Lactobacillus salivarius CPU-01 Ameliorates Temozolomide-Induced Intestinal Mucositis by Modulating Gut Microbiota, Maintaining Intestinal Barrier, and Blocking Pro-inflammatory Cytokines

Chemotherapy-induced intestinal mucositis is one of the major toxic side effects in the treatment of cancer patients. The purpose of this study is to screen lactic acid bacteria which could alleviate intestinal inflammation and damage induced by chemotherapeutic agents and explore the possible underlying mechanisms. Lactobacillus salivarius CPU-01 was selected from traditional Chinese fermented foods due to its protective effects on the toxicity of temozolomide in Caenorhabditis elegans. Eighteen ICR mice were randomly divided into 3 groups including control group, temozolomide-induced intestinal mucositis group, and temozolomide + L. salivarius CPU-01 group, and were used to investigate the effect of L. salivarius CPU-01 on chemotherapy-induced intestinal mucositis. It has been demonstrated that the administration of L. salivarius CPU-01 can prevent colon shortening and alleviate colon tissue damage caused by temozolomide-induced intestinal mucositis in mice. L. salivarius CPU-01 relieved the intestinal microbiota disorders caused by temozolomide and contributed to the growth of beneficial bacteria, such as Lactobacillus, Clostridia UCG - 014_norank, and Akkermansia. In vivo experiments also indicated that L. salivarius CPU-01 can suppress the level of temozolomide-induced pro-inflammatory cytokines in serum and mRNA expression in the small intestine tissues. It was also found that L. salivarius CPU-01 significantly increased the expressions of intestinal tight junction (TJ) proteins, ZO-1, and Occludin proteins in mice treated with temozolomide. These findings suggest that L. salivarius CPU-01 can ameliorate temozolomide-induced intestinal mucositis by modulating gut microbiota, blocking pro-inflammatory cytokines, and repairing the intestinal barrier. These findings suggest probiotics may serve as a potential alternative therapeutic strategy for the prevention of chemotherapy-induced intestinal mucositis in the future.

Mucosal bleeding correlates with submucosal microbial dysbiosis in peri-implant mucositis of patients with periodontitis

OBJECTIVES

This study aimed to investigate the relationship between microbial communities and the severity of peri-implant mucosal bleeding in peri-implant mucositis.

MATERIALS AND METHODS

Submucosal plaque samples were collected from 54 implants divided into the healthy implant (HI) group, peri-implant mucositis (PM) group, and peri-implantitis (PI) group. Sequencing of 16S rRNA was performed using the Illumina MiSeq platform. Alpha diversity (i.e., Shannon and Chao index) and beta diversity were used to measure microbial diversity within and between microbial communities, respectively. Differences in microbial taxa between groups were assessed via linear discriminate analysis effect size. Correlation between the modified sulcus bleeding index (mSBI) and microbial dysbiosis index (MDI) was examined using Spearman correlation analysis and linear models.

RESULTS

The submucosal bacterial richness (Chao index) was positively correlated with the mean mSBI in the PM group. As the mean mSBI increased in the PM group, the beta diversity became closer to that of the PI group. In the PM group, the abundances of 47 genera were significantly correlated with the mean mSBI, and the MDI was positively associated with the mean mSBI. Fourteen of the forty-seven genera were discriminative taxa between the HI and PI groups, and the abundances of these biomarkers became closer to those in the PI group in the progression of peri-implant disease.

CONCLUSIONS

A higher mSBI value corresponded to a higher risk of microbial dysbiosis in peri-implant mucositis. The biomarkers identified may be useful for monitoring the progression of peri-implant disease.

Do the progression of experimentally induced gingivitis and peri-implant mucositis present common features? A systematic review of clinical human studies

This systematic review evaluated the features of the progression of experimentally induced gingivitis and peri-implant mucositis in humans. Included were studies that evaluated clinical, immunological, or microbiological responses between experimentally induced gingivitis and peri-implant mucositis in periodontally healthy patients. A total of 887 articles were initially identified, but only 12 were included in the final analysis. Implants accumulate less biofilm and suffer the most heterogeneous alterations in the microbiota, in the abstinence of oral hygiene, compared with the tooth. Interestingly, although dental implants presented less biofilm accumulation, the peri-implant mucosa showed a more exacerbated clinical response than the gingival tissue. The risk of bias of the selected studies was moderate to low, with one study presenting serious risk. The progression events of peri-implant mucositis were similar to those of experimental gingivitis but led to a different host response. This review was registered in the PROSPERO database CRD420201 123360.

