 1.56). We observed a significant increase in salivary IL-8 concentrations after local probiotic supplementation (WMD: 31.82; 95% CI: 27.56, 36.08). In case of salivary IL-10 concentrations after local probiotic administration, no significant reduction was seen (WMD: -0.02; 95% CI: -0.10, 0.06). we found that oral and local administrations of probiotics might influence some of salivary cytokines. However, additional clinical trials are required to examine these effects on further pro- and anti-inflammatory cytokines and immunoglobulines.

In Vitro Study of Immune Properties of New Lactobacilli Isolates from Pheasant Gut

The goal of this paper was to study the effect of Lactobacillus reuteri B1/1, B2/1 and B6/1 on the relative expression of selected interleukins (IL-1β, IL-15), macrophage inflammatory protein (MIP-1β), and the relative percentage of T lymphocyte subpopulations in peripheral mononuclear blood cells (PMBCs). The mRNA expression levels of interleukins and MIP-1β of PMBCs were evaluated at 24 h and 48 h post inoculation using the quantitative real-time polymerase chain reaction (qRT-PCR). The percentage of T lymphocyte subpopulations in PMBCs was determined by flow cytometry. The group that was administered L. reuteri B1/1 had the most significant stimulation of the expression of pro-inflammatory interleukins and MIP-1β, in particular after 24 h. Similarly, we observed a rise in the relative percentage of T cells including CD3+, CD4+ and CD8+ lymphocytes in the groups with L. reuteri B1/1 and L. reuteri B2/1. Overall, L. reuteri B1/1 and L. reuteri B2/1 showed a promising stimulatory effect on the relative expression of pro-inflammatory interleukins, MIP-1β and percentage of T cell subpopulations in vitro. On the flip side, L. reuteri B6/1 did not induce the expression of the IL-1β gene.

Oral microbiota and Alzheimer's disease: Do all roads lead to Rome?

Alzheimer's disease (AD) is a progressive neurodegenerative pathology affecting milions of people worldwide associated with deposition of senile plaques. While the genetic and environmental risk factors associated with the onset and consolidation of late onset AD are heterogeneous and sporadic, growing evidence also suggests a potential link between some infectious diseases caused by oral microbiota and AD. Oral microbiota dysbiosis is purported to contribute either directly to amyloid protein production, or indirectly to neuroinflammation, occurring as a consequence of bacterial invasion. Over the last decade, the development of Human Oral Microbiome database (HOMD) has deepened our understanding of oral microbes and their different roles during the human lifetime. Oral pathogens mostly cause caries, periodontal disease, and edentulism in aged population, and, in particular, alterations of the oral microbiota causing chronic periodontal disease have been associated with the risk of AD. Here we describe how different alterations of the oral microbiota may be linked to AD, highlighting the importance of a good oral hygiene for the prevention of oral microbiota dysbiosis.

The inhibitory effect of quaternary ammonium salt on bacteria in root canal

Persisting apical periodontitis is a primary reason for multiple intervention in root canal. Persisting bacteria in root canal is related with the persisting infection. Despite the advancement in treatment strategies the persisting infection is a major challenge for endodontist. Here we tested two newly developed quaternary ammonium methacrylates (QAMs) against endodontic bacteria and their biofilms. Their antibacterial and antibiofilm efficiency were compared with chlorhexidine (CHX) and sodium hypochlorite (NaOCl). We measured the MIC, MBC and MBIC of DMADDM and DMAHDM respectively. We also detected the ratio of live/dead bacteria and bacterial composition in the biofilms treated by DMADDM and DMAHDM. We found that DMADDM and DMAHDM could inhibit the growth of bacteria and biofilms formation. The result showed that novel QAMs were remarkably efficient than CHX against biofilms. In addition, we found that Streptococcus gordonii (S. gordonii) and Enterococcus faecalis (E. faecalis) were frequent isolates after treatment with antimicrobial compounds.

A novel role of probiotics in improving host defence of elite rugby union athlete: A double blind randomised controlled trial

OBJECTIVE

To examine the effects of a probiotic protocol on the incidence and severity of respiratory and gastrointestinal infections in elite rugby union athletes across an international competition season. Associations were also investigated between salivary biomarkers of stress (cortisol, alpha-amylase) and mucosal immunity (secretory(s)-IgA).

