Immunomodulating potential of supplementation with probiotics: a dose–response study in healthy young adults

The use of probiotics and prebiotics in decolonizing pathogenic bacteria from the gut; a systematic review and meta-analysis of clinical outcomes

Repeated exposure to antibiotics and changes in the diet and environment shift the gut microbial diversity and composition, making the host susceptible to pathogenic infection. The emergence and ongoing spread of AMR pathogens is a challenging public health issue. Recent evidence showed that probiotics and prebiotics may play a role in decolonizing drug-resistant pathogens by enhancing the colonization resistance in the gut. This review aims to analyze available evidence from human-controlled trials to determine the effect size of probiotic interventions in decolonizing AMR pathogenic bacteria from the gut. We further studied the effects of prebiotics in human and animal studies. PubMed, Embase, Web of Science, Scopus, and CINAHL were used to collect articles. The random-effects model meta-analysis was used to pool the data. GRADE Pro and Cochrane collaboration tools were used to assess the bias and quality of evidence. Out of 1395 citations, 29 RCTs were eligible, involving 2871 subjects who underwent either probiotics or placebo treatment to decolonize AMR pathogens. The persistence of pathogenic bacteria after treatment was 22%(probiotics) and 30.8%(placebo). The pooled odds ratio was 0.59(95% CI:0.43-0.81), favoring probiotics with moderate certainty (p = 0.0001) and low heterogeneity (I2 = 49.2%, p = 0.0001). The funnel plot showed no asymmetry in the study distribution (Kendall'sTau = -1.06, p = 0.445). In subgroup, C. difficile showed the highest decolonization (82.4%) in probiotics group. Lactobacillus-based probiotics and Saccharomyces boulardii decolonize 71% and 77% of pathogens effectively. The types of probiotics (p < 0.018) and pathogens (p < 0.02) significantly moderate the outcome of decolonization, whereas the dosages and regions of the studies were insignificant (p < 0.05). Prebiotics reduced the pathogens from 30% to 80% of initial challenges. Moderate certainty of evidence suggests that probiotics and prebiotics may decolonize pathogens through modulation of gut diversity. However, more clinical outcomes are required on particular strains to confirm the decolonization of the pathogens. Protocol registration: PROSPERO (ID = CRD42021276045).

Kidney Stone Prevention: Is There a Role for Complementary and Alternative Medicine?

Complementary and alternative medicine (CAM) is often implemented in kidney stone patients. It consists of preparations including different ingredients, such as herbs, probiotics, and vitamins, often together with alkali, that are classified within the dietary supplementation category. The majority of dietary supplements claiming to treat or prevent kidney stones contain ingredients with conflicting or no scientific evidence to support their claims. Clinicians should advise stone formers that the effects of most supplements are unknown or unstudied in humans and that the absence of evidence does not imply absence of potential harm. Unfortunately, the CAM preparation consists of a mix of different molecules, often including alkali, with different potential mechanisms of action and, even when favorable results are reported, the role of the single molecules cannot be assessed. Despite all these concerns, CAM products remain quite popular among kidney stone patients. The scarce knowledge in this field prevents one from recommending CAM products in daily clinical practice; only a weak suggestion for their use in kidney stone patients may be reasonable.

Bifidobacterium lactis BL-99 protects mice with osteoporosis caused by colitis via gut inflammation and gut microbiota regulation

Patients diagnosed with inflammatory bowel disease or related conditions also frequently suffer from osteoporosis as a consequence of changes in the intestinal microenvironment and consequent dysbiosis. We hypothesized that anti-inflammatory probiotic treatment would be sufficient to alleviate intestinal inflammation and thereby prevent the development of osteoporosis. To that end, the ability of Bifidobacterium lactis BL-99 administration to protect against bone loss in an experimental model of dextran sodium sulfate-induced ulcerative colitis (UC) was analyzed, and the underlying molecular mechanisms were interrogated in detail. The results of these analyses revealed that BL-99 administration suppressed colitis-associated weight loss (P < 0.05), disease activity index scores, and the production of proinflammatory cytokines (TNF-α, IL-1β, IL-6, and IL-17) (P < 0.05). Colon tissue pathological sections similarly revealed BL-99-mediated reductions in tissue injury severity. Micro-computed tomography (Micro-CT) analyses further exhibited significant improvements in percent bone volume (BV/TV) as well as trabecular number and thickness in BL-99-treated animals (P < 0.05). Such probiotic supplementation also resulted in pronounced changes in the composition of the gut microbiota. Moreover, BL-99 intervention markedly increased the expression of intestinal barrier-related proteins (Claudin-1, MUC2, ZO-1, and Occludin). Together, these results suggest that BL-99 can be utilized as a beneficial probiotic preparation to prevent the incidence of osteoporosis in UC patients owing to its ability to shape the intestinal microflora and to suppress inflammatory cytokine production.