Mucosal Respiratory Syndrome: A Systematic Literature Review

BACKGROUND

Mycoplasma pneumoniae atypical pneumonia is frequently associated with erythema multiforme. Occasionally, a mycoplasma infection does not trigger any cutaneous but exclusively mucosal lesions. The term mucosal respiratory syndrome is employed to denote the latter condition. Available reviews do not address the possible association of mucosal respiratory syndrome with further atypical bacterial pathogens such as Chlamydophila pneumoniae, Chlamydophila psittaci, Coxiella burnetii, Francisella tularensis, or Legionella species. We therefore performed a systematic review of the literature addressing this issue in the National Library of Medicine, Excerpta Medica, and Web of Science databases.

SUMMARY

We found 63 patients (≤18 years, n = 36; >18 years, n = 27; 54 males and 9 females) affected by a mucosal respiratory syndrome. Fifty-three cases were temporally associated with a M. pneumoniae and 5 with a C. pneumoniae infection. No cases temporally associated with C. psittaci, C. burnetii, F. tularensis, or Legionella species infection were found. Two cases were temporally associated with Epstein-Barr virus or influenzavirus B, respectively.

Neutrophil elastase inhibitor (MPH-966) improves intestinal mucosal damage and gut microbiota in a mouse model of 5-fluorouracil-induced intestinal mucositis

BACKGROUND

5-Fluorouracil (5-FU)-based chemotherapy is first-line chemotherapy for colorectal cancer. However, 5-FU-induced intestinal mucositis (FUIIM) is a common adverse effect that severely impairs drug tolerance and results in poor patient health.

METHODS

Male C57BL/6 mice were given 5-FU (50 mg/kg/day, i.p.) and treated with MPH-966 (5 and 7.5 mg/kg/day, p.o.) for five days. The body weight loss and the amount of food intake, and histopathological findings were recorded and analyzed. In addition, the neutrophil infiltration, levels of neutrophil serine proteases and pro-inflammatory cytokines, and tight junction proteins expression in intestinal tissues were determined. The ecology of gut microbiota was performed through next-generation sequencing technologies.

RESULTS

Neutrophil elastase (NE) overexpression is a key feature in FUIIM. This study showed that treatment with the specific NE inhibitor MPH-966 (7.5 mg/kg/day, p.o.) significantly reversed 5-FU-induced loss in body weight and food intake; reversed villous atrophy; significantly suppressed myeloperoxidase, NE, and proteinase 3 activity; and reduced pro-inflammatory cytokine expression in an FUIIM mouse model. In addition, MPH-966 prevented 5-FU-induced intestinal barrier dysfunction, as indicated by the modulated expression of the tight junction proteins zonula occludin-1 and occludin. MPH-966 also reversed 5-FU-induced changes in gut microbiota diversity and abundances, specifically the Firmicutes-to-Bacteroidetes ratio; Muribaculaceae, Ruminococcaceae, and Eggerthellaceae abundances at the family level; and Candidatus Arthromitus abundance at the genus level.

CONCLUSION

These data indicate that NE inhibitor is a key treatment candidate to alleviate FUIIM by regulating abnormal inflammatory responses, intestinal barrier dysfunction, and gut microbiota imbalance.

Prophylactic and therapeutic supplementation using fructo-oligosaccharide improves the intestinal homeostasis after mucositis induced by 5- fluorouracil

The beneficial effects of prebiotic, such as fructo-oligosaccharides (FOS), in intestinal inflammation have been demonstrated in several studies. Herein, we evaluate whether joint treatment with FOS, both before and during mucositis, had additional beneficial effects and investigated the mechanisms underlying in the action of FOS on the intestinal barrier. BALB/c mice were randomly divided into five groups: CTR (without mucositis + saline solution), FOS (without mucositis + 6 % FOS), MUC (mucositis + saline solution), PT (mucositis + 6 % FOS supplementation before disease induction), and TT (mucositis + 6 % FOS supplementation before and during disease induction). Mucositis was induced by intraperitoneal injection (300 mg/kg) of 5-fluorouracil (5-FU). After 72 h, the animals were euthanized and intestinal permeability (IP), tight junction, bacterial translocation (BT), histology and morphometry, and immunoglobulin A secretory (sIgA), inflammatory infiltrate, and production of short-chain fatty acids (acetate, butyrate and propionate) were evaluated. The MUC group showed an increase in the IP, BT, and inflammatory infiltrate but a decrease in the tight junction expression and butyrate and propionate levels (P < 0.05). In the PT and TT groups, FOS supplementation maintained the IP, tight junction expression, and propionate concentration within physiologic levels, increased butyrate levels, and reduced BT and inflammatory infiltrate (P < 0.05). Total treatment with FOS (TT group) was more effective in maintaining histological score, morphometric parameters, and sIgA production. Thus, total treatment (prophylactic and therapeutic supplementation) with FOS was more effective than pretreatment alone, in reducing 5-FU-induced damage to the intestinal barrier.

