Lactobacilli and bifidobacteria in the prevention of antibiotic-associated diarrhoea and Clostridium difficile diarrhoea in older inpatients (PLACIDE): a randomised, double-blind, placebo-controlled, multicentre trial

Imbalanced dietary intake alters the colonic microbial profile in growing rats

An imbalanced dietary intake is associated with alteration of intestinal ecosystem. We investigated the impact of imbalanced diets on colonic microbiota, concentrations of short chain fatty acid in colonic digesta and serum immunoglobulins (Igs) of growing rats. Compared to the control diet, consuming diets high in fat, sucrose, or processed meat, or low in iron, increased the abundance of the pathogenic bacteria such as Clostridium, Escherichia coli, and Salmonella species, and decreased the beneficial bacteria, like Bifidobacteria, Lactobacillus, Akkermansia, Phascolarctobacterium, Alistipes, and butyrate producing species of bacteria in the colon of growing rats. The heatmap of metagenomics indicated that each group was separated into distinct clusters, and the ID group in particular, showed significantly (P < 0.01) reduced alpha diversity of colonic microbiota in comparison to the control group. All experimental groups showed significantly (P < 0.05 or P < 0.01) decreased concentration of acetate and butyrate in the colonic digesta and lower levels of serum IgG or IgA, compared to the control. These results indicated that the imbalanced dietary intake negatively altered intestinal ecosystem and immunity.

Validity and safety of ID-JPL934 in lower gastrointestinal symptom improvement

The study evaluated the efficacy of ID-JPL934, a probiotic preparation containing Lactobacillus johnsonii IDCC 9203, Lactobacillus plantarum IDCC 3501 and Bifidobacterium lactis IDCC 4301, in relieving lower gastrointestinal symptoms. A total of 112 subjects with lower gastrointestinal symptoms were consecutively enrolled. They were randomized into either ID-JPL934 administration group or placebo group. Bristol stool form, stool frequency, and abnormal bowel movement symptoms were recorded at baseline and week 2, 6, and 8. Primary endpoint was improvement in overall symptoms at week 8. Fecal samples were collected to measure the probiotic levels in feces using quantitative polymerase chain reaction (qPCR), and to perform metagenomic analysis of microbiome originating from bacteria-derived extracellular vesicles and bacterial cells via 16S rDNA sequencing. Of the 112 subjects, 104 (54 in ID-JPL934 group and 50 in placebo group) completed the entire study protocol. A higher relief of overall symptoms was found in ID-JPL934 group than in placebo group (p = 0.016). Among lower gastrointestinal symptoms, abdominal pain and bloating scores were more decreased in ID-JPL934 group than in placebo group (p < 0.05). The fecal microbiome profiles of the two groups did not differ. However, the qPCR analysis showed significant increase in the levels of Lactobacillus johnsonii and Bifidobacterium lactis in feces post-treatment in ID-JPL934 group than in placebo group (p < 0.05 by repeated measure ANOVA). In conclusion, ID-JPL934 is effective in relieving lower gastrointestinal symptoms. Exposure to ID-JPL934 may increase the abundance of Lactobacillus johnsonii and Bifidobacterium lactis in the gut.

Trial registration: ClinicalTrials.gov number, NCT03395626.

Incidence and predictive biomarkers of Clostridioides difficile infection in hospitalized patients receiving broad-spectrum antibiotics

Trial enrichment using gut microbiota derived biomarkers by high-risk individuals can improve the feasibility of randomized controlled trials for prevention of Clostridioides difficile infection (CDI). Here, we report in a prospective observational cohort study the incidence of CDI and assess potential clinical characteristics and biomarkers to predict CDI in 1,007 patients ≥ 50 years receiving newly initiated antibiotic treatment with penicillins plus a beta-lactamase inhibitor, 3rd/4th generation cephalosporins, carbapenems, fluoroquinolones or clindamycin from 34 European hospitals. The estimated 90-day cumulative incidences of a first CDI episode is 1.9% (95% CI 1.1-3.0). Carbapenem treatment (Hazard Ratio (95% CI): 5.3 (1.7-16.6)), toxigenic C. difficile rectal carriage (10.3 (3.2-33.1)), high intestinal abundance of Enterococcus spp. relative to Ruminococcus spp. (5.4 (2.1-18.7)), and low Shannon alpha diversity index as determined by 16 S rRNA gene profiling (9.7 (3.2-29.7)), but not normalized urinary 3-indoxyl sulfate levels, predicts an increased CDI risk.

Gastrointestinal Microenvironment and the Gut-Lung Axis in the Immune Responses of Severe COVID-19

The global pandemic of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is an unprecedented threat to the human health. A close association of the digestive tract is implied by the high frequency of gastrointestinal syndromes among COVID-19 patients. A better understanding of the role of intestinal microenvironment in COVID-19 immunopathology will be helpful to improve the control of COVID-19 associated morbidity and mortality. This review summarizes the immune responses associated with the severity of COVID-19, the current evidence of SARS-CoV-2 intestinal tropism, and the potential involvement of gut microenvironment in COVID-19 severity. Additionally, we discuss the therapeutic potential of probiotics as an alternative medicine to prevent or alleviate severe COVID-19 outcome.

A randomized controlled trial of Lactobacillus rhamnosus GG on antimicrobial-resistant organism colonization

OBJECTIVE

Alteration of the colonic microbiota following antimicrobial exposure allows colonization by antimicrobial-resistant organisms (AROs). Ingestion of a probiotic, such as Lactobacillus rhamnosus GG (LGG), could prevent colonization or infection with AROs by promoting healthy colonic microbiota. The purpose of this trial was to determine the effect of LGG administration on ARO colonization in hospitalized patients receiving antibiotics.

DESIGN

Prospective, double-blinded, randomized controlled trial of LGG versus placebo among patients receiving broad-spectrum antibiotics.

SETTING

Tertiary care center.

PATIENTS

In total, 88 inpatients receiving broad-spectrum antibiotics were enrolled.

INTERVENTION

Patients were randomized to receive 1 capsule containing 1×1010 cells of LGG twice daily (n = 44) or placebo (n = 44), stratified by ward type. Stool or rectal-swab specimens were collected for culture at enrollment, during admission, and at discharge. Using selective media, specimens were cultured for Clostridioides difficile, vancomycin-resistant Enterococcus spp (VRE), and antibiotic-resistant gram-negative bacteria. The primary outcome was any ARO acquisition. Secondary outcomes included loss of any ARO if colonized at enrollment, and acquisition or loss of individual ARO.

RESULTS

ARO colonization prevalence at study enrollment was similar (LGG 39% vs placebo 39%). We detected no difference in any ARO acquisition (LGG 30% vs placebo 33%; OR,1.19; 95% CI, 0.38-3.75) nor for any individual ARO acquisition. There was no difference in the loss of any ARO (LGG 18% vs placebo 24%; OR, 1.44; 95% CI, 0.27-7.68) nor for any individual ARO.

CONCLUSION

LGG administration neither prevented acquisition of ARO nor accelerated loss of ARO colonization.

