Safety of Bifidobacterium animalis subsp. lactis (B. lactis) strain BB-12-supplemented yogurt in healthy adults on antibiotics: a phase I safety study

Effects of Bifidobacterium animalis subsp. lactis BB-12 and yogurt on mice during oral antibiotic administration

Probiotics have the potential to prevent disruptions to normal gastrointestinal function caused by oral antibiotic use. In this study, we examined the capacity of Bifidobacterium animalis subspecies lactis BB-12 (BB-12) and yogurt, separately and combined, to mitigate the effects of the antibiotic amoxicillin-clavulanate (AMC) on the gut microbiota and metabolomes of C57BL/6 J mice. Male and female mice were administered either BB-12, yogurt, BB-12 in yogurt, or saline for 10 days concurrent with the inclusion of AMC in the drinking water. Male mice exposed to AMC exhibited significant reductions (p<0.05) in body weight over the course of the study compared to sham (no AMC) controls whereas no such effects were observed for female mice. AMC administration resulted in rapid alterations to the intestinal microbiota in both sexes irrespective of BB-12 or yogurt treatment, including significant (p<0.05) losses in bacterial cell numbers and changes in microbial alpha-diversity and beta-diversity in the feces and cecal contents. The effects of AMC on the gut microbiota were observed within one day of administration and the bacterial contents continued to change over time, showing a succession marked by rapid reductions in Muribaculaceae and Lachnospiraceae and temporal increases in proportions of Acholeplasmataceae (day 1) and Streptococcaceae and Leuconostocaceae (day 5). By day 10 of AMC intake, high proportions of Gammaproteobacteria assigned as Erwiniaceae or Enterobacteriaceae (average of 63 %), were contained in the stools and were similarly enriched in the cecum. The cecal contents of mice given AMC harbored significantly reduced concentrations of (branched) short-chain fatty acids (SCFA), aspartate, and other compounds, whereas numerous metabolites, including formate, lactate, and several amino acids and amino acid derivatives were significantly enriched. Despite the extensive impact of AMC, starting at day 7 of the study, the body weights of male mice given yogurt or BB-12 (in saline) with AMC were similar to the healthy controls. BB-12 (in saline) and yogurt intake was associated with increased Streptococcaceae and both yogurt and BB-12 resulted in lower proportions of Erwiniaceae in the fecal and cecal contents. The cecal contents of mice fed BB-12 in yogurt contained levels of formate, glycine, and glutamine that were equivalent to the sham controls. These findings highlight the potential of BB-12 and yogurt to mitigate antibiotic-induced gut dysbiosis.

The effect of bovine dairy products and their components on the incidence and natural history of infection: a systematic literature review

BACKGROUND

Dairy products and their components may impact immune function, although the current evidence base has some research gaps. As part of a larger systematic literature review of dairy products/components (including probiotics, dairy proteins, and dairy fats) and immune function, we identified the available epidemiologic research on the impact of dairy products/components on incidence and natural history of infectious diseases.

METHODS

PubMed and Embase databases were systematically searched through May 2022 to identify eligible studies using pre-defined Population, Intervention, Comparator, Outcomes, and Study design criteria. Herein, we focused on describing the impacts of dairy product/component on infectious disease outcomes, including the effect on leukocyte and cytokine response in humans. Risk of bias assessment was performed using the Academy of Nutrition and Dietetics Quality Criteria Checklist. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines were followed.

RESULTS

Among 9,832 studies identified from the larger literature search, 133 relevant publications from 128 studies reported on dairy product/component and infectious disease outcomes. Few studies are available on the impact of non-fermented milk and traditional yogurt on infectious disease. Evidence was identified to suggest milk and yogurt drinks fermented with Lactobacillus strains reduce the risk and burden of common infectious diseases (CIDs), although the findings are mixed and difficult to reconcile due to heterogenous study populations, bacterial strains, and study methods. Few studies are available on the impact of dairy products/components on the natural history of infection, with the available findings indicating probiotics may both improve gastrointestinal symptoms among HIV-infected persons and help eradicate and alleviate the symptoms of Heliobacter (H.) pylori. The available evidence also suggests lactoferrin may reduce the virological burden of COVID-19 and hepatitis C virus. No consistent changes in leukocytes or cytokine production were observed for any type of dairy product or their components, but probiotics appeared to enhance natural killer cell levels/activity and the phagocytic process.

