Commercial Probiotic Products: A Call for Improved Quality Control. A Position Paper by the ESPGHAN Working Group for Probiotics and Prebiotics

The Influence of the Gut Microbiota on Host Health: A Focus on the Gut-Lung Axis and Therapeutic Approaches

The human gut microbiota is a complex ecosystem harboring thousands of microbial strains that play a crucial role in maintaining the overall well-being of its host. The composition of the gut microbiota varies with age from infancy to adulthood and is influenced by dietary habits, environment, and genetic disposition. Recent advances in culture-independent techniques and nucleic acid sequencing have improved our understanding of the diversity of the gut microbiota. The microbial species present in the gut release short-chain fatty acids (SCFAs), which have anti-inflammatory properties. The gut microbiota also plays a substantial role in modulating the host's immune system, promoting immune tolerance, and maintaining homeostasis. The impact of the gut microbiota on the health of the host is quite evident, as gut dysbiosis has been linked to various diseases, including metabolic disorders, autoimmune diseases, allergies, and inflammatory bowel diseases. The gut microbiota has bidirectional communication with the respiratory system, creating the gut-lung axis, which has been associated with different respiratory diseases. Therapeutic approaches targeting the gut microbiota, such as probiotics, prebiotics, dietary interventions, and fecal microbiota transplantation (FMT), aim to restore microbial balance and promote the growth of beneficial strains in the gut. Nonetheless, gaining knowledge of the complex interactions between the gut microbiota and the host is necessary to develop personalized medicine approaches and microbiota-based therapies for various conditions. This review summarizes studies related to the gut-lung axis with particular emphasis on the role of the microbiota. Future research directions are also discussed.

Unlocking the Potential of Probiotics: A Comprehensive Review on Research, Production, and Regulation of Probiotics

This review provides a comprehensive overview of the current state of probiotic research, covering a wide range of topics, including strain identification, functional characterization, preclinical and clinical evaluations, mechanisms of action, therapeutic applications, manufacturing considerations, and future directions. The screening process for potential probiotics involves phenotypic and genomic analysis to identify strains with health-promoting properties while excluding those with any factor that could be harmful to the host. In vitro assays for evaluating probiotic traits such as acid tolerance, bile metabolism, adhesion properties, and antimicrobial effects are described. The review highlights promising findings from in vivo studies on probiotic mitigation of inflammatory bowel diseases, chemotherapy-induced mucositis, dysbiosis, obesity, diabetes, and bone health, primarily through immunomodulation and modulation of the local microbiota in human and animal models. Clinical studies demonstrating beneficial modulation of metabolic diseases and human central nervous system function are also presented. Manufacturing processes significantly impact the growth, viability, and properties of probiotics, and the composition of the product matrix and supplementation with prebiotics or other strains can modify their effects. The lack of regulatory oversight raises concerns about the quality, safety, and labeling accuracy of commercial probiotics, particularly for vulnerable populations. Advancements in multi-omics approaches, especially probiogenomics, will provide a deeper understanding of the mechanisms behind probiotic functionality, allowing for personalized and targeted probiotic therapies. However, it is crucial to simultaneously focus on improving manufacturing practices, implementing quality control standards, and establishing regulatory oversight to ensure the safety and efficacy of probiotic products in the face of increasing therapeutic applications.

Microbiome's Universe: Impact on health, disease and cancer treatment

The human microbiome is a diverse ecosystem of microorganisms that reside in the body and influence various aspects of health and well-being. Recent advances in sequencing technology have brought to light microbial communities in organs and tissues that were previously considered sterile. The gut microbiota plays an important role in host physiology, including metabolic functions and immune modulation. Disruptions in the balance of the microbiome, known as dysbiosis, have been linked to diseases such as cancer, inflammatory bowel disease and metabolic disorders. In addition, the administration of antibiotics can lead to dysbiosis by disrupting the structure and function of the gut microbial community. Targeting strategies are the key to rebalancing the microbiome and fighting disease, including cancer, through interventions such as probiotics, fecal microbiota transplantation (FMT), and bacteria-based therapies. Future research must focus on understanding the complex interactions between diet, the microbiome and cancer in order to optimize personalized interventions. Multidisciplinary collaborations are essential if we are going to translate microbiome research into clinical practice. This will revolutionize approaches to cancer prevention and treatment.

Next generation probiotics for human health: An emerging perspective

Over recent years, the scientific community has acknowledged the crucial role of certain microbial strains inhabiting the intestinal ecosystem in promoting human health, and participating in various beneficial functions for the host. These microorganisms are now referred to as next-generation probiotics and are currently considered as biotherapeutic products and food or nutraceutical supplements. However, the majority of next-generation probiotic candidates pose nutritional demands and exhibit high sensitivity towards aerobic conditions, leading to numerous technological hurdles in large-scale production. This underscores the need for the development of suitable delivery systems capable of enhancing the viability and functionality of these probiotic strains. Currently, potential candidates for next generation probiotics (NGP) are being sought among gut bacteria linked to health, which include strains from the genera Bacteroids, Faecalibacterium, Akkermansia and Clostridium. In contrast to Lactobacillus spp. and Bifidobacterium spp., NGP, particularly Bacteroids spp. and Clostridium spp., appear to exhibit greater ambiguity regarding their potential to induce infectious diseases. The present review provides a comprehensive overview of NGPs in terms of their health beneficial effects, regulation framework and risk assessment targeting relevant criteria for commercialization in food and pharmaceutical markets.

Tackling transmission of infectious diseases: A probiotic-based system as a remedy for the spread of pathogenic and resistant microbes

Built environments (BEs) currently represent the areas in which human beings spend most of their life. Consistently, microbes populating BEs mostly derive from human occupants and can be easily transferred from BE to occupants. The hospital microbiome is a paradigmatic example, representing a reservoir for harmful pathogens that can be transmitted to susceptible patients, causing the healthcare-associated infections (HAIs). Environmental cleaning is a crucial pillar in controlling BE pathogens and preventing related infections, and chemical disinfectants have been largely used so far towards this aim. However, despite their immediate effect, chemical-based disinfection is unable to prevent recontamination, has a high environmental impact, and can select/increase antimicrobial resistance (AMR) in treated microbes. To overcome these limitations, probiotic-based sanitation (PBS) strategies were recently proposed, built on the use of detergents added with selected probiotics able to displace surrounding pathogens by competitive exclusion. PBS was reported as an effective and low-impact alternative to chemical disinfection, providing stable rebalance of the BE microbiome and significantly reducing pathogens and HAIs compared to disinfectants, without exacerbating AMR and pollution concerns. This minireview summarizes the most significant results obtained by applying PBS in sanitary and non-sanitary settings, which overall suggest that PBS may effectively tackle the infectious risk meanwhile preventing the further spread of pathogenic and resistant microbes.

