Strain-Specificity and Disease-Specificity of Probiotic Efficacy: A Systematic Review and Meta-Analysis

Effects of Bacterial Lysates and Metabolites on Collagen Homeostasis in TNF-α-Challenged Human Dermal Fibroblasts

During skin aging, the production of extracellular matrix (ECM) proteins, such as type I collagen, decreases and the synthesis of ECM-degrading matrix metalloproteinases (MMPs) rises, leading to an imbalance in homeostasis and to wrinkle formation. In this study, we examined the effects of bacterial lysates and metabolites from three bifidobacteria and five lactobacilli on collagen homeostasis in human dermal fibroblasts during challenge with tumor necrosis factor alpha (TNF-α), modeling an inflammatory condition that damages the skin's structure. Antiaging properties were measured, based on fibroblast cell viability and confluence, amount of type I pro-collagen, ratio of MMP-1 to type I pro-collagen, cytokines, and growth factors. The TNF-α challenge increased the MMP-1/type I pro-collagen ratio and levels of proinflammatory cytokines, as expected. With the probiotics, differences were clearly dependent on bacterial species, strain, and form. In general, the lysates elicited less pronounced responses in the biomarkers. Of all strains, the Bifidobacterium animalis ssp. lactis strains Bl-04 and B420 best maintained type I pro-collagen production and the MMP-1/collagen type I ratio under no-challenge and challenge conditions. Metabolites that were produced by bifidobacteria, but not their lysates, reduced several proinflammatory cytokines (IL-6, IL-8, and TNF-α) during the challenge, whereas those from lactobacilli did not. These results indicate that B. animalis ssp. lactis-produced metabolites, especially those of strains Bl-04 and B420, could support collagen homeostasis in the skin.

ESKAPEE Pathogen Biofilm Control on Surfaces with Probiotic Lactobacillaceae and Bacillus species

Combatting the rapidly growing threat of antimicrobial resistance and reducing prevalence and transmission of ESKAPEE pathogens in healthcare settings requires innovative strategies, one of which is displacing these pathogens using beneficial microorganisms. Our review comprehensively examines the evidence of probiotic bacteria displacing ESKAPEE pathogens, with a focus on inanimate surfaces. A systematic search was conducted using the PubMed and Web of Science databases on 21 December 2021, and 143 studies were identified examining the effects of Lactobacillaceae and Bacillus spp. cells and products on the growth, colonization, and survival of ESKAPEE pathogens. While the diversity of study methods limits evidence analysis, results presented by narrative synthesis demonstrate that several species have the potential as cells or their products or supernatants to displace nosocomial infection-causing organisms in a variety of in vitro and in vivo settings. Our review aims to aid the development of new promising approaches to control pathogen biofilms in medical settings by informing researchers and policymakers about the potential of probiotics to combat nosocomial infections. More targeted studies are needed to assess safety and efficacy of different probiotic formulations, followed by large-scale studies to assess utility in infection control and medical practice.

Current Viewpoint on Female Urogenital Microbiome-The Cause or the Consequence?

An increasing amount of evidence implies that native microbiota is a constituent part of a healthy urinary tract (UT), making it an ecosystem on its own. What is still not clear is whether the origin of the urinary microbial community is the indirect consequence of the more abundant gut microbiota or a more distinct separation exists between these two systems. Another area of uncertainty is the existence of a link between the shifts in UT microbial composition and both the onset and persistence of cystitis symptoms. Cystitis is one of the most common reasons for antimicrobial drugs prescriptions in primary and secondary care and an important contributor to the problem of antimicrobial resistance. Despite this fact, we still have trouble distinguishing whether the primary cause of the majority of cystitis cases is a single pathogen overgrowth or a systemic disorder affecting the entire urinary microbiota. There is an increasing trend in studies monitoring changes and dynamics of UT microbiota, but this field of research is still in its infancy. Using NGS and bioinformatics, it is possible to obtain microbiota taxonomic profiles directly from urine samples, which can provide a window into microbial diversity (or the lack of) underlying each patient's cystitis symptoms. However, while microbiota refers to the living collection of microorganisms, an interchangeably used term microbiome referring to the genetic material of the microbiota is more often used in conjunction with sequencing data. It is this vast amount of sequences, which are truly "Big Data", that allow us to create models that describe interactions between different species contributing to an UT ecosystem, when coupled with machine-learning techniques. Although in a simplified predator-prey form these multi-species interaction models have the potential to further validate or disprove current beliefs; whether it is the presence or the absence of particular key players in a UT microbial ecosystem, the exact cause or consequence of the otherwise unknown etiology in the majority of cystitis cases. These insights might prove to be vital in our ongoing struggle against pathogen resistance and offer us new and promising clinical markers.

Modern Approaches to the Diagnosis and treatment of <i>Clostridioides difficile (C. difficile)</i>-associated Disease in Adults (literature Review and Expert Council Resolution)

Aim: to review the modern approaches to the diagnosis and treatment ofC. difficile-associated disease in adults and present the resolution of the Expert Council held on March 25, 2023 in Moscow.

General provisions.C. difficileis the most important nosocomial pathogen which spores are also commonly found in the environment. Microbiota impairment, primarily due to the use of antibacterial drugs, is a key stage in the development ofC. difficile-associated disease. A search for an infection should be carried out only in patients with diarrhea, and it is advisable to use at least 2 laboratory methods. The drug of choice for first-line treatment is vancomycin. If drug treatment is ineffective or the patient has recurrent clostridial infection, fecal microbiota transplantation should be considered. The probiotic strainSaccharomyces boulardii CNCM I-745has a direct inhibitory effect onC. difficiletoxin A, promotes normalization of the intestinal microbiota composition, and decreases the inflammatory reaction in colonic mucosa colonized with a toxigenic strain ofC. difficile.

Conclusions. Addition of the probiotic strainSaccharomyces boulardii CNCM I-745to antibacterial therapy promotes both primary and secondary prevention ofC. difficile-associated disease.

Biochemical, functional and genomic characterization of a new probiotic Ligilactobacillus salivarius F14 from the gut of tribes of Odisha

Characterization of new potential probiotics is desirable in the field of research on probiotics for their extensive use in health and disease. Tribes could be an unusual source of probiotics due to their unique food habits and least dependence on medications and consumption of antibiotics. The aim of the present study is to isolate lactic acid bacteria from tribal fecal samples of Odisha, India, and characterize their genetic and probiotic attributes. In this context one of the catalase-negative and Gram-positive isolates, identified using 16S rRNA sequencing as Ligilactobacillus salivarius, was characterized in vitro for its acid and bile tolerance, cell adhesion and antimicrobial properties. The whole genome sequence was obtained and analyzed for strain level identification, presence of genomic determinants for probiotic-specific features, and safety. Genes responsible for its antimicrobial and immunomodulatory functions were detected. The secreted metabolites were analyzed using high resolution mass spectroscopy; the results indicated that the antimicrobial potential could be due to the presence of pyroglutamic acid, propionic acid, lactic acid, 2-hydroxyisocaproic acid, homoserine, and glutathione, and the immuno-modulating activity, contributed by the presence of short chain fatty acids such as acetate, propionate, and butyrate. So, to conclude we have successfully characterized a Ligilactobacillus salivarius species with potential antimicrobial and immunomodulatory ability. The health-promoting effects of this probiotic strain and/or its derivatives will be investigated in future.

Familial Hypercholesterolemia and Acute Coronary Syndromes: The Microbiota-Immunity Axis in the New Diagnostic and Prognostic Frontiers

Familial hypercholesterolemia is a common genetic disorder with a propensity towards early onset of atherosclerotic cardiovascular disease (CVD). The main goal of therapy is to reduce the LDL cholesterol and the current treatment generally consists of statin, ezetimibe and PCSK9 inhibitors. Unfortunately, lowering LDL cholesterol may be difficult for many reasons such as the variation of response to statin therapy among the population or the high cost of some therapies (i.e., PCSK9 inhibitors). In addition to conventional therapy, additional strategies may be used. The gut microbiota has been recently considered to play a part in chronic systemic inflammation and hence in CVD. Several studies, though they are still preliminary, consider dysbiosis a risk factor for various CVDs through several mechanisms. In this review, we provide an update of the current literature about the intricate relation between the gut microbiota and the familial hypercholesterolemia.

