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

Oral microbiota of adolescents with dental caries: A systematic review

OBJECTIVE

This systematic review summarizes the current knowledge on the association between the oral microbiota and dental caries in adolescents.

DESIGN

An electronic search was carried out across five databases. Studies were included if they conducted research on generally healthy adolescents, applied molecular-based microbiological analyses and assessed caries status. Data extraction was performed by two reviewers and the Newcastle-Ottawa Scale was applied for quality assessment.

RESULTS

In total, 3935 records were reviewed which resulted in a selection of 20 cross-sectional studies (published 2005-2022) with a sample size ranging from 11 to 614 participants including adolescents between 11 and 19 years. The studies analyzed saliva, dental biofilm or tongue swabs with Checkerboard DNA-DNA hybridization, (q)PCR or Next-Generation Sequencing methods. Prevotella denticola, Scardoviae Wiggsiae, Streptococcus sobrinus and Streptococcus mutans were the most frequently reported species presenting higher abundance in adolescents with caries. The majority of the studies reported that the microbial diversity was similar between participants with and without dental caries.

CONCLUSION

This systematic review is the first that shows how the oral microbiota composition in adolescents appears to differ between those with and without dental caries, suggesting certain taxa may be associated with increased caries risk. However, there is a need to replicate and expand these findings in larger, longitudinal studies that also focus on caries severity and take adolescent-specific factors into account.

Real-time PCR methods for identification and stability monitoring of Bifidobacterium longum subsp. longum UABl-14 during shelf life

Bifidobacterium longum subsp. longum UABl-14™ is an important probiotic strain that was found to support digestive health. Here we present the development and validation of real-time PCR methods for strain-specific identification and enumeration of this important strain. The identification method was evaluated for specificity using 22 target samples and 30 non-target samples. All target samples successfully amplified, while no amplification was observed from any non-target samples including other B. longum strains. The identification method was evaluated for sensitivity using three DNA dilution series and the limit of detection was 2 pg. of DNA. Coupled with a viability dye, the method was further validated for quantitative use to enumerate viable cells of UABl-14. The viability dye treatment (PMAxx) was optimized, and a final concentration of 50 μM was found as an effective concentration to inactivate DNA in dead cells from reacting in PCR. The reaction efficiency, linear dynamic range, repeatability, and reproducibility were also evaluated. The reaction efficiency was determined to be 97.2, 95.2, and 95.0% with R2 values of 99%, in three replicates. The linear dynamic range was 1.3 × 102 to 1.3 × 105 genomes. The relative standard deviation (RSD%) for repeatability ranged from 0.03 to 2.80, and for reproducibility ranged from 0.04 to 2.18. The ability of the validated enumeration method to monitor cell counts during shelf life was evaluated by determining the viable counts and total counts of strain UABl-14 in 18 multi-strain finished products. The viable counts were lower than label claims in seven products tested post-expiration and were higher than label claims in products tested pre-expiration, with a slight decrease in viable counts below label claim in three samples that were tested 2-3 months pre-expiration. Interestingly, the total counts of strain UABl-14 were consistently higher than label claims in all 18 products. Thus, the method enables strain-specific stability monitoring in finished products during shelf life, which can be difficult or impossible to achieve using the standard plate count method. The validated methods allow for simultaneous and cost-effective identification and enumeration of strain UABl-14 and represent an advancement in the quality control and quality assurance of probiotics.

Lactobacillus rhamnosus GG Stimulates Dietary Tryptophan-Dependent Production of Barrier-Protecting Methylnicotinamide

BACKGROUND & AIMS

Lacticaseibacillus rhamnosus GG (LGG) is the world's most consumed probiotic but its mechanism of action on intestinal permeability and differentiation along with its interactions with an essential source of signaling metabolites, dietary tryptophan (trp), are unclear.

METHODS

Untargeted metabolomic and transcriptomic analyses were performed in LGG monocolonized germ-free mice fed trp-free or -sufficient diets. LGG-derived metabolites were profiled in vitro under anaerobic and aerobic conditions. Multiomic correlations using a newly developed algorithm discovered novel metabolites tightly linked to tight junction and cell differentiation genes whose abundances were regulated by LGG and dietary trp. Barrier-modulation by these metabolites were functionally tested in Caco2 cells, mouse enteroids, and dextran sulfate sodium experimental colitis. The contribution of these metabolites to barrier protection is delineated at specific tight junction proteins and enterocyte-promoting factors with gain and loss of function approaches.

RESULTS

LGG, strictly with dietary trp, promotes the enterocyte program and expression of tight junction genes, particularly Ocln. Functional evaluations of fecal and serum metabolites synergistically stimulated by LGG and trp revealed a novel vitamin B3 metabolism pathway, with methylnicotinamide (MNA) unexpectedly being the most robust barrier-protective metabolite in vitro and in vivo. Reduced serum MNA is significantly associated with increased disease activity in patients with inflammatory bowel disease. Exogenous MNA enhances gut barrier in homeostasis and robustly promotes colonic healing in dextran sulfate sodium colitis. MNA is sufficient to promote intestinal epithelial Ocln and RNF43, a master inhibitor of Wnt. Blocking trp or vitamin B3 absorption abolishes barrier recovery in vivo.

CONCLUSIONS

Our study uncovers a novel LGG-regulated dietary trp-dependent production of MNA that protects the gut barrier against colitis.

Environmental and Nutritional Parameters Modulating Genetic Expression for Virulence Factors of Clostridioides difficile

Clostridioides difficile infections (CDIs) continue to be a persistent healthcare concern despite newer antibiotic treatments, enhanced infection control practices, and preventive strategies focused on restoring the protective intestinal microbial barrier. Recent strides in gene sequencing research have identified many genes regulating diverse virulence factors for CDIs. These genes may be over- or under-expressed when triggered by various environmental and nutritional factors. The aims of this paper are to review the important genes involved in C. difficile pathogenesis and to identify modifiable environmental, nutritional, and other factors that may trigger the expression of these genes and thus offer new strategies to prevent CDIs.

Oral Biofilm Composition, Dissemination to Keratinocytes, and Inflammatory Attenuation Depend on Probiotic and Synbiotic Strain Specificity

Several inflammatory diseases are characterized by a disruption in the equilibrium between the host and its microbiome. Due to the increase in resistance, the use of antibiotics for the widespread, nonspecific killing of microorganisms is at risk. Pro-microbial approaches focused on stimulating or introducing beneficial species antagonistic toward pathobionts may be a viable alternative for restoring the host-microbiome equilibrium. Unfortunately, not all potential probiotic or synbiotic species and even subspecies (to strain level) are equally effective for the designated pathology, leading to conflicting accounts of their efficacy. To assess the extent of these species- and strain-specific effects, 13 probiotic candidates were evaluated for their probiotic and synbiotic potential with glycerol on in vitro oral biofilms, dissemination from biofilms to keratinocytes, and anti-inflammatory activity. Species- and strain-specific effects and efficacies were observed in how they functioned as probiotics or synbiotics by influencing oral pathobionts and commensals within biofilms and affected the dissemination of pathobionts to keratinocytes, ranging from ineffective strains to strains that reduced pathobionts by 3 + log. In addition, a minority of the candidates exhibited the ability to mitigate the inflammatory response of LPS-stimulated monocytes. For a comprehensive assessment of probiotic therapy for oral health, a judicious selection of fully characterized probiotic strains that are specifically tailored to the designated pathology is required. This approach aims to challenge the prevailing perception of probiotics, shifting the focus away from "form over function." Rather than using unproven, hypothetical probiotic strains from known genera or species, one should choose strains that are actually functional in resolving the desired pathology before labelling them probiotics.

Probiotic supplementation and risk of necrotizing enterocolitis and mortality among extremely preterm infants-the Probiotics in Extreme Prematurity in Scandinavia (PEPS) trial: study protocol for a multicenter, double-blinded, placebo-controlled, and registry-based randomized controlled trial

BACKGROUND

Extremely preterm infants, defined as those born before 28 weeks' gestational age, are a very vulnerable patient group at high risk for adverse outcomes, such as necrotizing enterocolitis and death. Necrotizing enterocolitis is an inflammatory gastrointestinal disease with high incidence in this cohort and has severe implications on morbidity and mortality. Previous randomized controlled trials have shown reduced incidence of necrotizing enterocolitis among older preterm infants following probiotic supplementation. However, these trials were underpowered for extremely preterm infants, rendering evidence for probiotic supplementation in this population insufficient to date.