Mycoplasma Pneumoniae-Induced Rash and Mucositis: A Longitudinal Perspective and Proposed Management Criteria

PURPOSE

To evaluate the natural history and ophthalmologic morbidity of Mycoplasma pneumoniae-induced rash and mucositis (MIRM) and propose a treatment algorithm.

DESIGN

Retrospective, interventional case series.

METHODS

Retrospective chart review of all MIRM patients examined by the department of ophthalmology at a tertiary children's hospital. Diagnosis was established clinically concomitant with either positive Mycoplasma pneumoniae IgM or PCR testing from January 1, 2010, until December 31, 2019. The main outcome measures were best-corrected visual acuity, long-term ocular sequelae, and duration and type of ophthalmic intervention.

RESULTS

There were 15 patients (10 male and 5 female) aged 10.9 ± 4.2 years who had primary episodes of MIRM; of those, 4 had multiple episodes. All patients required topical steroid treatment, 3 required amniotic membrane transplantation, and 1 patient underwent placement of a sutureless biologic corneal badage device. There were no patients who suffered visual loss, but 1 was left with mild symblephara near the lateral canthus in each eye and 2 others had scarring of the eyelid margins and blepharitis.

CONCLUSIONS

The ocular morbidity is significantly less in MIRM than in other closely related syndromes such as erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis. However, these patients still require close observation and a low threshold for intervention to avoid permanent ophthalmic sequelae and possible blindness.

Microbiota from alginate oligosaccharide-dosed mice successfully mitigated small intestinal mucositis

BACKGROUND

The increasing incidence of cancer and intestinal mucositis induced by chemotherapeutics are causing worldwide concern. Many approaches such as fecal microbiota transplantation (FMT) have been used to minimize mucositis. However, it is still unknown whether FMT from a donor with beneficial gut microbiota results in more effective intestinal function in the recipient. Recently, we found that alginate oligosaccharides (AOS) benefit murine gut microbiota through increasing "beneficial" microbes to rescue busulfan induced mucositis.

RESULTS

In the current investigation, FMT from AOS-dosed mice improved small intestine function over FMT from control mice through the recovery of gene expression and an increase in the levels of cell junction proteins. FMT from AOS-dosed mice showed superior benefits over FMT from control mice on recipient gut microbiotas through an increase in "beneficial" microbes such as Leuconostocaceae and recovery in blood metabolome. Furthermore, the correlation of gut microbiota and blood metabolites suggested that the "beneficial" microbe Lactobacillales helped with the recovery of blood metabolites, while the "harmful" microbe Mycoplasmatales did not.

CONCLUSION

The data confirm our hypothesis that FMT from a donor with superior microbes leads to a more profound recovery of small intestinal function. We propose that gut microbiota from naturally produced AOS-treated donor may be used to prevent small intestinal mucositis induced by chemotherapeutics or other factors in recipients. Video Abstract.

Search and Selection of Probiotics That Improve Mucositis Symptoms in Oncologic Patients. A Systematic Review

Mucositis is a common and severe adverse effect of radiotherapy and/or chemotherapy treatments applied to oncologic patients. The development of effective therapies and adjuvant treatments to increase their efficacy and reduce adverse effect is a priority in cancer therapy. Probiotics are non-pathogenic live microorganisms that when ingested in adequate amounts can colonize the intestinal tract promoting the restoration of a healthy gut microbiota and contributing to all its functions including the maintenance of the integrity of the mucosa and the modulation of the immune system. In order to check the possible efficacy and safety of these microorganisms to prevent or ameliorate mucositis' symptoms, we have systematically searched the bibliographic databases MEDLINE (via Pubmed), EMBASE, The Cochrane library, Scopus, Web of science, and Latin American and Caribbean Literature in Health of Sciences (LILACS) using the descriptors "Mucositis", "Probiotics", "Neoplasms", "Humans", and "Clinical Trials". After applying our inclusion and exclusion criteria, 15 studies were accepted for review and critical analysis. Our analysis suggests that a combination of Bifidobacterium longum, Lactobacillus acidophilus, Bifidobacterium breve, Bifidobacterium infantis, and Saccharomyces boulardii could be a good combination of probiotics to reduce incident rates of mucositis or ameliorate its symptoms in chemo or radiotherapy treated patients.

[STRESS AS A PREDICTOR OF PERI-IMPLANTITIS DEVELOPMENT (REWIEV)]

In the era of modern technology is becoming increasingly popular implantation. This method is one of the leading methods in prosthetics of dental patients. Implantation solves a number of problems both aesthetic and functional. However, the percentage of complications, such as peri-implantitis and mucositis, leading to a violation of the chewing function of the dentition, is steadily increasing. To date, the etiology and pathogenesis of post-implantation complications have not been definitively clarified. One of the leading predictors is psychoemotional stress. On the basis of the literature analysis method to study stress, its impact on the development of periimplantitis, is laser Doppler flowmetry, allows you to quickly assess the state of microcirculation of the oral cavity at the stage of diagnosis, prior to the commencement of pharmacotherapy and in the dynamics of treatment and to adjust treatment regimen to prevent postoperative complications. The obtained LDF-grams allow to reflect the state of the regulatory systems of the body, and therefore it is possible to use LDF for the diagnosis of psychological stress.