Reevaluating the FDA's warning against the use of probiotics in preterm neonates: A societal statement by ESPGHAN and EFCNI

The recent advisory issued by the United States Food and Drug Administration, cautioning against the routine administration of probiotics in preterm neonates, has sparked a lively debate within the scientific community. This commentary presents a perspective from members of the Special Interest Group on Gut Microbiota and Modifications within the European Society for Paediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) and other authors who contributed to the ESPGHAN position paper on probiotics for preterm infants, as well as representatives from the European Foundation for the Care of Newborn Infants. We advocate for a more nuanced and supportive approach to the use of certain probiotics in this vulnerable population, balancing the demonstrated benefits and risks.

A Shotgun Metagenomics Investigation into Labeling Inaccuracies in Widely Sold Probiotic Supplements in the USA

While probiotics are generally considered safe, concerns persist regarding the accuracy of labels on these supplements and their potential contribution to the spread of antibiotic resistance genes. Given that probiotics are predominantly ingested with a view towards obtaining particular health benefits. The objective of this study is to assess the composition of 50 widely available probiotic supplements in the USA using shotgun metagenome sequencing. The study also determines the potential resistome profile, and the functional characteristics of these products. This study finds that 67% of products does not contain any labeling inaccuracies. Antimicrobial Resistance Genes (ARGs) are identified in several products, particularly Bacillus-based products carrying between 10 and 56 genes. The risk posed by the presence of these ARGs requires further study. Functional analysis reveals differences in metabolic profiles among probiotic supplements, indicating the importance of strain-level selection for personalized probiotics. This study provides updated and comprehensive analysis to evaluate a snapshot of the USA market. The study demonstrates that label inaccuracies occur on approximately one third of popular dietary supplement products sold in the USA, supporting the need for improved approaches to marketing and quality control. Further, the risk of antibiotic resistance, especially in Bacillus-based formulations, should be assessed.

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.

Evaluation of Safety and Beneficial Health Effects of the Human-Milk Strain Bifidobacterium breve DSM32583: An Infant Pilot Trial

Human milk promotes the growth of bifidobacteria in the infant gut. Adding bifidobacterial species to infant formula may contribute to increasing their presence in the gut of formula-fed infants. Therefore, the safety and anti-infectious effects of Bifidobacterium breve DSM32583, a breast milk isolate, were assessed in a pilot trial involving 3-month-old infants. The infants were randomly assigned to either the probiotic (PG) or the control (CG) groups. All the infants consumed the same formula, although it was supplemented with the strain (1 × 107 cfu/g of formula) in the PG. Overall, 160 infants (80 per group) finished the intervention. Infants in CG gained more weight compared to PG (p < 0.05), but the weights for age Z-scores at 6 months were within the normal distribution for this age group. The rates of infections affecting the gastrointestinal and respiratory tracts and antibiotic therapy were significantly lower in the PG. The bifidobacterial population and the level of short-chain fatty acids were higher (p < 0.05) in the fecal samples of PG infants. No adverse events related to formula consumption were observed. In conclusion, the administration of an infant formula with B. breve DSM32583 was safe and exerted potential beneficial effects on gut health.

Safety and Effectiveness of Probiotics in Preterm Infants with Necrotizing Enterocolitis

Although necrotizing enterocolitis is a leading cause of morbidity and mortality among preterm infants, its underlying pathophysiology is not fully understood. Gut dysbiosis, an imbalance between commensal and pathogenic microbes, in the preterm infant is likely a major contributor to the development of necrotizing enterocolitis. In this review, we will discuss the increasing use of probiotics in the NICU, an intervention aimed to mitigate alterations in the gut microbiome. We will review the existing evidence regarding the safety and effectiveness of probiotics, and their potential to reduce rates of necrotizing enterocolitis in preterm infants.

Safety and Effectiveness of Probiotics in Preterm Infants with Necrotizing Enterocolitis

Although necrotizing enterocolitis is a leading cause of morbidity and mortality among preterm infants, its underlying pathophysiology is not fully understood. Gut dysbiosis, an imbalance between commensal and pathogenic microbes, in the preterm infant is likely a major contributor to the development of necrotizing enterocolitis. In this review, we will discuss the increasing use of probiotics in the NICU, an intervention aimed to mitigate alterations in the gut microbiome. We will review the existing evidence regarding the safety and effectiveness of probiotics, and their potential to reduce rates of necrotizing enterocolitis in preterm infants.

Current Regulatory Issues for the Use of Probiotics

The chapter provides an overview of the current regulatory challenges surrounding the use of probiotics. It explores the global regulatory landscape, noting the need for uniform regulations across various regions. It emphasizes that these inconsistencies pose challenges for consumers, healthcare professionals, and industry stakeholders. Furthermore, the chapter highlights the ongoing efforts at the Codex Alimentarius to establish harmonized probiotic guidelines. The chapter also discusses labeling regulations, stressing the need for more accurate and comprehensive information on probiotic products to aid in evidence-based decision-making. Finally, it addresses safety concerns, particularly for vulnerable populations like children, and calls for a multi-layered approach to safety assessments. The chapter concludes by advocating harmonizing regulations and guidelines to facilitate probiotics' safer and more effective use.

Role of Probiotics in the Treatment and Prevention of Common Gastrointestinal Conditions in Children

Probiotics are live microorganisms that confer health benefits to the host when administered in adequate amounts. Although recommendations for probiotic use should be strain-specific, many systematic reviews, including recommendations from different societies, recommend probiotic use in general, providing no relevant information for healthcare professionals regarding which probiotic to recommend for which clinical indication, at what dose, and for how long. This narrative review aimed to present the available evidence on the use of probiotics in the prevention and treatment of common gastrointestinal diseases in children, considering the strain and dose used. Furthermore, this study summarizes the evidence on the possible side effects and quality of products containing probiotics.

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.