The Acid-Dependent and Independent Effects of Lactobacillus acidophilus CL1285, Lacticaseibacillus casei LBC80R, and Lacticaseibacillus rhamnosus CLR2 on Clostridioides difficile R20291

Clostridioides difficile infections (CDI) result from antibiotic use and cause severe diarrhea which is life threatening and costly. A specific probiotic containing Lactobacillus acidophilus CL1285, Lacticaseibacillus casei LBC80R, and Lacticaseibacillus rhamnosus CLR2 has demonstrated a strong inhibitory effect on the growth of several nosocomial C. difficile strains by production of antimicrobial metabolites during fermentation. Though there are several lactobacilli shown to inhibit C. difficile growth by processes relying on acidification, this probiotic has demonstrated potency for CDI prevention among hospitalized patients. Here, we describe the acid-dependent and independent mechanisms by which these strains impair the cytotoxicity of a hypervirulent strain, C. difficile R20291 (CD). These bacteria were co-cultured in a series of experiments under anaerobic conditions in glucose-rich and no-sugar medium to inhibit or stimulate CD toxin production, respectively. In glucose-rich medium, there was low CD toxin production, but sufficient amounts to cause cytotoxic damage to human fibroblast cells. In co-culture, there was acidification by the lactobacilli resulting in growth inhibition as well as ≥ 99% reduced toxin A and B production and no observable cytotoxicity. In the absence of glucose, CD produced much more toxin. In co-culture, the lactobacilli did not acidify the medium and CD growth was unaffected; yet, the amount of detected toxin A and B was decreased by 20% and 41%, respectively. Despite the high concentration of toxin, cells exposed to the supernatant from the co-culture were able to survive. These results suggest that in addition to known acid-dependent effects, the combination of L. acidophilus CL1285, L. casei LBC80R, and L. rhamnosus CLR2 can interfere with CD pathogenesis without acidification: (1) reduced toxin A and B production and (2) toxin neutralization. This might explain the strain specificity of this probiotic in potently preventing C. difficile-associated diarrhea in antibiotic-treated patients compared with other probiotic formulae.

Clostridioides difficile Infection in Chronic Kidney Disease-An Overview for Clinicians

Increased incidence of Clostridioides difficile infection (CDI), occurrence of severe and complicated CDI, and more frequent occurrence of drug-resistant, recurrent or non-hospital CDI has become a worldwide clinical problem. CDI is more common in patients with chronic kidney disease (CKD) than in the general population. CDI seems to be associated with frequent hospitalization, frequently used antibiotic therapy, dysbiosis, and abnormalities of the immune system observed in CKD patients. Dysbiosis is a common disorder found in CKD patients. It may be related to insufficient fiber content in the diet, reduced amount of consumed fluids and often reduced physical activity, constipation, impaired gastrointestinal motility, multidrug pharmacotherapy, and uremic milieu in CKD stage 5. In patients with CKD the clinical manifestations of CDI are similar to the general population; however, more frequent recurrence of CDI and higher prevalence of severe CDI are reported. Moreover, the increase in CDI related mortality is observed more in CKD patients than in the general population. The aim of this review paper is to summarize the current knowledge concerning the epidemiology, pathogenesis, clinical picture, and prevention and treatment in CKD patients.

Aging, Frailty, and the Microbiome-How Dysbiosis Influences Human Aging and Disease

The human gut microbiome is a collection of bacteria, protozoa, fungi, and viruses that coexist in our bodies and are essential in protective, metabolic, and physiologic functions of human health. Gut dysbiosis has traditionally been linked to increased risk of infection, but imbalances within the intestinal microbial community structure that correlate with untoward inflammatory responses are increasingly recognized as being involved in disease processes that affect many organ systems in the body. Furthermore, it is becoming more apparent that the connection between gut dysbiosis and age-related diseases may lie in how the gut microbiome communicates with both the intestinal mucosa and the systemic immune system, given that these networks have a common interconnection to frailty. We therefore discuss recent advances in our understanding of the important role the microbiome plays in aging and how this knowledge opens the door for potential novel therapeutics aimed at shaping a less dysbiotic microbiome to prevent or treat age-related diseases.

ACG Clinical Guideline: Management of Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is a highly prevalent, chronic disorder that significantly reduces patients' quality of life. Advances in diagnostic testing and in therapeutic options for patients with IBS led to the development of this first-ever American College of Gastroenterology clinical guideline for the management of IBS using Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) methodology. Twenty-five clinically important questions were assessed after a comprehensive literature search; 9 questions focused on diagnostic testing; 16 questions focused on therapeutic options. Consensus was obtained using a modified Delphi approach, and based on GRADE methodology, we endorse the following: We suggest that a positive diagnostic strategy as compared to a diagnostic strategy of exclusion be used to improve time to initiating appropriate therapy. We suggest that serologic testing be performed to rule out celiac disease in patients with IBS and diarrhea symptoms. We suggest that fecal calprotectin be checked in patients with suspected IBS and diarrhea symptoms to rule out inflammatory bowel disease. We recommend a limited trial of a low fermentable oligosaccharides, disacchardies, monosaccharides, polyols (FODMAP) diet in patients with IBS to improve global symptoms. We recommend the use of chloride channel activators and guanylate cyclase activators to treat global IBS with constipation symptoms. We recommend the use of rifaximin to treat global IBS with diarrhea symptoms. We suggest that gut-directed psychotherapy be used to treat global IBS symptoms. Additional statements and information regarding diagnostic strategies, specific drugs, doses, and duration of therapy can be found in the guideline.

Mechanisms of Colonization Resistance Against Clostridioides difficile

Clostridioides difficile is an urgent antimicrobial-resistant bacterium, causing mild to moderate and sometimes life-threatening disease. Commensal gut microbes are critical for providing colonization resistance against C difficile and can be leveraged as non-antibiotic alternative therapeutics for the prevention and treatment of C difficile infection.

Probiotics Modulate Intestinal Motility and Inflammation in Zebrafish Models

This study was aimed to assess effects of three strains of probiotics Lactobacillus acidophilus NCFM, Lactobacillus rhamnosus HN001, and Bifidobacterium animalis subsp. lactis Bi-07 on the intestinal motility and inflammation in the zebrafish models. The intestinal motility model was established using 5 days postfertilization (dpf) zebrafish administered with a fluorescent dye Nile red at 10 ng/mL for 16 h, followed by probiotics treatment for 24 h and the intestinal motility was inversely proportional to the intestinal fluorescence intensity that was quantitatively measured by image analysis. The intestinal inflammation was induced by treating 3 dpf neutrophil fluorescent zebrafish with 0.0125% of trinitrobenzenesulfonic acid for 48 h. Probiotics were administered at low, moderate, and high concentrations determined based on maximum tolerable concentration through soaking. All three strains of probiotics promoted intestinal movement, of which B. animalis subsp. lactis Bi-07 was most potent at lower concentrations. L. rhamnosus HN001 and B. animalis subsp. lactis Bi-07 had the therapeutic effects on the intestinal inflammation and the inflammation-associated mucosal damage recovery. The anti-inflammatory mechanisms of L. rhamnosus HN001 was related to both reduce inflammatory factor interleukin-6 (IL-6) and restored tissue repair factor transforming growth factor-β-1 (TGFβ-1); whereas B. animalis subsp. lactis Bi-07 was probably only associated with TGFβ-1 elevation. Using larval zebrafish models for probiotics screening and assessment would speed up product research and development and improve products' efficacy and quality.