Big Data for a Small World: A Review on Databases and Resources for Studying Microbiomes

Microorganisms are ubiquitous in nature and form complex community networks to survive in various environments. This community structure depends on numerous factors like nutrient availability, abiotic factors like temperature and pH as well as microbial composition. Categorising accessible biomes according to their habitats would help in understanding the complexity of the environment-specific communities. Owing to the recent improvements in sequencing facilities, researchers have started to explore diverse microbiomes rapidly and attempts have been made to study microbial crosstalk. However, different metagenomics sampling, preprocessing, and annotation methods make it difficult to compare multiple studies and hinder the recycling of data. Huge datasets originating from these experiments demand systematic computational methods to extract biological information beyond microbial compositions. Further exploration of microbial co-occurring patterns across the biomes could help us in designing cross-biome experiments. In this review, we catalogue databases with system-specific microbiomes, discussing publicly available common databases as well as specialised databases for a range of microbiomes. If the new datasets generated in the future could maintain at least biome-specific annotation, then researchers could use those contemporary tools for relevant and bias-free analysis of complex metagenomics data.

Potential of Bifidobacterium lactis IDCC 4301 isolated from breast milk-fed infant feces as a probiotic and functional ingredient

Probiotics provide important health benefits to the host by improving intestinal microbial balance and have been widely consumed as dietary supplements. In this study, we investigated whether Bifidobacterium lactis IDCC 4301 (BL), isolated from feces of breast milk-fed infants, is safe to consume. Based on the guidelines established by the European Food Safety Authority (EFSA), safety tests such as antibiotic susceptibility, hemolysis, toxic compound formation (i.e., biogenic amine and d-lactate), single-dose acute oral toxicity, and extracellular enzymatic activities were performed. In addition, toxigenic genes, antibiotic resistance genes, and mobile genetic elements were investigated by analyzing the genome sequence of BL. BL was susceptible to eight antibiotics except for vancomycin and the absence of transferable resistance in the genome of this strain implied that vancomycin resistance is likely to be intrinsic. With regard to phenotypic characteristics, there was no concern of toxicity of this strain. Furthermore, BL utilized various carbohydrates and their conjugates through the activity of various endogenous carbohydrate-utilizing enzymes. Interestingly, the supernatant of the BL showed strong antipathogenic activity against various infectious pathogens. Therefore, we suggest that BL should be a safe probiotic and can be used as a functional ingredient in the food, cosmetic, and pharmaceutical industries.

The Role of the Gut Microbiome in Cancer Immunotherapy: Current Knowledge and Future Directions

Cancer immunotherapy is a treatment modality that aims to stimulate the anti-tumor immunity of the host to elicit favorable clinical outcomes. Immune checkpoint inhibitors (ICIs) gained traction due to the lasting effects and better tolerance in patients carrying solid tumors in comparison to conventional treatment. However, a significant portion of patients may present primary or acquired resistance (non-responders), and thus, they may have limited therapeutic outcomes. Resistance to ICIs can be derived from host-related, tumor-intrinsic, or environmental factors. Recent studies suggest a correlation of gut microbiota with resistance and response to immunotherapy as well as with the incidence of adverse events. Currently, preclinical and clinical studies aim to elucidate the unique microbial signatures related to ICI response and anti-tumor immunity, employing metagenomics and/or multi-omics. Decoding this complex relationship can provide the basis for manipulating the malleable structure of the gut microbiota to enhance therapeutic success. Here, we delve into the factors affecting resistance to ICIs, focusing on the intricate gut microbiome–immunity interplay. Additionally, we review clinical studies and discuss future trends and directions in this promising field.

Lactobacillus Bacteremia and Probiotics: A Review

Lactobacilli are widely found in nature, are commensal microbes in humans, and are commonly used as probiotics. Concerns about probiotic safety have arisen due to reports of bacteremia and other Lactobacillus-associated infections. We reviewed the literature for articles on the pathogenicity of Lactobacillus spp. bacteremia and reports of probiotics in these patients. Our aim is to review these articles and update the present knowledge on the epidemiology of Lactobacillus spp. bacteremia and determine the role of probiotics in Lactobacillus bacteremia. Lactobacillus bacteremia is infrequent but has a higher risk of mortality and risk factors, including severe underlying diseases, immune system suppression, admission to intensive care units, and use of central venous catheters. A variety of Lactobacillus species may cause bacteremia and may or may not be associated with probiotic exposure. To determine if oral probiotics are the source of these infections, the blood isolates and the oral probiotic strain(s) must be compared by sensitive identification methods. The prevalence of Lactobacillus bacteremia is infrequent but is more common in patients taking probiotics compared to those not taking probiotics. Three probiotics (Lacticaseibacillus rhamnosus GG, Lactiplantibacillus plantarum, and Lacticaseibacillus paracasei) were directly linked with blood isolates from bacteremia patients using molecular identification assays.

A review of probiotics in the treatment of autism spectrum disorders: Perspectives from the gut–brain axis

Autism spectrum disorders (ASD) are a class of neurodevelopmental conditions with a large societal impact. Despite existing evidence suggesting a link between ASD pathogenesis and gut–brain axis dysregulation, there is no systematic review of the treatment of probiotics on ASD and its associated gastrointestinal abnormalities based on the gut–brain axis. Therefore, we performed an analysis for ASD based on preclinical and clinical research to give a comprehensive synthesis of published evidence of a potential mechanism for ASD. On the one hand, this review aims to elucidate the link between gastrointestinal abnormalities and ASD. Accordingly, we discuss gut microbiota dysbiosis regarding gut–brain axis dysfunction. On the other hand, this review suggests that probiotic administration to regulate the gut–brain axis might improve gastrointestinal symptoms, restore ASD-related behavioral symptoms, restore gut microbiota composition, reduce inflammation, and restore intestinal barrier function in human and animal models. This review suggests that targeting the microbiota through agents such as probiotics may represent an approach for treating subsets of individuals with ASD.

A Microbial-Based Approach to Mental Health: The Potential of Probiotics in the Treatment of Depression

Probiotics are currently the subject of intensive research pursuits and also represent a multi-billion-dollar global industry given their vast potential to improve human health. In addition, mental health represents a key domain of healthcare, which currently has limited, adverse-effect prone treatment options, and probiotics may hold the potential to be a novel, customizable treatment for depression. Clinical depression is a common, potentially debilitating condition that may be amenable to a precision psychiatry-based approach utilizing probiotics. Although our understanding has not yet reached a sufficient level, this could be a therapeutic approach that can be tailored for specific individuals with their own unique set of characteristics and health issues. Scientifically, the use of probiotics as a treatment for depression has a valid basis rooted in the microbiota-gut-brain axis (MGBA) mechanisms, which play a role in the pathophysiology of depression. In theory, probiotics appear to be ideal as adjunct therapeutics for major depressive disorder (MDD) and as stand-alone therapeutics for mild MDD and may potentially revolutionize the treatment of depressive disorders. Although there is a wide range of probiotics and an almost limitless range of therapeutic combinations, this review aims to narrow the focus to the most widely commercialized and studied strains, namely Lactobacillus and Bifidobacterium, and to bring together the arguments for their usage in patients with major depressive disorder (MDD). Clinicians, scientists, and industrialists are critical stakeholders in exploring this groundbreaking concept.

The effects of Bacillus coagulans MTCC 5856 on functional gas and bloating in adults: A randomized, double-blind, placebo-controlled study

BACKGROUND

Gut microbiome dysbiosis is a major cause of abdominal gas, bloating, and distension. Bacillus coagulans MTCC 5856 (LactoSpore) is a spore-forming, thermostable, lactic acid-producing probiotic that has numerous health benefits. We evaluated the effect of Lacto Spore on improving the clinical symptoms of functional gas and bloating in healthy adults.

METHODS

Multicenter, randomized, double-blind, placebo-controlled study at hospitals in southern India. Seventy adults with functional gas and bloating with a gastrointestinal symptom rating scale (GSRS) indigestion score ≥ 5 were randomized to receive B coagulans MTCC 5856 (2 billion spores/day, N = 35) or placebo (N = 35) for 4 weeks. Changes in the GSRS-Indigestion subscale score for gas and bloating and global evaluation of patient's scores from screening to the final visit were the primary outcomes. The secondary outcomes were Bristol stool analysis, brain fog questionnaire, changes in other GSRS subscales, and safety.

RESULTS

Two participants from each group withdrew from the study and 66 participants (n = 33 in each group) completed the study. The GSRS indigestion scores changed significantly (P < .001) in the probiotic group (8.91-3.06; P < .001) compared to the placebo (9.42-8.43; P = .11). The median global evaluation of patient's scores was significantly better (P < .001) in the probiotic group (3.0-9.0) than in the placebo group (3.0-4.0) at the end of the study. The cumulative GSRS score, excluding the indigestion subscale, decreased from 27.82 to 4.42% (P < .001) in the probiotic group and 29.12 to 19.33% (P < .001) in the placebo group. The Bristol stool type improved to normal in both the groups. No adverse events or significant changes were observed in clinical parameters throughout the trial period.