State of the Art of Probiotic Use in Neonatal Intensive Care Units in French-Speaking European Countries

The effectiveness of probiotics in reducing the incidence of necrotizing enterocolitis has been supported by a very large number of studies. However, the utilization of probiotics in preterm infants remains a topic of debate. This study aims to assess the rate of probiotic use in European neonatal intensive care units (NICUs), compare administration protocols, and identify barriers and concerns associated with probiotic use. An online questionnaire was distributed via email to European NICUs between October 2020 and June 2021. Different questions related to the frequency of probiotic use were proposed. Data on probiotic administration protocols and reasons for non-utilization were collected. The majority of responses were from France and Switzerland, with response rates of 85% and 89%, respectively. A total of 21% of French NICUs and 100% of Swiss NICUs reported routine probiotic use. There was significant heterogeneity in probiotic administration protocols, including variations in probiotic strains, administration, and treatment duration. The main obstacles to routine probiotic use were the absence of recommendations, lack of consensus on strain selection, insufficient scientific evidence, and concerns regarding potential adverse effects. The rate of routine probiotic administration remains low in European NICUs, with heterogeneity among protocols. Further trials are necessary to elucidate optimal treatment modalities and ensure safety of administration.

Insights from metagenome-assembled genomes on the genetic stability and safety of over-the-counter probiotic products

The demand for and acceptance of probiotics is determined by their quality and safety. Illumina NGS sequencing and analytics were used to examine eight marketed probiotics. Up to the species level, sequenced DNA was taxonomically identified, and relative abundances were determined using Kaiju. The genomes were constructed using GTDB and validated through PATRICK and TYGS. A FastTree 2 phylogenetic tree was constructed using several type strain sequences from relevant species. Bacteriocin and ribosomally synthesized polypeptide (RiPP) genes were discovered, and a safety check was performed to test for toxins, antibiotic resistance, and genetic drift genes. Except for two products with unclaimed species, the labeling was taxonomically correct. In three product formulations, Lactobacillus acidophilus, Limosilactobacillus reuteri, Lacticaseibacillus paracasei, and Bifidobacterium animalis exhibited two to three genomic alterations, while Streptococcus equinus was found in one. TYGS and GDTB discovered E. faecium and L. paracasei in distinctly different ways. All the bacteria tested had the genetic repertoire to tolerate GIT transit, although some exhibited antibiotic resistance, and one strain had two virulence genes. Except for Bifidobacterium strains, the others revealed a variety of bacteriocins and ribosomally synthesized polypeptides (RiPP), 92% of which were unique and non-homologous to known ones. Plasmids and mobile genetic elements are present in strains of L. reuteri (NPLps01.et_L.r and NPLps02.uf_L.r), Lactobacillus delbrueckii (NPLps01.et_L.d), Streptococcus thermophilus (NPLps06.ab_S.t), and E. faecium (NPLps07.nf_E.f). Our findings support the use of metagenomics to build better and efficient production and post-production practices for probiotic quality and safety assessment.

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.

Probiotics and prebiotics: potential prevention and therapeutic target for nutritional management of COVID-19?

Scientists are working to identify prevention/treatment methods and clinical outcomes of coronavirus disease 2019 (COVID-19). Nutritional status and diet have a major impact on the COVID-19 disease process, mainly because of the bidirectional interaction between gut microbiota and lung, that is, the gut-lung axis. Individuals with inadequate nutritional status have a pre-existing imbalance in the gut microbiota and immunity as seen in obesity, diabetes, hypertension and other chronic diseases. Communication between the gut microbiota and lungs or other organs and systems may trigger worse clinical outcomes in viral respiratory infections. Thus, this review addresses new insights into the use of probiotics and prebiotics as a preventive nutritional strategy in managing respiratory infections such as COVID-19 and highlighting their anti-inflammatory effects against the main signs and symptoms associated with COVID-19. Literature search was performed through PubMed, Cochrane Library, Scopus and Web of Science databases; relevant clinical articles were included. Significant randomised clinical trials suggest that specific probiotics and/or prebiotics reduce diarrhoea, abdominal pain, vomiting, headache, cough, sore throat, fever, and viral infection complications such as acute respiratory distress syndrome. These beneficial effects are linked with modulation of the microbiota, products of microbial metabolism with antiviral activity, and immune-regulatory properties of specific probiotics and prebiotics through Treg cell production and function. There is a need to conduct clinical and pre-clinical trials to assess the combined effect of consuming these components and undergoing current therapies for COVID-19.

Bio-yogurt with the inclusion of phytochemicals from carrots (Daucus carota): a strategy in the design of functional dairy beverage with probiotics

The development of yogurt with functional characteristics from bioactive compounds such as fiber, antioxidants, and probiotics represents a novel strategy in designing value-added dairy beverages. However, biotechnological challenges are present in these bioprocesses, such as the selection of probiotic strains, as well as the correlation with the physicochemical characteristics of the fermentative metabolism of probiotic microorganisms. Therefore, yogurt could be a vehicle for including probiotic bacteria, bioactive compounds, and phytochemicals that allow synergistic effects in the development of bioprocesses with potential benefits for the host's health. Therefore, this article aims to review the current conditions of bio-yogurt production, discuss the physicochemical and bioactive composition (sugars, fiber, vitamins), and include phytochemicals from carrots to establish synergistic relationships with probiotic microorganisms to obtain a functional dairy beverage.

Single-cell rapid identification, in situ viability and vitality profiling, and genome-based source-tracking for probiotics products

Rapid expansion of the probiotics industry demands fast, sensitive, comprehensive, and low-cost strategies for quality assessment. Here, we introduce a culture-free, one-cell-resolution, phenome-genome-combined strategy called Single-Cell Identification, Viability and Vitality tests, and Source-tracking (SCIVVS). For each cell directly extracted from the product, the fingerprint region of D2O-probed single-cell Raman spectrum (SCRS) enables species-level identification with 93% accuracy, based on a reference SCRS database from 21 statutory probiotic species, whereas the C-D band accurately quantifies viability, metabolic vitality plus their intercellular heterogeneity. For source-tracking, single-cell Raman-activated Cell Sorting and Sequencing can proceed, producing indexed, precisely one-cell-based genome assemblies that can reach ~99.40% genome-wide coverage. Finally, we validated an integrated SCIVVS workflow with automated SCRS acquisition where the whole process except sequencing takes just 5 h. As it is >20-fold faster, >10-time cheaper, vitality-revealing, heterogeneity-resolving, and automation-prone, SCIVVS is a new technological and data framework for quality assessment of live-cell products.