DESIGN

A double-blind RCT was conducted over 27-weeks, divided into three stages: (1) control period; (2) domestic competition; and (3) international competition.

METHODS

Athletes were assigned a probiotic (n = 9) or placebo (n = 10) supplement. Ultrabiotic 60™ or placebo was taken with food twice daily for 17 weeks and SB Floractiv™ 250 mg added twice daily during stage three.

RESULTS

Five infections were diagnosed by the team sports physician across the 27-weeks, three within the intervention period in athletes randomised to the placebo group. No significant group x time interaction effects for salivary cortisol, alpha-amylase or s-IgA were identified over the 27-week time period, although a significant main effect for group and time was identified for salivary cortisol, alpha-amylase, and s-IgA (p < 0.05 for all). When considering stage, significant differences were identified in stage one with s-IgA lower in the probiotic group (p = 0.015). In stage two and three, salivary cortisol was higher in the probiotic group (p = 0.016 and p = 0.001 respectively), and salivary alpha-amylase was higher in the probiotic group in stage three (p = 0.007).

CONCLUSION

The probiotic protocol used in this study was associated with an increase in salivary alpha-amylase supporting its possible role as a host defence peptide.

Serum and Salivary IgA, IgG, and IgM Levels in Oral Lichen Planus: A Systematic Review and Meta-Analysis of Case-Control Studies

Immunoglobulins (IgA, IgG, and IgM) are significant anti-inflammatory factors. The meta-analysis aimed to assess the serum and salivary levels of Igs as more important immunoglobulins in patients affected by oral lichen planus (OLP) compared to the healthy controls. Four databases, including PubMed/Medline, Scopus, Web of Science, and Cochrane Library as well as Iranian databases were checked up to January 2018 without language restriction. The quality of each involved study was done using the Newcastle⁻Ottawa Quality Assessment Scale (NOS) questionnaire. A random-effects model analysis was done by RevMan 5.3 software applying the mean difference (MD) plus 95% confidence intervals (CIs). The CMA 2.0 software was applied to calculate the publication bias among the studies. Out of 70 studies found in the databases, 8 studies were involved and analyzed in the meta-analysis. The meta-analysis included 282 OLP patients and 221 healthy controls. The pooled MDs of serum levels of IgA, IgG, and IgM were -0.13 g/L [95% CI: -0.24, -0.02; P = 0.02], 1.01 g/L [95% CI: -0.91, 2.93; P = 0.30], and -0.06 g/L [95% CI: -0.25, 0.14; P = 0.56], respectively; whereas, the salivary IgA and IgG levels were 71.54 mg/L [95% CI: 12.01, 131.07; P = 0.02] and 0.59 mg/L [95% CI: -0.20, 1.38; P = 0.14], respectively. Considering the few studies performed on saliva, the results suggested that the salivary levels, especially IgA level had higher values than the serum levels. Therefore, the salivary immunoglobulins can play a significant function in the OLP pathogenesis.

Role of Lactobacillus reuteri in Human Health and Diseases

Lactobacillus reuteri (L. reuteri) is a well-studied probiotic bacterium that can colonize a large number of mammals. In humans, L. reuteri is found in different body sites, including the gastrointestinal tract, urinary tract, skin, and breast milk. The abundance of L. reuteri varies among different individuals. Several beneficial effects of L. reuteri have been noted. First, L. reuteri can produce antimicrobial molecules, such as organic acids, ethanol, and reuterin. Due to its antimicrobial activity, L. reuteri is able to inhibit the colonization of pathogenic microbes and remodel the commensal microbiota composition in the host. Second, L. reuteri can benefit the host immune system. For instance, some L. reuteri strains can reduce the production of pro-inflammatory cytokines while promoting regulatory T cell development and function. Third, bearing the ability to strengthen the intestinal barrier, the colonization of L. reuteri may decrease the microbial translocation from the gut lumen to the tissues. Microbial translocation across the intestinal epithelium has been hypothesized as an initiator of inflammation. Therefore, inflammatory diseases, including those located in the gut as well as in remote tissues, may be ameliorated by increasing the colonization of L. reuteri. Notably, the decrease in the abundance of L. reuteri in humans in the past decades is correlated with an increase in the incidences of inflammatory diseases over the same period of time. Direct supplementation or prebiotic modulation of L. reuteri may be an attractive preventive and/or therapeutic avenue against inflammatory diseases.