METHODS

The Probiotics in Extreme Prematurity in Scandinavia (PEPS) trial is a multicenter, double-blinded, placebo-controlled and registry-based randomized controlled trial conducted among extremely preterm infants (n = 1620) born at six tertiary neonatal units in Sweden and four units in Denmark. Enrolled infants will be allocated to receive either probiotic supplementation with ProPrems® (Bifidobacterium infantis, Bifidobacterium lactis, and Streptococcus thermophilus) diluted in 3 mL breastmilk or placebo (0.5 g maltodextrin powder) diluted in 3 mL breastmilk per day until gestational week 34. The primary composite outcome is incidence of necrotizing enterocolitis and/or mortality. Secondary outcomes include incidence of late-onset sepsis, length of hospitalization, use of antibiotics, feeding tolerance, growth, and body composition at age of full-term and 3 months corrected age after hospital discharge.

DISCUSSION

Current recommendations for probiotic supplementation in Sweden and Denmark do not include extremely preterm infants due to lack of evidence in this population. However, this young subgroup is notably the most at risk for experiencing adverse outcomes. This trial aims to investigate the effects of probiotic supplementation on necrotizing enterocolitis, death, and other relevant outcomes to provide sufficiently powered, high-quality evidence to inform probiotic supplementation guidelines in this population. The results could have implications for clinical practice both in Sweden and Denmark and worldwide.

TRIAL REGISTRATION

( Clinicaltrials.gov ): NCT05604846.

Comparison of the effectiveness of probiotic supplementation in glucose metabolism, lipid profile, inflammation and oxidative stress in pregnant women

Objective: The optimal probiotic supplementation in pregnant women has not been thoroughly evaluated. By employing a network meta-analysis (NMA) approach, we compared the effectiveness of different probiotic supplementation strategies for pregnant women. Methods: A comprehensive search across multiple databases was performed to identify studies comparing the efficacy of probiotic supplements with each other or the control (placebo) among pregnant women. Results: This NMA, including 32 studies, systematically evaluated 6 probiotic supplement strategies: Lactobacillus, Lacticaseibacillus rhamnosus and Bifidobacterium (LRB), Lactobacillus acidophilus and Bifidobacterium (LABB), Lactobacillus acidophilus, Lacticaseibacillus casei, and Bifidobacterium bifidum (LLB), multi-combination of four probiotics (MP1), and multi-combination of six or more probiotics (MP2). Among these strategies, LLB, MP1, and MP2 all contain LABB. The NMA findings showed that MP1 was the most effective in reducing fasting blood sugar (FBS) (surface under the cumulative ranking curve [SUCRA]: 80.5%). In addition, MP2 was the most efficacious in lowering the homeostasis model assessment of insulin resistance (HOMA-IR) (SUCRA: 89.1%). LABB was ranked as the most effective in decreasing low-density lipoprotein cholesterol (LDLC) (SUCRA: 95.5%), total cholesterol (TC) (SUCRA: 95.5%), and high-sensitivity C-reactive protein (hs-CRP) (SUCRA: 94.8%). Moreover, LLB was ranked as the most effective in raising total antioxidant capacity (TAC) (SUCRA: 98.5%). Conclusion: Multi-combination of probiotic strains, especially those strategies containing LABB, may be more effective than a single probiotic strain in glycolipid metabolism, inflammation, and oxidative stress of pregnant women.

Probiotics ameliorate endocrine disorders via modulating inflammatory pathways: a systematic review

Probiotics has offered a new prospect to treat and manage a variety of endocrine disorders such as obesity, diabetes, non- alcoholic fatty liver disease and metabolic syndrome. The precise mechanisms by which probiotics exert their beneficial effects on endocrine disorders and its associated problems are still indecisive. It seems that regulating the immune system and suppressing pro-inflammatory pathways like tumor necrosis factor-α and interleukin-6 or triggering anti-inflammatory pathways like interleukin-4 and 10 may be one of the potential mechanisms in the managing of endocrine disorders. In this systematic review, we hypothesized that various probiotic strains (Lactobacillus, Biofidiobacteria, Streptococcus, Entrococcus, Clostridium, and Bacillus) alone or in combination with each other could manage endocrine disorders via modulating inflammatory pathways such as suppressing pro-inflammatory cytokines (IL-6, IL-12, TNF-α, TNF-β, NFκB, and MCP-1), stimulating anti-inflammatory cytokines (IL-4,IL-6, IL-22, IL-23, IL-33, and TGF-β) and maintaining other factors like C-reactive protein, Toll like receptors, LPS, and NK cells. Data source this search was performed in PubMed and Scopus. Both human and animal studies were included. Among more than 15,000 papers, 25 studies were identified as eligible for more assessments. Quality assessment of the studies was cheeked by two researchers independently by title and abstract screening, then article which have inclusion criteria were included, and data retrieved from the included full text studies as the authors had originally reported. Results specified that Lactobacillus has been the most widely used probiotic as well as which one exhibiting the extend of the therapeutic effects on endocrine disorders, especially obesity by modulating immune responses. Also, most studies have revealed that probiotics through suppressing pro-inflammatory pathways specially via reducing levels TNF-α cytokine exhibited protective or beneficial effects on endocrine diseases particularly obesity as well as through decreasing level of IL-6 induced therapeutic effects in diabetes. This systematic review suggests that probiotics could ameliorate endocrine disorders via their immunomodulatory effects.

Prebiotics and Probiotics for Gastrointestinal Disorders

The complex role of the gut microbiome in the pathogenesis of gastrointestinal (GI) disorders is an emerging area of research, and there is considerable interest in understanding how diet can alter the composition and function of the microbiome. Prebiotics and probiotics have been shown to beneficially modulate the gut microbiome, which underlies their potential for benefit in GI conditions. Formulating specific recommendations for the public regarding these dietary supplements has been difficult due to the significant heterogeneity between strains, doses, and duration of treatment investigated across studies, as well as safety concerns with administering live organisms. This review aims to summarize the existing evidence for the use of prebiotics and probiotics in various GI disorders, paying special attention to strain-specific effects that emerged and any adverse effects noted.

Probiotic characterization of Bacillus smithii: Research advances, concerns, and prospective trends

Bacillus smithii is a thermophilic Bacillus that can be isolated from white wine, hot spring soil, high-temperature compost, and coffee grounds, with various biofunctions and wide applications. It is resistant to both gastric acid and high temperature, which makes it easier to perform probiotic effects than traditional commercial probiotics, so it can maintain good vitality during food processing and has great application prospects. This paper starts with the taxonomy and genetics and focuses on aspects, including genetic transformation, functional enzyme production, waste utilization, and application in the field of food science as a potential probiotic. According to available studies during the past 30 years, we considered that B. smithii is a novel class of microorganisms with a wide range of functional enzymes such as hydrolytic enzymes and hydrolases, as well as resistance to pathogenic bacteria. It is available in waste degradation, organic fertilizer production, the feed and chemical industries, the pharmaceutical sector, and food fortification. Moreover, B. smithii has great potentials for applications in the food industry, as it presents high resistance to the technological processes that guarantee its health benefits. It is also necessary to systematically evaluate the safety, flavor, and texture of B. smithii and explore its biological mechanism of action, which is of great value for further application in multiple fields, especially in food and medicine.

Probiotics: Health benefits, food application, and colonization in the human gastrointestinal tract

Probiotics have become increasingly popular over the past two decades due to the continuously expanding scientific evidence indicating their beneficial effects on human health. Therefore, they have been applied in the food industry to produce functional food, which plays a significant role in human health and reduces disease risk. However, maintaining the viability of probiotics and targeting the successful delivery to the gastrointestinal tract remain two challenging tasks in food applications. Specifically, this paper reviews the potentially beneficial properties of probiotics, highlighting the use and challenges of probiotics in food application and the associated health benefits. Of foremost importance, this paper also explores the potential underlying molecular mechanisms of the enhanced effect of probiotics on gastrointestinal epithelial cells, including a discussion on various surface adhesion‐related proteins on the probiotic cell surface that facilitate colonization.

Probiotics Supplementation during Pregnancy: Can They Exert Potential Beneficial Effects against Adverse Pregnancy Outcomes beyond Gestational Diabetes Mellitus?

BACKGROUND

Probiotics, as supplements or food ingredients, are considered to exert promising healthy effects when administered in adequate quantity. Probiotics' healthy effects are related with the prevention of many diseases, as well as decreasing symptom severity. Currently, the most available data concerning their potential health effects are associated with metabolic disorders, including gestational diabetes mellitus. There is also clinical evidence supporting that they may exert beneficial effects against diverse adverse pregnancy outcomes. The purpose of the current narrative study is to extensively review and analyze the current existing clinical studies concerning the probable positive impacts of probiotics supplementation during pregnancy as a protective agent against adverse pregnancy outcomes beyond gestational diabetes mellitus.