CONCLUSIONS

Dairy products, particularly those with added probiotics, may represent an easily accessible nutritional intervention to prevent and improve the course of infectious diseases. This review highlights the need for additional research in this potentially impactful area.

PROSPERO REGISTRATION

CRD42022333780.

Benefits and concerns of probiotics: an overview of the potential genotoxicity of the colibactin-producing Escherichia coli Nissle 1917 strain

Recently, the mounting integration of probiotics into human health strategies has gathered considerable attention. Although the benefits of probiotics have been widely recognized in patients with gastrointestinal disorders, immune system modulation, and chronic-degenerative diseases, there is a growing need to evaluate their potential risks. In this context, new concerns have arisen regarding the safety of probiotics as some strains may have adverse effects in humans. Among these strains, Escherichia coli Nissle 1917 (EcN) exhibited traits of concern due to a pathogenic locus in its genome that produces potentially genotoxic metabolites. As the use of probiotics for therapeutic purposes is increasing, the effects of potentially harmful probiotics must be carefully evaluated. To this end, in this narrative review article, we reported the findings of the most relevant in vitro and in vivo studies investigating the expanding applications of probiotics and their impact on human well-being addressing concerns arising from the presence of antibiotic resistance and pathogenic elements, with a focus on the polyketide synthase (pks) pathogenic island of EcN. In this context, the literature data here discussed encourages a thorough profiling of probiotics to identify potential harmful elements as done for EcN where potential genotoxic effects of colibactin, a secondary metabolite, were observed. Specifically, while some studies suggest EcN is safe for gastrointestinal health, conflicting findings highlight the need for further research to clarify its safety and optimize its use in therapy. Overall, the data here presented suggest that a comprehensive assessment of the evolving landscape of probiotics is essential to make evidence-based decisions and ensure their correct use in humans.

Heat-Killed Lacticaseibacillus paracasei Repairs Lipopolysaccharide-Induced Intestinal Epithelial Barrier Damage via MLCK/MLC Pathway Activation

Intestinal epithelial barrier function is closely associated with the development of many intestinal diseases. Heat-killed Lacticaseibacillus paracasei (HK-LP) has been shown to improve intestinal health and enhance immunity. However, the function of HK-LP in the intestinal barrier is still unclear. This study characterized the inflammatory effects of seven HK-LP (1 μg/mL) on the intestinal barrier using lipopolysaccharide (LPS) (100 μg/mL)-induced Caco-2 cells. In this study, HK-LP 6105, 6115, and 6235 were selected, and their effects on the modulation of inflammatory factors and tight junction protein expression (claudin-1, zona occludens-1, and occludin) were compared. The effect of different cultivation times (18 and 48 h) was investigated in response to LPS-induced intestinal epithelial barrier dysfunction. Our results showed that HK-LP 6105, 6115, and 6235 improved LPS-induced intestinal barrier permeability reduction and transepithelial resistance. Furthermore, HK-LP 6105, 6115, and 6235 inhibited the pro-inflammatory factors (TNF-α, IL-1β, IL-6) and increased the expression of the anti-inflammatory factors (IL-4, IL-10, and TGF-β). HK-LP 6105, 6115, and 6235 ameliorated the inflammatory response. It inhibited the nuclear factor kappa B (NF-κB) signaling pathway-mediated myosin light chain (MLC)/MLC kinase signaling pathway by downregulating the Toll-like receptor 4 (TLR4)/NF-κB pathway. Thus, the results suggest that HK-LP 6150, 6115, and 6235 may improve intestinal health by regulating inflammation and TJ proteins. Postbiotics produced by these strains exhibit anti-inflammatory properties that can protect the intestinal barrier.