CONCLUSIONS

Bacillus coagulans MTCC 5856 may be a potential supplement to reduce gastrointestinal symptoms in adults with abdominal gas and distension.

Saccharomyces boulardii prophylaxis for targeted antibiotics and infectious indications to reduce healthcare facility-onset Clostridioides difficile infection

BACKGROUND

Probiotic prophylaxis for Clostridioides difficile infection (CDI) is controversial stemming from deficits in strain and disease specificity considerations and concern for adverse effects. Here risk for healthcare facility-onset CDI (HO-CDI) dependent on concomitant antibiotic and infectious indication is assessed to identify opportunities for targeted prophylaxis.

METHODS

Retrospective matched-cohort study from January 2016 through March 2019. Patient-admissions administered high risk antibiotics were categorized by Saccharomyces boulardii administration and matched 1:1 to non-recipients. Unadjusted and adjusted HO-CDI risk estimated using Cox proportional hazards regression.

RESULTS

S. boulardii administration was associated with 48% risk reduction for HO-CDI compared to non-recipients (aHR 0.52, 95% CI: 0.31-0.87). Patient-admissions administered antibiotics and S. boulardii for a pneumonia indication exhibited a 57% reduction in risk for HO-CDI (aHR 0.43, 95% CI: 0.19-0.95). Administration of S. boulardii with ceftriaxone was associated with a 76% reduced risk of HO-CDI (aHR 0.24, 95% CI: 0.11-0.53) compared to ceftriaxone without S. boulardii, number needed to treat of 100.

CONCLUSIONS

S. boulardii administration is associated with a significant HO-CDI risk reduction for inpatients receiving antibiotics associated with CDI. Institutions interested in targeted use of S. boulardii to limit potential adverse effects may consider prophylaxis for inpatients with pneumonia or receiving ceftriaxone.

Restorative effects of probiotics on memory impairment in sleep-deprived mice

BACKGROUND

Insufficient sleep is a serious public health epidemic in modern society, impairing memory and other cognitive functions. In this study, partial sleep deprivation (SD) was used to induce cognitive impairment in mice to determine the effects of probiotics on subsequent cognitive deficits.

METHODS

Lactiplantibacillus plantarum Lp-115 (Lp-115), Lacticaseibacillus paracasei Lpc-37 (Lpc-37), Bifidobacterium animalis subsp. lactis 420 (B420) and their combination were administered to mice subjected to partial SD and compared with non-SD and SD vehicle groups. Mice were administered a daily oral gavage containing either 1 × 10⁹ colony forming units (CFU) of single-strain, 1.5 × 10⁹ CFU of multi-strain (5 × 10⁸ CFU/strain), or vehicle for thirty days prior to and for nine days during a behavioural test paradigm. The novel object recognition (NOR) test, spontaneous alternation Y-maze (Y-maze), and the step-through passive avoidance (STPA) task were applied to evaluate learning and memory performance following partial SD.

RESULTS

Partial SD had a significant impact on cognitive function in vehicle mice. Intervention with Lpc-37 significantly improved recognition memory deficits in the NOR test, spatial working memory deficits in the Y-maze, and contextual long-term memory impairments in the STPA task, in mice subjected to partial SD compared to the SD vehicle group. The multi-strain significantly improved recognition memory deficits in the NOR test and spatial working memory deficits in the Y-maze in mice subjected to partial SD compared to the SD vehicle group.

CONCLUSIONS

These findings demonstrate that Lpc-37 and the multi-strain may play a role in alleviating memory impairments and improve cognitive function in partially sleep-deprived mice.

Orally Ingested Probiotic, Prebiotic, and Synbiotic Interventions as Countermeasures for Gastrointestinal Tract Infections in Nonelderly Adults: A Systematic Review and Meta-Analysis

Meta-analyses have not examined the prophylactic use of orally ingested probiotics, prebiotics, and synbiotics for preventing gastrointestinal tract infections (GTIs) of various etiologies in adult populations, despite evidence that these gut microbiota-targeted interventions can be effective in treating certain GTIs. This systematic review and meta-analysis aimed to estimate the effects of prophylactic use of orally ingested probiotics, prebiotics, and synbiotics on GTI incidence, duration, and severity in nonelderly, nonhospitalized adults. CENTRAL, PubMed, Scopus, and Web of Science were searched through January 2022. English-language, peer-reviewed publications of randomized, placebo-controlled studies testing an orally ingested probiotic, prebiotic, or synbiotic intervention of any dose for ≥1 wk in adults who were not hospitalized, immunosuppressed, or taking antibiotics were included. Results were analyzed using random-effects meta-analyses of intention-to-treat (ITT) and complete case (CC) cohorts. Heterogeneity was explored by subgroup meta-analysis and meta-regression. The risk of bias was assessed using the Cochrane risk-of-bias 2 tool. Seventeen publications reporting 20 studies of probiotics (n = 16), prebiotics (n = 3), and synbiotics (n = 1) were identified (n > 6994 subjects). In CC and ITT analyses, risk of experiencing ≥1 GTI was reduced with probiotics (CC analysis-risk ratio: 0.86; 95% CI: 0.73, 1.01) and prebiotics (risk ratio: 0.80; 95% CI: 0.66, 0.98). No effects on GTI duration or severity were observed. Sources of heterogeneity included the study population and number of probiotic strains administered but were often unexplained, and a high risk of bias was observed for most studies. The specific effects of individual probiotic strains and prebiotic types could not be assessed owing to a lack of confirmatory studies. Findings indicated that both orally ingested probiotics and prebiotics, relative to placebo, demonstrated modest benefit for reducing GTI risk in nonelderly adults. However, results should be interpreted cautiously owing to the low number of studies, high risk of bias, and unexplained heterogeneity that may include probiotic strain-specific or prebiotic-specific effects. This review was registered at PROSPERO as CRD42020200670.

Effects of a high-prebiotic diet versus probiotic supplements versus synbiotics on adult mental health: The "Gut Feelings" randomised controlled trial

Background

Preliminary evidence supports the use of dietary interventions and gut microbiota-targeted interventions such as probiotic or prebiotic supplementation for improving mental health. We report on the first randomised controlled trial (RCT) to examine the effects of a high-prebiotic dietary intervention and probiotic supplements on mental health.

Methods

"Gut Feelings" was an 8-week, 2 × 2 factorial RCT of 119 adults with moderate psychological distress and low prebiotic food intake. Treatment arms: (1) probiotic supplement and diet-as-usual (probiotic group); (2) high-prebiotic diet and placebo supplement (prebiotic diet group); (3) probiotic supplement and high-prebiotic diet (synbiotic group); and (4) placebo supplement and diet-as-usual (placebo group). The primary outcome was assessment of total mood disturbance (TMD; Profile of Mood States Short Form) from baseline to 8 weeks. Secondary outcomes included anxiety, depression, stress, sleep, and wellbeing measures.

Results

A modified intention-to-treat analysis using linear mixed effects models revealed that the prebiotic diet reduced TMD relative to placebo at 8 weeks [Cohen's d = -0.60, 95% confidence interval (CI) = -1.18, -0.03; p = 0.039]. There was no evidence of symptom improvement from the probiotic (d = -0.19, 95% CI = -0.75, 0.38; p = 0.51) or synbiotic treatments (d = -0.03, 95% CI = -0.59, 0.53; p = 0.92). Improved anxiety, stress, and sleep were noted in response to the prebiotic diet while the probiotic tentatively improved wellbeing, relative to placebo. No benefit was found in response to the synbiotic intervention. All treatments were well tolerated with few adverse events.

Conclusion

A high-prebiotic dietary intervention may improve mood, anxiety, stress, and sleep in adults with moderate psychological distress and low prebiotic intake. A synbiotic combination of high-prebiotic diet and probiotic supplement does not appear to have a beneficial effect on mental health outcomes, though further evidence is required. Results are limited by the relatively small sample size.

Clinical trial registration

https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=372753, identifier ACTRN12617000795392.

A Single-Center, Retrospective Cohort Study Evaluating the Use of Probiotics for the Prevention of Hospital-Onset Clostridioides difficile Infection in Hospitalized Patients Receiving Intravenous Antibiotics

Background

Exposure to antimicrobials is a known risk factor for Clostridioides difficile infection (CDI). Antimicrobials cause collateral damage by disrupting the natural intestinal microbiota allowing for C. difficile to thrive and production of C. difficile toxins. Probiotics could modulate the onset and course of CDI. However, the data on probiotics for the prevention of CDI is conflicting.

Objective

To evaluate the rates of hospital-onset Clostridioides difficile infection (HO-CDI) among patients who received intravenous (IV) antibiotics plus probiotics versus IV antibiotics alone.

Design

Retrospective, single-center cohort study.