Probiotic Supplementation Has a Limited Effect on Circulating Immune and Inflammatory Markers in Healthy Adults: A Systematic Review of Randomized Controlled Trials

BACKGROUND

A main mechanism of action proposed for oral probiotic supplementation is immunomodulation, which is expected to impart health benefits in the host by influencing circulating immune and inflammatory factors. To date, the effectiveness of probiotic supplementation for immunomodulation in healthy adults without disease has not been evaluated in a systematic review.

OBJECTIVE

The objective of this systematic review was to evaluate the effect of probiotic supplementation on circulating immune and inflammatory markers of healthy adults compared to placebo.

METHODS

PubMed, SCOPUS, ISI Web of Science, ProQuest, and Cochrane databases were searched for English articles up to May 15, 2019. Additional papers were identified by checking references of relevant papers. Only randomized controlled trials studying the administration of probiotic supplements compared to placebo on immune and inflammatory markers in healthy adults (aged 18 to 65 years), without acute or chronic disease, and in generally good health were examined. Independent extraction of articles was conducted by two authors using predefined search terms and restrictions/filters. The methodologic quality of each study was appraised using the Academy of Nutrition and Dietetics Evidence Analysis Library Quality Rating Worksheet and the body of evidence was assessed using the Academy of Nutrition and Dietetics Grade Definitions and Conclusion Grading Table.

RESULTS

Eighteen articles, including 819 subjects, met eligibility criteria and were included in the present systematic review. Five articles were rated neutral in quality and 13 were rated high in quality. Eight articles reported a significant effect on immune and/or inflammatory parameters including increases in natural killer cells, lymphocytes, and monocytes, and decreases in proinflammatory cytokine concentrations.

CONCLUSIONS

Based on the 18 articles extracted in this systemic review, probiotic supplementation was concluded to have a limited effect on immune and inflammatory markers in healthy adults. Overall, the evidence was heterogenous, precluding a meta-analysis, and difficult to aggregate and conclude on effect size.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO ref CRD42018110856.

Exertional-heat stress-associated gastrointestinal perturbations during Olympic sports: Management strategies for athletes preparing and competing in the 2020 Tokyo Olympic Games

Exercise-induced gastrointestinal syndrome (EIGS) is a common characteristic of exercise. The causes appear to be multifactorial in origin, but stem primarily from splanchnic hypoperfusion and increased sympathetic drive. These primary causes can lead to secondary outcomes that include increased intestinal epithelial injury and gastrointestinal hyperpermeability, systemic endotoxemia, and responsive cytokinemia, and impaired gastrointestinal function (i.e. transit, digestion, and absorption). Impaired gastrointestinal integrity and functional responses may predispose individuals, engaged in strenuous exercise, to gastrointestinal symptoms (GIS), and health complications of clinical significance, both of which may have exercise performance implications. There is a growing body of evidence indicating heat exposure during exercise (i.e. exertional-heat stress) can substantially exacerbate these gastrointestinal perturbations, proportionally to the magnitude of exertional-heat stress, which is of major concern for athletes preparing for and competing in the upcoming 2020 Tokyo Olympic Games. To date, various hydration and nutritional strategies have been explored to prevent or ameliorate exertional-heat stress associated gastrointestinal perturbations. The aims of the current review are to comprehensively explore the impact of exertional-heat stress on markers of EIGS, examine the evidence for the prevention and (or) management of EIGS in relation to exertional-heat stress, and establish best-practice nutritional recommendations for counteracting EIGS and associated GIS in athletes preparing for and competing in Tokyo 2020.