Lactobacillus gasseri LGV03 isolated from the cervico-vagina of HPV-cleared women modulates epithelial innate immune responses and suppresses the growth of HPV-positive human cervical cancer cells

Persistent human papillomavirus (HPV) infections is necessary for the development of cervical cancers. An increasing number of retrospective studies have found the depletion of Lactobacillus microbiota in the cervico-vagina facilitate HPV infection and might be involved in viral persistence and cancer development. However, there have been no reports confirming the immunomodulatory effects of Lactobacillus microbiota isolated from cervico-vaginal samples of HPV clearance in women. Using cervico-vaginal samples from HPV persistent infection and clearance in women, this study investigated the local immune properties in cervical mucosa. As expected, type I interferons, such as IFN-α and IFN-β, and TLR3 globally downregulated in HPV+ persistence group. Luminex cytokine/chemokine panel analysis revealed that L. jannaschii LJV03, L. vaginalis LVV03, L. reuteri LRV03, and L. gasseri LGV03 isolated from cervicovaginal samples of HPV clearance in women altered the host's epithelial immune response, particularly L. gasseri LGV03. Furthermore, L. gasseri LGV03 enhanced the poly (I:C)-induced production of IFN by modulating the IRF3 pathway and attenuating poly (I:C)-induced production of proinflammatory mediators by regulating the NF-κB pathway in Ect1/E6E7 cells, indicating that L. gasseri LGV03 keeps the innate system alert to potential pathogens and reduces the inflammatory effects during persistent pathogen infection. L. gasseri LGV03 also markedly inhibited the proliferation of Ect1/E6E7 cells in a zebrafish xenograft model, which may be attributed to an increased immune response mediated by L. gasseri LGV03.

Probiotics and novel probiotic delivery systems

Necrotizing enterocolitis (NEC) is an infectious and inflammatory intestinal disease that is the most common surgical emergency in the premature patient population. Although the etiology of the disease is multifactorial, intestinal dysbiosis is a hallmark of this disease. Based on this, probiotics may play a therapeutic role in NEC by introducing beneficial bacteria with immunomodulating, antimicrobial, and anti-inflammatory functions into the gastrointestinal tract. Currently, there is no Food and Drug Administration (FDA)-approved probiotic for the prevention and treatment of NEC. All probiotic clinical studies to date have administered the bacteria in their planktonic (free-living) state. This review will discuss established probiotic delivery systems including planktonic probiotics, prebiotics, and synbiotics, as well as novel probiotic delivery systems such as biofilm-based and designer probiotics. We will also shed light on whether or not probiotic efficacy is influenced by administration with breast milk. Finally, we will consider the challenges associated with developing an FDA-approved probiotic for NEC.

Analysis of the microbial content of probiotic products commercialized worldwide and survivability in conditions mimicking the human gut environment

Introduction

Probiotics are living microorganisms that, when administered in adequate amounts, confer a health benefit on the host. Adequate number of living microbes, the presence of specific microorganisms, and their survival in the gastrointestinal (GI) environment are important to achieve desired health benefits of probiotic products. In this in vitro study, 21 leading probiotic formulations commercialized worldwide were evaluated for their microbial content and survivability in simulated GI conditions.

Methods

Plate-count method was used to determine the amount of living microbes contained in the products. Culture-dependent Matrix-Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry and culture-independent metagenomic analysis through 16S and 18S rDNA sequencing were applied in combination for species identification. To estimate the potential survivability of the microorganisms contained in the products in the harsh GI environment, an in vitro model composed of different simulated gastric and intestinal fluids was adopted.

Results

The majority of the tested probiotic products were concordant with the labels in terms of number of viable microbes and contained probiotic species. However, one product included fewer viable microbes than those displayed on the label, one product contained two species that were not declared, and another product lacked one of the labeled probiotic strains. Survivability in simulated acidic and alkaline GI fluids was highly variable depending on the composition of the products. The microorganisms contained in four products survived in both acidic and alkaline environments. For one of these products, microorganisms also appeared to grow in the alkaline environment.

Conclusion

This in vitro study demonstrates that most globally commercialized probiotic products are consistent with the claims described on their labels with respect to the number and species of the contained microbes. Evaluated probiotics generally performed well in survivability tests, although viability of microbes in simulated gastric and intestinal environments showed large variability. Although the results obtained in this study indicate a good quality of the tested formulations, it is important to stress that stringent quality controls of probiotic products should always be performed to provide optimal health benefits for the host.

Screening, Identification and Physiological Characteristics of Lactobacillus rhamnosus M3 (1) against Intestinal Inflammation

The probiotic role of lactic acid bacteria (LAB) in regulating intestinal microbiota to promote human health has been widely reported. However, the types and quantities of probiotics used in practice are still limited. Therefore, isolating and screening LAB with potential probiotic functions from various habitats has become a hot topic. In this study, 104 strains of LAB were isolated from and identified in traditionally fermented vegetables, fresh milk, healthy infant feces, and other environments. The antibacterial properties-resistance to acid, bile salts, and digestive enzymes-and adhesion ability of the strains were determined, and the biological safety of LAB with better performance was studied. Three LAB with good comprehensive performance were obtained. These bacteria had broad-spectrum antibacterial properties and good acid resistance and adhesion ability. They exhibited some tolerance to pig bile salt, pepsin, and trypsin and showed no hemolysis. They were sensitive to the selected antibiotics, which met the required characteristics and safety evaluation criteria for probiotics. An in vitro fermentation experiment and milk fermentation performance test of Lactobacillus rhamnosus (L. rhamnosus) M3 (1) were carried out to study its effect on the intestinal flora and fermentation performance in patients with inflammatory bowel disease (IBD). Studies have shown that this strain can effectively inhibit the growth of harmful microorganisms and produce a classic, pleasant flavor. It has probiotic potential and is expected to be used as a microecological agent to regulate intestinal flora and promote intestinal health. It can also be used as an auxiliary starter to enhance the probiotic value of fermented milk.

Recent Innovations in Non-dairy Prebiotics and Probiotics: Physiological Potential, Applications, and Characterization

Non-dairy sources of prebiotics and probiotics impart various physiological functions in the prevention and management of chronic metabolic disorders, therefore nutraceuticals emerged as a potential industry. Extraction of prebiotics from non-dairy sources is economical and easily implemented. Waste products during food processing, including fruit peels and fruit skins, can be utilized as a promising source of prebiotics and considered "Generally Recognized As Safe" for human consumption. Prebiotics from non-dairy sources have a significant impact on gut microbiota and reduce the population of pathogenic bacteria. Similarly, next-generation probiotics could also be isolated from non-dairy sources. These sources have considerable potential and can give novel strains of probiotics, which can be the replacement for dairy sources. Such strains isolated from non-dairy sources have good probiotic properties and can be used as therapeutic. This review will elaborate on the potential non-dairy sources of prebiotics and probiotics, their characterization, and significant physiological potential.