Leaky Gut and the Ingredients That Help Treat It: A Review

The human body is in daily contact with potentially toxic and infectious substances in the gastrointestinal tract (GIT). The GIT has the most significant load of antigens. The GIT can protect the intestinal integrity by allowing the passage of beneficial agents and blocking the path of harmful substances. Under normal conditions, a healthy intestinal barrier prevents toxic elements from entering the blood stream. However, factors such as stress, an unhealthy diet, excessive alcohol, antibiotics, and drug consumption can compromise the composition of the intestinal microbiota and the homeostasis of the intestinal barrier function of the intestine, leading to increased intestinal permeability. Intestinal hyperpermeability can allow the entry of harmful agents through the junctions of the intestinal epithelium, which pass into the bloodstream and affect various organs and systems. Thus, leaky gut syndrome and intestinal barrier dysfunction are associated with intestinal diseases, such as inflammatory bowel disease and irritable bowel syndrome, as well as extra-intestinal diseases, including heart diseases, obesity, type 1 diabetes mellitus, and celiac disease. Given the relationship between intestinal permeability and numerous conditions, it is convenient to seek an excellent strategy to avoid or reduce the increase in intestinal permeability. The impact of dietary nutrients on barrier function can be crucial for designing new strategies for patients with the pathogenesis of leaky gut-related diseases associated with epithelial barrier dysfunctions. In this review article, the role of functional ingredients is suggested as mediators of leaky gut-related disorders.

Bifidobacterium animalis subsp. lactis BB-12 Protects against Antibiotic-Induced Functional and Compositional Changes in Human Fecal Microbiome

The administration of broad-spectrum antibiotics is often associated with antibiotic-associated diarrhea (AAD), and impacts gastrointestinal tract homeostasis, as evidenced by the following: (a) an overall reduction in both the numbers and diversity of the gut microbiota, and (b) decreased short-chain fatty acid (SCFA) production. Evidence in humans that probiotics may enhance the recovery of microbiota populations after antibiotic treatment is equivocal, and few studies have addressed if probiotics improve the recovery of microbial metabolic function. Our aim was to determine if Bifidobacterium animalis subsp. lactis BB-12 (BB-12)-containing yogurt could protect against antibiotic-induced fecal SCFA and microbiota composition disruptions. We conducted a randomized, allocation-concealed, controlled trial of amoxicillin/clavulanate administration (days 1-7), in conjunction with either BB-12-containing or control yogurt (days 1-14). We measured the fecal levels of SCFAs and bacterial composition at baseline and days 7, 14, 21, and 30. Forty-two participants were randomly assigned to the BB-12 group, and 20 participants to the control group. Antibiotic treatment suppressed the fecal acetate levels in both the control and probiotic groups. Following the cessation of antibiotics, the fecal acetate levels in the probiotic group increased over the remainder of the study and returned to the baseline levels on day 30 (-1.6% baseline), whereas, in the control group, the acetate levels remained suppressed. Further, antibiotic treatment reduced the Shannon diversity of the gut microbiota, for all the study participants at day 7. The magnitude of this change was larger and more sustained in the control group compared to the probiotic group, which is consistent with the hypothesis that BB-12 enhanced microbiota recovery. There were no significant baseline clinical differences between the two groups. Concurrent administration of amoxicillin/clavulanate and BB-12 yogurt, to healthy subjects, was associated with a significantly smaller decrease in the fecal SCFA levels and a more stable taxonomic profile of the microbiota over time than the control group.