Methods

We included adult patients that received at least 1 dose of IV antibiotics and had a hospital length of stay of at least 3 days between August 2017 and July 2020. Patients were separated into 2 cohorts, either receipt of probiotics or non-receipt of probiotics. Patients with positive C. difficile toxin test prior to antibiotic therapy, or receipt of only C. difficile active treatment were excluded. The primary outcome was incidence of HO-CDI in patients who received IV antibiotics plus probiotics compared to those that received IV antibiotics alone. Logistic regression was performed to account for confounding variables.

Results

We identified 17 598 patients that received IV antibiotics alone and 2659 patients received IV antibiotics plus probiotics. HO-CDI occurred in 46 (0.26%) of those that received antibiotics alone compared to 5 (0.19%) of those that received probiotics with IV antibiotics (OR 0.72, 95% CI 0.28-1.81). ICU admission (OR 1.81, 95% CI 1.02-3.19) and history of CDI (OR 3.37, 95% CI 1.07-10.97) in the past 12 months were associated with a higher incidence of HO-CDI.

Conclusion

The addition of probiotics did not reduce the incidence of HO-CDI among inpatients receiving IV antibiotics.

In Vitro Screen of Lactobacilli Strains for Gastrointestinal and Vaginal Benefits

Traditional probiotics comprise mainly lactic acid bacteria that are safe for human use, tolerate acid and bile, and adhere to the epithelial lining and mucosal surfaces. In this study, one hundred commercial and non-commercial strains that were isolated from human feces or vaginal samples were tested with regards to overall growth in culture media, tolerance to acid and bile, hydrogen peroxide (H₂O₂) production, and adhesion to vaginal epithelial cells (VECs) and to blood group antigens. As a result, various of the tested lactobacilli strains were determined to be suitable for gastrointestinal or vaginal applications. Commercial strains grew better than the newly isolated strains, but tolerance to acid was a common property among all tested strains. Tolerance to bile varied considerably between the strains. Resistance to bile and acid correlated well, as did VEC adhesion and H₂O₂ production, but H₂O₂ production was not associated with resistance to bile or acid. Except for L. iners strains, vaginal isolates had better overall VEC adhesion and higher H₂O₂ production. Species- and strain-specific differences were evident for all parameters. Rank-ordered clustering with nine clusters was used to identify strains that were suitable for gastrointestinal or vaginal health, demonstrating that the categorization of strains for targeted health indications is possible based on the parameters that were measured in this study.

Commercial probiotic products in public health: current status and potential limitations

Consumption of commercial probiotics for health improvement and disease treatment has increased in popularity among the public in recent years. The local shops and pharmacies are brimming with various probiotic products such as probiotic food, dietary supplement and pharmaceuticals that herald a range of health benefits, from nutraceutical benefits to pharmaceutical effects. However, although the probiotic market is expanding rapidly, there is increasing evidence challenging it. Emerging insights from microbiome research and public health demonstrate several potential limitations of the natural properties, regulatory frameworks, and market consequences of commercial probiotics. In this review, we highlight the potential safety and performance issues of the natural properties of commercial probiotics, from the genetic level to trait characteristics and probiotic properties and further to the probiotic-host interaction. Besides, the diverse regulatory frameworks and confusing probiotic guidelines worldwide have led to product consequences such as pathogenic contamination, overstated claims, inaccurate labeling and counterfeit trademarks for probiotic products. Here, we propose a plethora of available methods and strategies related to strain selection and modification, safety and efficacy assessment, and some recommendations for regulatory agencies to address these limitations to guarantee sustainability and progress in the probiotic industry and improve long-term public health and development.

Antimicrobial potential of known and novel probiotics on in vitro periodontitis biofilms

Several oral diseases are characterized by a shift within the oral microbiome towards a pathogenic, dysbiotic composition. Broad-spectrum antimicrobials are often part of patient care. However, because of the rising antibiotic resistance, alternatives are increasingly desirable. Alternatively, supplying beneficial species through probiotics is increasingly showing favorable results. Unfortunately, these probiotics are rarely evaluated comparatively. In this study, the in vitro effects of three known and three novel Lactobacillus strains, together with four novel Streptococcus salivarius strains were comparatively evaluated for antagonistic effects on proximal agar growth, antimicrobial properties of probiotic supernatant and the probiotic's effects on in vitro periodontal biofilms. Strain-specific effects were observed as differences in efficacy between genera and differences within genera. While some of the Lactobacillus candidates were able to reduce the periodontal pathobiont A. actinomycetemcomitans, the S. salivarius strains were not. However, the S. salivarius strains were more effective against periodontal pathobionts P. intermedia, P. gingivalis, and F. nucleatum. Vexingly, most of the Lactobacillus strains also negatively affected the prevalence of commensal species within the biofilms, while this was lower for S. salivarius strains. Both within lactobacilli and streptococci, some strains showed significantly more inhibition of the pathobionts, indicating the importance of proper strain selection. Additionally, some species showed reductions in non-target species, which can result in unexpected and unexplored effects on the whole microbiome.

Real-time polymerase chain reaction methods for strain specific identification and enumeration of strain Lacticaseibacillus paracasei 8700:2

Introduction

Reliable and accurate methods for probiotic identification and enumeration, at the strain level plays a major role in confirming product efficacy since probiotic health benefits are strain-specific and dose-dependent. In this study, real-time PCR methods were developed for strain specific identification and enumeration of L. paracasei 8700:2, a probiotic strain that plays a role in fighting the common cold.

Methods

The assay was designed to target a unique region in L. paracasei 8700:2 genome sequence to achieve strain level specificity. The identification assay was evaluated for specificity and sensitivity. The enumeration viability real-time PCR (v-qPCR) method was first optimized for the viability treatment, then the method was evaluated for efficiency, limit of quantification, precision, and its performance was compared to plate count (PC) and viability droplet digital PCR (v-ddPCR) methods.

Results

The identification method proved to be strain specific and highly sensitive with a limit of detection of 0.5 pg of DNA. The optimal viability dye (PMAxx) concentration was 50 μM. The method was efficient (> 90% with R 2 values > 0.99), with a linear dynamic range between 6*102 and 6*105 copies. The method was highly precise with a relative standard deviation below 5%. The Pearson correlation coefficient (r) was 0.707 for PC and v-qPCR methods, and 0.922 for v-qPCR and v-ddPCR. Bland-Altman method comparison showed that v-qPCR always gave higher values compared to PC method (relative difference ranging from 119% to 184%) and showed no consistent trend (relative difference ranging from -20% to 22%) when comparing v-qPCR and v-ddPCR methods.

Discussion

The difference between PC and v-PCR methods can potentially be attributed to the proportion of cells that exist in a viable but non culturable (VBNC) state, which can be count by v-PCR but not with PC. The developed v-qPCR method was confirmed to be strain specific, sensitive, efficient, with low variance, able to count VBNC cells, and has shorter time to results compared to plate count methods. Thus, the identification and enumeration methods developed for L. paracasei 8700:2 will be of great importance to achieve high quality and efficacious probiotic products.

Fungal feelings in the irritable bowel syndrome: the intestinal mycobiome and abdominal pain

Although the gut microbiota consists of bacteria, viruses, and fungi, most publications addressing the microbiota-gut-brain axis in irritable bowel syndrome (IBS) have a sole focus on bacteria. This may relate to the relatively low presence of fungi and viruses as compared to bacteria. Yet, in the field of inflammatory bowel disease research, the publication of several papers addressing the role of the intestinal mycobiome now suggested that these low numbers do not necessarily translate to irrelevance. In this review, we discuss the available clinical and preclinical IBS mycobiome data, and speculate how these recent findings may relate to earlier observations in IBS. By surveying literature from the broader mycobiome research field, we identified questions open to future IBS-oriented investigations.

Microbiome-targeting therapies in the neonatal intensive care unit: safety and efficacy

Microbiome-targeting therapies have received great attention as approaches to prevent disease in infants born preterm, but their safety and efficacy remain uncertain. Here we summarize the existing literature, focusing on recent meta-analyses and systematic reviews that evaluate the performance of probiotics, prebiotics, and/or synbiotics in clinical trials and studies, emphasizing interventions for which the primary or secondary outcomes were prevention of necrotizing enterocolitis, late-onset sepsis, feeding intolerance, and/or reduction in hospitalization length or all-cause mortality. Current evidence suggests that probiotics and prebiotics are largely safe but conclusions regarding their effectiveness in the neonatal intensive care unit have been mixed. To address this ambiguity, we evaluated publications that collectively support benefits of probiotics with moderate to high certainty evidence in a recent comprehensive network meta-analysis, highlighting limitations in these trials that make it difficult to support with confidence the routine, universal administration of probiotics to preterm infants.