Probiotic therapy, African fermented foods and food-derived bioactive peptides in the management of SARS-CoV-2 cases and other viral infections

The current paper focuses on the impact of probiotics, African fermented foods and bioactive peptides on severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection severity and related viral infections. Using probiotics or bioactive peptides as therapeutic adjuncts appears superior to standard care alone. Probiotics play critical roles in innate and adaptive immune modulation by balancing the gut microbiota to combat viral infections, secondary bacterial infections and microbial dysbiosis. African fermented foods contain abundant potential probiotic microorganisms such as the lactic acid bacteria (LAB), Saccharomyces, and Bacillus. More so, fermented food-derived bioactive peptides play vital roles in preventing cardiovascular diseases, hypertension, lung injury, diabetes, and other COVID-19 comorbidities. Regularly incorporating potential probiotics and bioactive peptides into diets should enable a build-up of the benefits in the body system that may result in a better prognosis, especially in COVID-19 patients with underlying complexities. Despite the reported therapeutic potentials of probiotics and fermented foods, numerous setbacks exist regarding their application in disease management. These shortfalls underscore an evident need for more studies to evaluate the specific potentials of probiotics and traditional fermented foods in ameliorating SARS-CoV-2 and other viral infections.

Nanopore Sequencing Discloses Compositional Quality of Commercial Probiotic Feed Supplements

The market for the application of probiotics as a livestock health improvement supplement has increased in recent years. However, most of the available products are quality-controlled using low-resolution techniques and un-curated databases, resulting in misidentification and incorrect product labels. In this work, we deployed two workflows and compared results obtained by full-length 16S rRNA genes (16S) and metagenomic (Meta) data to investigate their reliability for the microbial composition of both liquid and solid forms of animal probiotic products using Oxford Nanopore long-read-only (without short-read). Our result revealed that 16S amplicon data permits to detect the bacterial microbiota even with the low abundance in the samples. Moreover, the 16S approach has the potential to provide species-level resolution for prokaryotes but not for assessing yeast communities. Whereas, Meta data has more power to recover of high-quality metagenome-assembled genomes that enables detailed exploration of both bacterial and yeast populations, as well as antimicrobial resistance genes, and functional genes in the population. Our findings clearly demonstrate that implementing these workflows with long-read-only monitoring could be applied to assessing the quality and safety of probiotic products for animals and evaluating the quality of probiotic products on the market. This would benefit the sustained growth of the livestock probiotic industry.

In Vitro Evaluation of Commercial Probiotic Products Containing Streptococcus salivarius K12 by Assessment of Probiotic Viability and Inhibitory Potency against Respiratory Pathogens

Upper respiratory infections (URI) are the most frequent illnesses, especially in children. The majority of those infections are prescribed broad-spectrum antibiotics, which are associated with various side effects and with the increase in multi-drug-resistant strains. A promising alternative approach is the administration of the probiotic strain Streptococcus salivarius K12 (SSK12) that colonizes the upper respiratory tract (URT) and produces the salivaricins A2 and B, which strongly antagonize the growth of key respiratory pathogens. However, since for food supplements no quality controls of the active probiotic ingredient are mandatory, the efficacy of commercial products containing SSK12 may vary. This study aimed to investigate the in vitro efficacy of several commercial SSK12-containing probiotics, positioned for the prevention of respiratory infections. The parameters evaluated to determine the in vitro efficacy included the viability of the probiotic bacterial strain and the minimum inhibitory dilution (MID) of the probiotic, determined by the agar spot method, against the pathogenic/potential pathogenic bacterial strains Streptococcus pyogenes FF22 and Micrococcus luteus T18. All tests were carried out both 12 and 24 months after manufacturing (AM) for each commercial product. The viability ranged from 9 × 108 to 4.4 × 109 CFU/serving at 12 months AM and from 8.5 × 107 to 2.8 × 109 CFU/serving at 24 months AM. The MID was, in general, positively correlated with the probiotic bacterium viability and varied between the commercial products, ranging from 10−5 to 10−7 at 12 months AM and from 10−4 to 10−7 at 24 months AM. Moreover, the inhibition zones related to the two indicator strains were variable in diameter for different products. The high variation of the in vitro efficacy of commercial products containing SSK12 may explain the different results reported in the literature regarding the clinical benefits of these preparations, and the determination of this parameter may be useful to evaluate the quality of probiotic products containing this bacterial strain.

Strain-Specificity of Probiotics in Pediatrics: A Rapid Review of the Clinical Evidence

OBJECTIVE

The dogma of probiotic strain-specificity is widely accepted. However, only the genus- and species-specific effects of probiotics are supported by evidence from clinical trials. The aim of this rapid review was to assess clinical evidence supporting the claim that the efficacy of probiotics in the pediatric population is strain-specific.

METHODS

The Cochrane Library, MEDLINE, and EMBASE databases were searched (up to August 2022) for randomized controlled trials (RCTs) conducted in children aged 0-18 years evaluating the effects of prophylactic or therapeutic administration of probiotics (well-characterized at the strain level) for conditions such as antibiotic-associated diarrhea, acute diarrhea, necrotizing enterocolitis, respiratory tract infections, Helicobacter pylori infection, and atopic dermatitis. To allow evaluation of strain-specificity, a trial could only be included in the review if at least one additional RCT assessed the effect of a different strain of the same species against the same comparator. RCTs without proper strain-level data were excluded. In the absence of identifying head-to-head strain versus strain RCTs, indirect comparisons were made between interventions.

RESULTS

Twenty-three RCTs were eligible for inclusion. Out of the 11 performed comparisons, with 1 exception (two Lacticaseibacillus paracasei strains in reducing atopic dermatitis symptoms), no significant differences between the clinical effects of different strains of the same probiotic species were found.

CONCLUSIONS

Head-to-head comparison is an optimal study design to compare probiotic strains, but such comparisons are lacking. Based on indirect comparisons, this rapid review demonstrates insufficient clinical evidence to support or refute the claim that probiotic effects in children are strain-specific.

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.

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.

Could paraprobiotics be a safer alternative to probiotics for managing cancer chemotherapy-induced gastrointestinal toxicities?