Effect of Probiotic Use on Antibiotic Administration Among Care Home Residents: A Randomized Clinical Trial

IMPORTANCE

Probiotics are frequently used by residents in care homes (residential homes or nursing homes that provide residents with 24-hour support for personal care or nursing care), although the evidence on whether probiotics prevent infections and reduce antibiotic use in these settings is limited.

OBJECTIVE

To determine whether a daily oral probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp lactis BB-12 compared with placebo reduces antibiotic administration in care home residents.

DESIGN, SETTING, AND PARTICIPANTS

Placebo-controlled randomized clinical trial of 310 care home residents, aged 65 years and older, recruited from 23 care homes in the United Kingdom between December 2016 and May 2018, with last follow-up on October 31, 2018.

INTERVENTIONS

Study participants were randomized to receive a daily capsule containing a probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp lactis BB-12 (total cell count per capsule, 1.3 × 1010 to 1.6 × 1010) (n = 155), or daily matched placebo (n = 155), for up to 1 year.

MAIN OUTCOMES AND MEASURES

The primary outcome was cumulative antibiotic administration days for all-cause infections measured from randomization for up to 1 year.

RESULTS

Among 310 randomized care home residents (mean age, 85.3 years; 66.8% women), 195 (62.9%) remained alive and completed the trial. Participant diary data (daily data including study product use, antibiotic administration, and signs of infection) were available for 98.7% randomized to the probiotic group and 97.4% randomized to placebo. Care home residents randomized to the probiotic group had a mean of 12.9 cumulative systemic antibiotic administration days (95% CI, 0 to 18.05), and residents randomized to placebo had a mean of 12.0 days (95% CI, 0 to 16.95) (absolute difference, 0.9 days [95% CI, -3.25 to 5.05]; adjusted incidence rate ratio, 1.13 [95% CI, 0.79 to 1.63]; P = .50). A total of 120 care home residents experienced 283 adverse events (150 adverse events in the probiotic group and 133 in the placebo group). Hospitalizations accounted for 94 of the events in probiotic group and 78 events in the placebo group, and deaths accounted for 33 of the events in the probiotic group and 32 of the events in the placebo group.

CONCLUSIONS AND RELEVANCE

Among care home residents in the United Kingdom, a daily dose of a probiotic combination of Lactobacillus rhamnosus GG and Bifidobacterium animalis subsp lactis BB-12 did not significantly reduce antibiotic administration for all-cause infections. These findings do not support the use of probiotics in this setting.

TRIAL REGISTRATION

ISRCTN Identifier:16392920.

[Updated review of Clostridium difficile infection in elderly]

Clostridium difficile infection is the most common cause of health care-associated diarrhoea, and its incidence increases with age. Clinical challenges, risk of resistance to treatment, risk of recurrence, and treatment responses are different in elderly. The aim of this review is to discuss the updated epidemiology, pathophysiology, diagnosis, and therapeutic management of C. difficile infection in elderly with the available data.

The Effect of Saccharomyces boulardii Primary Prevention on Risk of Hospital-onset Clostridioides difficile Infection in Hospitalized Patients Administered Antibiotics Frequently Associated With C. difficile Infection

Background

Hospital-onset Clostridioides difficile infection (HO-CDI) is a costly problem leading to readmissions, morbidity, and mortality. We evaluated the effect of a single probiotic strain, Saccharomyces boulardii, at a standardized dose on the risk of HO-CDI within hospitalized patients administered antibiotics frequently associated with HO-CDI.

Methods

This retrospective cohort study merged hospital prescribing data with HO-CDI case data. The study assessed patients hospitalized from January 2016 through March 2017 who were administered at least 1 dose of an antibiotic frequently associated with HO-CDI during hospitalization. Associations between S. boulardii administration, including timing, and HO-CDI incidence were evaluated by multivariable logistic regression.

Results

The study included 8763 patients. HO-CDI incidence was 0.66% in the overall cohort. HO-CDI incidence was 0.56% and 0.82% among patients coadministered S. boulardii with antibiotics and not coadministered S. boulardii, respectively. In adjusted analysis, patients coadministered S. boulardii had a reduced risk of HO-CDI (odds ratio [OR], 0.57 [95% confidence interval {CI}, .33–.96]; P = .04) compared to patients not coadministered S. boulardii. Patients coadministered S. boulardii within 24 hours of antibiotic start demonstrated a reduced risk of HO-CDI (OR, 0.47 [95% CI, .23–.97]; P = .04) compared to those coadministered S. boulardii after 24 hours of antibiotic start.

Conclusions

Saccharomyces boulardii administered to hospitalized patients prescribed antibiotics frequently linked with HO-CDI was associated with a reduced risk of HO-CDI.

A prospective longitudinal study on the microbiota composition in amyotrophic lateral sclerosis

BACKGROUND

A connection between amyotrophic lateral sclerosis (ALS) and altered gut microbiota composition has previously been reported in animal models. This work is the first prospective longitudinal study addressing the microbiota composition in ALS patients and the impact of a probiotic supplementation on the gut microbiota and disease progression.

METHODS

Fifty patients and 50 matched controls were enrolled. The microbial profile of stool samples from patients and controls was analyzed via PCR-Denaturing Gradient Gel Electrophoresis, and the main microbial groups quantified via qPCR. The whole microbiota was then analyzed via next generation sequencing after amplification of the V3-V4 region of 16S rDNA. Patients were then randomized to receive probiotic treatment or placebo and followed up for 6 months with ALSFRS-R, BMI, and FVC%.

RESULTS

The results demonstrate that the gut microbiota of ALS patients is characterized by some differences with respect to controls, regardless of the disability degree. Moreover, the gut microbiota composition changes during the course of the disease as demonstrated by the significant decrease in the number of observed operational taxonomic unit during the follow-up. Interestingly, an unbalance between potentially protective microbial groups, such as Bacteroidetes, and other with potential neurotoxic or pro-inflammatory activity, such as Cyanobacteria, has been shown. The 6-month probiotic treatment influenced the gut microbial composition; however, it did not bring the biodiversity of intestinal microbiota of patients closer to that of control subjects and no influence on the progression of the disease measured by ALSFRS-R was demonstrated.

CONCLUSIONS

Our study poses the bases for larger clinical studies to characterize the microbiota changes as a novel ALS biomarker and to test new microbial strategy to ameliorate the health status of the gut.

TRIAL REGISTRATION

CE 107/14, approved by the Ethics Committee of the "Maggiore della Carità" University Hospital, Italy.

Effects of probiotic supplementation on serum trimethylamine-N-oxide level and gut microbiota composition in young males: a double-blinded randomized controlled trial

PURPOSE

To explore whether probiotic supplementation could attenuate serum trimethylamine-N-oxide (TMAO) level and impact the intestinal microbiome composition.

DESIGN

Forty healthy males (20-25 years old) were randomized into the probiotic group (1.32 × 10¹¹ CFU live bacteria including strains of Lactobacillus acidophilus, Lactobacillus rhamnosus GG, Bifidobacterium animalis, and Bifidobacterium longum daily) or the control group for 4 weeks. All participants underwent a phosphatidylcholine challenge test (PCCT) before and after the intervention. Serum TMAO and its precursors (TMA, choline and betaine) were measured by UPLC-MS/MS. The faecal microbiome was analyzed by 16S rRNA sequencing.