Safety and functional enrichment of gut microbiome in healthy subjects consuming a multi-strain fermented milk product: a randomised controlled trial

Many clinical studies have evaluated the effect of probiotics, but only a few have assessed their dose effects on gut microbiota and host. We conducted a randomized, double-blind, controlled intervention clinical trial to assess the safety (primary endpoint) of and gut microbiota response (secondary endpoint) to the daily ingestion for 4 weeks of two doses (1 or 3 bottles/day) of a fermented milk product (Test) in 96 healthy adults. The Test product is a multi-strain fermented milk product, combining yogurt strains and probiotic candidate strains Lactobacillus paracasei subsp. paracasei CNCM I-1518 and CNCM I-3689 and Lactobacillus rhamnosus CNCM I-3690. We assessed the safety of the Test product on the following parameters: adverse events, vital signs, hematological and metabolic profile, hepatic, kidney or thyroid function, inflammatory markers, bowel habits and digestive symptoms. We explored the longitudinal gut microbiota response to product consumption and dose, by 16S rRNA gene sequencing and functional contribution by shotgun metagenomics. Safety results did not show any significant difference between the Test and Control products whatever the parameters assessed, at the two doses ingested daily over a 4-week-period. Probiotic candidate strains were detected only during consumption period, and at a significantly higher level for the three strains in subjects who consumed 3 products bottles/day. The global structure of the gut microbiota as assessed by alpha and beta-diversity, was not altered by consumption of the product for four weeks. A zero-inflated beta regression model with random effects (ZIBR) identified a few bacterial genera with differential responses to test product consumption dose compared to control. Shotgun metagenomics analysis revealed a functional contribution to the gut microbiome of probiotic candidates.

Reduction in the Choking Phenomenon in Elite Diving Athletes Through Changes in Gut Microbiota Induced by Yogurt Containing Bifidobacterium animalis subsp. lactis BB-12: A Quasi Experimental Study

Objective: The aims of this study are as follows: (1) to understand the relationship between gut microbiota and the choking phenomenon in diving athletes, and (2) to regulate the gut microbiota in diving athletes by drinking yogurt containing Bifidobacterium animalis subsp. lactis BB-12 and observe changes in the choking phenomenon in diving athletes. Methods: Experiment 1: A total of 20 diving athletes were tested in low- and high-pressure situations. Gut microbiota (n = 18) composition was then determined and differences in the gut microbiota composition among diving athletes who presented choking vs. no choking were identified. Experiment 2: A total of 16 divers who presented choking were divided into a high yogurt group (n = 6) and a low yogurt group (n = 10) for 15 days. Results: (1) The content of Veillonellaceae in divers who presented choking was significantly higher when compared to divers who did not present choking (p < 0.05). Bifidobacteriaceae (r = −0.52, p < 0.05) and Lactobacillaceae (r = −0.66, p < 0.05) were negatively correlated with the choking index. (2) During experiment 2, the average daily intake of the high yogurt group was 611.78 ± 94.94 mL and the average daily intake of the low yogurt group was 338 ± 71.45 mL and the abundance of Bifidobacteriaceae was significantly higher in the high yogurt group than in the low yogurt group. After the experiment, the choking index in the high yogurt group became significantly lower than that of the low yogurt group (z = −3.26, p < 0.001). Conclusion: The intake of yogurt containing B. animalis subsp. lactis can increase the abundance of Bifidobacteriaceae in elite diving athletes and their performance under high pressure. Hence, gut microbiota may affect the choking phenomenon in elite diving athletes.

Recent Advancements in the Development of Modern Probiotics for Restoring Human Gut Microbiome Dysbiosis

A healthy gut is predominantly occupied by bacteria which play a vital role in nutrition and health. Any change in normal gut homeostasis imposes gut dysbiosis. So far, efforts have been made to mitigate the gastrointestinal symptoms using modern day probiotics. The majority of the probiotics strains used currently belong to the genera Lactobacillus, Clostridium, Bifidobacterium and Streptococcus. Recent advancements in culturomics by implementing newer techniques coupled with the use of gnotobiotic animal models provide a subtle ground to develop novel host specific probiotics therapies. In this review article, the recent advances in the development of microbe-based therapies which can now be implemented to treat a wide spectrum of diseases have been discussed. However, these probiotics are not classified as drugs and there is a lack of stringent law enforcement to protect the end users against the pseudo-probiotic products. While modern probiotics hold strong promise for the future, more rigorous regulations are needed to develop genuine probiotic products and characterize novel probiotics using the latest research and technology. This article also highlights the possibility of reducing antibiotic usage by utilizing probiotics developed using the latest concepts of syn and ecobiotics.