Clinical oncology has shown outstanding progress improving patient survival due to the incorporation of new drugs. However, treatment success may be reduced by the emergency of dose-limiting side effects, such as intestinal mucositis and diarrhea. Mucositis and diarrhea management is symptomatic, and there is no preventive therapy. Bacterial and fungal-based compounds have been suggested as an alternative for preventing the development of diarrhea in cancer patients. Using probiotics is safe and effective in immunocompetent individuals, but concerns remain during immunosuppressive conditions. Paraprobiotics, formulations composed of non-viable microorganisms, have been proposed to overcome such limitation. The present literature review discusses current evidence regarding the possible use of paraprobiotics as an alternative to probiotics to prevent gastrointestinal toxicity of cancer chemotherapy.

Probiotics Mechanism of Action on Immune Cells and Beneficial Effects on Human Health

Immune cells and commensal microbes in the human intestine constantly communicate with and react to each other in a stable environment in order to maintain healthy immune activities. Immune system-microbiota cross-talk relies on a complex network of pathways that sustain the balance between immune tolerance and immunogenicity. Probiotic bacteria can interact and stimulate intestinal immune cells and commensal microflora to modulate specific immune functions and immune homeostasis. Growing evidence shows that probiotic bacteria present important health-promoting and immunomodulatory properties. Thus, the use of probiotics might represent a promising approach for improving immune system activities. So far, few studies have been reported on the beneficial immune modulatory effect of probiotics. However, many others, which are mainly focused on their metabolic/nutritional properties, have been published. Therefore, the mechanisms behind the interaction between host immune cells and probiotics have only been partially described. The present review aims to collect and summarize the most recent scientific results and the resulting implications of how probiotic bacteria and immune cells interact to improve immune functions. Hence, a description of the currently known immunomodulatory mechanisms of probiotic bacteria in improving the host immune system is provided.

Probiotics to improve the gut microbiome in premature infants: are we there yet?

Gut microbiome maturation in infants born prematurely is uniquely influenced by the physiological, clinical, and environmental factors surrounding preterm birth and early life, leading to altered patterns of microbial succession relative to term infants during the first months of life. These differences in microbiome composition are implicated in acute clinical conditions that disproportionately affect preterm infants, including necrotizing enterocolitis (NEC) and late-onset sepsis (LOS). Probiotic supplementation initiated early in life is an effective prophylactic measure for preventing NEC, LOS, and other clinical concerns relevant to preterm infants. In parallel, reported benefits of probiotics on the preterm gut microbiome, metabolome, and immune function are beginning to emerge. This review summarizes the current literature on the influence of probiotics on the gut microbiome of preterm infants, outlines potential mechanisms by which these effects are exerted, and highlights important clinical considerations for determining the best practices for probiotic use in premature infants.

The power of DNA based methods in probiotic authentication

Introduction

The global probiotic market is growing rapidly, and strict quality control measures are required to ensure probiotic product efficacy and safety. Quality assurance of probiotic products involve confirming the presence of specific probiotic strains, determining the viable cell counts, and confirming the absence of contaminant strains. Third-party evaluation of probiotic quality and label accuracy is recommended for probiotic manufacturers. Following this recommendation, multiple batches of a top selling multi-strain probiotic product were evaluated for label accuracy.

Methods

A total of 55 samples (five multi-strain finished products and 50 single-strain raw ingredients) containing a total of 100 probiotic strains were evaluated using a combination of molecular methods including targeted PCR, non-targeted amplicon-based High Throughput Sequencing (HTS), and non-targeted Shotgun Metagenomic Sequencing (SMS).

Results

Targeted testing using species-specific or strain-specific PCR methods confirmed the identity of all strains/species. While 40 strains were identified to strain level, 60 strains were identified to species level only due to lack of strain-specific identification methods. In amplicon based HTS, two variable regions of 16S rRNA gene were targeted. Based on V5-V8 region data, ~99% of total reads per sample corresponded to target species, and no undeclared species were detected. Based on V3-V4 region data, ~95%-97% of total reads per sample corresponded to target species, while ~2%-3% of reads matched undeclared species (Proteus species), however, attempts to culture Proteus confirmed that all batches were free from viable Proteus species. Reads from SMS assembled to the genomes of all 10 target strains in all five batches of the finished product.

Discussion

While targeted methods enable quick and accurate identification of target taxa in probiotic products, non-targeted methods enable the identification of all species in a product including undeclared species, with the caveats of complexity, high cost, and long time to result.

Probiotics and Postbiotics as the Functional Food Components Affecting the Immune Response

The food market is one of the most innovative segments of the world economy. Recently, among consumers there is a forming trend of a healthier lifestyle and interest in functional foods. Products with positive health properties are a good source of nutrients for consumers' nutritional needs and reduce the risk of metabolic diseases such as diabetes, atherosclerosis, or obesity. They also seem to boost the immune system. One of the types of functional food is "probiotic products", which contain viable microorganisms with beneficial health properties. However, due to some technical difficulties in their development and marketing, a new alternative has started to be sought. Many scientific studies also point to the possibility of positive effects on human health, the so-called "postbiotics", the characteristic metabolites of the microbiome. Both immunobiotics and post-immunobiotics are the food components that affect the immune response in two ways: as inhibition (suppressing allergies and inflammation) or as an enhancement (providing host defenses against infection). This work's aim was to conduct a literature review of the possibilities of using probiotics and postbiotics as the functional food components affecting the immune response, with an emphasis on the most recently published works.

Drugging the microbiome and bacterial live biotherapeutic consortium production

Research leading to characterization, quantification, and functional attribution of the microbes throughout the human body has led to many drug-development programs. These programs aim to manipulate a patient's microbiome through the addition of new strains or functions, the subtraction of deleterious microbes, or the rebalancing of the existing population through various drug modalities. Here, we present a general overview of those modalities with a specific focus on bacterial live biotherapeutic products (LBPs). The bacterial LBP modality has unique concerns to ensure product quality, thus, topics related to manufacturing, quality control, and regulation are addressed.

Probiotics media: significance, challenges, and future perspective - a mini review

The health benefits associated with probiotics have increased their application in pharmaceutical formulations and functional food development. High production of probiotic biomass requires a cost-effective production method and nutrient media optimization. The biomass production of probiotics can be enhanced by optimizing growth parameters such as substrate, pH, incubation time, etc. For economical industrial production of probiotic biomass, it is required to design a new medium with low cost. Wastes from the food industries are promising components for the development of the low-cost medium. Industrial wastes such as cheese whey and corn steep liquor are excellent examples of reliable sources of nitrogen for the biomass production of probiotic bacteria. The increased yield of biomass reduced the cost of production. This review focuses on the importance of probiotic media for biomass production and its challenges.