Effect of probiotic and synbiotic supplementation on inflammatory markers in health and disease status: A systematic review and meta-analysis of clinical trials

The current systematic review and meta-analysis investigated the effect of probiotic/synbiotic on a wide range of inflammatory and anti-inflammatory markers in healthy and various disease conditions. PubMed, SCOPUS and Web of Science databases were searched. All clinical trials which investigated the effect of oral administration of probiotic or synbiotic on inflammatory markers (C-reactive protein (CRP), interleukin (IL) 1β, IL-4, IL-6, IL-8, IL-10, IL-12, tumor necrosis factor (TNF) α, interferon (IFN) γ and transforming growth factor (TGF) β) for more than one week with concurrent control groups were included. One-hundred sixty seven publications was analysed. Results were as follows: CRP decreased in healthy, metabolic disorders, inflammatory bowel disease (IBD), arthritis and critically ill condition but not in renal failure. IL-1B: no change in healthy subjects and arthritis. TNF-α: decreased in healthy, fatty liver, IBD and hepatic cirrhosis, no change in diabetes, metabolic syndrome (MS) + PCOS (polycystic ovary syndrome) and arthritis. IL-6: no change in healthy, metabolic disorders and arthritis, increased in cirrhosis and renal failure, decreased in PCOS + MS. IL-10: no change in healthy, IBD and metabolic disorders, increased in arthritis. IL-4, IL-8, IL-12, IFN-g and TGF-b: no change in healthy subjects. In conclusion, probiotic/synbiotic decreased some of the inflammatory markers. The intervention was most effective in CRP and TNF-α reduction in healthy or disease state. Moreover, the intervention decreased inflammation most effectively in the following disease conditions, respectively: IBD, arthritis, fatty liver. PROSPERO REGISTRATION NUMBER: CRD42018088688.

Recurrent urinary tract infections in women: How promising is the use of probiotics?

Urinary tract infections (UTIs) currently rank amongst the most prevalent bacterial infections, representing a major health hazard. UTIs in females usually start as vaginal infections and ascend to the urethra and bladder. Recurrent UTIs (rUTIs) can be defined as at least three episodes of UTI in 1 year or two episodes in 6 months. Various antibiotics have been the mainstay of therapy in ameliorating the incidence of UTIs, but recurrent infections continue to afflict many women. It necessitates the exploitation of alternative antimicrobial therapy. Probiotics have been shown to be effective in varied clinical trials for long-term preventions of rUTI. Because Escherichia coli is the primary pathogen involved in UTIs which spreads from the rectum to vagina and then ascends up the sterile urinary tract, improving the gut or vaginal flora will thus impact the urinary tract. Since a healthy vaginal microbiota is mainly dominated by Lactobacillus species, in this context, exogenously administered probiotics containing Lactobacilli play a pivotal role in reducing the risk of rUTI. The concept of artificially boosting the Lactobacilli numbers through probiotic administration has long been conceived but has been recently shown to be possible. Lactobacilli may especially be useful for women with a history of recurrent, complicated UTIs or on prolonged antibiotic use. Probiotics do not cause antibiotic resistance and may offer other health benefits due to vaginal re-colonisation with Lactobacilli. However, more comprehensive research is still needed, to recommend for probiotics as an alternative to antibiotics.

Current, experimental, and future treatments in inflammatory bowel disease: a clinical review

Inflammatory bowel diseases (IBDs) may result from dysregulated mucosal immune responses directed toward the resident intestinal microbiota. This review describes the hallmark immunobiology of Crohn's disease and ulcerative colitis as well as therapeutic targets and mechanisms of action for current, experimental, and future treatments in IBD. Conventional therapies include 5-aminosalicylic acid, glucocorticosteroids, thiopurines, and methotrexate. Since 1997, monoclonal antibodies have gained widespread use. These consist of antibodies directed against pro-inflammatory cytokines such as tumor necrosis factor α, interleukin (IL)-12, and IL-23, or anti-homing antibodies directed against α4β7 integrin. Emerging oral therapies include modulators of intracellular signal transduction such as Janus kinase inhibitors. Vitamin D may help to regulate innate and adaptive immune responses. Modulation of the intestinal microbiota, using live microorganisms (probiotics), substrates for the colonic microbiota (prebiotics), or fecal microbiota transplantation (FMT), is in development. Dietary supplements are in widespread use, but providing evidence for their benefit is challenging. Stem cell treatment and nervous stimulation are promising future treatments.