Gut Microbiota Dysbiosis Associated With Altered Production of Short Chain Fatty Acids in Children With Neurodevelopmental Disorders

While gut microbiota dysbiosis has been linked with autism, its role in the etiology of other neurodevelopmental disorders (NDD) is largely underexplored. To our knowledge this is the first study to evaluate gut microbiota diversity and composition in 36 children from the Republic of Serbia diagnosed with NDD and 28 healthy children. The results revealed an increased incidence of potentially harmful bacteria, closely related to Clostridium species, in the NDD patient group compared to the Control group: Desulfotomaculum guttoideum (P < 0.01), Intestinibacter bartlettii (P < 0.05), and Romboutsia ilealis (P < 0.001). On the other hand, significantly lower diversity of common commensal bacteria in the NDD group of patients was noticed. Enterococcus faecalis (P < 0.05), Enterococcus gallinarum (P < 0.01), Streptococcus pasteurianus (P < 0.05), Lactobacillus rhamnosus (P < 0.01) and Bifidobacteria sp. were detected in lower numbers of patients or were even absent in some NDD patients. In addition, butyrate-producing bacteria Faecalibacterium prausnitzii (P < 0.01), Butyricicoccus pullicaecorum (P < 0.05), and Eubacterium rectale (P = 0.07) were less frequent in the NDD patient group. In line with that, the levels of fecal short chain fatty acids (SCFAs) were determined. Although significant differences in SCFA levels were not detected between NDD patients and the Control group, a positive correlation was noted between number of rDNA amplicons obtained with universal primers and level of propionic acid, as well as a trend for levels of total SCFAs and butyric acid in the Control group. This correlation is lost in the NDD patient group, indicating that NDD patients' microbiota differs from the microbiota of healthy children in the presence or number of strong SCFA-producing bacteria. According to a range-weighted richness index it was observed that microbial diversity was significantly lower in the NDD patient group. Our study reveals that the intestinal microbiota from NDD patients differs from the microbiota of healthy children. It is hypothesized that early life microbiome might have an impact on GI disturbances and accompanied behavioral problems frequently observed in patients with a broad spectrum of NDD.

Bifidobacterium lactis BB-12 Attenuates Macrophage Aging Induced by D-Galactose and Promotes M2 Macrophage Polarization

Immunosenescence comprises a set of dynamic changes occurring in innate and adaptive immune systems, and macrophage aging plays an important role in innate and adaptive immunosenescence. However, function and polarization changes in aging macrophages have not been fully evaluated, and no effective method for delaying macrophage senescence is currently available. The results of this study reveal that D-galactose (D-gal) can promote J774A.1 macrophage senescence and induce macrophage M1 polarization differentiation. Bifidobacterium lactis BB-12 can significantly inhibit J774A.1 macrophage senescence induced by D-gal. IL-6 and IL-12 levels in the BB-12 groups remarkably decreased compared with that in the D-gal group, and the M2 marker, IL-10, and Arg-1 mRNA levels increased in the BB-12 group. BB-12 inhibited the expression of p-signal transducer and activator of transcription 1 (STAT1) and promoted p-STAT6 expression. In summary, the present study indicates that BB-12 can attenuate the J774A.1 macrophage senescence and induce M2 macrophage polarization, thereby indicating the potential of BB-12 to slow down immunosenescence and inflamm-aging.