METHODS

a comprehensive and thorough literature search was conducted in the most precise scientific databases, such as PubMed, Scopus, and Web of Sciences, utilizing efficient, representative, and appropriate keywords.

RESULTS

in the last few years, recent research has been conducted concerning the potential beneficial effects against several adverse pregnancy outcomes such as lipid metabolism dysregulation, gestational hypertensive disorders, preterm birth, excessive gestational weight gain, caesarean risk section, vaginal microbiota impairment, mental health disturbances, and others.

CONCLUSION

up to the present day, there is only preliminary clinical data and not conclusive results for probiotics' healthy effects during pregnancy, and it remains questionable whether they could be used as supplementary treatment against adverse pregnancy outcomes beyond gestational diabetes mellitus.

The role of Weizmannia (Bacillus) coagulans LMG S-31876 in treating IBS-diarrhea

Introduction

Irritable bowel syndrome (IBS) is a common gastrointestinal condition. Some studies have shown the efficacy of probiotics in the treatment of irritable bowel syndrome (IBS). Weizmannia (Bacillus) coagulans LMG S-31876 has been marketed as a dietary ingredient, but to date, its efficacy in diarrhea-predominant irritable bowel syndrome (IBS) condition has not been clinically elucidated. Thus, a double-blind placebo-controlled multi-centered trial was planned to evaluate the safety and efficacy of Weizmannia (Bacillus) coagulans LMG S-31876 in diarrhea-predominant IBS patients.

Experimental design

Study participants (n = 50) diagnosed with IBS prominent symptoms that include abdominal pain and other GI-related symptoms were treated with ProBC Plus (2 billion CFU) along with a placebo capsule once daily for approximately 8 weeks. Study participants were evaluated for the treatment success determined by the differences in stool consistency and frequency per day between the intervention and placebo groups over the study period.

Results

The vital signs and the biochemistry parameters were under the normal range; the other parameters showed a significant result as compared to the placebo during the study period.

Conclusion

This study depicts a significant decline in the clinical symptoms such as abdominal pain, bloating, diarrhea, and frequency of the stool as compared to the placebo. All the parameters such as hematology, lipid profile, and vital signs were in the normal range during the supplementation of ProBC Plus for a period of 8 weeks. Furthermore, the study verified that Weizmannia (Bacillus) coagulans LMG S-31876 and its probiotic product ProBC Plus at a dose of 2 billion/CFU/day has a prominent action in the relief from the clinical symptoms of IBS-D. Therefore, the product is intended safe to utilize for IBS-related symptoms.Clinical trial registration: The clinical study has been registered with CTRI/2023/01/048644 with https://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=77708&EncHid=24313.96864&userName=CTRI/2023/01/048644 [CTRI/2023/01/048644].

Levilactobacillus brevis MZ384011 and Levilactobacillus brevis MW362779 can mitigate lead induced hepato-renal damage by regulating visceral dispersion and fecal excretion

Heavy metal pollution is a global issue. Current study provides evidence on Pb toxicity ameliorative potential and safe nature of Levilactobacillus brevis MZ384011 (S1) and Levilactobacillus brevis MW362779 (S2), isolated from carnivore gut and human milk, respectively. In a 60-days experiment, the rats were distributed into six groups. G-I, G-V and G-VI were kept on normal diet, while GII-IV were fed on lead nitrate (500 mg/kg) supplemented food, throughout experiment. After confirmation of Pb toxicity in GII-IV at 15th day, S1 was orally administered to G-III and G-V while S2 was given to G-IV and G-VI at a dose of 1 × 109 CFU/animal/day. On day 60 of experiment, positive control (G-II) displayed significant reduction in body weight, total protein, albumin, globulin, mineral profile, erythrocyte count, hemoglobin, hematocrit and hematological indices and elevation in leukocyte count, alanine aminotransferase, aspartate aminotransferase, bilirubin, uric acid and creatinine along with alterations in hepato-renal architecture. With reference to G-II, the G-III and G-IV displayed significant improvement in all aforementioned parameters, 40-60% reduction in tissue Pb levels (blood, liver, kidney and adipose tissue) and elevation in fecal Pb contents (p = 0.000). The groups V and VI did not show any sign of toxicity. The findings confirm that strains are safe for biological application and can reverse Pb toxicity by facilitating fecal Pb excretion and reducing its systemic dispersal. To best of our information this is the first report on Pb toxicity ameliorative role of Levilactobacillus brevis from human milk, the safest source.

Probiotics in Infancy and Childhood for Food Allergy Prevention and Treatment

Food allergy represents a failure of oral tolerance mechanisms to dietary antigens. Over the past few years, food allergies have become a growing public health problem worldwide. Gut microbiota is believed to have a significant impact on oral tolerance to food antigens and in initiation and maintenance of food allergies. Therefore, probiotics have also been proposed in this field as a possible strategy for modulating both the gut microbiota and the immune system. In recent years, results from preclinical and clinical studies suggest a promising role for probiotics in food allergy prevention and treatment. However, future studies are needed to better understand the mechanisms of action of probiotics in food allergies and to design comparable study protocols using specific probiotic strains, defined doses and exposure times, and longer follow-up periods.

Identification and quantification of viable Lacticaseibacillus rhamnosus in probiotics using validated PMA-qPCR method

The identification and quantification of viable bacteria at the species/strain level in compound probiotic products is challenging now. Molecular biology methods, e.g., propidium monoazide (PMA) combination with qPCR, have gained prominence for targeted viable cell counts. This study endeavors to establish a robust PMA-qPCR method for viable Lacticaseibacillus rhamnosus detection and systematically validated key metrics encompassing relative trueness, accuracy, limit of quantification, linear, and range. The inclusivity and exclusivity notably underscored high specificity of the primers for L. rhamnosus, which allowed accurate identification of the target bacteria. Furthermore, the conditions employed for PMA treatment were fully verified by 24 different L. rhamnosus including type strain, commercial strains, etc., confirming its effective discrimination between live and dead bacteria. A standard curve constructed by type strain could apply to commercial strains to convert qPCR Cq values to viable cell numbers. The established PMA-qPCR method was applied to 46 samples including pure cultures, probiotics as food ingredients, and compound probiotic products. Noteworthy is the congruity observed between measured and theoretical values within a 95% confidence interval of the upper and lower limits of agreement, demonstrating the relative trueness of this method. Moreover, accurate results were obtained when viable L. rhamnosus ranging from 103 to 108 CFU/mL. The comprehensive appraisal of PMA-qPCR performances provides potential industrial applications of this new technology in quality control and supervision of probiotic products.

Detection and absolute quantification of Lactiplantibacillus plantarum ATCC 202195 by quantitative real-time PCR

IMPORTANCE

When administered for seven consecutive days shortly after birth, the probiotic bacterium Lactiplantibacillus plantarum ATCC 202195 plus fructooligosaccharide (FOS) was reported to reduce sepsis and lower respiratory tract infection events during early infancy in a randomized trial in India. Since probiotic effects are often strain specific, strain-level detection and quantification by routine molecular methods enables the monitoring of safety outcomes, such as probiotic-associated bacteremia, and allows for the quality of probiotic interventions to be assessed and monitored (i.e., verify strain identity and enumerate). Despite the potential clinical applications of L. plantarum ATCC 202195, an assay to detect and quantify this strain has not previously been described. Herein, we report the design of primer and probe sequences to detect L. plantarum ATCC 202195 and the development and optimization of a real-time PCR assay to detect and quantify the strain with high specificity and high sensitivity.