RESULTS

Serum TMAO and its precursors were markedly increased after the PCCT. No statistical differences were observed in the probiotic and the control group in area under the curve (AUC) (14.79 ± 0.97 μmol/L 8 h vs. 19.17 ± 2.55 μmol/L 8 h, P = 0.106) and the pre- to post-intervention AUC alterations (∆AUC) (- 6.33 ± 2.00 μmol/L 8 h vs. - 0.73 ± 3.04 μmol/L 8 h, P = 0.131) of TMAO; however, higher proportion of participants in probiotic group showed their TMAO decrease after the intervention (78.9% vs. 45.0%, P = 0.029). The abundance of Faecalibacterium prausnitzii (P = 0.043) and Prevotella (P = 0.001) in the probiotic group was significantly increased after the intervention but without obvious differences in α- and β-diversity.

CONCLUSIONS

The current probiotic supplementation resulted in detectable change of intestinal microbiome composition but failed to attenuate the serum TMAO elevation after PCCT. CLINICALTRIALS.

GOV IDENTIFIER

NCT03292978. CLINICALTRIALS.GOV WEBSITE: https://clinicaltrials.gov/ct2/show/NCT03292978 .

Probiotics use for antibiotic-associated diarrhea: a pragmatic participatory evaluation in nursing homes

BACKGROUND

Antibiotic-associated diarrhea (AAD) occurs in 2-25% of nursing home residents, which may lead to dehydration, malnutrition, severe complications and hospitalizations. Research shows that probiotics can be effective and safe in reducing AAD. However, probiotics are not routinely used in Dutch nursing homes. The objectives of this evaluation were to develop a procedure for the implementation of probiotics to prevent AAD in nursing homes, to evaluate effects on AAD occurrence, and to evaluate the implementation process of probiotics in daily care.

METHODS

A pragmatic participatory evaluation (PPE) design was chosen, as it seemed a suitable approach for implementation of probiotics, as well as for evaluation of its effectiveness in daily nursing home practice. Probiotics administration was implemented in three nursing homes of the Rivas Zorggroep for residents with somatic and/or psychogeriatric conditions. Ninety-three residents provided data on 167 episodes of antibiotics use, of which 84 episodes that included supplementation with probiotics and 83 episodes with no probiotics supplementation. A multispecies probiotics was administered twice daily upon start of antibiotic treatment, up to 1 week after completing the antibiotics course. The occurrence of AAD was monitored and a process evaluation was conducted to assess facilitators and barriers of probiotics implementation.

RESULTS

The number of episodes with AAD when using probiotics was significantly lower than when no probiotics was used (20% vs 36%; p = 0,022, Chi-square). No significant differences in the occurrence of AAD were found between the residents taking amoxicillin/clavulanic acid or ciprofloxacin. Reported facilitators for implementation were perceived benefits of probiotics and prescription by medical staff. Reported challenges were probiotics intake by residents and individual decision-making as to which resident would benefit from it.

CONCLUSION

Successful implementation of probiotics demonstrated the prevention of AAD in nursing home residents.

TRIAL REGISTRATION

ISRCTN 94786163, retrospectively registered on 3 February 2020.

The Preventive Effect of Lactoferrin-Containing Yogurt on Gastroenteritis in Nursery School Children-Intervention Study for 15 Weeks

To evaluate the effects of bovine lactoferrin (LF)-containing yogurt on gastroenteritis in nursery school children during the winter season, we conducted a randomized prospective study. A total of 1296 children were randomized into a group in which LF was provided in yogurt (LF group, n = 661) and a non-LF consumption group (control group, n = 635). The LF group was given LF-containing yogurt (100 mg/day) on all 5 weekdays for approximately 15 weeks, and the control group consumed fruit jelly instead of the yogurt. The final totals of 578 children as the LF group and 584 as the control group were analyzed. The total number of children who were absent from school due to vomiting was significantly lower in the LF group compared to the control, accounting for ≥3 days in any week: 10/234 (4.3%) vs. 49/584 (8.4%), respectively; p = 0.04. Regarding the relationship between absences due to vomiting and the consumption of the LF-containing yogurt, the adjusted odds ratio for absence due to vomiting was 2.48 (95% CI: 1.19–5.14) in the LF children who consumed LF-containing yogurt ≤2 days/week compared to the LF children who consumed the yogurt ≥ 3 days/week. The consumption of LF-containing yogurt (100 mg/day) for ≥3 days/week might help alleviate the symptom of vomiting in nursery school children during the winter.

Recommendations for the diagnosis and treatment of Clostridioides difficile infection: An official clinical practice guideline of the Spanish Society of Chemotherapy (SEQ), Spanish Society of Internal Medicine (SEMI) and the working group of Postoperative Infection of the Spanish Society of Anesthesia and Reanimation (SEDAR)

This document gathers the opinion of a multidisciplinary forum of experts on different aspects of the diagnosis and treatment of Clostridioides difficile infection (CDI) in Spain. It has been structured around a series of questions that the attendees considered relevant and in which a consensus opinion was reached. The main messages were as follows: CDI should be suspected in patients older than 2 years of age in the presence of diarrhea, paralytic ileus and unexplained leukocytosis, even in the absence of classical risk factors. With a few exceptions, a single stool sample is sufficient for diagnosis, which can be sent to the laboratory with or without transportation media for enteropathogenic bacteria. In the absence of diarrhoea, rectal swabs may be valid. The microbiology laboratory should include C. difficile among the pathogens routinely searched in patients with diarrhoea. Laboratory tests in different order and sequence schemes include GDH detection, presence of toxins, molecular tests and toxigenic culture. Immediate determination of sensitivity to drugs such as vancomycin, metronidazole or fidaxomycin is not required. The evolution of toxin persistence is not a suitable test for follow up. Laboratory diagnosis of CDI should be rapid and results reported and interpreted to clinicians immediately. In addition to the basic support of all diarrheic episodes, CDI treatment requires the suppression of antiperistaltic agents, proton pump inhibitors and antibiotics, where possible. Oral vancomycin and fidaxomycin are the antibacterials of choice in treatment, intravenous metronidazole being restricted for patients in whom the presence of the above drugs in the intestinal lumen cannot be assured. Fecal material transplantation is the treatment of choice for patients with multiple recurrences but uncertainties persist regarding its standardization and safety. Bezlotoxumab is a monoclonal antibody to C. difficile toxin B that should be administered to patients at high risk of recurrence. Surgery is becoming less and less necessary and prevention with vaccines is under research. Probiotics have so far not been shown to be therapeutically or preventively effective. The therapeutic strategy should be based, rather than on the number of episodes, on the severity of the episodes and on their potential to recur. Some data point to the efficacy of oral vancomycin prophylaxis in patients who reccur CDI when systemic antibiotics are required again.