Gut microbiome modulation during treatment of mucositis with the dairy bacterium Lactococcus lactis and recombinant strain secreting human antimicrobial PAP

Mucositis is an inflammatory condition of the gut, caused by an adverse effect of chemotherapy drugs, such as 5-fluorouracil (5-FU). In an attempt to develop alternative treatments for the disease, several research groups have proposed the use of probiotics, in particular, Lactic Acid Bacteria (LAB). In this context, the use of recombinant LAB, for delivering anti-inflammatory compounds has also been explored. In previous work, we demonstrated that either Lactococcus lactis NZ9000 or a recombinant strain expressing an antimicrobial peptide involved in human gut homeostasis, the Pancreatitis-associated Protein (PAP), could ameliorate 5-FU-induced mucositis in mice. However, the impact of these strains on the gut microbiota still needs to be elucidated. Therefore, in the present study, we aimed to characterize the effects of both Lactococci strains in the gut microbiome of mice through a 16 S rRNA gene sequencing metagenomic approach. Our data show 5-FU caused a significant decrease in protective bacteria and increase of several bacteria associated with pro-inflammatory traits. The Lactococci strains were shown to reduce several potential opportunistic microbes, while PAP delivery was able to suppress the growth of Enterobacteriaceae during inflammation. We conclude the strain secreting antimicrobial PAP was more effective in the control of 5-FU-dysbiosis.

Mycoplasma pneumoniae, more than a lung disease

Mycoplasma pneumoniae-induced rash and mucositis (MIRM) is a recently described clinical entity and should be considered in children who present with oral (94% of patients), ocular (82% of patients), and urogenital lesions (63% of patients). MIRM was first described as a distinct clinical entity from Stevens Johnson syndrome/Toxic epidermal necrolysis (SJS)/(TEN) in 2015 [1]. As a new, uncommon diagnosis it frequently poses a diagnostic and therapeutic challenge for pediatricians and dermatologists. We report a case of MIRM in a previously healthy 15-year-old boy.

[Risk factor of intestinal colonization with vancomycin resistant Enterococcus spp in hospitalized pediatric patients with oncological disease]

BACKGROUND

The isolation of vancomycin-resistant Enterococcus spp (ERV) has increased significantly within the last few years, along with the risk of infection and dissemination of these bacteria. Our aim was to determine risk factors (RF) for intestinal colonization in hospitalized pediatric patients with oncological disease at Hospital de Niños Roberto del Río.

METHODS

Between January 2012 and December 2013 a transversal study was performed with 107 rectal swabs and processed with a PCR for ERV. The patients were classified as "colonized with ERV" and "not colonized with ERV" and we evaluated possible RF for intestinal colonization in both groups.

RESULTS

VRE colonization was found in 51 patients (52%). The median of time elapsed between oncological diagnosis and VRE colonization was 35 days. The significant RF associated with VRE colonization were days of hospitalization prior to study, neutropenia and treatment with antibiotics within 30 days prior to study and mucositis.

CONCLUSIONS

According to the RF revealed in this study we may suggest prevention standards to avoid ERV colonization. This is the first investigation in our country in hospitalized pediatric patients with oncological disease and processed with a multiplex PCR for ERV, therefore it is a great contribution about this subject in Chile.

Probiotic supplements and debridement of peri-implant mucositis: a randomized controlled trial

OBJECTIVE

The aim of this double-blind randomized placebo-controlled trial was to evaluate the effects of probiotic supplements in adjunct to conventional management of peri-implant mucositis.

MATERIALS AND METHODS

Forty-nine adult patients with peri-implant mucositis were consecutively recruited after informed consent. After initial mechanical debridement and oral hygiene instructions, the patients received a topical oil application (active or placebo) followed by twice-daily intake of lozenges (active or placebo) for 3 months. The active products contained a mix of two strains of Lactobacillus reuteri. Patients were clinically monitored and sampled at baseline and after 1, 2, 4, 12 and 26 weeks. The clinical end-points were pocket-probing depth (PPD), plaque index (PI) and bleeding on probing (BOP). In addition, the subgingival microbiota was processed with checkerboard DNA-DNA hybridization and samples of gingival crevicular fluid (GCF) were analyzed for selected cytokines with the aid of multiplex immunoassays.