Effect of Probiotic Supplementation on Intestinal Permeability in Overweight and Obesity: A Systematic Review of Randomized Controlled Trials and Animal Studies

Overweight and obesity are associated with increased intestinal permeability, characterized by loss of gut epithelial integrity, resulting in unregulated passage of lipopolysaccharide (LPS) and other inflammatory triggers into circulation, i.e., metabolic endotoxemia. In obesity, shifts in the gut microbiome negatively impact intestinal permeability. Probiotics are an intervention that can target the gut microbiome by introducing beneficial microbial species, potentially restoring gut barrier integrity. Currently, the role of probiotic supplementation in ameliorating obesity- and overweight-associated increases in gut permeability has not been reviewed. This systematic review aimed to summarize findings from both animal and clinical studies that evaluated the effect of probiotic supplementation on obesity-induced impairment in intestinal permeability (International Prospective Register of Systematic Reviews, CRD42022363538). A literature search was conducted using PubMed (Medline), Web of Science, and CAB Direct from origin until August 2023 using keywords of intestinal permeability, overweight or obesity, and probiotic supplementation. Of 920 records, 26 eligible records were included, comprising 12 animal and 14 clinical studies. Clinical trials ranged from 3 to 26 wk and were mostly parallel-arm (n = 13) or crossover (n = 1) design. In both animal and clinical studies, plasma/serum LPS was the most common measure of intestinal permeability. Eleven of 12 animal studies reported a positive effect of probiotic supplementation in reducing intestinal permeability. However, results from clinical trials were inconsistent, with half reporting reductions in serum LPS and half reporting no differences after probiotic supplementation. Bifidobacterium, Lactobacillus, and Akkermansia emerged as the most common genera in probiotic formulations among the animal and clinical studies that yielded positive results, suggesting that specific bacteria may be more effective at reducing intestinal permeability and improving gut barrier function. However, better standardization of strain use, dosage, duration, and the delivery matrix is needed to fully understand the probiotic impact on intestinal permeability in individuals with overweight and obesity.

A systematic scoping review of study methodology for randomized controlled trials investigating probiotics in athletic and physically active populations

BACKGROUND

The purported ergogenic and health effects of probiotics have been a topic of great intrigue among researchers, practitioners, and the lay public alike. There has also been an increased research focus within the realm of sports science and exercise medicine on the athletic gut microbiota. However, compared to other ergogenic aids and dietary supplements, probiotics present unique study challenges. The objectives of this systematic scoping review were to identify and characterize study methodologies of randomized controlled trials investigating supplementation with probiotics in athletes and physically active individuals.

METHODS

Four databases (MEDLINE, CINAHL, Cochrane CENTRAL, and Cochrane Database of Systematic Reviews) were searched for randomized controlled studies involving healthy athletes or physically active individuals. An intervention with probiotics and inclusion of a control and/or placebo group were essential. Only peer-reviewed articles in English were considered, and there were no date restrictions. Results were extracted and presented in tabular form to detail study protocols, characteristics, and outcomes. Bias in randomized controlled trials was determined with the RoB 2.0 tool.

RESULTS

A total of 45 studies were included in the review, with 35 using a parallel group design and 10 using a cross-over design. Approximately half the studies used a single probiotic and the other half a multi-strain preparation. The probiotic dose ranged from 2 × 108 to 1 × 1011 colony forming units daily, and the length of intervention was between 7 and 150 days. Fewer than half the studies directly assessed gastrointestinal symptoms, gut permeability, or the gut microbiota. The sex ratio of participants was heavily weighted toward males, and only 3 studies exclusively investigated females. Low-level adverse events were reported in only 2 studies, although the methodology of reporting varied widely. The risk of bias was generally low, although details on randomization were lacking in some studies.

CONCLUSION

There is a substantial body of research on the effects of probiotic supplementation in healthy athletes and physically active individuals. Considerable heterogeneity in probiotic selection and dosage as well as outcome measures has made clinical and mechanistic interpretation challenging for both health care practitioners and researchers. Attention to issues of randomization of participants, treatments and interventions, selection of outcomes, demographics, and reporting of adverse events will facilitate more trustworthy interpretation of probiotic study results and inform evidence-based guidelines.

Advice to People with Parkinson's in My Clinic: Probiotics and Prebiotics

There is increasing evidence that microbial-based therapies can be useful in people with Parkinson's disease (PD). In this viewpoint, we provide a state-of-the-art review of the clinical and pre-clinical evidence for probiotics and prebiotics in PD. Currently, short-term clinical studies, including double-blind placebo-controlled randomized clinical trials, have demonstrated safety, and efficacy primarily in improving constipation-related symptoms. Pre-clinical studies consistently reported improvements in a range of biological markers and outcomes, including evidence for attenuation of gut dysfunction and neuroprotection. Bacteria from the genus Lactobacillus and Bifidobacterium have been the most frequently studied both in clinical and pre-clinical probiotics studies, while research into prebiotics is still limited and primarily involved resistant starch and fructooligosaccharides. We provide practical suggestions for clinicians on how to advise patients in the clinic regarding these popular treatments, and important caveats to be aware of. Finally, areas for further advancements are highlighted. It is envisaged that in the future, microbial-based therapies may benefit from personalization based on an enhanced understanding of a whole range of host factors and host-microbiome interactions.

Shaping the Future of Probiotics: Novel Methodologies, Applications, and Mechanisms of Action

Probiotics are defined as live microorganisms that, when consumed in appropriate amounts, can promote host homeostasis, and induce health-promoting effects [...].

Postbiotic Activities of Bifidobacterium adolescentis: Impacts on Viability, Structural Integrity, and Cell Death Markers in Human Intestinal C2BBe1 Cells

Acute diarrheal disease (ADD) caused by rotavirus (RV) contributes significantly to morbidity and mortality in children under five years of age. Currently, there are no specific drugs for the treatment of RV infections. Previously, we reported the anti-rotaviral activity of the protein metabolites derived from Bifidobacterium adolescentis. In this study, our aim was to assess the impact of B. adolescentis-secreted proteins (BaSP), with anti-rotaviral activity on the human intestinal C2BBe1 cell line. We initiated the production of BaSP and subsequently confirmed its anti-rotaviral activity by counting the infectious foci using immunocytochemistry. We then exposed the C2BBe1 cells to various concentrations of BaSP (≤250 µg/mL) for 72 h. Cell viability was assessed using the MTT assay, cell monolayer integrity was monitored through transepithelial electrical resistance (TEER), and cytoskeleton architecture and tight junctions (TJs) were examined using confocal microscopy with F-actin and occludin staining. Finally, we utilized a commercial kit to detect markers of apoptosis and necrosis after 24 h of treatment. The results demonstrated that BaSP does not have adverse effects on C2BBe1 cells. These findings confirm that BaSP inhibits rotavirus infectivity and has the potential to strengthen intestinal defense against viral and bacterial infections via the paracellular route.

Probiotics Bifidobacterium lactis M8 and Lactobacillus rhamnosus M9 prevent high blood pressure via modulating the gut microbiota composition and host metabolic products

IMPORTANCE

Elevated blood pressure affects 40% of the adult population, which accounts for high cardiovascular disease risk and further high mortality yearly. The global understanding of the gut microbiome for hypertension may provide important insights into the prevention. Bifidobacterium lactis M8 and Lactobacillus rhamnosus M9 originated from human breast milk, were able to decrease blood pressure, and modified metabolites in a high fructose-induced elevated blood pressure mouse model. Moreover, we found there was a close relationship between unexplored gut microbes and elevated blood pressure. Also, subsequently, the cross-link was explored among gut microbes, metabolites, and some metabolic pathways in gut microbial environment through introducing novel prediction methodology and bioinformatic analysis. It allowed us to hypothesize that probiotics can prevent elevated blood pressure via gut microbiota and related metabolism.Thus, utilization of dietary strategies (such as probiotics) to maintain the blood pressure level is of crucial importance.

A key genetic factor governing arabinan utilization in the gut microbiome alleviates constipation

Impaired gastrointestinal motility is associated with gut dysbiosis. Probiotics, such as Bifidobacteria, can improve this bowel disorder; however, efficacy is strain-dependent. We determine that a genetic factor, the abfA cluster governing arabinan utilization, in Bifidobacterium longum impacts treatment efficacy against functional constipation (FC). In mice with FC, B. longum, but not an abfA mutant, improved gastrointestinal transit time, an affect that was dependent upon dietary arabinan. abfA genes were identified in other commensal bacteria, whose effects in ameliorating murine FC were similarly abfA-dependent. In a double-blind, randomized, placebo-controlled clinical trial, supplementation with abfA-cluster-carrying B. longum, but not an abfA-deficient strain, enriched arabinan-utilization residents, increased beneficial metabolites, and improved FC symptoms. Across human cohorts, abfA-cluster abundance can predict FC, and transplantation of abfA cluster-enriched human microbiota to FC-induced germ-free mice improved gut motility. Collectively, these findings demonstrate a role for microbial abfA cluster in ameliorating FC, establishing principles for genomics-directed probiotic therapies.