Anti-arthritic activity of cell wall content of Lactobacillus plantarum in freund's adjuvant-induced arthritic rats: involvement of cellular inflammatory mediators and other biomarkers

Alteration of microbiota is related with rheumatoid arthritis (RA) and administration of certain probiotics showed an improvement in RA. The present study was designed to find out the anti-arthritic activity of cell wall content of Lactobacillus plantarum in complete Freund's adjuvant (CFA)-induced arthritis in rats. Freund's adjuvant was injected into the left footpad in female rats on day 0 and dexamethasone (1 mg kg^-1, s.c.) & cell wall content of L. plantarum (10⁵, 10⁷, and 10⁹ cfu/animal, s.c.) treatment were given from day 7 to 21. The change in body weight, paw volume and arthritic index, joint stiffness, gait test, mobility test, erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP) level, serum rheumatoid factor (RF), and serum TNF-α was measured on day 21. Cell wall content of L. plantarum treated animals showed improvement in all the parameters as compared to that in CFA-treated animals and exert anti-arthritic activity.

Lactobacillus helveticus Lafti L10 Supplementation Modulates Mucosal and Humoral Immunity in Elite Athletes: A Randomized, Double-Blind, Placebo-Controlled Trial

Michalickova, DM, Kostic-Vucicevic, MM, Vukasinovic-Vesic, MD, Stojmenovic, TB, Dikic, NV, Andjelkovic, MS, Djordjevic, BI, Tanaskovic, BP, and Minic, RD. Lactobacillus helveticus Lafti L10 supplementation modulates mucosal and humoral immunity in elite athletes: a randomized, double-blind, placebo-controlled trial. J Strength Cond Res 31(1): 62-70, 2017-To test the influence of probiotic supplementation on humoral immune response, a double-blind, placebo-controlled trial was conducted. Thirty athletes (24 males and 6 females, females: V[Combining Dot Above]O2max 38.2 ± 4.9 ml·kg·min, age 23.2 ± 1.4 years; males: V[Combining Dot Above]O2max 57.5 ± 9.2 ml·kg·min, age 24.0 ± 2.4 years, mean ± SD) were randomized either to the probiotic group (Lactobacillus helveticus Lafti L10, 2 × 10 colony-forming units) or to the placebo group. Serum and saliva samples were collected at the baseline and after 14 weeks. Total and specific antibacterial antibody levels of IgM, IgG, and IgA classes were determined for different bacteria in the serum, and in saliva, total and specific antibacterial IgA levels were examined. Total IgM was elevated in both probiotic (18%, 15-20%; mean, 90% confidence interval; p = 0.02) and placebo group (35%, 22-47%; p = 0.02), without observed differences in changes between the groups. No significant changes in IgM levels specific for tested bacteria were found. Total IgG level was constant in both groups. A significant (16%, -2.8 to 35%, p = 0.04) reduction of anti-Enterococcus faecalis IgG was noted in the placebo group, in comparison with the probiotic group. There was a substantial decrease in total IgA level in the placebo group, when measured either in serum (15%, 12-18%, p = 0.04) or in saliva (35%, -1.4 to 53%, p = 0.03). Significantly reduced levels of serum anti-lactic acid bacteria IgA antibodies in the placebo group compared with the probiotic group were detected for Lactobacillus rhamnosus LA68 (24%, 5.8-42%, p = 0.02) and for L. rhamnosus LB64 (15%, 2.7-27%, p = 0.02). Probiotic administration could have beneficial effects on systemic humoral and mucosal immune responses.