Orally Administered Probiotics in the Prevention of Chemotherapy (± Radiotherapy)-Induced Gastrointestinal Toxicity: A Systematic Review With Meta-Analysis of Randomized Trials

BACKGROUND

Chemoradiotherapy-induced gastrointestinal toxicity may lead to a significant impairment of the oncological patient's quality of life, as well as to reduced adherence to the treatment, which may have a negative impact on survival and mortality rates.

OBJECTIVE

The aim of this review was to investigate whether oral probiotic administration prevents chemotherapy (± radiotherapy)-induced gastrointestinal toxicity, particularly diarrhea.

METHODS

We searched the MEDLINE, Web of Science, and SCOPUS databases for randomized controlled trials in English published between 1990 and 2020. We conducted statistical data analyses expressing the treatment effect size as a risk ratio (RR) together with a 95% confidence interval (CI). Implications are based on trials rated as having a low risk of bias (RoB).

RESULTS

We included 8 trials (n = 697 participants), from which 3 studies rated as low RoB contained primary endpoint data; the risk of developing grade 3/4 diarrhea in patients receiving probiotics was reduced by 78% compared to the control group (RR = 0.22 [95% CI 0.05-1.08]; P = .06; n = 114 participants). Probiotics showed preventive effects in patients treated with chemotherapy alone (RR = 0.34 [0.12-0.94]; P = .04, n = 121 participants) and in patients with colorectal cancer (RR = 0.56 [0.34-0.92]; P = .02; n = 208 participants). The reduction in the incidence of overall diarrhea was not significant.

CONCLUSIONS

Probiotics failed to prove a preventive effect of statistical significance against the development of severe and overall diarrhea in cancer patients treated with chemotherapy (± radiotherapy). However, we cannot rule out that the effects of probiotics are clinically relevant, especially in certain subgroups of patients. This needs to be clarified in further well-performed studies.

Probiotic Bifidobacteria Mitigate the Deleterious Effects of para-Cresol in a Drosophila melanogaster Toxicity Model

Renal impairment associated with chronic kidney disease (CKD) causes the buildup of uremic toxins that are deleterious to patient health. Current therapies that manage toxin accumulation in CKD offer an incomplete therapeutic effect against toxins such as para-cresol (p-cresol) and p-cresyl sulfate. Probiotic therapies can exploit the wealth of microbial diversity to reduce toxin accumulation. Using in vitro culture techniques, strains of lactobacilli and bifidobacteria from a 24-strain synbiotic were investigated for their ability to remove p-cresol. Four strains of bifidobacteria internalized p-cresol from the extracellular environment. The oral supplementation of these toxin-clearing probiotics was more protective than control strains in a Drosophila melanogaster toxicity model. Bifidobacterial supplementation was also associated with higher abundance of lactobacilli in the gut microbiota of p-cresol-exposed flies. The present findings suggest that these strains might reduce p-cresol in the gut in addition to increasing the prevalence of other beneficial bacteria, such as lactobacilli, and should be tested clinically to normalize the dysbiotic gut microbiota observed in CKD patients. IMPORTANCE Chronic kidney disease (CKD) affects approximately 10% of the global population and has limited treatment options. The accumulation of gut microbiota-derived uremic toxins, such as para-cresol (p-cresol) and p-cresyl sulfate, is associated with the onset of comorbidities (i.e., atherosclerosis and cognitive disorders) in CKD. Unfortunately, dialysis, the gold standard therapy is unable to remove these toxins from the bloodstream due to their highly protein-bound nature. Some strains of Bifidobacterium have metabolic properties that may be useful in managing uremic toxicity. Using a Drosophila model, the present work highlights why dosing with certain probiotic strains may be clinically useful in CKD management.

The Mechanism of Important Components in Canine Fecal Microbiota Transplantation

Fecal microbiota transplantation (FMT) is a potential treatment for many intestinal diseases. In dogs, FMT has been shown to have positive regulation effects in treating Clostridioides difficile infection (CDI), inflammatory bowel disease (IBD), canine parvovirus (CPV) enteritis, acute diarrhea (AD), and acute hemorrhagic diarrhea syndrome (AHDS). FMT involves transplanting the functional components of a donor's feces into the gastrointestinal tract of the recipient. The effective components of FMT not only include commensal bacteria, but also include viruses, fungi, bacterial metabolites, and immunoglobulin A (IgA) from the donor feces. By affecting microbiota and regulating host immunity, these components can help the recipient to restore their microbial community, improve their intestinal barrier, and induce anti-inflammation in their intestines, thereby affecting the development of diseases. In addition to the above components, mucin proteins and intestinal epithelial cells (IECs) may be functional ingredients in FMT as well. In addition to the abovementioned indications, FMT is also thought to be useful in treating some other diseases in dogs. Consequently, when preparing FMT fecal material, it is important to preserve the functional components involved. Meanwhile, appropriate fecal material delivery methods should be chosen according to the mechanisms these components act by in FMT.

Probiotics and synbiotics in chronic constipation in adults: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND & AIMS

Probiotics and synbiotics have been increasingly investigated for the management of chronic constipation. We aimed to investigate the effect of probiotics and synbiotics on stool output, gut transit time, symptoms and quality of life in adults with chronic constipation via a systematic review and meta-analysis of randomized controlled trials (RCTs).

METHODS

Studies were identified using electronic databases, backward citation and hand-searching abstracts. The search date was 10 July 2022. RCTs reporting administration of probiotics or synbiotics in adults with chronic constipation were included. Risk of bias (RoB) was assessed with the Cochrane RoB 2.0 tool. Meta-analysis was conducted separately for probiotics and synbiotics. Results were synthesized using risk ratios (RRs), mean differences or standardized mean differences (SMDs) and 95% confidence intervals (CIs) using a random-effects model.

RESULTS

Thirty RCTs investigating probiotics and four RCTs investigating synbiotics were included. Overall, 369/647 (57%) responded to probiotic treatment and 252/567 (44%) to control (RR 1.28, 95% CI 1.07, 1.52, p = 0.007). Probiotics increased stool frequency (SMD 0.71, 95% CI 0.37, 1.04, p < 0.00001), with Bifidobacterium lactis having a significant effect, but not mixtures of probiotics, Bacillus coagulans Unique IS2 or Lactobacillus casei Shirota. Probiotics did not impact stool consistency (SMD 0.26, 95% CI -0.03, 0.54, p = 0.08). Probiotics improved integrative symptom scores compared to control (SMD -0.46, 95% CI -0.89, -0.04). Synbiotics did not impact stool output or integrative symptom scores compared to control.

CONCLUSIONS

Certain probiotics may improve response to treatment, stool frequency and integrative constipation symptoms, providing cautious optimism for their use as a dietary management option. There is currently insufficient evidence to recommend synbiotics in the management of chronic constipation. Caution is needed when interpreting these results due to high heterogeneity and risk of bias amongst the studies.

[Diverticular disease: treatment and management by general practitioners in Germany - high importance of probiotics in primary care]

INTRODUCTION

The symptomatic uncomplicated diverticular disease (SUDD) is often difficult to treat and guidelines only provide few evidence-based treatment options.

METHOD

For the German-wide survey, a questionnaire was sent to 13790 physicians. It contained questions concerning the status of medical care for patients with diverticula and queried their individual option in regards to current treatment options and challenges for the daily medical routine.

RESULTS

In total, 526 questionnaires were sent back for analysis. The biggest challenge for doctors handling patients with chronic diverticular disease (SUDD) is to make the correct diagnosis (17%) and the distinction to the irritable bowel syndrome (22%). Despite the high abundance of SUDD pathology, only 6% of the medical practitioners feel themselves sufficiently informed about it. The support for general practitioners by medical specialists (gastroenterologists) is limited: In the case of a SUDD or a diverticulitis diagnosis, the physicians sometimes receive an acute therapy plan (27%), but rarely get recommendations for diverticulitis pre- and post-care (11% and 18%), or assisting information for patient education (4%). For primary prophylaxis for persons with asymptomatic diverticula, practitioners give nutrition (41%) and life style (37%) recommendations, as well as probiotics (18%). After an acute diverticulitis, 42% recommend life style and nutrition modifications and 26% the intake of probiotics. For the treatment of SUDD symptoms, they advise mostly life style and nutrition modifications (45%) and probiotics (30%). About 60% of the doctors are satisfied with the efficacy of probiotics. Another 15% stated that they have not yet used them to treat SUDD. The main reasons for it seem to be the lack of reimbursability for probiotics (31%), the poor adherence of patients to therapy (20%) due to the slow onset of positive effects, and the difficulty of finding an evidence-based probiotic (16%).