RESULTS

After 4 and 12 weeks, all clinical parameters were improved in both the test and the placebo group. PPD and BOP were significantly reduced compared with baseline (p < 0.05), but no significant differences were displayed between the groups. The clinical improvements persisted 3 months after the intervention. No major alterations of the subgingival microflora were disclosed and the levels of inflammatory mediators in GCF did not differ between the groups.

CONCLUSIONS

Mechanical debridement and oral hygiene reinforcement resulted in clinical improvement of peri-implant mucositis and a reduction in cytokine levels. Probiotic supplements did not provide added benefit to placebo.

Reproducibility of subgingival bacterial samples from patients with peri-implant mucositis

OBJECTIVE

The aim of the present study was to investigate the reproducibility of bacterial enumeration from subsequent subgingival samples collected from patients with peri-implant mucositis.

MATERIAL AND METHODS

Duplicate microbial samples from 222 unique implant sites in 45 adult subjects were collected with paper points and analyzed using the checkerboard DNA-DNA hybridization technique. Whole genomic probes of 74 preselected bacterial species were used. Based on the bacterial scores, Cohen's kappa coefficient was used to calculate the inter-annotator agreement for categorical data. The percentage agreement was considered as "good" when the two samples showed the same score or differed by 1 to the power of 10.

RESULTS

Moderate to fair kappa values were displayed for all bacterial species in the test panel (range 0.21-0.58). There were no significant differences between Gram-positive and Gram-negative species. The percentage of good agreement between the first and second samples averaged 74.7 % (n = 74; range 56-83 %), while the proportion of poor agreement ranged from 1 to 19 % for the various strains.

CONCLUSION

While an acceptable clinical agreement was obtained in most cases, diverging bacterial scores may appear in subgingival samples collected at the same time point from patients with peri-implant mucositis.

CLINICAL RELEVANCE

The broad bulky base of implant crowns may present an obstacle for the collection of reproducible subgingival samples with paper points.

Biomarkers of chemotherapy-induced diarrhoea: a clinical study of intestinal microbiome alterations, inflammation and circulating matrix metalloproteinases

PURPOSE

A common side effect of chemotherapy treatment is diarrhoea. Unfortunately, the underlying mechanisms of chemotherapy-induced diarrhoea (CD) are poorly understood. We aimed to determine if faecal microbes of CD patients were displaced, if faecal calprotectin increased during CD and if there were alterations in circulating matrix metalloproteinases, nuclear factor kappa B (NF-κB), IL-1β and TNF.

PATIENTS AND METHODS

Twenty-six cancer patients receiving chemotherapy were enrolled and requested to provide stool samples and blood samples at various times during their chemotherapy cycle. Stool samples were analysed using conventional culture techniques and qRT-PCR. ELISA kits determined faecal calprotectin levels, levels of circulating matrix metalloproteinases and circulating NF-κB, IL-1β and TNF.

RESULTS

The majority of patients with CD showed decreases in Lactobacillus spp., Bifidobacterium spp., Bacteroides spp. and Enterococcus spp. Increases were observed in Escherichia coli and Staphylococcus spp. Methanogenic archaea were also quantified, with all patients except one showing a decrease. Faecal calprotectin levels were increased in 81.25 % of patients with CD. Circulating MMP-3 and MMP-9 significantly increased following chemotherapy. Circulating levels of NF-κB, IL-1β and TNF were increased following chemotherapy, although this did not reach significance.

CONCLUSIONS

We demonstrated that CD is associated with marked changes in intestinal microflora, methanogenic archaea, matrix metalloproteinase and serum levels of NF-κB, IL-1β and TNF. These changes may result in diminished bacterial functions within the gut, altering gut function and initiating intestinal damage, resulting in the onset of diarrhoea. More importantly, these changes may provide clinicians with a possible new target for biomarkers of toxicity.

[Mycoplasma-pneumoniae-associated mucositis]

BACKGROUND

The pathogen Mycoplasma pneumonia is a frequent cause of respiratory tract infections, especially in adolescents. Less well known is that this infection may also be associated with extrapulmonary manifestations including M. pneumonia associated mucositis (MPAM).

CASE DESCRIPTION

A 19-year-old Dutch man was admitted to the hospital with severe mucositis, stomatitis, bilateral conjunctivitis, urethritis and mild exanthema on his arms. He had a one-week history of coughing and fever. Thorough microbiological investigations were implemented. After a few days both the IgM titre and polymerase chain reaction investigations for M. pneumonia from a throat swab taken on admission proved to be positive. Treatment with doxycycline resulted in rapid improvement in clinical condition. All mucosal lesions almost healed within two weeks.

CONCLUSION

M. pneumonia infections may be associated with the triad of stomatitis, conjunctivitis and urethritis in the absence of extensive skin manifestations. The prognosis is favourable.