Tolerogenic probiotics: potential immunoregulators in Systemic Lupus Erythematosus

Probiotics are commensal or nonpathogenic microbes that colonize the gastrointestinal tract and confer beneficial effects on the host through several mechanisms such as competitive exclusion, anti-bacterial effects, and modulation of immune responses. There is growing evidence supporting the immunomodulatory ability of some probiotics. Several experimental and clinical studies have been shown beneficial effect of some probiotic bacteria, particularly Lactobacillus and Bifidobacteria strains, on inflammatory and autoimmune diseases. Systemic lupus erythematosus (SLE) is an autoimmune disease that is mainly characterized by immune intolerance towards self-antigens. Some immunomodulatory probiotics have been found to regulate immune responses via tolerogenic mechanisms. Dendritic and T regulatory (Treg) cells, IL-6, IFN-γ, IL-17, and IL-23 can be considered as the most determinant dysregulated mediators in tolerogenic status. As demonstrated by documented experimental and clinical trials on inflammatory and autoimmune diseases, a number of probiotic bacterial strains can restore tolerance in host through modification of such dysregulated mediators. Since there are limited reports regarding to impact of probiotic supplementation in SLE patients, the preset review was aimed to suggest a number of probiotics bacteria, mainly from Bifidobacteria and Lactobacillus strains that are able to ameliorate immune responses. The aim was followed through literature survey on immunoregulatory probiotics that can restore tolerance and also modulate the important dysregulated pro/anti-inflammatory cytokines contributing to the pathogenesis of SLE.

The Comparison of Food and Supplement as Probiotic Delivery Vehicles

Probiotics are live bacteria which have frequently been reported to be beneficial in preventing a wide range of diseases as well as playing a major role in treating the existing ailments. Thus far, a variety of probiotic products have been developed which can be categorized into two groups: probiotic foods and supplements. Both foods and supplements have been able to confer the health benefits claimed for them. However, it is not known which one can be clinically more efficient, and to the best of our knowledge, until now no research has been conducted to investigate this issue. The present review aims to discuss this matter, based on the evidence available in the literature. To do so, articles indexed in PubMed and ScienceDirect between 2000 and 2011 were reviewed. The articles included the clinical trials in which either foods or supplements were used to administer the probiotics to either patients suffering from different diseases or healthy subjects. Although both foods and supplements seem to have been efficient carriers for the beneficial bacteria, to generally promote public health in communities, probiotic foods appear to be preferred to probiotic supplements.

A review of dose-responses of probiotics in human studies

The probiotic definition requires the administration of an 'adequate amount' in order to obtain a health benefit. What that amount should be is not indicated. Here, an overview is given of studies that investigated the dose-response relation of probiotics in human interventions. Studies were divided in; meta-analyses, meta-analyses on specific probiotic strains, and studies testing two or more doses of a probiotic (combination) in the same study. Meta-analyses on the effect of probiotics on antibiotic associated diarrhoea (AAD) suggest a dose-response effect; for Clostridium difficile-associated diarrhoea on the other hand no dose-response was observed. For other end-points; such as necrotising enterocolitis, prevention of atopic dermatitis and slow intestinal transit, no dose-response relation was identified in meta-analyses. For prophylaxis in colorectal cancer and relief of irritable bowel syndrome, no dose-response relation was determined. However, for blood pressure, a meta-analysis observed that higher doses (greater than 10¹¹ cfu) were more effective than lower doses. Meta-analyses of specific strains suggest a break-point for effectiveness of Lactobacillus rhamnosus GG in the treatment of acute gastroenteritis in children; no dose-response was observed for two other probiotics assessed. Studies comparing two or more doses indicate that faecal recovery and risk reduction of AAD follow a positive dose-response relationship. Other end-points such as immune markers, general health, and bowel function did not exhibit clear dose-response relations. For AAD, the findings are very compelling; both meta-analyses and dedicated dose-response studies observe a positive correlation between dose and AAD risk. These findings do not allow for extrapolation, but suggest that studying higher doses for this end-point would be worthwhile. The lack of a clear dose-response for other end-points, does not mean it does not exist; present data does just not allow drawing any conclusions.

Consumption of Bifidobacterium animalis subsp. lactis BB-12 in yogurt reduced expression of TLR-2 on peripheral blood-derived monocytes and pro-inflammatory cytokine secretion in young adults

PURPOSE

Probiotic bacteria modulate immune parameters and inflammatory outcomes. Emerging evidence demonstrates that the matrix used to deliver probiotics may influence the efficacy of probiotic interventions in vivo. The aims of the current study were to evaluate (1) the effect of one species, Bifidobacterium animalis subsp. lactis BB-12 at a dose of log10 ± 0.5 CFUs/day on immune responses in a randomized, partially blinded, 4-period crossover, free-living study, and (2) whether the immune response to BB-12 differed depending on the delivery matrix.