Microbiota and Dose Response: Evolving Paradigm of Health Triangle

SRA Dose-Response and Microbial Risk Analysis Specialty Groups jointly sponsored symposia that addressed the intersections between the "microbiome revolution" and dose response. Invited speakers presented on innovations and advances in gut and nasal microbiota (normal microbial communities) in the first decade after the Human Microbiome Project began. The microbiota and their metabolites are now known to influence health and disease directly and indirectly, through modulation of innate and adaptive immune systems and barrier function. Disruption of healthy microbiota is often associated with changes in abundance and diversity of core microbial species (dysbiosis), caused by stressors including antibiotics, chemotherapy, and disease. Nucleic-acid-based metagenomic methods demonstrated that the dysbiotic host microbiota no longer provide normal colonization resistance to pathogens, a critical component of innate immunity of the superorganism. Diverse pathogens, probiotics, and prebiotics were considered in human and animal models (in vivo and in vitro). Discussion included approaches for design of future microbial dose-response studies to account for the presence of the indigenous microbiota that provide normal colonization resistance, and the absence of the protective microbiota in dysbiosis. As NextGen risk analysis methodology advances with the "microbiome revolution," a proposed new framework, the Health Triangle, may replace the old paradigm based on the Disease Triangle (focused on host, pathogen, and environment) and germophobia. Collaborative experimental designs are needed for testing hypotheses about causality in dose-response relationships for pathogens present in our environments that clearly compete in complex ecosystems with thousands of bacterial species dominating the healthy superorganism.

Factors Influencing the Gut Microbiota, Inflammation, and Type 2 Diabetes

The gut microbiota is a complex community of bacteria residing in the intestine. Animal models have demonstrated that several factors contribute to and can significantly alter the composition of the gut microbiota, including genetics; the mode of delivery at birth; the method of infant feeding; the use of medications, especially antibiotics; and the diet. There may exist a gut microbiota signature that promotes intestinal inflammation and subsequent systemic low-grade inflammation, which in turn promotes the development of type 2 diabetes. There are preliminary studies that suggest that the consumption of probiotic bacteria such as those found in yogurt and other fermented milk products can beneficially alter the composition of the gut microbiome, which in turn changes the host metabolism. Obesity, insulin resistance, fatty liver disease, and low-grade peripheral inflammation are more prevalent in patients with low α diversity in the gut microbiome than they are in patients with high α diversity. Fermented milk products, such as yogurt, deliver a large number of lactic acid bacteria to the gastrointestinal tract. They may modify the intestinal environment, including inhibiting lipopolysaccharide production and increasing the tight junctions of gut epithelia cells.

Safety of Bifidobacterium animalis Subsp. Lactis (B. lactis) Strain BB-12-Supplemented Yogurt in Healthy Children

OBJECTIVES

Probiotics are live microorganisms that may provide health benefits to the individual when consumed in sufficient quantities. For studies conducted on health or disease endpoints on probiotics in the United States, the Food and Administration has required those studies to be conducted as investigational new drugs. This phase I, double-blinded, randomized, controlled safety study represents the first requirement of this pathway. The purpose of the study was to determine the safety of Bifidobacterium animalis subsp. lactis (B lactis) strain BB-12 (BB-12)-supplemented yogurt when consumed by a generally healthy group of children. The secondary aim was to assess the effect of BB-12-supplemented yogurt on the gut microbiota of the children.

METHODS

Sixty children ages 1 to 5 years were randomly assigned to consume 4 ounces of either BB-12-supplemented yogurt or nonsupplemented control yogurt daily for 10 days. The primary outcome was to assess safety and tolerability, as determined by the number of reported adverse events.

RESULTS

A total of 186 nonserious adverse events were reported, with no significant differences between the control and BB-12 groups. No significant changes due to probiotic treatment were observed in the gut microbiota of the study cohort.

CONCLUSIONS

BB-12-supplemented yogurt is safe and well-tolerated when consumed by healthy children. The present study will form the basis for future randomized clinical trials investigating the potential effects of BB-12-supplemented yogurt in different disease states.