The Gut Microbiota and Its Implication in the Development of Atherosclerosis and Related Cardiovascular Diseases

The importance of gut microbiota in health and disease is being highlighted by numerous research groups worldwide. Atherosclerosis, the leading cause of heart disease and stroke, is responsible for about 50% of all cardiovascular deaths. Recently, gut dysbiosis has been identified as a remarkable factor to be considered in the pathogenesis of cardiovascular diseases (CVDs). In this review, we briefly discuss how external factors such as dietary and physical activity habits influence host-microbiota and atherogenesis, the potential mechanisms of the influence of gut microbiota in host blood pressure and the alterations in the prevalence of those bacterial genera affecting vascular tone and the development of hypertension. We will also be examining the microbiota as a therapeutic target in the prevention of CVDs and the beneficial mechanisms of probiotic administration related to cardiovascular risks. All these new insights might lead to novel analysis and CVD therapeutics based on the microbiota.

Which probiotic has the best effect on preventing Clostridium difficile-associated diarrhea? A systematic review and network meta-analysis

OBJECTIVE

Clostridium difficile-associated diarrhea (CDAD) accounts for up to 25% of patients with antibiotic-associated diarrhea (AAD). We aimed to determine which probiotic is most effective in preventing CDAD using a network meta-analysis.

METHODS

Studies were identified by searching PubMed, EMBASE and the Cochrane Library databases for randomized controlled trials (RCTs) that evaluated the efficacy of probiotic interventions for CDAD. Primary outcomes were the incidence rates of AAD and CDAD, and secondary outcomes were the duration of diarrhea and the time until onset of diarrhea. The PROSPERO registered number of this study is CRD42018106115.

RESULTS

Ten RCTs including 11 analyses and including 4 692 patients were identified. Compared with the control group, probiotic intervention reduced the incidence rates of CDAD (odds ratio [OR] 0.33, 95% confidence interval [CI] 0.17-0.61) and AAD (OR 0.39, 95% CI 0.23-0.66). Similar results were observed regarding the duration of diarrhea and the time until onset of diarrhea. Meta-regression analysis showed a correlation between the type of probiotic used and the incidence of CDAD and AAD. All nine kinds of probiotic interventions were statistically more effective than the placebo, with Lactobacillus casei ranking as the best intervention (OR 0.19, 95% credible interval [CrI] 0.06-0.63) for decreasing the incidence rate of CDAD. L. casei also ranked the highest in reducing the incidence rate of AAD (OR 0.32, 95% CrI 0.14-0.74).

CONCLUSION

Lactobacilli strains, especially L. casei, have a good effect on the prevention of CDAD and AAD.

The effect of probiotics on the incidence of Clostridioides difficile: Retrospective cohort analysis

BACKGROUND

Conflicting evidence exists regarding probiotics and the incidence of Clostridioides difficile infection (CDI). This study evaluates whether probiotics are efficacious for CDI prophylaxis in patients receiving antibiotics.

METHODS

A retrospective cohort analysis of patients admitted to NYU Winthrop Hospital who received at least 1 dose of antibiotics considered high risk of inducing CDI. Patients were grouped according to probiotic use; association between probiotic use and incident CDI was examined. A model for incident CDI adjusting for known CDI risk factors was estimated.

RESULTS

Of 3,267 patients, 4.6% had CDI within 12 weeks of antibiotics initiation. A total of 5.1% received probiotics within 24 hours of initiation, and 6.6% initiated probiotics during the 12-week follow-up. Of those taking probiotics within 24 hours of antibiotics, 9.6% had CDI, and of those not taking probiotics 4.2% had CDI (relative risk, 2.3; 95% confidence interval, 1.4, 3.7). In time-dependent Cox models accounting for probiotic initiation and adjusting for potential confounders, a positive association between probiotics and CDI remained significant (hazard ratio, 2.7; P < .001).

DISCUSSION

Patients who received antibiotics with concurrent probiotics were more likely to have an incident of CDI compared with those who did not receive probiotics. Additional risk factors were histamine 2 receptor antagonists, proton pump inhibitors, and administration of multiple antibiotics simultaneously.

CONCLUSIONS

The present study, because of its large population and inclusion of multiple variables playing a role in CDI, serves as a valuable resource when considering efficacy of probiotics as CDI prophylaxis.

Lactobacillus sp as a Probiotic for the Prevention of Clostridium difficile Associated Diarrhea

Background: Antibiotic treatment can disturb the resistance of the gastrointestinal flora to colonization. This may result in complications, the most serious of which is Clostridium difficile associated diarrhea (CDAD). The aim of this study was to determine the effectiveness of probiotics for the prevention of CDAD.Method: The databases used were Scopus, Proquest, CINAHL, Medline, Pubmed and ScienceDirect, limited to having been published in the last 5 years. A literature review followed the keyword search. The keywords used were probiotics, Clostridium difficile, associated, diarrhea, randomized, control and trial using "AND" and “OR”. Twelve trials with 5102 participants were included. Eight trials reported a preventive effect for CDAD using a mixture of 2 strains of lactobacillus, a mixture of 4 combination strains, a mixture of lactobacillus and Saccharomyces or a mixture of Bifidobacterium, Lactobacillus and Saccharomyces.Result: Our findings indicate that probiotics may prevent CDAD. Most probiotics contain a singular strain. The combination with lactobacillus sp was the most effective at preventing CDAD.Conclusion: In addition, 6 out of 8 trials had an in relation to preventing CDAD containing lactobacillus sp. Four studies said that there were some factors that meant that the probiotic could not reduce or prevent the CDAD.

Enterococcus faecalis Isolated From Infant Feces Inhibits Toxigenic Clostridioides (Clostridium) difficile

Clostridioides (Clostridium) difficile infection is implicated as a major cause of antibiotic-associated diarrhea in hospitals worldwide. Probiotics, especially lactic acid bacteria, are the most frequently used alternative treatment. This study aims to identify potential probiotic enterococci strains that act against C. difficile strains and exert a protective effect on colon adenocarcinoma cells (HT-29 cells). To this end, nine Enterococcus strains isolated from the feces of breast-fed infants were investigated. They were identified as E. faecalis by 16s rRNA sequencing and MALDI-TOF. The probiotic properties including their viabilities in simulated gastrointestinal condition, cell adhesion ability, and their safety were evaluated. All strains exhibited more tolerance toward both pepsin and bile salts and adhered more tightly to HT-29 cells compared with the reference probiotic strain Lactobacillus plantarum ATCC 14917. Polymerase chain reaction (PCR) results exhibited that six of nine strains carried at least one virulence determinant gene; however, none exhibited virulence phenotypes or carried transferable antibiotic resistance genes. These strains did not infect Galleria mellonella when compared to pathogenic E. faecalis strain (p < 0.05). Moreover, their antibacterial activities against C. difficile were examined using agar well-diffusion, spore production, and germination tests. The six safe strains inhibited spore germination (100 - 98.20% ± 2.17%) and sporulation, particularly in C. difficile ATCC 630 treated with E. faecalis PK 1302. Furthermore, immunofluorescence assay showed that the cytopathic effects of C. difficile of HT-29 cells were reduced by the treatment with the cell-free supernatant of E. faecalis strains. These strains prevented rounding of HT-29 cells and preserved the F-actin microstructure and tight junctions between adjacent cells, which indicated their ability to reduce the clostridial cytopathic effects. Thus, the study identified six E. faecalis isolates that have anti-C. difficile activity. These could be promising probiotics with potential applications in the prevention of C. difficile colonization and treatment of C. difficile infection.

