Effects of Streptococcus salivarius K12 with nystatin on oral candidiasis-RCT

Antifungal mechanism and application to phytopathogenic fungi after anaerobic fermentation of Gracilaria agar wastewater

Agar production is accompanied by a large amount of wastewater, which threatens the ecological environment and wastes biomass resources. The high-value utilization of biomass resources in wastewater is one of the key factors in wastewater treatment. We investigated the conversion process and antifungal mechanism of large molecule polysaccharides in wastewater into small molecule substances with antifungal activity through anaerobic fermentation. The results indicated that anaerobic fermentation of GAW achieved inhibition rates of 91.06 % and 88.94 % against Alternaria alternata and Alternaria spp. 16S rDNA sequencing and metabolomics revealed that dominant species such as Blautia, Agathobacter and Sphingomonas converted polysaccharide into phenolic acids like procyanidin C and columbidin. These substances disrupted the integrity of fungal cells, leading to their death. The preparation of composite antifungal agents using fermentation products effectively inhibited cherry tomato spoilage and toxin production. This study provided reliable technical support for the reuse of seaweed waste resources.

Prognostic factors of fungal infection in anti-melanoma differentiation-associated gene 5 antibody-positive associated interstitial lung disease

OBJECTIVE

To investigate the potential risk factors for mortality in fungal infection in anti-melanoma differentiation-associated gene 5 antibody-positive associated interstitial lung disease (MDA5-ILD).

METHODS

Patients diagnosed with MDA5-ILD from April 2017 to November 2022 were included. The demographic data, laboratory examinations, therapeutic and follow-up information were recorded. Fungal infection diagnosis was established based on a combinations of host factors, clinical features and mycologic evidences. High-dose corticosteroid therapy was defined as the initial corticosteroid doses > 240mg/d. The primary endpoint was mortality. Potential factors for fungal infection occurrence and prognostic factors were analyzed using logistic regression analysis and Cox proportional hazards regression.

RESULTS

In total, 121 patients with MDA5-ILD were included. During follow-up, 41 (33.9%) patients had suffered fungal infection and 39.0% (16/41) of whom had ever received high-dose corticosteroid therapy. The median interval from corticosteroid use to the occurrence of fungal infection was 29 (10-48) days. The mean survival time of patients with fungal infection was 234.32 ± 464.76 days. The mortality in MDA5-ILD with fungal infection was 85.4% (35/41), which was significantly higher than those without (85.4% VS 56.3%, P < 0.001). High-dose corticosteroid therapy (P = 0.049) was independent risk factor for fungal infection occurrence. Decreased serum albumin level (P = 0.024) and high-dose corticosteroid therapy (P = 0.008) were both associated with increased mortality in MDA5-ILD patients with fungal infection.

CONCLUSION

Fungal infection is associated with an increased mortality in MDA5-ILD. The serum albumin level and corticosteroid dose should be taken into consideration when treating MDA5-ILD. Key Points • This study showed fungal infection is associated with an increased mortality in MDA5-ILD. In MDA5-ILD patients with fungal infection, the presence of decreased serum albumin level and high-dose corticosteroid therapy were identified as predictors for mortality.

Antigingivitis and Antiplaque Effects of Oral Probiotic Containing the Streptococcus salivarius M18 Strain: A Randomized Clinical Trial

We aimed to assess the effect of oral probiotic containing the Streptococcus salivarius M18 strain on gingival inflammation, bleeding on probing, and oral biofilm. Sixty-one consenting participants aged between 18 and 25 with gingivitis were recruited in this double-blind, parallel-group study and randomly divided into the probiotic group (n = 31) and the placebo group (n = 30). Fifty-seven participants completed the entire study protocol, 27 in the probiotic group and 30 in the placebo group. The outcomes were assessed after 4 weeks of intervention and 4 weeks of follow-up. There was a significant decrease in the Gingival Index, with the effect size of 0.58 [95%CI 0.05-1.10], and Turesky modification of the Quigley and Hein Plaque Index, with the effect size of 0.55 [95%CI: 0.02-1.07], in the probiotic group after the intervention. However, after a 4-week follow-up, the only significant treatment outcome was improved gingival condition according to the Gingival Index. The Gingival Bleeding Index also decreased significantly in the probiotic group after the intervention period; after the follow-up, this parameter did not differ significantly in both groups from the baseline values. In the placebo group, there were no significant improvements in the assessed parameters throughout this study. No serious side effects were registered. Within the limitations of this study, we conclude that the use of oral probiotic containing the Streptococcus salivarius M18 strain resulted in a significant improvement in gingival condition and oral hygiene level in young adults with gingivitis. Trial registration NCT05727436. Funding: none.