CONCLUSION

In the daily medical routine the correct diagnosing of SUDD is a major challenge and supporting information by medical specialist is scarce. Physicians frequently choose life style and nutrition recommendations and the use of probiotics as treatment options. The majority of the general practitioners is thereby satisfied with the efficacy of probiotics for patients with chronic diverticular disease, even though the choice of an evidence-based probiotic is an obstacle.

An Integrated Analytical Approach for the Characterization of Probiotic Strains in Food Supplements

Research surrounding health benefits from probiotics is becoming popular because of the increasing demand for safer products with protective and therapeutic effects. Proven benefits are species- or genus-specific; however, no certified assays are available for their characterization and quantification at the strain level in the food supplement industry. The objective of this study was to develop a strain-specific Real-time quantitative polymerase chain reaction (RT-qPCR)-based method to be implemented in routine tests for the identification and quantification of Bifidobacterium longum, Bifidobacterium animalis spp. lactis, Lactobacillus paracasei, Lactobacillus rhamnosus, Lactobacillus casei, Bifidobacterium breve, Lactobacillus acidophilus, Lactobacillus plantarum, and Lactobacillus helveticus, starting from a powder mixture of food supplements. The method optimization was carried out in combination with flow cytometry to compare results between the two strategies and implement the analytical workflow with the information also regarding cell viability. These assays were validated in accordance with the International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use (ICH) criteria using the plate count enumeration as the gold standard reference. Briefly, probiotic DNAs were extracted from two powder food supplements. Strain-specific primers targeting unique sequence regions of 16S RNA were identified and amplified by RT-qPCR. Primers were tested for specificity, sensitivity, and efficiency. Both RT-qPCR and flow-cytometry methods described in our work for the quantification and identification of Lactobacillus and Bifidobacterium strains were specific, sensitive, and precise, showing better performances with respect to the morphological colony identification. This work demonstrated that RT-qPCR can be implemented in the quality control workflow of commercial probiotic products giving more standardized and effective results regarding species discrimination.

Effects of early postnatal life nutritional interventions on immune-microbiome interactions in the gastrointestinal tract and implications for brain development and function

The gastrointestinal (GI) microbiota has co-evolved with the host in an intricate relationship for mutual benefit, however, inappropriate development of this relationship can have detrimental effects. The developing GI microbiota plays a vital role during the first 1,000 days of postnatal life, during which occurs parallel development and maturation of the GI tract, immune system, and brain. Several factors such as mode of delivery, gestational age at birth, exposure to antibiotics, host genetics, and nutrition affect the establishment and resultant composition of the GI microbiota, and therefore play a role in shaping host development. Nutrition during the first 1,000 days is considered to have the most potential in shaping microbiota structure and function, influencing its interactions with the immune system in the GI tract and consequent impact on brain development. The importance of the microbiota-GI-brain (MGB) axis is also increasingly recognized for its importance in these developmental changes. This narrative review focuses on the importance of the GI microbiota and the impact of nutrition on MGB axis during the immune system and brain developmental period in early postnatal life of infants.

[Efficacy of Saccharomyces boulardii CNCM I-745 probiotic drug in the prevention and treatment of diarrhea in hospitalized patients with new coronavirus infection COVID-19]

AIM

To evaluate the efficacy of Saccharomyces boulardii (S. boulardii) CNCM I-745 probiotic drug in preventing and treating diarrhea in hospitalized patients with COVID-19.

MATERIALS AND METHODS

A prospective comparative study was conducted in two parallel groups. The study included males and females aged 18 to 60 with the following diagnosis confirmed by polymerase chain reaction: U07.2 Coronavirus infection COVID-19, caused by SARS-CoV-2 virus (grade 1-3 pneumonia according to CT scan). All patients received antibiotic therapy. The patients were subdivided into two equal groups (n=60) depending on the administration of S. boulardii CNCM I-745 probiotic drug in addition to standard treatment. The probiotic was prescribed by the attending physician; the dose was 2 capsules per day (500 mg/day) 30 min before the meal for 10 days. All patients were monitored for main clinical, laboratory, and instrumental parameters during the study. In addition, the symptom of diarrhea (stool with a frequency of more than 3 times a day of type 6 and 7 according to the Bristol stool scale), including its frequency, duration, and the number of bowel movements of loose stool per day were precisely evaluated in both groups.

RESULTS

In the overall patient pool, diarrhea was reported in 21.7% of in-patients during the observation period (95% confidence interval [CI] 14.2-29.1) with a mean duration of 4.6154 days (95% CI 3.7910-5.4398). The incidence of diarrhea in group 1 was 13.3% (95% CI 4.5-22.2), and in group 2, it was 30.0% (95% CI 18.1-41.9). Relative risk showed that the use of the S. boulardii CNCM I-745 probiotic drug leads to a significant reduction in the risk of diarrhea in hospitalized patients with COVID-19 infection receiving antibiotic therapy (odds ratio [OR] 0.3590, 95% CI 0.1421-0.9069; p=0.0303). In group 1, the duration of diarrhea was 3.1250 days (95% CI 2.5892-3.6608) versus 5.2778 days (95% CI 4.2290-6.3265) in group 2, p=0.0112. The mean daily frequency of loose stools in patients with diarrhea in group 1 was 3.2500 (95% CI 2.6588-3.8412) versus 4.3889 (95% CI 3.7252-5.0525) in group 2, p=0.0272. The secondary endpoint, duration of hospital stay, was also significantly shorter in group 1 patients - 11.6833 days (95% CI 11.2042-12.1625) versus 12.7333 days (95% CI 12.1357-13.3309) in group 2, p=0.0120.

CONCLUSION

The present prospective comparative study demonstrated that adding S. boulardii CNCM I-745 probiotic drug into the standard treatment regimen of patients with new coronavirus infection COVID-19 receiving antibiotic therapy helps reduce the incidence of diarrhea and its severity during hospitalization, as well as the duration of hospital stay.

Meta-analysis of 16S rRNA microbial data identified alterations of the gut microbiota in COVID-19 patients during the acute and recovery phases

BACKGROUND

Dozens of studies have demonstrated gut dysbiosis in COVID-19 patients during the acute and recovery phases. However, a consensus on the specific COVID-19 associated bacteria is missing. In this study, we performed a meta-analysis to explore whether robust and reproducible alterations in the gut microbiota of COVID-19 patients exist across different populations.

METHODS

A systematic review was conducted for studies published prior to May 2022 in electronic databases. After review, we included 16 studies that comparing the gut microbiota in COVID-19 patients to those of controls. The 16S rRNA sequence data of these studies were then re-analyzed using a standardized workflow and synthesized by meta-analysis.

RESULTS

We found that gut bacterial diversity of COVID-19 patients in both the acute and recovery phases was consistently lower than non-COVID-19 individuals. Microbial differential abundance analysis showed depletion of anti-inflammatory butyrate-producing bacteria and enrichment of taxa with pro-inflammatory properties in COVID-19 patients during the acute phase compared to non-COVID-19 individuals. Analysis of microbial communities showed that the gut microbiota of COVID-19 recovered patients were still in unhealthy ecostates.

CONCLUSIONS

Our results provided a comprehensive synthesis to better understand gut microbial perturbations associated with COVID-19 and identified underlying biomarkers for microbiome-based diagnostics and therapeutics.

Probiotics beyond the farm: Benefits, costs, and considerations of using antibiotic alternatives in livestock

The increasing global expansion of antimicrobial resistant infections warrants the development of effective antibiotic alternative therapies, particularly for use in livestock production, an agricultural sector that is perceived to disproportionately contribute to the antimicrobial resistance (AMR) crisis by consuming nearly two-thirds of the global antibiotic supply. Probiotics and probiotic derived compounds are promising alternative therapies, and their successful use in disease prevention, treatment, and animal performance commands attention. However, insufficient or outdated probiotic screening techniques may unintentionally contribute to this crisis, and few longitudinal studies have been conducted to determine what role probiotics play in AMR dissemination in animal hosts and the surrounding environment. In this review, we briefly summarize the current literature regarding the efficacy, feasibility, and limitations of probiotics, including an evaluation of their impact on the animal microbiome and resistome and their potential to influence AMR in the environment. Probiotic application for livestock is often touted as an ideal alternative therapy that might reduce the need for antibiotic use in agriculture and the negative downstream impacts. However, as detailed in this review, limited research has been conducted linking probiotic usage with reductions in AMR in agricultural or natural environments. Additionally, we discuss the methods, including limitations, of current probiotic screening techniques across the globe, highlighting approaches aimed at reducing antibiotic usage and ensuring safe and effective probiotic mediated health outcomes. Based on this information, we propose economic and logistical considerations for bringing probiotic therapies to market including regulatory roadblocks, future innovations, and the significant gaps in knowledge requiring additional research to ensure probiotics are suitable long-term options for livestock producers as an antibiotic alternative therapy.