Probiotic Yogurt for the Prevention of Antibiotic-associated Diarrhea in Adults: A Randomized Double-blind Placebo-controlled Trial

GOAL

To evaluate the effect of yogurt supplemented with probiotic bacteria on the prevention of antibiotic-associated diarrhea (AAD) in hospitalized patients.

BACKGROUND

Diarrhea following antibiotic administration is a frequent clinical problem. The usefulness of probiotics for the prevention of AAD in the hospitalized adult population remains unclear.

STUDY

A randomized, double-blind, placebo-controlled clinical trial was conducted in hospitalized patients who started antibiotic treatment. Patients were randomized (2:2:1) to receive a daily amount of 200 mL of placebo-yogurt (Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus), 200 mL of probiotic yogurt (previous plus Lactobacillus acidophilus La-5, Bifidobacterium animalis subsp. lactis Bb-12 and Lactobacillus casei subsp. casei Lc-01 or no yogurt (unblinded control) within 48 hours of beginning the antibiotic therapy and up to 5 days after stopping the antibiotic. Patients were followed up with for 1 month to determine occurrence of diarrhea.

RESULTS

We included 314 patients, mean age 76 years. The rate of diarrhea was 23.0% in the probiotic group versus 17.6% in the placebo group, absolute risk reduction -5.35% (95% confidence interval, -15.4% to 4.7%; P=0.30). Rate of diarrhea was similar in the unblinded external control and in the blinded study groups combined (20.9% vs. 20.2% respectively; P=0.91). There was no difference in the duration of diarrhea, maximum number of bowel movements or prolonged admission because of diarrhea among the groups. All-cause mortality did not differ between groups.

CONCLUSIONS

The combined probiotic strains LA-5, BB-12, and LC-01 do not have an effect in the prevention of AAD in hospitalized patients.

Gut microbiotas and immune checkpoint inhibitor therapy response: a causal or coincidental relationship?

As the largest immune organ, human gut microbiome could influence the efficacy of immune checkpoint inhibitor therapy (ICI). However, identifying contributory microbes from over 35,000 species is virtually impossible and the identified microbes are not consistent among studies. The reason for the disparity may be that the microbes found in feces are markers of other factors that link immune response and microbiotas. Notably, gut microbiome is influenced by stool consistency, diet and other lifestyle factors. Therefore, the ICI and microbiotas relationship must be adjusted for potential confounders and analyzed longitudinally. Moreover, a recent study where 11 low-abundance commensal bacteria induced interferon-γ-producing CD8 T cells, challenges the validity of the abundance-oriented microbiotas investigations. This study also confirmed the hierarchy in immunogenic roles among microbiotas. Fecal transplantation trials in germ-free mice provided “the proof of principle” that germ-free mice reproduce the donor’s microbiome and corresponding ICI efficacy. However, species-specific biological differences prevent direct extrapolation between the results in murine and human models. Fecal transplantation or supplementation with microbes found in ICI responders requires caution due to potential adverse events.

Management of Clostridioides (formerly Clostridium) difficile infection (CDI) in solid organ transplant recipients: Guidelines from the American Society of Transplantation Community of Practice

These updated guidelines from the American Society of Transplantation Infectious Diseases Community of Practice address the prevention and management of Clostridium difficile infection in solid organ transplant (SOT) recipients. Clostridioides (formerly Clostridium) difficile infection (CDI) is among the most common hospital acquired infections. In SOT recipients, the incidence of CDI varies by type and number or organs transplanted. While a meta-analysis of published literature found the prevalence of postoperative CDI in the general surgical population to be approximately 0.51%, the prevalence of CDI that is seen in the solid organ transplant population ranges from a low of 3.2% in the pancreatic transplant population to 12.7% in those receiving multiple organ transplants. There are no randomized, controlled trials evaluating the management of CDI in the SOT population. Herein is a review and summary of the currently available literature that has been synthesized into updated treatment guidelines for the management of CDI in the SOT population.

Non-antibiotic therapy for Clostridioides difficile infection: a review

Clostridioides difficile infection (CDI) is a common infectious disease that is mainly caused by antibiotics. Antibiotic therapy is still the dominant treatment for CDI, although it is accompanied by side effects. Probiotics, fecal microbiota transplantation (FMT), engineered microorganisms, bacteriophages, diet, natural active substances, nanoparticles and compounds are examples of emerging non-antibiotic therapies that have received a great amount of attention. In this review, we collected data about different non-antibiotic therapies for CDI and provided a comprehensive analysis and detailed comparison of these therapies. The mechanism of action, therapeutic efficacy, and the strengths and weaknesses of these non-antibiotic therapies have been investigated to provide a basis for the reasonable alternative of non-antibiotic therapies for CDI. In summary, probiotics and FMT are currently the best choice for non-antibiotic therapy for CDI.

Probiotic use as prophylaxis for Clostridium difficile-associated diarrhea in a community hospital

This study was a retrospective chart review from January 1, 2015 through June 30, 2017, comparing the incidence of Clostridium difficile-associated diarrhea (CDAD) in patients taking select broad spectrum antibiotics with probiotics versus without probiotics. The purpose was to determine if probiotic use was associated with a reduction in the incidence of CDAD. A total of 5,574 hospital encounters were reviewed, showing a 0.96% incidence of CDAD in patients receiving a probiotic compared to a 2.19% incidence of CDAD in patients with no probiotic (risk ratio = 0.442; P = .00743). These findings show probiotic use was associated with a statistically significant lower incidence of positive C. difficile test results compared to no probiotic use.

Probiotics and prebiotics in clinical tests: an update

Probiotics have been explored in an exponentially increasing number of clinical trials for their health effects. Drawing conclusions from the published literature for the medical practitioner is difficult since rarely more than two clinical trials were conducted with the same probiotic strain against the same medical condition. Consequently, the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) made a few recommendations restricting it to probiotic use against acute gastroenteritis and antibiotic-associated diarrhea. Recent studies also made a strong case for probiotic use against sepsis in preterm and term infants from developing countries. Conclusions on the value of probiotics are best based on detailed meta-analyses (MA) of randomized controlled trials (RCT). Outcomes of MA are discussed in the present review for a number of gastroenterology conditions. Since these MA pool data from trials using different probiotic species, large RCT published sometimes come to different conclusions than MA including these studies. This is not necessarily a contradiction but may only mean that the specific probiotic species did not work under the specified conditions. Positive or negative generalization about probiotics and prebiotics should be avoided. Credible effects are those confirmed in independent trials with a specified probiotic strain or chemically defined prebiotic in a specified patient population under the specified treatment conditions. Even distinct technological preparations of the same probiotic strain might affect clinical outcomes if they alter bacterial surface structures. Underpowered clinical trials are another problem in the probiotic field. Data obtained with sophisticated omics technologies, but derived from less than ten human subjects should be interpreted with caution even when published in high impact journals.

Follow-on RifAximin for the Prevention of recurrence following standard treatment of Infection with Clostridium Difficile (RAPID): a randomised placebo controlled trial

BACKGROUND

Clostridium difficile infection (CDI) recurs after initial treatment in approximately one in four patients. A single-centre pilot study suggested that this could be reduced using 'follow-on' rifaximin treatment. We aimed to assess the efficacy of rifaximin treatment in preventing recurrence.