Severe Mycoplasma pneumoniae-associated mucositis treated with immunoglobulins

Mycoplasma pneumoniae-associated mucositis (MPAM), previously labelled as atypical Stevens-Johnson syndrome (SJS), SJS with minimal or no skin manifestations, is a rare non-respiratory manifestation of Mycoplasma pneumoniae infection. The nineteen cases described so far in children and young adults were characterized by a high male gender prevalence (16/19) and a good response to appropriate antibiotic treatment and supportive care in the majority of patients. We describe a case of MPAM in a previously healthy girl, who improved after a 0.5 g/kg daily dose of intravenous immunoglobulins (IVIG) for four consecutive days, after traditional therapy had failed.

CONCLUSION

The successful treatment with IVIG described in this report suggests that, where appropriate antibiotic and supportive therapy fails to improve the clinical course of severe MPAM, IVIG treatment is worth considering.

Quantitative evaluation of biofilm formation in yeast nitrogen base (YNB) broth and in bovine serum (BS) of Candida albicans strains isolated from mucosal infections

Candida albicans is a major human fungal pathogen especially as an etiologic agent of opportunistic oral and genital infections. Moreover, C. albicans can be involved in the deep infections and recent evidence suggests that the majority of diseases produced by this pathogen are associated with biofilm growth. The aims of this study were to evaluate biofilm production ability of C. albicans strains isolated from different sources, and to evaluate the effect of serum for enhancement the growth of biofilm. The strains used in this study were obtained from three sources; 12 from feces of patients with gastrointestinal disturbances, 13 from the oral cavity of patients with oral candidiasis, and 16 from the vagina of patients with Candida vulvovaginitis (CVV). Polystyrene 96-well plates were used to grow biofilms and crystal violet (CV) staining method was used to evaluate the growth. There were no differences in biofilm growth expressed as CV absorbance between C. albicans strains from different origins neither in Yeast Nitrogen Base broth (YNB) or in bovine serum (BS) (ANOVA, P = 0.1648, P = 0.5106, respectively). In the BS, the biofilm production was greater than in YNB medium for all samples (ANOVA, P = 0.0003).

The role of intestinal microbiota in the development and severity of chemotherapy-induced mucositis

Mucositis, also referred to as mucosal barrier injury, is one of the most debilitating side effects of radiotherapy and chemotherapy treatment. Clinically, mucositis is associated with pain, bacteremia, and malnutrition. Furthermore, mucositis is a frequent reason to postpone chemotherapy treatment, ultimately leading towards a higher mortality in cancer patients. According to the model introduced by Sonis, both inflammation and apoptosis of the mucosal barrier result in its discontinuity, thereby promoting bacterial translocation. According to this five-phase model, the intestinal microbiota plays no role in the pathophysiology of mucositis. However, research has implicated a prominent role for the commensal intestinal microbiota in the development of several inflammatory diseases like inflammatory bowel disease, pouchitis, and radiotherapy-induced diarrhea. Furthermore, chemotherapeutics have a detrimental effect on the intestinal microbial composition (strongly decreasing the numbers of anaerobic bacteria), coinciding in time with the development of chemotherapy-induced mucositis. We hypothesize that the commensal intestinal microbiota might play a pivotal role in chemotherapy-induced mucositis. In this review, we propose and discuss five pathways in the development of mucositis that are potentially influenced by the commensal intestinal microbiota: 1) the inflammatory process and oxidative stress, 2) intestinal permeability, 3) the composition of the mucus layer, 4) the resistance to harmful stimuli and epithelial repair mechanisms, and 5) the activation and release of immune effector molecules. Via these pathways, the commensal intestinal microbiota might influence all phases in the Sonis model of the pathogenesis of mucositis. Further research is needed to show the clinical relevance of restoring dysbiosis, thereby possibly decreasing the degree of intestinal mucositis.

Comparison of five parameters as risk factors for peri-mucositis

PURPOSE

The aim of this study was to identify risk factors for the development of clinical signs of peri-implant mucositis and for the presence of periodontal pathogens and to determine a possible correlation between these clinical signs and the presence of periodontal pathogens.

MATERIALS AND METHODS

In 100 patients, a modified Plaque Index (PI), a modified Sulcular Bleeding Index (BOP), and pocket probing depth (PPD) were recorded. Patients with one implant site that scored positive for PI, BOP, and PPD greater than or equal to 5 mm were considered to have peri-implant mucositis. A sample taken at the implant with the deepest pocket was analyzed for periodontal pathogens. Implant surface roughness, smoking, augmentation at the implant site, type of dentition, and radiation therapy were recorded as possible cofactors in the disease process.