Prevalence of Antibiotic Resistance Genes among Human Gut-Derived Bifidobacteria

The microbiota of the human gastrointestinal tract (GIT) may regularly be exposed to antibiotics, which are used to prevent and treat infectious diseases caused by bacteria and fungi. Bacterial communities of the gut retain a reservoir of antibiotic resistance (AR) genes, and antibiotic therapy thus positively selects for those microorganisms that harbor such genetic features, causing microbiota modulation. During the first months following birth, bifidobacteria represent some of the most dominant components of the human gut microbiota, although little is known about their AR gene complement (or resistome). In the current study, we assessed the resistome of the Bifidobacterium genus based on phenotypic and genotypic data of members that represent all currently recognized bifidobacterial (sub)species. Moreover, a comparison between the bifidobacterial resistome and gut metagenome data sets from adults and infants shows that the bifidobacterial community present at the first week following birth possesses a reduced AR arsenal compared to that present in the infant bifidobacterial population in subsequent weeks of the first year of life. Our findings reinforce the concept that the early infant gut microbiota is more susceptible to disturbances by antibiotic treatment than the gut microbiota developed at a later life stage.

IMPORTANCE

The spread of resistance to antibiotics among bacterial communities has represented a major concern since their discovery in the last century. The risk of genetic transfer of resistance genes between microorganisms has been extensively investigated due to its relevance to human health. In contrast, there is only limited information available on antibiotic resistance among human gut commensal microorganisms such as bifidobacteria, which are widely exploited by the food industry as health-promoting microorganisms or probiotic ingredients. In the current study, we explored the occurrence of antibiotic resistance genes in the genomes of bifidobacteria and evaluated their genetic mobility to other human gut commensal microorganisms.

Probiotic and functional characterization of bifidobacteria of Indian human origin

AIMS

To identify and characterize the probiotic and functional attributes of bifidobacteria isolated from human sources by in vitro methods.

METHODS AND RESULTS

Twelve isolates of bifidobacteria were obtained from different human sources viz; human milk, infant and adult faeces. The preliminary identification of isolates was done using genus-specific PCR followed by species level identification using 16S rRNA sequencing. All the isolates invariably showed potential probiotic characteristics. Finally, three most promising isolates were subjected to safety evaluation and were found to be safe. These were further evaluated for their potential functional characteristics like, antioxidative, antimutagenic and cholesterol assimilation. The isolates viz; NBIF-5 (73·55 ± 0·03%) and NBIF-7 (64·06 ± 0·03%) assimilated significantly higher cholesterol than NBIF-2. The maximum antioxidative activity was observed in NBIF-2 (56·56 ± 0·28% of radical inhibition). High percentage antimutagenicity scores of 52·41 ± 2·25% and 53·68 ± 1·98% against sodium azide (NaN3) were shown by NBIF-2 and NBIF-7 respectively.

CONCLUSIONS

Three strains (NBIF-2, NBIF-5 and NBIF-7) were found to be endowed with appreciable probiotic and functional activities.

SIGNIFICANCE AND IMPACT OF THE STUDY

With growing demands for probioitcs and bifidobacteria being prominent ones, new strains of diversified origin have the potential to be explored for commercial and functional applications and thus can be added to the existing commercially available strains of this genera.

Advancing probiotic research in humans in the United States: Challenges and strategies

This is a summary from a workshop convened as part of the 13(th) annual meeting of the International Scientific Association for Probiotics and Prebiotics. A group of 24 stakeholders, including clinical experts, researchers, federal government officials, funding agencies, lawyers and industry experts met to review the challenges of the current regulatory approach to human research on probiotics in the USA and to discuss ways to move research forward. There was agreement that some of the current regulatory requirements imposed on probiotic research in the United States hindered research progress and increased cost without improving study subject safety. Many situations were outlined by clinical investigators demonstrating the impact of regulatory delays on research progress. Additionally, research is compromised when study designs and outcomes require manipulation so as to invoke less burdensome regulatory requirements. These responses by investigators to regulatory requirements have placed United States' researchers at a disadvantage. The public ultimately suffer when research to clarify the role of these products on health is stalled. Workshop participants concurred that regulatory oversight should balance study subject vulnerability with documented safety for the intended use for the probiotic strain, and that human research on foods and supplements should not be be regulated as drug research. Challenges and potential improvement strategies are discussed.