METHODS

A multisite, parallel group, randomised, placebo controlled trial recruiting patients aged ≥18 years immediately after resolution of CDI through treatment with metronidazole or vancomycin. Participants received either rifaximin 400 mg three times a day for 2 weeks, reduced to 200 mg three times a day for a further 2 weeks or identical placebo. The primary endpoint was recurrence of CDI within 12 weeks of trial entry.

RESULTS

Between December 2012 and March 2016, 151 participants were randomised to either rifaximin or placebo. Primary outcome data were available on 130. Mean age was 71.9 years (SD 15.3). Recurrence within 12 weeks was 29.5% (18/61) among participants allocated to placebo compared with 15.9% (11/69) among those allocated to rifaximin, a difference between groups of 13.7% (95% CI -28.1% to 0.7%, p=0.06). The risk ratio was 0.54 (95% CI 0.28 to 1.05, p=0.07). During 6-month safety follow-up, nine participants died in each group (12%). Adverse event rates were similar between groups.

CONCLUSION

While 'follow-on' rifaximin after CDI appeared to halve recurrence rate, we failed to reach our recruitment target in this group of frail elderly patients, so the estimated effect of rifaximin lacks precision. A meta-analysis including a previous trial suggests that rifaximin may be effective; however, further, larger confirmatory studies are needed.

Evaluating probiotics for the prevention of ventilator-associated pneumonia: a randomised placebo-controlled multicentre trial protocol and statistical analysis plan for PROSPECT

INTRODUCTION

Ventilator-associated pneumonia (VAP) is the most common healthcare-associated infection in critically ill patients. Prior studies suggest that probiotics may reduce VAP and other infections in critically ill patients; however, most previous randomised trials were small, single centre studies. The Probiotics: Prevention of Severe Pneumonia and Endotracheal Colonization Trial (PROSPECT) aims to determine the impact of the probiotic Lactobacillus rhamnosus GG on VAP and other clinically important outcomes in critically ill adults.

METHODS

PROSPECT is a multicentre, concealed, randomised, stratified, blinded, controlled trial in patients ≥18 years old, anticipated to be mechanically ventilated ≥72 hours, in intensive care units (ICUs) in Canada, the USA and Saudi Arabia. Patients receive either 1×10¹⁰ colony forming units of L. rhamnosus GG twice daily or an identical appearing placebo. Those at increased risk of probiotic infection are excluded. The primary outcome is VAP. Secondary outcomes are other ICU-acquired infections including Clostridioides difficile infection, diarrhoea (including antibiotic-associated diarrhoea), antimicrobial use, ICU and hospital length of stay and mortality. The planned sample size of 2650 patients is based on an estimated 15% VAP rate and will provide 80% power to detect a 25% relative risk reduction.

ETHICS AND DISSEMINATION

This protocol and statistical analysis plan outlines the methodology, primary and secondary analyses, sensitivity analyses and subgroup analyses. PROSPECT is approved by Health Canada (#9427-M1133-45C), the research ethics boards of all participating hospitals and Public Health Ontario. Results will be disseminated via academic channels (peer reviewed journal publications, professional healthcare fora including international conferences) and conventional and social media. The results of PROSPECT will inform practice guidelines worldwide.

TRIALREGISTRATION NUMBER

NCT02462590; Pre-results.

The Philosophy of Evidence-Based Principles and Practice in Nutrition

The practice of evidence-based nutrition involves using the best available nutrition evidence, together with clinical experience, to conscientiously work with patients' values and preferences to help them prevent (sometimes), resolve (sometimes), or cope with (often) problems related to their physical, mental, and social health. This article outlines the 3 fundamental principles of evidence-based practice as applied to the field of clinical nutrition. First, optimal clinical decision making requires awareness of the best available evidence, which ideally will come from unbiased systematic summaries of that evidence. Second, evidence-based nutrition provides guidance on how to decide which evidence is more or less trustworthy-that is, how certain can we be of our patients' prognosis, diagnosis, or of our therapeutic options? Third, evidence alone is never sufficient to make a clinical decision. Decision makers must always trade off the benefits with the risks, burden, and costs associated with alternative management strategies, and, in so doing, consider their patients' unique predicament, including their values and preferences.

Development of a bedside scoring system for predicting a first recurrence of Clostridium difficile-associated diarrhea

PURPOSE

A scoring system for identifying patients at high or low risk for recurrent Clostridium difficile-associated diarrhea (CDAD) is described.

METHODS

A retrospective cohort study was performed using data on adults with CDAD admitted to a 3-hospital system from 2009 to 2014. The primary endpoint was the rate of recurrent CDAD within 60 days of clinical cure of CDAD. Risk factors for CDAD recurrence were identified, and a risk prediction tool was developed using multivariate logistic regression.

RESULTS

The CDAD cure rate in the study cohort (n = 340) was 92.3%; the 60-day recurrence rate was 16.9%. Five factors were significantly associated with high recurrence risk: presence of CDAD at admission, body temperature of >37.8 °C at admission, leukocytosis, nosocomial CDAD, and abdominal distention on CDAD presentation. From that information a risk prediction tool, the CDAD "recurrence score," was developed (1 point is assigned for each factor present, for a maximum score of 5). Validation testing of the recurrence score indicated an area under the receiver operating characteristic curve of 0.72 (95% confidence interval, 0.65-0.80). A score of ≥2 had a negative predictive value of 91%, while a score of ≥4 had a positive predictive value of 70%.

CONCLUSION

If externally validated in future studies, a tool for predicting the risk of recurrent CDAD using data readily available at the time of presentation could allow clinicians to identify patients at high risk for recurrence, address modifiable risk factors, and select tailored treatments to improve patient outcomes.

Post-Antibiotic Gut Mucosal Microbiome Reconstitution Is Impaired by Probiotics and Improved by Autologous FMT

Probiotics are widely prescribed for prevention of antibiotics-associated dysbiosis and related adverse effects. However, probiotic impact on post-antibiotic reconstitution of the gut mucosal host-microbiome niche remains elusive. We invasively examined the effects of multi-strain probiotics or autologous fecal microbiome transplantation (aFMT) on post-antibiotic reconstitution of the murine and human mucosal microbiome niche. Contrary to homeostasis, antibiotic perturbation enhanced probiotics colonization in the human mucosa but only mildly improved colonization in mice. Compared to spontaneous post-antibiotic recovery, probiotics induced a markedly delayed and persistently incomplete indigenous stool/mucosal microbiome reconstitution and host transcriptome recovery toward homeostatic configuration, while aFMT induced a rapid and near-complete recovery within days of administration. In vitro, Lactobacillus-secreted soluble factors contributed to probiotics-induced microbiome inhibition. Collectively, potential post-antibiotic probiotic benefits may be offset by a compromised gut mucosal recovery, highlighting a need of developing aFMT or personalized probiotic approaches achieving mucosal protection without compromising microbiome recolonization in the antibiotics-perturbed host.