RESULTS

Thirty-one patients showed clinical signs of peri-implant mucositis and, in 25 implant sites, periodontal pathogens were found. Smoking showed a statistically significant correlation with clinical signs of peri-implant mucositis (univariate analysis). For periodontal pathogens at the implant site, the type of dentition was statistically significant. In the multivariate analysis of the clinical signs of peri-implant mucositis, smoking and radiation therapy were significant explanatory variables. Seventy-two percent of the patients showed agreement for finding either clinical signs of peri-implant mucositis and periodontal pathogens or for no clinical signs and no pathogens. The sensitivity for diagnosis of peri-implant mucositis was 45%, and the specificity was 84%.

CONCLUSIONS

Smoking was the most important risk factor in the formation of peri-implant mucositis. Radiation therapy was an explanatory variable for the occurrence of inflammation. Implant surface roughness, augmentation at the implant site, and type of dentition had little influence on clinical signs of peri-implant mucositis. The type of dentition influences the periodontal microbiota at the implant site.

Gastrointestinal microflora and mucins may play a critical role in the development of 5-Fluorouracil-induced gastrointestinal mucositis

5-Fluorouracil (5-FU) is a commonly used chemotherapy agent in clinical oncology practice. Two of its major side effects are mucositis and diarrhoea. The structure of mucins offers mucosal protection, and allows maintenance of intestinal flora by providing attachment sites and preventing bacterial overgrowth and/or penetration. The aim of this study was to investigate changes in mucin secretion and microflora following treatment with 5-FU. Female DA rats were given a single 150 mg/ kg i.p. dose of 5-FU. Rats were killed at various time points after treatment. Control rats received no treatment. Jejunum, colon and faecal samples were collected. Standard microbiological culture techniques were used to identify bacteria, and real-time PCR was used to quantify bacteria in faecal samples. Goblet cells and cavitated goblet cells (having undergone mucus exocytosis) were also counted. Statistical analysis was carried out using Kruskal-Wallis test, a non-parametric method of testing equality of group medians. Following treatment with 5-FU, we showed decreases in Clostridium spp., Lactobacillus spp. and Streptococcus spp., and an increase in Escherichia spp. in the jejunum. In the colon, 5-FU caused decreases in Enterococcus spp., Lactobacillus spp. and Streptococcus spp. Real-time PCR of faecal samples showed decreasing trends in Lactobacillus spp. and Bacteroides spp., and an increasing trend in E. coli. Significant increases (P < 0.05) were seen in Clostridium spp. and Staphylococcus spp. at 24 h. Goblet cell numbers decreased significantly in the jejunum from 24-72 h, with a significant increase in the percentage of cavitated goblet cells. In conclusion, 5-FU treatment causes significant changes in intestinal flora and mucin secretion in rats. These changes could result in systemic effects and, in particular, may contribute to the development of chemotherapy-induced mucositis.

Yoghurts containing probiotics reduce disruption of the small intestinal barrier in methotrexate-treated rats

Small intestinal permeability was employed to assess the efficacy of commercially available yoghurts containing probiotics in a rat model of methotrexate (MTX)-induced mucositis. Male Sprague-Dawley rats were allocated to four groups (n = 8): MTX + water, MTX + cow's milk yoghurt (CY; fermented with Lactobacillus johnsonii), MTX + sheep's milk yoghurt (SY; containing Lactobacillus bulgaricus and Streptococcus thermophilus), and saline. Treatment gavage occurred twice daily for 7 days pre-MTX and 5 days post-MTX. Intestinal permeability was assessed on days -7, -1, 2, and 5 of the trial. Intestinal sections were collected at sacrifice for histological and biochemical analyses. Histology revealed that rats receiving CY and SY did not have a significantly damaged duodenum compared to controls. However, an improved small intestinal barrier function was evident, determined by a decreased lactulose/mannitol ratio. Probiotics containing SY and CY may be useful in preventing disruption to intestinal barrier function in MTX-induced mucositis.

Mucositis in the cancer patient and immunosuppressed host

Oral mucositis is a serious complication of cancer therapy and in severely immunosuppressed patients. In immunosuppressed patients, the signs and symptoms of infection often are muted because of limited host response, and accurate diagnosis and appropriate treatment may be difficult. Prevention of mucosal breakdown, suppression of microbial colonization, control of viral reactivation, and effective management of severe xerostomia are all critical steps to reducing the overall morbidity and mortality of oromucosal infections.

Infection at titanium implants with or without a clinical diagnosis of inflammation

OBJECTIVES

To assess the microbiota at implants diagnosed with peri-implantitis, implant mucositis, or being clinically healthy.

MATERIAL AND METHODS

Clinical and microbiological data were collected from 213 subjects (mean age: 65.7+/-14) with 976 implants in function (mean: 10.8 years, SD+/-1.5). Forty species were identified by the checkerboard DNA-DNA hybridization method.