Probiotic and postbiotic analytical methods: a perspective of available enumeration techniques

Probiotics are the largest non-herbal/traditional dietary supplements category worldwide. To be effective, a probiotic strain must be delivered viable at an adequate dose proven to deliver a health benefit. The objective of this article is to provide an overview of the various technologies available for probiotic enumeration, including a general description of each technology, their advantages and limitations, and their potential for the future of the probiotics industry. The current "gold standard" for analytical quantification of probiotics in the probiotic industry is the Plate Count method (PC). PC measures the bacterial cell's ability to proliferate into detectable colonies, thus PC relies on cultivability as a measure of viability. Although viability has widely been measured by cultivability, there has been agreement that the definition of viability is not limited to cultivability. For example, bacterial cells may exist in a state known as viable but not culturable (VBNC) where the cells lose cultivability but can maintain some of the characteristics of viable cells as well as probiotic properties. This led to questioning the association between viability and cultivability and the accuracy of PC in enumerating all the viable cells in probiotic products. PC has always been an estimate of the number of viable cells and not a true cell count. Additionally, newer probiotic categories such as Next Generation Probiotics (NGPs) are difficult to culture in routine laboratories as NGPs are often strict anaerobes with extreme sensitivity to atmospheric oxygen. Thus, accurate quantification using culture-based techniques will be complicated. Another emerging category of biotics is postbiotics, which are inanimate microorganisms, also often referred to as tyndallized or heat-killed bacteria. Obviously, culture dependent methods are not suitable for these products, and alternative methods are needed for their quantification. Different methodologies provide a more complete picture of a heterogeneous bacterial population versus PC focusing exclusively on the eventual multiplication of the cells. Alternative culture-independent techniques including real-time PCR, digital PCR and flow cytometry are discussed. These methods can measure viability beyond cultivability (i.e., by measuring cellular enzymatic activity, membrane integrity or membrane potential), and depending on how they are designed they can achieve strain-specific enumeration.

Strain-specific metabolomic diversity of Lactiplantibacillus plantarum under aerobic and anaerobic conditions

The chemotaxonomic diversity of 20 Lactiplantibacillus plantarum strains was investigated using non-targeted metabolite profiling under different culture conditions. Multivariate and metabolic pathway analyses based on GC-MS and LC-MS/MS datasets showed that amino acid metabolism, especially 2-hydroxy acids, was enriched under aerobic conditions (AE), whereas fatty acid & sugar metabolism was increased under anaerobic conditions (AN). Based on the metabolite profiles, L. plantarum strains were clustered into three main groups (A, B, and C). Overall, 79 and 83 significantly discriminant metabolites were characterized as chemical markers of AE and AN growth conditions, respectively. Notably, alcohols were more abundant in group A whereas amino acids, peptides, purines, and pyrimidines were significantly higher in group C. 2-hydroxy acids and oxylipins biosynthesized through amino acid and fatty acid metabolism, respectively, were more abundant in groups A and B. Furthermore, we observed a strong correlation between the chemical diversity of L. plantarum groups and their antioxidant activity from metabolite extracts. We propose a non-targeted metabolomic workflow to comprehensively characterize the chemodiversity of L. plantarum strain under different culture conditions, which may help reveal specific biomarkers of individual strains depending on the culture conditions.

Bifidobacterium infantis as a probiotic in preterm infants: a systematic review and meta-analysis

BACKGROUND

Bifidobacterium infantis has special abilities to utilise human milk oligosaccharides. Hence we hypothesised that probiotic supplements containing B. infantis may confer greater benefits to preterm infants than probiotic supplements without B. infantis.

METHODS

A systematic review with meta-analysis was conducted according to standard guidelines. We selected RCTs evaluating probiotics compared to placebo or no treatment in preterm and/or low birth weight infants. Probiotic effects on Necrotizing Enterocolitis (NEC), Late Onset Sepsis (LOS) and Mortality were analysed separately for RCTs in which the supplemented probiotic product contained B. infantis and those that did not contain B. infantis.

RESULTS

67 RCTs were included (n = 14,606), of which 16 used probiotics containing B. infantis (Subgroup A) and 51 RCTs did not (Subgroup B) Meta-analysis of all RCTs indicated that probiotics reduced the risk of NEC, LOS, and mortality. The subgroup meta-analysis demonstrated greater reduction in the incidence of NEC in subgroup A than subgroup B [(relative risk in subgroup A: 0.38; 95% CI, 0.27-0.55) versus (0.67; 95% CI, 0.55-0.81) in subgroup B; p value for subgroup difference: 0.01].

CONCLUSIONS

These results provide indirect evidence that probiotic supplements that include B. infantis may be more beneficial for preterm infants. Well-designed RCTs are necessary to confirm these findings.

IMPACT

Evidence is emerging that beneficial effects of probiotics are species and strain specific. This systematic review analyses if B. infantis supplementation provides an advantage to preterm infants. This is the first systematic review evaluating the effects of probiotics containing B. infantis in preterm infants. The results of this systematic review provides indirect evidence that probiotics that include B. infantis may be more beneficial for preterm infants. These results will help in guiding future research and clinical practice for using B. infantis as a probiotic in preterm infants.

Inhibition of intestinal FXR activity as a possible mechanism for the beneficial effects of a probiotic mix supplementation on lipid metabolism alterations and weight gain in mice fed a high fat diet

Supplementation with probiotics has emerged as a promising therapeutic tool to manage metabolic diseases. We investigated the effects of a mix of Bifidobacterium animalis subsp. lactis LA804 and Lactobacillus gasseri LA806 on high-fat (HF) diet -induced metabolic disease in mice. Supplementation with the probiotic mix in HF diet-fed mice (HF-Pr2) reduced weight and fat mass gains, decreased hepatic lipid accumulation, and lowered plasma triglyceride peak during an oral lipid tolerance test. At the molecular level, the probiotic mix protected against HF-induced rise in mRNA levels of genes related to lipid uptake, metabolism, and storage in the liver and white adipose tissues, and strongly decreased mRNA levels of genes related to inflammation in the white adipose tissue and to oxidative stress in the liver. Regarding intestinal homeostasis, the probiotic mix did not prevent HF-induced gut permeability but slightly modified microbiota composition without correcting the dysbiosis induced by the HF diet. Probiotic supplementation also modified the cecal bile acid (BA) profile, leading to an increase in the Farnesoid-X-Receptor (FXR) antagonist/agonist ratio between BA species. In agreement, HF-Pr2 mice exhibited a strong inhibition of FXR signaling pathway in the ileum, which was associated with lipid metabolism protection. This is consistent with recent reports proposing that inhibition of intestinal FXR activity could be a potent mechanism to overcome metabolic disorders. Altogether, our results demonstrate that the probiotic mix evaluated, when administered preventively to HF diet-fed mice could limit obesity and associated lipid metabolism disorders, likely through the inhibition of FXR signaling in the intestinal tract.

Recommendations to Improve Quality of Probiotic Systematic Reviews With Meta-Analyses

Importance

Systematic reviews and meta-analyses often report conflicting results when assessing evidence for probiotic efficacy, partially because of the lack of understanding of the unique features of probiotic trials. As a consequence, clinical decisions on the use of probiotics have been confusing.

Objective

To provide recommendations to improve the quality and consistency of systematic reviews with meta-analyses on probiotics, so evidence-based clinical decisions can be made with more clarity.

Evidence Review

For this consensus statement, an updated literature review was conducted (January 1, 2020, to June 30, 2022) to supplement a previously published 2018 literature search to identify areas where probiotic systematic reviews with meta-analyses might be improved. An expert panel of 21 scientists and physicians with experience on writing and reviewing probiotic reviews and meta-analyses was convened and used a modified Delphi method to develop recommendations for future probiotic reviews.

Findings

A total of 206 systematic reviews with meta-analysis components on probiotics were screened and representative examples discussed to determine areas for improvement. The expert panel initially identified 36 items that were inconsistently reported or were considered important to consider in probiotic meta-analyses. Of these, a consensus was reached for 9 recommendations to improve the quality of future probiotic meta-analyses.

Conclusions and Relevance

In this study, the expert panel reached a consensus on 9 recommendations that should promote improved reporting of probiotic systematic reviews with meta-analyses and, thereby, assist in clinical decisions regarding the use of probiotics.