Graphical Abstract

Probiotic knowledge of adults with cystic fibrosis is limited but is associated with probiotic use: A cross-sectional survey study

Background: Probiotics are used by people with cystic fibrosis (CF) and other chronic diseases to manage gastrointestinal symptoms. Aim: To describe probiotic knowledge; its relationship with probiotic use, probiotic information sources and factors influencing choice in adults with CF and a general population control group. Methods: A cross-sectional questionnaire study was conducted in adults with CF (n = 205) and Controls (n = 158). Probiotic knowledge was compared between CF and Controls using a knowledge score (maximum 5) based on predefined criteria: (1a) bacteria/microorganism; (1b) live; (2a) administered; (2b) adequate dose and (3) health benefit, using independent samples t-test. Two-way analysis of variance explored knowledge scores between CF and Control and between Ever User and Never User groups. Chi-square and Fisher's exact tests compared knowledge criterion, probiotic sources and influences on probiotic choice between groups. Thematic analysis of open-text responses explored probiotic-related knowledge and influences on probiotic decision making. Results: Knowledge scores (mean ± SD) did not differ between CF (1.70 ± 1.12) and Controls (1.89 ± 0.99), p = 0.13. Probiotic use was associated with knowledge score (p < 0.001). More CF Ever Users than Never Users correctly identified criteria 1a (65% vs. 38%), 1b (16% vs. 0%), 2a (45% vs. 22%) and 3 (73% vs. 42%) (all p < 0.005). CF participants considered 'dairy yoghurt' (69%), 'live cultures' (64%) and 'fermented foods' (37%) as 'all/mostly' probiotic sources. The internet was the commonest source of probiotic-related information. Conclusion: Probiotic knowledge and use were associated in adults with CF. Understanding of probiotic characteristics and sources were limited. Education is needed to help guide patient probiotic decision making.

Sheep Milk Symbiotic Ice Cream: Effect of Inulin and Apple Fiber on the Survival of Five Probiotic Bacterial Strains during Simulated In Vitro Digestion Conditions

We conducted a study to determine the survival of bacterial cells under in vitro digestion. For this purpose, ice cream mixes were prepared: control, with 4% inulin, 2.5% inulin and 1.5% apple fiber and 4% apple fiber. Each inoculum (pH = 4.60 ± 0.05), containing 9 log cfu g^-1 bacteria, at 5% (w/w) was added to the ice cream mixes (Lacticaseibacilluscasei 431, Lactobacillus acidophilus LA-5, Lacticaseibacillus paracasei L-26, Lacticaseibacillusrhamnosus, Bifidobacterium animalis ssp. lactis BB-12) and fermentation was carried out to pH 4.60 ± 0.05. The in vitro digestion method simulated the stages of digestion that occur in the mouth, stomach and small intestine under optimal controlled conditions (pH value, time and temperature). At each stage of digestion, the survival rate of probiotic bacteria was determined using the plate-deep method. As expected, in the oral stage, there was no significant reduction in the viability of the probiotic bacteria in any ice cream group compared to their content before digestion. In the stomach stage, Bifidobacterium animalis ssp. lactis BB-12 strain had the highest viable counts (8.48 log cfu g^-1) among the control samples. Furthermore, a 4% addition of inulin to ice cream with Bifidobacterium BB-12 increased gastric juice tolerance and limited strain reduction by only 16.7% compared to the number of bacterial cells before digestion. Regarding ice cream samples with Bifidobacterium BB-12, replacing part of the inulin with apple fiber resulted in increased survival at the stomach stage and a low reduction in the bacterial population of only 15.6% compared to samples before digestion. At the stomach stage, the positive effect of the addition of inulin and apple fiber was also demonstrated for ice cream samples with Lacticaseibacilluscasei 431 (9.47 log cfu g^-1), Lactobacillus acidophilus LA-5 (8.06 log cfu g^-1) and Lacticaseibacillus paracasei L-26 (5.79 log cfu g^-1). This study showed the highest sensitivity to simulated gastric stress for ice cream samples with Lacticaseibacillusrhamnosus (4.54 log cfu g^-1). Our study confirmed that the 4% addition of inulin to ice cream increases the survival rate of L. casei and Bifidobacterium BB-12 in simulated intestinal juice with bile by 0.87 and 2.26 log cfu g^-1, respectively. The highest viable count in the small intestine stage was observed in ice cream with L. acidophilus. The addition of inulin increased the survival of L. rhamnosus by 10.8% and Bifidobacterium BB-12 by about 22% under conditions of simulated in vitro digestion compared to their control samples. The survival rates of L. casei and L. paracasei were also highly affected by the 4% addition of apple fiber, where the increase under gastrointestinal passage conditions was determined to range from 7.86-11.26% compared to their control counterparts. In comparison, the lowest survival rate was found in the control ice cream with L. rhamnosus (47.40%). In our study at the intestinal stage, only five ice cream groups: a sample with 4% inulin and L. acidophilus, a control sample with Bifidobacterium BB12, a sample with 2.5% inulin and 1.5% apple fiber with Bifidobacterium BB12, a control sample with L. rhamnosus, a sample with 4% fiber and L. rhamnosus reported bacterial cell counts below 6 log cfu g^-1 but higher than 5 log cfu g^-1. However, in the remaining ice cream groups, viable counts of bacterial cells ranged from 6.11 to 8.88 log cfu g^-1, ensuring a therapeutic effect. Studies have clearly indicated that sheep milk ice cream could provide a suitable matrix for the delivery of probiotics and prebiotics and contribute to intestinal homeostasis. The obtained results have an applicative character and may play an essential role in developing new functional sheep milk ice cream.

Current Progress and Future Perspectives on the Use of Bacillus clausii

Bacillus clausii is a probiotic that benefits human health. Its key characteristics include the ability to form spores; the resulting tolerance to heat, acid, and salt ensures safe passage through the human gastrointestinal tract with no loss of cells. Although B. clausii has been widely used for many decades, the beneficial properties of other probiotics, such as Lactobacillus spp. and Bifidobacterium spp., are better disseminated in the literature. In this review, we summarize the physiological, antimicrobial, and immunomodulatory properties of probiotic B. clausii strains. We also describe findings from studies that have investigated B. clausii probiotics from the perspective of quality and safety. We highlight innovative properties based on biochemical investigations of non-probiotic strains of B. clausii, revealing that B. clausii may have further health benefits in other therapeutic areas.