In Vitro Assessment of Probiotic and Technological Properties of Lactic Acid Bacteria Isolated from Indigenously Fermented Cereal-Based Food Products

The present study concerns the isolation and characterization of potential probiotic bacteria isolated from indigenously fermented cereal-based products commonly produced by tribal people of the Aravali hills region of India and the documentation of their unexplored probiotic attributes. The isolated strains were evaluated for probiotic attributes, such as bile salt and acid tolerance, lysozyme and phenol tolerance, antagonistic and antifungal activity, cell autoaggregation, cell-surface hydrophobicity, simulated gastric and pancreatic digestion, antioxidative potential, bile salt hydrolase activity, and H2O2 production. The safety of isolates was assessed by antibiotic sensitivity, hemolytic activity, DNase activity, and biogenic amine production assays, while technological properties, such as fermenting ability, amylolytic activity, and EPS production, were also evaluated. A total of 70 LAB isolates were screened initially, and 6 strains showed good potential as probiotic candidates in in vitro assessments. The efficient strains were identified using phenotyping and biochemical characterization, which results were further confirmed and recognized at the strain level using phylogenetic analysis and 16S rDNA sequencing. The current study has shown that Lactiplantibacillus plantarum KMUDR7 isolated from “Makka ki Raab” has excellent probiotic attributes and could be a potential probiotic for product preparation. However, other strains, Lactobacillus delbrueckii subsp. bulgaricus KMUDR1 and Lacticaseibacillus rhamnosus KMUDR9, showed good properties, while KMUDR14, -17, and -20 also have comparable probiotic attributes.

Ameliorative effect of Lactobacillus rhamnosus GG on acetaminophen-induced hepatotoxicity via PKC/Nrf2/PGC-1α pathway

Background

Acetaminophen (APAP) overdose is a common cause of hepatotoxicity. Antioxidants like N-acetyl cysteine are recommended as a therapeutic option; nevertheless, it has limitations. The search for efficient alternatives is ongoing. Probiotics are live microorganisms that maintain a healthy gut microecology. Lactobacillus rhamnosus GG (LGG) is one of the widely used probiotics. Our study aimed to assess the protective and therapeutic effects of probiotic LGG on APAP-induced hepatotoxicity and evaluate the molecular pathways behind this effect.

Methods

Wistar Albino male rats were randomly distributed into the following experimental groups: group 1, non-treated rats (vehicle); group 2, rats received oral gavage of suspension of probiotic LGG (5 × 10¹⁰ CFU GG/0.5 ml in PBS) daily for 2 weeks (probiotic control); group 3, rats received APAP dose of 2 g/kg body weight (positive control); group 4, rats received oral gavage of suspension of probiotic LGG for 2 weeks followed by a single dose of APAP injection (prophylactic); and group 5, rats received a single dose of APAP and then 24 h later treated with oral gavage of probiotic LGG daily for 2 weeks (treatment).

Results

Our study revealed that administration of probiotic LGG (either as prophylactic or treatment) exhibited a remarkable reduction in APAP-induced liver injury as resembled by the decrease in liver enzymes (ALT and AST) and the histopathological features of liver sections. Moreover, the significant reduction in the oxidative marker malondialdehyde, along with the enhancement in glutathione reductase, and the significant reduction in inflammatory markers (nitric oxide and tumor necrosis factor-α) were all indicators of the efficiency of LGG in ameliorating the alterations accompanied with APAP-induced hepatotoxicity. Our findings also demonstrate that LGG administration boosted the expression of Nrf2 and PGC-1 while decreasing the expression of protein kinase C (PKC). As a result, the nuclear abundance of Nrf2 is increased, and the expression of various antioxidants is eventually upregulated.

Conclusion

Our study shows that probiotic LGG supplementation exerts a prophylactic and therapeutic effect against APAP-induced hepatotoxicity through modulating the expression of PKC and the Nrf2/PGC-1α signaling pathway and eventually suppressing oxidative damage from APAP overdose.

Benefits of probiotic use on COVID-19: A systematic review and meta-analysis

SARS-CoV-2 is the virus that causes the new global pandemic, which has already resulted in millions of deaths, affecting the world's health and economy. Probiotics have shown benefits in a variety of diseases, including respiratory infections, and may be beneficial in the adjunctive treatment of COVID-19. This study analyzed the effectiveness of probiotics as adjunctive treatment in reducing symptoms of patients with COVID-19, through a systematic review with meta-analysis. The EMBASE (Elsevier), Pubmed, Scopus, Web of Science and International Clinical Trials Registry Platform (ICTRP) were searched through March 16, 2022. The risk ratio (RR) with 95% confidence intervals (CIs) was estimated using a fixed-effect model. RoB 2 and ROBINS I were used to assess the risk of bias of the included studies. Nine studies were included (7 clinical trials and 2 cohorts), of which three clinical trials comprised the meta-analysis. Results showed that probiotics were associated with a significant 51% reduction in symptoms reported by COVID-19 patients (RR 0.49, 95% CI 0.40-0.61). There was a significant improvement in cough (RR 0.56, 95% CI 0.37-0.83), headaches (RR 0.17, 95% CI 0.05-0.65), and diarrhea (RR 0. 33, 95% CI 0.12-0.96) of patients on probiotic therapy. These findings suggest that probiotic supplementation is effective in improving symptoms of COVID-19.

Lactobacilli: Legal Regulation and Prospects for New Generation Drugs

The global probiotics industry has been undergoing major changes in recent years. Approaches to finding and creating new probiotics, as well as a paradigm of their use in food, medicine, and pharmacology are changing. The catalyst proved to be the increasing popularity and availability of omics technologies, in particular, metagenomic studies of human and animal microbiomes. However, the efficiency and safety of drugs based on probiotic strains, as well as their marketing rates, largely depend on the levels of legal and technical regulation in the field. The present review discusses the aspects of legal regulation in Russia, the European Union and the United States, along with the advantages and disadvantages of probiotics and postbiotics. A consensus is emerging that postbiotics have a number of advantages over classical live probiotic cultures. The review also focuses on the lactobacilli family, which includes the largest number of probiotic strains studied so far and still holds a leading position among probiotics. On the legislative front, Russia is often ahead of its time with adopting such laws as the Federal Law No. 492-FZ on biosecurity, which defined the concept of human and animal microbiota and set forth legislative guidelines for its preservation. The new field of research referred to as microbiome nutrigenomics aims to achieve this goal.

Randomized, direct comparison study of Saccharomyces boulardii CNCM I-745 versus multi-strained Bacillus clausii probiotics for the treatment of pediatric acute gastroenteritis

BACKGROUND

The choice of an appropriate probiotic for pediatric acute gastroenteritis (PAGE) can be confusing. Our aim was to compare the efficacy and safety of 2 probiotics (Saccharomyces boulardii CNCM I-745 vs a 4-strain mixture of Bacillus clausii O/C, SIN, N/R, T) for the treatment of PAGE.

METHODS

A 2-arm parallel, randomized trial recruited children (6 months to 5 years old) with mild-moderate acute diarrhea, from 8 centers in Argentina. A total of 317 children were enrolled and blindly randomized to 5 days of either S boulardii CNCM I-745 (n = 159) or a 4-strain mixture of B clausii (n = 158), then followed for 7 days post-probiotic treatment. A stool sample was collected at inclusion for pathogen identification. The primary outcome was duration of diarrhea defined as the time from enrollment to the last loose stool followed by the first 24-hour period with stool consistency improvement. Secondary outcomes included frequency of loose stools/day, severity of diarrhea, number reporting no diarrhea at Day 6, time-to-first formed stool, recurrence of diarrhea by study end (Day 12) and safety outcomes.

RESULTS

Three hundred twelve (98%) children completed the study. S boulardii CNCM I-745 showed a significant reduction (P = .04) in the mean duration of diarrhea (64.6 hours, 95% confidence interval [CI] 56.5-72.8) compared to those given B clausii (78.0 hours, 95% CI 69.9-86.1). Both probiotics showed improvement in secondary outcomes and were well-tolerated.

CONCLUSION

In this study, S boulardii CNCM I-745 demonstrated better efficacy than B clausii mix for reducing the duration of pediatric acute diarrhea.