Snapshot of the Probiotic Potential of Kluveromyces marxianus DMKU-1042 Using a Comparative Probiogenomics Approach

Kluyveromyces marxianus is a rapidly growing thermotolerant yeast that secretes a variety of lytic enzymes, utilizes different sugars, and produces ethanol. The probiotic potential of this yeast has not been well explored. To evaluate its probiotic potential, the yeast strain Kluyveromyces marxianus DMKU3-1042 was analyzed using next-generation sequencing technology. Analysis of the genomes showed that the yeast isolates had a GC content of 40.10-40.59%. The isolates had many genes related to glycerol and mannose metabolism, as well as genes for acetoin and butanediol metabolism, acetolactate synthase subunits, and lactic acid fermentation. The strain isolates were also found to possess genes for the synthesis of different vitamins and Coenzyme A. Genes related to heat and hyperosmotic shock tolerance, as well as protection against reactive oxygen species were also found. Additionally, the isolates contained genes for the synthesis of lysine, threonine, methionine, and cysteine, as well as genes with anticoagulation and anti-inflammatory properties. Based on our analysis, we concluded that the strain DMKU3-1042 possesses probiotic properties that make it suitable for use in food and feed supplementation.

Immunomodulatory action of synbiotic comprising of newly isolated lactic acid producing bacterial strains against allergic asthma in mice

Given the reported role of gut-microbiota in asthma pathogenesis, the present work was carried to evaluate immunomodulatory action of newly isolated lactic acid producing bacterial strains Bifidobacterium breve Bif11 and Lactiplantibacillus plantarum LAB31 against asthma using ovalbumin (OVA) based mouse model. Our results show that both strains modulate Th2 immune response potentially through production of short chain fatty acids (SCFAs), resulting in suppression of OVA-induced airway inflammation. Furthermore, synbiotic comprising of both strains and prebiotic, Isomaltooligosaccharide exhibited superior potential in amelioration of OVA-induced airway inflammation through improved modulation of Th2 immune response. Further, synbiotic protects against OVA-induced mucus hyper-production and airway-hyperresponsiveness. Such protection was associated with normalization of gut microbiome and enhanced production of SCFAs in cecum which correlates closely with population of T-regulatory cells in spleen. Overall, our novel synbiotic possesses the ability to fine-tune the immune response for providing protection against allergic asthma.

Development of a Multiplex PCR Assay for Efficient Detection of Two Potential Probiotic Strains Using Whole Genome-Based Primers

Probiotics are microorganisms that exert strain-specific health-promoting effects on the host. Τhey are employed in the production of functional dairy or non-dairy food products; still, their detection in these complex matrices is a challenging task. Several culture-dependent and culture-independent methods have been developed in this direction; however, they present low discrimination at the strain level. Here, we developed a multiplex PCR assay for the detection of two potential probiotic lactic acid bacteria (LAB) strains, Lactiplantibacillus plantarum L125 and Lp. pentosus L33, in monocultures and yogurt samples. Unique genomic regions were identified via comparative genomic analysis and were used to produce strain-specific primers. Then, primer sets were selected that produced distinct electrophoretic DNA banding patterns in multiplex PCR for each target strain. This method was further implemented for the detection of the two strains in yogurt samples, highlighting its biotechnological applicability. Moreover, it can be applied with appropriate modifications to detect any bacterial strain with available WGS.

Efficacy and safety of probiotics and synbiotics for functional constipation in children: A systematic review and meta-analysis of randomized clinical trials

BACKGROUND & AIM

We aimed to evaluate the efficacy and safety of probiotics and synbiotics in childhood functional constipation.

METHODS

PubMed, Embase, Cochrane Library, ClinicalTrials.gov, and the International Clinical Trials Registry Platform (ICTRP) were searched up to June 2023. Randomized controlled trials involving children diagnosed with FC with Rome III/IV criteria were included. Treatment success, defecation frequency, stool consistency, painful defecation, fecal incontinence, and adverse events were assessed as outcomes. Odds ratios (ORs) and standard mean difference (SMD) with 95% confidence intervals (CIs) were calculated for dichotomous and continuous variables as appropriate. Cochrane risk-of-bias tool version 2 assessed the risk of bias.

RESULTS

Seventeen RCTs with 1504 patients were included. Compared to placebo, probiotics significantly improved defecation frequency (SMD 0.40, 95% CI 0.10 to 0.70, I2 = 0%) and fecal incontinence (OR 0.53, 95% CI 0.29 to 0.96, I2 = 0%). However, it did not significantly improve treatment success, painful defecation, and abdominal pain. Probiotics, as add-on therapy, failed to yield a significant difference in treatment success (OR 0.82, 95% CI 0.15 to 4.48, I2 = 52%), defecation frequency (SMD 0.13, 95% CI -0.13 to 0.39, I2 = 0%), defecation consistency (SMD -0.01, 95% CI -0.40 to 0.38, I2 = 1%), fecal incontinence (OR 0.95, 95% CI 0.48 to 1.90, I2 = 0%), and abdominal pain (OR, 0.60, 95% CI 0.24 to 1.53, I2 = 0%) versus laxatives monotherapy. Synbiotics plus laxatives showed no significant effect on defecation frequency (SMD -0.57; 95% CI -1.29 to 0.14, I2 = 74%) and painful defecation (OR, 3.39; 95% CI 0.74 to 15.55, I2 = 0%) versus laxatives alone.

CONCLUSIONS

Current evidence did not advocate using probiotics and synbiotics in treating functional constipation in children. At this time, the effects of strain-specific probiotics, probiotics mixtures, and the optimal doses and treatment durations of the probiotics and synbiotics were unclear. Additional rigorous evidence is required to evaluate and establish the effectiveness and safety of probiotics and synbiotics for childhood functional constipation.

PROSPERO ID

CRD42020195869.

Species- or genus-dependent immunostimulatory effects of gut-derived potential probiotics

The immune regulatory effects of probiotics have been widely recognized to be strain-specific. However, it is unknown if there is a species- or genus-dependent manner. In this study, we use an in vitro mesenteric lymph node (MLN) model to systematically evaluate the immunostimulatory effects of gut-derived potential probiotics. The results exhibit an obvious species or genus consensus immune response pattern. RNA-seq shows that T cell-dependent B cell activation and antibody responses may be inherent to this model. Of the five tested genera, Akkermansia spp. and Clostridium butyrium directly activate the immune response in vitro, as indicated by the secretion of interleukin-10. Bifidobacterium spp. and Bacteroides spp. activate immune response with the help of stimuli (anti-CD3 and anti-CD28 antibodies). Lactobacillus spp. blunt the immune response with or without stimuli. Further investigations show that the cell surface protein of A. muciniphila AH39, which may serve as a T cell receptor cognate antigen, might evoke an in vitro immune activation. In vivo, oral administration of A. muciniphila AH39 influences the proportion of T regulatory cells (Tregs) in MLNs and the spleen under homeostasis in both specific pathogen-free and germ-free mice. All these findings indicate the distinct effects of different genera or species of potential gut-derived probiotics on intestinal and systemic immunity.

Unique Properties of Yeast Probiotic Saccharomyces boulardii CNCM I-745: A Narrative Review

Probiotics, both bacterial and yeast, have long been associated with a beneficial health history and human well-being. Among yeasts, Saccharomyces is a genus that is efficacious in rendering better human health, with Saccharomyces boulardii (S. boulardii) CNCM I-745 being classified as a probiotic agent. The present review highlights the unique properties of S. boulardii and its rolein the prevention of antibiotic-associated diarrhea (AAD) and pediatric acute gastroenteritis (PAGE) in comparison to bacterial probiotics. Its unique properties,such as viability over a wide pH range, inability to acquire antibiotic resistance genes, and property to achieve a steady state rapidly, have given S. boulardii an edge over bacterial probiotics. In AAD patients, prophylactic use of S. boulardii has shown a significantly lower risk of AAD (in comparison to controls) and restored the diversity of gut microbiota. Among Indian children with PAGE, S. boulardii CNCM I-745 was found superior to Lactobacillus rhamnosus GG and four strains of Bacillus clausii in shortening the duration of diarrhea and reducing the length of hospital stay. S. boulardii CNCM I-745 being considered a safe probiotic for use in children and adults also finds recommendations in several international guidelines for the management of acute diarrhea. The current review discusses evidence for the proven efficacy and safety of S. boulardii CNCM I-745 as a probiotic for preventing gastrointestinal disorders.

Clostridioides difficile infection in a skilled nursing facility (SNF): cost savings of an automated, standardized probiotic antimicrobial stewardship programme (ASP) policy

Background

With multiple comorbidities and frequent exposures to antibiotics, patients in skilled nursing facilities (SNFs) are much more vulnerable to healthcare-acquired infections. We conducted a quality-improvement, retrospective analysis of all patients with Clostridioides difficile infection (CDI) from 2009 to 2021 at an SNF. Probiotics were initially added to a bundle of antimicrobial stewardship programme (ASP) CDI prevention strategies. Formulations and durations of probiotics were standardized for both oral and enteral administration. To reach all eligible patients, an ASP probiotic policy provided probiotics with every antibiotic course.