The right bug in the right place: opportunities for bacterial vaginosis treatment

Bacterial vaginosis (BV) is a condition in which the vaginal microbiome presents an overgrowth of obligate and facultative anaerobes, which disturbs the vaginal microbiome balance. BV is a common and recurring vaginal infection among women of reproductive age and is associated with adverse health outcomes and a decreased quality of life. The current recommended first-line treatment for BV is antibiotics, despite the high recurrence rate. Live biopharmaceutical products/probiotics and vaginal microbiome transplantation (VMT) have also been tested in clinical trials for BV. In this review, we discuss the advantages and challenges of current BV treatments and interventions. Furthermore, we provide our understanding of why current clinical trials with probiotics have had mixed results, which is mainly due to not administering the correct bacteria to the correct body site. Here, we propose a great opportunity for large clinical trials with probiotic strains isolated from the vaginal tract (e.g., Lactobacillus crispatus) and administered directly into the vagina after pretreatment.

Functional Microbes and Their Incorporation into Foods and Food Supplements: Probiotics and Postbiotics

Life expectancy has dramatically increased over the past 200 years, but modern life factors such as environmental exposure, antibiotic overuse, C-section deliveries, limited breast-feeding, and diets poor in fibers and microbes could be associated with the rise of noncommunicable diseases such as overweight, obesity, diabetes, food allergies, and colorectal cancer as well as other conditions such as mental disorders. Microbial interventions that range from transplanting a whole undefined microbial community from a healthy gut to an ill one, e.g., so-called fecal microbiota transplantation or vaginal seeding, to the administration of selected well-characterized microbes, either live (probiotics) or not (postbiotics), with efficacy demonstrated in clinical trials, may be effective tools to treat or prevent acute and chronic diseases that humans still face, enhancing the quality of life.

Best Practices for Probiotic Research in Athletic and Physically Active Populations: Guidance for Future Randomized Controlled Trials

Probiotic supplementation, traditionally used for the prevention or treatment of a variety of disease indications, is now recognized in a variety of population groups including athletes and those physically active for improving general health and performance. However, experimental and clinical trials with probiotics commonly suffer from design flaws and different outcome measures, making comparison and synthesis of conclusions difficult. Here we review current randomized controlled trials (RCTs) using probiotics for performance improvement, prevention of common illnesses, or general health, in a specific target population (athletes and those physically active). Future RCTs should address the key elements of (1) properly defining and characterizing a probiotic intervention, (2) study design factors, (3) study population characteristics, and (4) outcome measures, that will allow valid conclusions to be drawn. Careful evaluation and implementation of these elements should yield improved trials, which will better facilitate the generation of evidence-based probiotic supplementation recommendations for athletes and physically active individuals.

Assessing Viability and Stress Tolerance of Probiotics—A Review

The interest in probiotics has increased rapidly the latest years together with the global market for probiotic products. Consequently, establishing reliable microbiological methods for assuring the presence of a certain number of viable microorganisms in probiotic products has become increasingly important. To assure adequate numbers of viable cells, authorities are enquiring for information on viability rates within a certain shelf-life in colony forming units (CFU). This information is obtained from plate count enumeration, a method that enables detection of bacterial cells based on their ability to replicate. Although performing plate count enumeration is one manner of assessing viability, cells can still be viable without possessing the ability to replicate. Thus, to properly assess probiotic viability, further analysis of a broader group of characteristics using several types of methods is proposed. In addition to viability, it is crucial to identify how well the cells in a probiotic product can survive in the gastrointestinal tract (GIT) and thus be able to mediate the desired health benefit while passing through the human body. A broad spectrum of different assay designs for assessing probiotic gastric tolerance have been used in research and quality control. However, the absence of any consensus on how to assess these qualities makes it difficult to compare between laboratories and to translate the results into in vivo tolerance. This review presents and discusses the complexity of assuring that a probiotic is suitable for beneficial consumption. It summarizes the information that can be subtracted from the currently available methods for assessment of viability and stress tolerance of a probiotic, hereby altogether defined as “activity.” Strengths and limitations of the different methods are presented together with favorable method combinations. Finally, the importance of choosing a set of analyses that reveals the necessary aspects of probiotic activity for a certain product or application is emphasized.

Locked Nucleic Acid Hydrolysis Probes for the Specific Identification of Probiotic Strains Bifidobacterium animalis subsp. lactis DSM 15954 and Bi-07™

Probiotic health benefits are now well-recognized to be strain specific. Probiotic strain characterization and identification is thus important in clinical research and in the probiotic industry. This is becoming especially important with reports of probiotic products failing to meet the declared strain content, potentially compromising their efficacy. Availability of reliable identification methods is essential for strain authentication during discovery, evaluation and commercialization of a probiotic strain. This study aims to develop identification methods for strains Bifidobacterium animalis subsp. lactis DSM 15954 and Bi-07 (Bi-07™) based on real-time PCR, targeting single nucleotide polymorphisms (SNPs). The SNPs were targeted by PCR assays with locked nucleic acid (LNA) probes, which is a novel application in probiotic identification. The assays were then validated following the guidelines for validating qualitative real-time PCR assays. Each assay was evaluated for specificity against 22 non-target strains including closely related Bifidobacterium animalis subsp. lactis strains and were found to achieve 100% true positive and 0% false positive rates. To determine reaction sensitivity and efficiency, three standard curves were established for each strain. Reaction efficiency values were 86, 91, and 90% (R square values > 0.99), and 87, 84, and 86% (R square values > 0.98) for B. animalis subsp. lactis DSM 15954 and Bi-07 assays, respectively. The limit of detection (LOD) was 5.0 picograms and 0.5 picograms of DNA for DSM 15954 and Bi-07 assays, respectively. Each assay was evaluated for accuracy using five samples tested at three different DNA concentrations and both assays proved to be highly repeatable and reproducible. Standard deviation of Cq values between two replicates was always below 1.38 and below 1.68 for DSM 15954 and Bi-07 assays, respectively. The assays proved to be applicable to mono-strain and multi-strain samples as well as for samples in various matrices of foods or dietary supplement ingredients. Overall, the methods demonstrated high specificity, sensitivity, efficiency and precision and broad applicability to sample, matrix and machine types. These methods facilitate strain level identification of the highly monophyletic strains B. animalis subsp. lactis DSM 15954 and Bi-07 to ensure probiotic efficacy and provide a strategy to identify other closely related probiotics organisms.