Enterotoxic Clostridia: Clostridioides difficile Infections

Clostridioides difficile is a Gram-positive, anaerobic, spore forming pathogen of both humans and animals and is the most common identifiable infectious agent of nosocomial antibiotic-associated diarrhea. Infection can occur following the ingestion and germination of spores, often concurrently with a disruption to the gastrointestinal microbiota, with the resulting disease presenting as a spectrum, ranging from mild and self-limiting diarrhea to severe diarrhea that may progress to life-threating syndromes that include toxic megacolon and pseudomembranous colitis. Disease is induced through the activity of the C. difficile toxins TcdA and TcdB, both of which disrupt the Rho family of GTPases in host cells, causing cell rounding and death and leading to fluid loss and diarrhea. These toxins, despite their functional and structural similarity, do not contribute to disease equally. C. difficile infection (CDI) is made more complex by a high level of strain diversity and the emergence of epidemic strains, including ribotype 027-strains which induce more severe disease in patients. With the changing epidemiology of CDI, our understanding of C. difficile disease, diagnosis, and pathogenesis continues to evolve. This article provides an overview of the current diagnostic tests available for CDI, strain typing, the major toxins C. difficile produces and their mode of action, the host immune response to each toxin and during infection, animal models of disease, and the current treatment and prevention strategies for CDI.

Probiotics in the next-generation sequencing era

Technological developments, including massively parallel DNA sequencing, gnotobiotics, metabolomics, RNA sequencing and culturomics, have markedly propelled the field of microbiome research in recent years. These methodologies can be harnessed to improve our in-depth mechanistic understanding of basic concepts related to consumption of probiotics, including their rules of engagement with the indigenous microbiome and impacts on the human host. We have recently demonstrated that even during probiotic supplementation, resident gut bacteria in a subset of individuals resist the mucosal presence of probiotic strains, limiting their modulatory effect on the microbiome and on the host gut transcriptional landscape. Resistance is partly alleviated by antibiotics treatment, which enables probiotics to interact with the host at the gut mucosal interface, although rather than promoting reconstitution of the indigenous microbiome and of the host transcriptional profile, they inhibit these components from returning to their naïve pre-antibiotic configurations. In this commentary, we discuss our findings in the context of previous and recent works, and suggest that incorporating the state-of-the-art methods currently utilized in microbiome research into the field of probiotics may lead to improved understanding of their mechanisms of activity, as well as their efficacy and long-term safety.

Mapping the microbial interactome: Statistical and experimental approaches for microbiome network inference

IMPACT STATEMENT

This review provides a comprehensive description of experimental and statistical tools used for network analyses of the human gut microbiome. Understanding the system dynamics of microbial interactions may lead to the improvement of therapeutic approaches for managing microbiome-associated diseases. Microbiome network inference tools have been developed and applied to both cross-sectional and longitudinal experimental designs, as well as to multi-omic datasets, with the goal of untangling the complex web of microbe-host, microbe-environmental, and metabolism-mediated microbial interactions. The characterization of these interaction networks may lead to a better understanding of the systems dynamics of the human gut microbiome, augmenting our knowledge of the microbiome's role in human health, and guiding the optimization of effective, precise, and rational therapeutic strategies for managing microbiome-associated disease.

Intestinal Barrier Function-Non-alcoholic Fatty Liver Disease Interactions and Possible Role of Gut Microbiota

Non-alcoholic fatty liver disease (NAFLD) is a metabolic stress liver injury that is closely related to obesity, insulin resistance, type 2 diabetes, atherosclerosis, and metabolic syndrome. The pathological features are diffuse hepatic vesicular steatosis, including non-alcoholic steatohepatitis, liver fibrosis, and even liver cancer. A variety of pathological outcomes cause serious harm to human health. At present, an increasing number of researchers are investigating the pathogenesis of NAFLD from the perspective of changes in the function of the intestinal barrier. The physical, chemical, immunological, and microbiological barriers in the intestinal tract constitute the complete intestinal barrier, which plays an important defensive role against the invasion of harmful substances from the intestines. Protecting the function of the intestinal barrier is a new way to treat NAFLD and its related diseases. In this perspective, we summarized the current knowledge of the role of the intestinal barrier in NAFLD.

You are what you eat: diet, health and the gut microbiota

Since the renaissance of microbiome research in the past decade, much insight has accumulated in comprehending forces shaping the architecture and functionality of resident microorganisms in the human gut. Of the multiple host-endogenous and host-exogenous factors involved, diet emerges as a pivotal determinant of gut microbiota community structure and function. By introducing dietary signals into the nexus between the host and its microbiota, nutrition sustains homeostasis or contributes to disease susceptibility. Herein, we summarize major concepts related to the effect of dietary constituents on the gut microbiota, highlighting chief principles in the diet-microbiota crosstalk. We then discuss the health benefits and detrimental consequences that the interactions between dietary and microbial factors elicit in the host. Finally, we present the promises and challenges that arise when seeking to incorporate microbiome data in dietary planning and portray the anticipated revolution that the field of nutrition is facing upon adopting these novel concepts.

Utility of Probiotics for Maintenance or Improvement of Health Status in Older People - A Scoping Review

OBJECTIVE

To evaluate the available evidence on probiotic use in older adults from human studies.

DESIGN

systematic review.

METHODS

The databases Embase, CINAHL and Medline were searched in December of 2017 for studies in humans where probiotics were used to modify a health outcome in older people. The quality of studies was evaluated using the Critical Appraisal Skills Program (CASP) assessment tool and the Cochrane Risk of Bias Assessment tool.

PARTICIPANTS

Subjects aged over sixty years either through specified selection criteria or where the mean participant age was greater than sixty.

INTERVENTIONS

Probiotic supplements.

MEASUREMENTS

Pre-specified clinically measurable health outcomes in age related conditions.

RESULTS

1210 articles were identified. After quality assessment and selection criteria were applied, 33 articles were identified to be included for review. As these studies cover a variety of applications and used customised protocols accordingly, meta-analysis was not possible and synthesis is in narrative form.

CONCLUSIONS

A growing body of research has applied commercially available probiotic preparations across care settings for age related conditions including gut dysmotility, osteoporosis, common infectious diseases and cognitive impairment. Although methodologies vary, randomised controlled trials have reproduced results in these areas, and so warrant consideration of probiotics as a low risk adjuvant treatment for specific indications in the elderly.

Antidiarrheal Efficacy of Probiotic Bacteria in Castor Oil Induced Diarrheal Mice

Probiotics may offer a safe intervention for diarrheal diseases. The aim of the present study was the assessment of the antidiarrheal property of probiotic bacteria. For their antidiarrheal efficacy assessment, yogurt was prepared using the isolated bacteria from selective regional yogurt of Bangladesh, and mice model trails were conducted using castor oil induced diarrheal mice. The probiotic treatment was applied on three mice groups, each having 6 mice and their respective doses were 50 mL/kg body weight in treatment group (TG) 1, 100 mL/kg body weight in TG2, and 150 mL/kg body weight in TG3. A four week treatment of probiotic significantly (P<0.001) reduced the percentage (67.37%) of diarrhea in TG3 (150 mL yogurt/kg body weight). All the treatment groups showed a significant (P<0.001) increase in the latent periods, reduced the total fecal output, and frequency and fecal water content compared to the negative control group. Serum electrolytes (Na⁺ and K⁺) and total protein levels were higher in the TG3 compared to the negative control group. Further research regarding molecular characterization and identification of specific genes and proteins of interest may help to develop the next generation bacteriocins and antidiarrheal drugs.