Objectives

To assess the value of providing probiotic therapy to SNF patients at risk for CDI.

Patients and methods

Patients receiving oral or enteral feeding with antibiotics ordered were eligible to receive probiotics. The incremental cost of CDI prevention, treatment and related care were calculated and compared for each phase of probiotic policy change and feeding type. ASP records for the oral probiotic and level of treatment were used in modelling the cost-effectiveness.

Results

From quality improvement initiatives aimed at preventing facility-onset (FO) CDI, to ASP policies, probiotic formulations and delegation of ordering authority, the days of acute care treatment required was significantly reduced over the different phases of implementation [152 to 48, OR = 0.22 (0.16-0.31) to 4, OR = 0.08 (0.03-0.23)] after reducing total CDI from 5.8 to 0.3 cases per 10 000 patient-days. The annual cost of oral probiotics increased from $6019 to $14 652 but the modelled net annual savings for the facility was $72 544-$154 085.

Conclusions

With optimization, the use of probiotics for CDI prevention at an SNF was safe, efficacious and cost-effective.

Effects of systemic Bifidobacterium longum and Lactobacillus rhamnosus probiotics on the ligature-induced periodontitis in rat

Background/purpose

Probiotics might be beneficial in preventing periodontitis. Effects of Bifidobacterium and Lactobacillus on periodontitis were examined using the ligature-induced rat model.

Materials and methods

Thirty-five male Sprague-Dawley rats were divided into control, ligation, Bifidobacterium longum (BL986), Lactobacillus rhamnosus (LRH09), and combination groups. Periodontitis was induced in maxillary second molars. From the day before ligation, phosphate-buffered saline (for control and ligation groups) or probiotics (2 × 109 CFU/g for probiotic groups) were fed daily. On day 8, gingival mRNA expressions for interleukin (IL)-1β, IL-6, tissue necrosis factor (TNF)-α, IL-10, and NF-κB were determined via qPCR. Micro-computed tomography (μCT) and histomorphometry were employed to examine periodontal destruction.

Results

Compared to the ligation group, mRNA of IL-1β, TNF-α, IL-6, and NF-κB in probiotic groups were significantly decreased, but IL-10 was increased. Besides, the IL-10 was more significant in the combination group than in single-use group. Through μCT, the cementoenamel junction (CEJ)-to-bone distance and trabecular separation in combination group were less than that in ligation group, although the bone volume fraction and trabecular number/thickness showed an increase in three probiotic groups. Histopathologically, the combination group had significantly smaller gingival inflammatory cell-infiltrated area and CEJ-to-epithelium distance than the ligation group and the group with BL986 or LRH09. Additionally, the CEJ-to-bone distance was significantly smaller in the combination group than in the ligation and BL986 groups.

Conclusion

Systemic combination of BL986 and LRH09 had a synergistic effect on enhancing IL-10 and ameliorating the induced experimental periodontitis, although the single-use still presented partially alleviative effects.

Effects of Lactobacillus rhamnosus DSM7133 on Intestinal Porcine Epithelial Cells

Antimicrobial resistance is one of the biggest health challenges nowadays. Probiotics are promising candidates as feed additives contributing to the health of the gastrointestinal tract. The beneficial effect of probiotics is species/strain specific; the potential benefits need to be individually assessed for each probiotic strain or species. We established a co-culture model, in which gastrointestinal infection was modeled using Escherichia coli (E. coli) and Salmonella enterica serovar Typhimurium (S. enterica serovar Typhimurium). Using intestinal porcine epithelial cells (IPEC-J2), the effects of pre-, co-, and post-treatment with Lactobacillus (L.) rhamnosus on the barrier function, intracellular (IC) reactive oxygen species (ROS) production, proinflammatory cytokine (IL-6 and IL-8) response, and adhesion inhibition were tested. E. coli- and S. Typhimurium-induced barrier impairment and increased ROS production could be counteracted using L. rhamnosus (p < 0.01). S. Typhimurium-induced IL-6 production was reduced via pre-treatment (p < 0.05) and post-treatment (p < 0.01); increased IL-8 secretion was decreased via pre-, co-, and post-treatment (p < 0.01) with L. rhamnosus. L. rhamnosus demonstrated significant inhibition of adhesion for both S. Typhimurium (p < 0.001) and E. coli (p < 0.001 in both pre-treatment and post-treatment; p < 0.05 in co-treatment). This study makes a substantial contribution to the understanding of the specific benefits of L. rhamnosus. Our findings can serve as a basis for further in vivo studies carried out in pigs and humans.

Genome-Assisted Probiotic Characterization and Application of Lactiplantibacillus plantarum 18 as a Candidate Probiotic for Laying Hen Production

Probiotics gained significant attention for their potential to improve gut health and enhance productivity in animals, including poultry. This comprehensive study focused on the genetic analysis of Lactiplantibacillus plantarum 18 (LP18) to understand its survival and colonization characteristics in the gastrointestinal tract. LP18 was supplemented in the late-stage diet of laying hens to investigate its impact on growth performance, egg quality, and lipid metabolism. The complete genome sequence of LP18 was determined, consisting of 3,275,044 base pairs with a GC content of 44.42% and two circular plasmids. Genomic analysis revealed genes associated with adaptability, adhesion, and gastrointestinal safety. LP18 supplementation significantly improved the daily laying rate (p < 0.05) during the late-production phase and showed noteworthy advancements in egg quality, including egg shape index (p < 0.05), egg albumen height (p < 0.01), Haugh unit (p < 0.01), and eggshell strength (p < 0.05), with notable improvements in eggshell ultrastructure. Additionally, LP18 supplementation resulted in a significant reduction in serum lipid content, including LDL (p < 0.01), FFA (p < 0.05), and Gly (p < 0.05). These findings provide valuable insights into the genomic characteristics of LP18 and the genes that support its survival and colonization in the gastrointestinal tract. Importantly, this study highlights the potential of LP18 as a probiotic candidate to enhance productivity, optimize egg quality, and modulate lipid metabolism in poultry production.

Inhalable Excipient-Free Dry Powder of Tigecycline for the Treatment of Pulmonary Infections

Tigecycline (TIG) is a broad-spectrum antibiotic that has been approved for the treatment of a number of complicated infections, including community-acquired bacterial pneumonia. Currently it is available only as an intravenous injection that undergoes rapid chemical degradation and limits the use to in-patient scenarios. The use of TIG as an inhaled dry powder inhaler may offer a promising treatment option for patients with multidrug-resistant respiratory tract infections, such as Stenotrophomonas maltophilia (S. maltophilia). This study explores the feasibility of engineering an inhaled powder formulation of TIG that could administer relevant doses at a wide range of inhalation flow rates while maintaining stability of this labile drug. Using air-jet milling, micronized TIG had excellent aerosolization efficiency, with over 80% of the device emitted dose being within the respirable range. TIG was also readily dispersed using different inhaler devices even when tested at different pressure drops and flow rates. Additionally, micronized TIG was stable for 6 months at 25 °C/60% RH and 40 °C/75% RH. Micronized TIG maintained a low minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC) of 0.8 μM and >0.5 μM, respectively in S. maltophilia cultures in vitro. These results strongly suggest that the micronization of TIG results in a stable and respirable formulation that can be delivered via the pulmonary route for the treatment of lung infections.

Clinical Practice Guidelines of the Scientific Society for the Clinical Study of Human Microbiome, of the Russian Gastroenterological Association and the Russian Society for the Prevention of Noncommunicable Diseases on the Diagnosis and Treatment of <i>Clostridioides difficile</i> (<i>C. difficile</i>)-associated Disease in Adults

Аim: the clinical practice guidelines intended for gastroenterologists, internal medicine specialists, infectious disease specialists, general practitioners (family doctors), coloproctologists, surgeons and endoscopists present modern methods of diagnosis, prevention and treatment of C. difficile-associated disease.

Key points. C. difficile-associated disease is a disease that develops when the diversity of the intestinal microbiota decreases and C. difficile excessively colonizes the colon, the toxins of which damage the intestinal muco-epithelial barrier, followed by the development of inflammation in the colon wall, with diarrhea being a characteristic clinical manifestation. The clinical presentation of the disease can vary from asymptomatic carriage, mild to moderate diarrhea that resolves on its own, to profuse watery diarrhea and pseudomembranous colitis with development of life-threatening complications. The diagnosis of C. difficile-associated disease is based on an assessment of the clinical presentation, medical history, an objective examination of the patient and laboratory stool tests. The disease severity is determined by clinical symptoms and laboratory findings. Additional diagnostic methods that are used according to indications and contribute to the assessment of severity include endoscopy of the colon and abdominal cavity imaging methods. Treatment should be initiated in cases of characteristic clinical presentation of C. difficile-associated disease and positive laboratory stool testing. The choice of drug and treatment regimen depends on the severity of the episode, the presence of complications, and whether the episode is initial, recurrent, or reinfection.