Glycerol strengthens probiotic effect of Limosilactobacillus reuteri in oral biofilms: a synergistic synbiotic approach

Both in vitro and in vivo studies have shown that the probiotic Limosilactobacillus reuteri can improve oral health. L. reuteri species are known to produce the antimicrobial 'reuterin' from glycerol. In order to further increase its antimicrobial activity, this study evaluated the effect of the combined use of glycerol and Limosilactobacillus reuteri (ATCC PTA 5289) in view of using a synergistic synbiotic over a probiotic. An antagonistic agar growth and a multispecies biofilm model showed that the antimicrobial potential of the probiotic was significantly enhanced against periodontal pathobionts and anaerobic commensals when supplemented with glycerol. Synbiotic biofilms also showed a significant reduction in inflammatory expression of human oral keratinocytes (HOK-18A), but only when the keratinocytes were preincubated with the probiotic. Probiotic preincubation of keratinocytes or probiotic- and synbiotic treatment of biofilms alone were insufficient to significantly reduce inflammatory expression. Overall, this study shows that combining glycerol with the probiotic L. reuteri into a synergistic synbiotic can greatly improve the effectiveness of the latter. One sentence summary: The use of a synbiotic formulation of Limosilactobacillus reuteri with glycerol over the probiotic improves antimicrobial effects and reduced inflammatory response to oral biofilms. This article is protected by copyright. All rights reserved.

Antioxidant and Antibacterial Effects of Potential Probiotics Isolated from Korean Fermented Foods

A total of sixteen bacterial strains were isolated and identified from the fourteen types of Korean fermented foods that were evaluated for their in vitro probiotic potentials. The results showed the highest survivability for Bacillus sp. compared to Lactobacillus sp. in simulated gastric pH, and it was found to be maximum for B. inaquosorum KNUAS016 (8.25 ± 0.08 log10 CFU/mL) and minimum for L. sakei KNUAS019 (0.8 ± 0.02 log10 CFU/mL) at 3 h of incubation. Furthermore, B. inaquosorum KNUAS016 and L. brevis KNUAS017 also had the highest survival rates of 6.86 ± 0.02 and 5.37 ± 0.01 log10 CFU/mL, respectively, in a simulated intestinal fluid condition at 4 h of incubation. The percentage of autoaggregation at 6 h for L. sakei KNUAS019 (66.55 ± 0.33%), B. tequilensis KNUAS015 (64.56 ± 0.14%), and B. inaquosorum KNUAS016 (61.63 ± 0.19%) was >60%, whereas it was lower for L. brevis KNUAS017 (29.98 ± 0.09%). Additionally, B. subtilis KNUAS003 showed higher coaggregation at 63.84 ± 0.19% while B. proteolyticus KNUAS001 found at 30.02 ± 0.33%. Among them, Lactobacillus sp. showed the best non-hemolytic activity. The highest DPPH and ABTS radical scavenging activity was observed in L. sakei KNUAS019 (58.25% and 71.88%). The cell-free supernatant of Lactobacillus sp. considerably inhibited pathogenic growth, while the cell-free supernatant of Bacillus sp. was moderately inhibited when incubated for 24 h. However, the overall results found that B. subtilis KNUAS003, B. proteolyticus KNUAS012, L. brevis KNUAS017, L. graminis KNUAS018, and L. sakei KNUAS019 were recognized as potential probiotics through different functional and toxicity assessments.

Larval gut microbiome of Pelidnota luridipes (Coleoptera: Scarabaeidae): high bacterial diversity, different metabolic profiles on gut chambers and species with probiotic potential

Pelidnota luridipes Blanchard (1850) is a tropical beetle of the family Scarabaeidae, whose larvae live on wood without parental care. Microbiota of mid- and hindgut of larvae was evaluated by culture-dependent and independent methods, and the results show a diverse microbiota, with most species of bacteria and fungi shared between midgut and hindgut. We isolated 272 bacterial and 29 yeast isolates, identified in 57 and 7 species, respectively, while using metabarcoding, we accessed 1,481 and 267 OTUs of bacteria and fungi, respectively. The composition and abundance of bacteria and fungi differed between mid- and hindgut, with a tendency for higher richness and diversity of yeasts in the midgut, and bacteria on the hindgut. Some taxa are abundant in the intestine of P. luridipes larvae, such as Firmicutes, Bacteroidetes, Proteobacteria, and Actinobacteria; as well as Saccharomycetales and Trichosporonales yeasts. Mid- and hindgut metabolic profiles differ (e.g. biosynthesis of amino acids, cofactors, and lipopolysaccharides) with higher functional diversity in the hindgut. Isolates have different functional traits such as secretion of hydrolytic enzymes and antibiosis against pathogens. Apiotrichum siamense L29A and Bacillus sp. BL17B protected larvae of the moth Galleria mellonella, against infection by the pathogens Listeria monocytogenes ATCC19111 and Pseudomonas aeruginosa ATCC 9027. This is the first work with the larval microbiome of a Rutelini beetle, demonstrating its diversity and potential in prospecting microbial products as probiotics. The functional role of microbiota for the nutrition and adaptability of P. luridipes larvae needs to be evaluated in the future.

In vitro assessment of histamine and lactate production by a multi-strain synbiotic

Recent studies suggest histamine and d-lactate may negatively impact host health. As excess histamine is deleterious to the host, the identification of bacterial producers has contributed to concerns over the consumption of probiotics or live microorganisms in fermented food items. Some probiotic products have been suspected of inducing d-lactic-acidosis; an illness associated with neurocognitive symptoms such as ataxia. The goals of the present study were to test the in vitro production of histamine and d-lactate by a 24-strain daily synbiotic and to outline methods that others can use to test for their production. Using enzymatic based assays, no significant production of histamine was observed compared to controls (P > 0.05), while d-lactate production was comparable to a commercially available probiotic with no associated health risk. These assays provide a means to add to the safety profile of synbiotic and probiotic products.

Factors influencing development of the infant microbiota: from prenatal period to early infancy

During early life, the gut microbial composition rapidly changes by maternal microbiota composition, delivery mode, infant feeding mode, antibiotic usage, and various environmental factors, such as the presence of pets and siblings. An integrative study on the diet, the microbiota, and genomic activity at the transcriptomic level may give an insight into the role of diet in shaping the human/microbiome relationship. Disruption in the gut microbiota (i.e., gut dysbiosis) has been linked to necrotizing enterocolitis in infancy, as well as some chronic diseases in later, including obesity, diabetes, inflammatory bowel disease, cancer, allergies, and asthma. Therefore, understanding the impact of maternal-to-infant transfer of dysbiotic microbes and then modifying infant early colonization or correcting early-life gut dysbiosis might be a potential strategy to overcome chronic health conditions.

Orally administered Odoribacter laneus improves glucose control and inflammatory profile in obese mice by depleting circulating succinate

BACKGROUND

Succinate is produced by both human cells and by gut bacteria and couples metabolism to inflammation as an extracellular signaling transducer. Circulating succinate is elevated in patients with obesity and type 2 diabetes and is linked to numerous complications, yet no studies have specifically addressed the contribution of gut microbiota to systemic succinate or explored the consequences of reducing intestinal succinate levels in this setting.

RESULTS

Using germ-free and microbiota-depleted mouse models, we show that the gut microbiota is a significant source of circulating succinate, which is elevated in obesity. We also show in vivo that therapeutic treatments with selected bacteria diminish the levels of circulating succinate in obese mice. Specifically, we demonstrate that Odoribacter laneus is a promising probiotic based on its ability to deplete succinate and improve glucose tolerance and the inflammatory profile in two independent models of obesity (db/db mice and diet-induced obese mice). Mechanistically, this is partly mediated by the succinate receptor 1. Supporting these preclinical findings, we demonstrate an inverse correlation between plasma and fecal levels of succinate in a cohort of patients with severe obesity. We also show that plasma succinate, which is associated with several components of metabolic syndrome including waist circumference, triglycerides, and uric acid, among others, is a primary determinant of insulin sensitivity evaluated by the euglycemic-hyperinsulinemic clamp.

CONCLUSIONS

Overall, our work uncovers O. laneus as a promising next-generation probiotic to deplete succinate and improve glucose tolerance and obesity-related inflammation. Video Abstract.

The gut-immune-brain axis in neurodevelopment and neurological disorders

The gut-brain axis is gaining momentum as an interdisciplinary field addressing how intestinal microbes influence the central nervous system (CNS). Studies using powerful tools, including germ-free, antibiotic-fed, and fecal microbiota transplanted mice, demonstrate how gut microbiota perturbations alter the fate of neurodevelopment. Probiotics are also becoming more recognized as potentially effective therapeutic agents in alleviating symptoms of neurological disorders. While gut microbes may directly communicate with the CNS through their effector molecules, including metabolites, their influence on neuroimmune populations, including newly discovered brain-resident T cells, underscore the host immunity as a potent mediator of the gut-brain axis. In this review, we examine the unique immune populations within the brain, the effects of the gut microbiota on the CNS, and the efficacy of specific probiotic strains to propose the novel concept of the gut-immune-brain axis.