Antimicrobial and Antibiofilm Activity of the Probiotic Strain Streptococcus salivarius K12 against Oral Potential Pathogens

Oral probiotics are increasingly used in the harmonization of the oral microbiota in the prevention or therapy of various oral diseases. Investigation of the antimicrobial activity of the bacteriocinogenic strain Streptococcus salivarius K12 against oral pathogens shows promising results, not only in suppressing growth, but also in eliminating biofilm formation. Based on these findings, we decided to investigate the antimicrobial and antibiofilm activity of the neutralized cell-free supernatant (nCFS) of S. salivarius K12 at various concentrations against selected potential oral pathogens under in vitro conditions on polystyrene microtiter plates. The nCFS of S. salivarius K12 significantly reduced growth (p < 0.01) in Streptococcus mutans Clarke with increasing concentration from 15 to 60 mg/mL and also in Staphylococcus hominis 41/6 at a concentration of 60 mg/mL (p < 0.001). Biofilm formation significantly decreased (p < 0.001) in Schaalia odontolytica P10 at nCFS concentrations of 60 and 30 mg/mL. Biofilm inhibition (p < 0.001) was also observed in Enterobacter cloacae 4/2 at a concentration of 60 mg/mL. In Schaalia odontolytica P10 and Enterobacter cloacae 4/2, the nCFS had no effect on their growth.

Immunomodulatory mechanism of Bacillus subtilis R0179 in RAW 264.7 cells against Candida albicans challenge

This study was aimed to explore the immunomodulatory and anti-Candida mechanisms of Bacillus subtilis (B. subtilis) R0179 in macrophages. RAW 264.7 cells were first challenged with B. subtilis R0179. B. subtilis R0179 was found to down-regulate the signals of Dectin-1, Card9, P-Iκ-Bα, Iκ-Bα, and NF-κB. Meanwhile, it reduced the levels of cytokines interleukin (IL)-1β, IL-6, IL-12, and tumor necrosis factor (TNF)-α, but increased the level of cytokine IL-10. Then RAW 264.7 cells were pretreated with B. subtilis R0179 before challenged with Candida albicans (C. albicans) or RAW 264.7 cells were co-treated with B. subtilis R0179 and C. albicans. In the presence of C. albicans, B. subtilis R0179 also showed the similar immunomodulatory effects on RAW 264.7 cells. Hence, this study provides the first insight into the immunomodulatory mechanisms of B. subtilis R0179 on the Dectin-1-related downstream signaling pathways in macrophages, which may prevent tissue damage caused by excessive pro-inflammatory response during the infection of C. albicans.

Application of probiotics in candidiasis management

Candidiasis (e.g., oral, gastrointestinal, vaginal, urinary tract, systemic) is a worldwide growing problem, since antifungal resistance and immunosuppression states are rising. To address this problem, very few drugs are available for the treatment of Candida spp. infections. Therefore, novel therapeutic strategies are urgently required. Probiotics have been proposed for the prevention and treatment of bacterial infections due to their safety record and efficacy, however, little is still known about their potential role regarding fungal infections. The purpose of this review is to present an updated summary of the evidence of the antifungal effects of probiotics along with a discussion of their potential use as an alternative/complementary therapy against Candida spp. infections. Thus, we performed a literature search using appropriate keywords ("Probiotic + Candida", "Candidiasis treatment", and "Probiotic + candidiasis") to retrieve relevant studies (both preclinical and clinical) with special emphasis on the works published in the last 5 years. An increasing amount of evidence has shown the potential usefulness of probiotics in the management of oral and vulvovaginal candidiasis in recent years. Among other results, we found that, as for bacterial infections, Lactobacillus, Bifidobacterium, and Saccharomyces are the most studied and effective genus for this purpose. However, in other areas, particularly in skincandidiaisis, studies are low or lacking. Thus, further investigation is necessary including in vitro and in vivo studies to establish the usefulness of probiotics in the management of candidiasis.

Lactobacillus rhamnosus strains of oral and vaginal origin show strong antifungal activity in vitro

Background: Intake of probiotic bacteria may prevent oral Candida infection. Objective: To screen the antifungal activity of 14 Lactobacillus candidate strains of human origin, against six opportunistic C. albicans and non-albicans species. A second aim was to study the acid production of the four strains showing the strongest antifungal activity. Methods: We used an agar overlay growth inhibition assay to the assess the antifungal activity of the lactobacilli. The acid-producing capacity was measured with pH micro-sensors. Results: All 14 Lactobacillus candidates inhibited the growth of the Candida spp. The four best-performing strains were L. rhamnosus DSM 32992 (oral origin), L. rhamnosus DSM 32991 (oral), L. jensenii 22B42 (vaginal), and L. rhamnosus PB01 (vaginal). The difference between L. rhamnosus DSM 32992 and the other three strains was statistically significant (p < 0.001). The Candida spp. differed in susceptibility; C. parapsilosis was highly inhibited, while C. krusei was not or slightly inhibited. The oral L. rhamnosus DSM 32992 and DSM 32991 strains showed the lowest pH-values. Conclusion: Screening of probiotic lactobacilli showed significant strain-dependent variations in their antifungal capacity in a pH-dependent mode. Two strains of oral origin were most effective. A further characterization seems justified to elaborate on their probiotic properties.