Conclusion. Determination of target groups of patients for the diagnosis of clostridial infection is important in preventing overdiagnosis and subsequent unnecessary treatment. Timely diagnosis and treatment of C. difficile-associated disease help avoiding the development of life-threatening complications and improve the prognosis and quality of life of patients.

Crosstalk between the Resident Microbiota and the Immune Cells Regulates Female Genital Tract Health

The female genital tract (FGT) performs several functions related to reproduction, but due to its direct exposure to the external environment, it may suffer microbial infections. Both the upper (uterus and cervix) and lower (vagina) FGT are covered by an epithelium, and contain immune cells (macrophages, dendritic cells, T and B lymphocytes) that afford a robust protection to the host. Its upper and the lower part differ in terms of Lactobacillus spp., which are dominant in the vagina. An alteration of the physiological equilibrium between the local microbiota and immune cells leads to a condition of dysbiosis which, in turn, may account for the outcome of FGT infection. Aerobic vaginitis, bacterial vaginosis, and Chlamydia trachomatis are the most frequent infections, and can lead to severe complications in reproduction and pregnancy. The use of natural products, such as probiotics, polyphenols, and lactoferrin in the course of FGT infections is an issue of current investigation. In spite of positive results, more research is needed to define the most appropriate administration, according to the type of patient.

Microbial applications for sustainable space exploration beyond low Earth orbit

With the construction of the International Space Station, humans have been continuously living and working in space for 22 years. Microbial studies in space and other extreme environments on Earth have shown the ability for bacteria and fungi to adapt and change compared to "normal" conditions. Some of these changes, like biofilm formation, can impact astronaut health and spacecraft integrity in a negative way, while others, such as a propensity for plastic degradation, can promote self-sufficiency and sustainability in space. With the next era of space exploration upon us, which will see crewed missions to the Moon and Mars in the next 10 years, incorporating microbiology research into planning, decision-making, and mission design will be paramount to ensuring success of these long-duration missions. These can include astronaut microbiome studies to protect against infections, immune system dysfunction and bone deterioration, or biological in situ resource utilization (bISRU) studies that incorporate microbes to act as radiation shields, create electricity and establish robust plant habitats for fresh food and recycling of waste. In this review, information will be presented on the beneficial use of microbes in bioregenerative life support systems, their applicability to bISRU, and their capability to be genetically engineered for biotechnological space applications. In addition, we discuss the negative effect microbes and microbial communities may have on long-duration space travel and provide mitigation strategies to reduce their impact. Utilizing the benefits of microbes, while understanding their limitations, will help us explore deeper into space and develop sustainable human habitats on the Moon, Mars and beyond.

Microbiome-Related and Infection Control Approaches to Primary and Secondary Prevention of Clostridioides difficile Infections

Clostridioides difficile infections (CDIs) have decreased in the past years, but since 2021, some hospitals have reported an increase in CDI rates. CDI remains a global concern and has been identified as an urgent threat to healthcare. Although multiple treatment options are available, prevention strategies are more limited. As CDI is an opportunistic infection that arises after the normally protective microbiome has been disrupted, preventive measures aimed at restoring the microbiome have been tested. Our aim is to update the present knowledge on these various preventive strategies published in the past five years (2018-2023) to guide clinicians and healthcare systems on how to best prevent CDI. A literature search was conducted using databases (PubMed, Google Scholar, and clinicaltrials.gov) for phase 2-3 clinical trials for the primary or secondary prevention of CDI and microbiome and probiotics. As the main factor for Clostridium difficile infections is the disruption of the normally protective intestinal microbiome, strategies aimed at restoring the microbiome seem most rational. Some strains of probiotics, the use of fecal microbial therapy, and live biotherapeutic products offer promise to fill this niche; although, more large randomized controlled trials are needed that document the shifts in the microbiome population.

'Multi-omics' data integration: applications in probiotics studies

The concept of probiotics is witnessing increasing attention due to its benefits in influencing the host microbiome and the modulation of host immunity through the strengthening of the gut barrier and stimulation of antibodies. These benefits, combined with the need for improved nutraceuticals, have resulted in the extensive characterization of probiotics leading to an outburst of data generated using several 'omics' technologies. The recent development in system biology approaches to microbial science is paving the way for integrating data generated from different omics techniques for understanding the flow of molecular information from one 'omics' level to the other with clear information on regulatory features and phenotypes. The limitations and tendencies of a 'single omics' application to ignore the influence of other molecular processes justify the need for 'multi-omics' application in probiotics selections and understanding its action on the host. Different omics techniques, including genomics, transcriptomics, proteomics, metabolomics and lipidomics, used for studying probiotics and their influence on the host and the microbiome are discussed in this review. Furthermore, the rationale for 'multi-omics' and multi-omics data integration platforms supporting probiotics and microbiome analyses was also elucidated. This review showed that multi-omics application is useful in selecting probiotics and understanding their functions on the host microbiome. Hence, recommend a multi-omics approach for holistically understanding probiotics and the microbiome.

Qualitative Analysis of the Efficacy of Probiotic Strains in the Prevention of Antibiotic-Associated Diarrhea

Antibiotic-associated diarrhea is often managed by the withdrawal of the culprit antibiotics or the administration of alternative antibiotics when a Clostridium difficile infection (CDI) is suspected, an infection that tends to be the most common causative agent of the disease. Probiotics are also gaining popularity as alternative therapies, and it was hypothesized in this article that a Lactobacillus strain is the most efficacious probiotic for the prevention of antibiotic-associated diarrhea. This article conducted a literature review investigating the relative efficacy of the Lactobacillus, Bifidobacterium, and Saccharomyces probiotic strains as effective alternative therapies for antibiotic-associated diarrhea. The literature searched was from the PubMed database. The inclusion filters were: random control trials (RCTs), clinical trials, meta-analysis, last 10 years, full-text articles available in English, and all articles published in peer-reviewed journals. All three probiotic genera had strains that demonstrated significant efficacy in the prevention of antibiotic-associated diarrhea. However, Saccharomyces boulardii I-745 tends to outperform all the strains as the most effective and the one with the fewest, if any, adverse effects. Whenever probiotics are considered for the prevention of antibiotic-associated diarrhea (AAD) in both pediatric and adult patients, S. boulardii I-745 should probably be prioritized.

Behavioral screening of sleep-promoting effects of human intestinal and food-associated bacteria on Drosophila melanogaster

Commensal microbes influence various aspects of vertebrate and invertebrate brain function. We previously reported that Lactiplantibacillus plantarum SBT2227 promotes sleep in the fruit fly, Drosophila melanogaster. However, how widely the sleep-promoting effects are conserved in gut bacterial species remains unknown. In this study, we orally administered human intestinal and food-associated bacterial species (39 in total) to flies and investigated their effects on sleep. Six species of bacteria were found to have significant sleep-promoting effects. Of these, we further investigated Bifidobacterium adolescentis, which had the greatest sleep-promoting effect, and found that the strength of the sleep effect varied among strains of the same bacterial species. The B. adolescentis strains BA2786 and BA003 showed strong and weak effects on sleep, respectively. Transcriptome characteristics compared between the heads of flies treated with BA2786 or BA003 revealed that the gene expression of the insulin-like receptor (InR) was increased in BA2786-fed flies. Furthermore, a heterozygous mutation in InR suppressed the sleep-promoting effect of BA2786. These results suggest that orally administered sleep-promoting bacteria (at least BA2786), may act on insulin signaling to modulate brain function for sleep.

Probiotics for primary prevention of Clostridioides difficile infection: revisiting the evidence

Prophylactic probiotics have been shown to be effective in preventing Clostridioides difficile infection (CDI), according to multiple meta-analyses. However, different medical societies have varying recommendations on their use for preventing CDI. In this commentary, we discuss current evidence for probiotic use in primary prevention of CDI and the issues raised by professional societies when evaluating the evidence. We highlight four areas for future improvement: considering baseline risk for CDI, timing of probiotics with antibiotics, combining efficacy data from different probiotic strains, and safety. All societies agree on the need for more high-quality and adequately powered randomized controlled trials to further strengthen the evidence.