RESULTS

Implant mean % plaque score was 41.8+/-32.4%. Periodontitis defined by bone loss was found in 44.9% of subjects. Implant mucositis was diagnosed in 59% and peri-implantitis in 14.9% of all cases. Neisseria mucosa, Fusobacterium nucleatum sp. nucleatum, F. nucleatum sp. polymorphum, and Capnocytophaga sputigena dominated the implant sub-mucosal microbiota and the sub-gingival microbiota at tooth sites. Implant probing pocket depth at the implant site with the deepest probing depth was correlated with levels of Eikenella corrodens (r=0.16, P<0.05), the levels of F. nucleatum sp. vincentii (r=0.15, P<0.05), Porphyromonas gingivalis (r=0.14, P<0.05), and Micromonas micros (r=0.17, P=0.01). E. corrodens was found in higher levels at implants with mucositis compared with implant health (P<0.05). Subjects who lost teeth due to periodontitis had higher yields of F. nucleatum sp. vincentii (P<0.02) and N. mucosa (P<0.05). Independent of implant status subjects with teeth had higher levels of P. gingivalis (P<0.05), and Leptotrichia buccalis (P<0.05).

CONCLUSIONS

At implant sites studied, few bacteria differed by whether subjects were dentate or not or by implant status.

Chemotherapy-induced mucositis: the role of gastrointestinal microflora and mucins in the luminal environment

Collectively, mucositis refers to the damage caused to the mucous membranes of the body following cytotoxic cancer therapy. Diarrhea is one such manifestation of mucositis and is a common side effect of chemotherapy that remains poorly understood. It affects the entire gastrointestinal tract. The exact number of patients affected by diarrhea as a result of treatment is uncertain, although it is believed that approximately 10% of patients with advanced cancer will be affected. Despite advances in the understanding of oral and small intestinal mucositis over recent years, large intestinal mucositis, including diarrhea, has not been well defined, and the underlying mechanisms of the condition have yet to be established. The majority of the literature concerning diarrhea is based on clinical observations, with little basic research. However, from the research conducted, it is likely that the intestinal microflora play a role in the development of chemotherapy-induced diarrhea. This review will examine in detail what is known about the mechanisms of chemotherapy-induced diarrhea and will explore the potentially important relationship among intestinal microflora, the luminal environment, and the subsequent development of chemotherapy-induced diarrhea.

Mycoplasma pneumoniae and atypical Stevens-Johnson syndrome: a case series

Mycoplasma pneumoniae is a common cause of community-acquired respiratory illness in the adolescent population. Stevens-Johnson syndrome is an extrapulmonary manifestation that has been associated with M. pneumoniae infections. Three adolescent males presented within a 1-month period with M. pneumoniae respiratory illnesses and severe mucositis but without the classic rash typical of Stevens-Johnson. Diagnosis was facilitated by the use of a polymerase chain reaction-based assay. This case series highlights the potential for M. pneumoniae-associated Stevens-Johnson syndrome to occur without rash and supports the use of polymerase chain reaction for early diagnosis.

Oral ingestion of streptococcus thermophilus diminishes severity of small intestinal mucositis in methotrexate treated rats

BACKGROUND

Currently, there are no available effective preventative or adjunctive agents to alleviate symptoms of chemotherapy-induced mucositis. This is compounded by the absence of a recognized and validated noninvasive biomarker to assess gut function. This study investigated the effects of orally ingested Streptococcus thermophilus (TH-4) on chemotherapy-induced small intestinal damage in rats using the noninvasive (13)C-sucrose breath test (SBT).

METHODS

Gastrointestinal damage was induced in 27 female dark agouti rats (148 +/- 1g) with MTX (1.5 mg/kg; i.m.). Rats received MTX or saline at 0 h; with daily treatment of: TH-4 at doses of 10(9) (high), 10(8) (low) cfu/mL, or skim milk (vehicle), 48 h pre and 96 h post-MTX. The noninvasive (13)C-sucrose breath test (SBT) was conducted at -24, 24 and 96 h post-MTX to monitor gut function. At sacrifice, small intestinal tissues were collected for determinations of sucrase activity, myeloperoxidase (MPO) activity and histological assessment.

RESULTS

MTX + vehicle and MTX + low TH-4-treated rats produced significantly lower SBT and sucrase activity results compared to saline controls (p < 0.001). In contrast, MTX + high TH-4 treatment showed no significant differences in the SBT compared to saline controls, and the SBT results were significantly higher compared to MTX + vehicle and MTX + low TH-4 (p < 0.05). MPO levels were significantly elevated (p < 0.05) in MTX + vehicle and MTX + low TH-4, but not following MTX + high TH-4 treatment, compared to saline controls. This was further confirmed by histological analyses.

CONCLUSION

Oral ingestion of TH-4 at 10(9) cfu/mL is capable of partially attenuating small bowel damage in rats. The noninvasive SBT is a useful technique to longitudinally assess the efficacy of treatments or interventions for small bowel disease.