METHODS

Healthy adults (n = 30) aged 18-40 years were recruited and received four treatments in a random order: (A) yogurt smoothie alone; smoothie with BB-12 added (B) before or (C) after yogurt fermentation, or (D) BB-12 given in capsule form. At baseline and after each 4-week treatment, peripheral blood mononuclear cells (PBMCs) were isolated, and functional and phenotypic marker expression was assessed.

RESULTS

BB-12 interacted with peripheral myeloid cells via Toll-like receptor 2 (TLR-2). The percentage of CD14⁺HLA-DR⁺ cells in peripheral blood was increased in male participants by all yogurt-containing treatments compared to baseline (p = 0.0356). Participants who consumed yogurt smoothie with BB-12 added post-fermentation had significantly lower expression of TLR-2 on CD14⁺HLA-DR⁺ cells (p = 0.0186) and reduction in TNF-α secretion from BB-12- (p = 0.0490) or LPS-stimulated (p = 0.0387) PBMCs compared to baseline.

CONCLUSIONS

These findings not only demonstrate a potential anti-inflammatory effect of BB-12 in healthy adults, but also indicate that the delivery matrix influences the immunomodulatory properties of BB-12.

Effect of Lactobacillus paracasei subsp. paracasei, L. casei 431 on immune response to influenza vaccination and upper respiratory tract infections in healthy adult volunteers: a randomized, double-blind, placebo-controlled, parallel-group study

BACKGROUND

Probiotics can modulate the immune system in healthy individuals and may help reduce symptoms related to respiratory infections.

OBJECTIVE

The objective of the study was to investigate the effect of the probiotic strain Lactobacillus paracasei subsp. paracasei, L. casei 431 (Chr. Hansen A/S) (hereafter, L. casei 431) on immune response to influenza vaccination and respiratory symptoms in healthy adults.

DESIGN

A randomized double-blind, placebo-controlled trial was conducted in 1104 healthy subjects aged 18-60 y at 2 centers in Germany and Denmark. Subjects were randomly assigned to receive an acidified milk drink containing ≥10(9) colony-forming units of L. casei 431 (n = 553) or placebo (n = 551) for 42 d. After 21 d, subjects received the seasonal influenza vaccination. The primary outcome was seroprotection rate (anti-influenza antibody titers by hemagglutination inhibition) 21 d after vaccination. Other outcomes were seroconversion rate and mean titers, influenza A-specific antibodies and incidence, and duration and severity of upper respiratory symptoms. Antibiotic use and use of health care resources were recorded.

RESULTS

There was no effect of L. casei 431 on immune responses to influenza vaccination. Generalized linear mixed modeling showed a shorter duration of upper respiratory symptoms in the probiotic group than in the placebo group (mean ± SD: 6.4 ± 6.1 vs. 7.3 ± 9.7 d, P = 0.0059) in the last 3 wk of the intervention period. No statistically significant differences were found for incidence or severity.

CONCLUSIONS

Daily consumption of L. casei 431 resulted in no observable effect on the components of the immune response to influenza vaccination but reduced the duration of upper respiratory symptoms. The trial was registered at www.isrctn.com as ISRCTN08280229.

Probiotics supplementation for athletes - clinical and physiological effects

Probiotic supplementation has traditionally focused on gut health. However, in recent years, the clinical applications of probiotics have broadened to allergic, metabolic, inflammatory, gastrointestinal and respiratory conditions. Gastrointestinal health is important for regulating adaptation to exercise and physical activity. Symptoms such as nausea, bloating, cramping, pain, diarrhoea and bleeding occur in some athletes, particularly during prolonged exhaustive events. Several studies conducted since 2006 examining probiotic supplementation in athletes or highly active individuals indicate modest clinical benefits in terms of reduced frequency, severity and/or duration of respiratory and gastrointestinal illness. The likely mechanisms of action for probiotics include direct interaction with the gut microbiota, interaction with the mucosal immune system and immune signalling to a variety of organs and systems. Practical issues to consider include medical and dietary screening of athletes, sourcing of recommended probiotics and formulations, dose-response requirements for different probiotic strains, storage, handling and transport of supplements and timing of supplementation in relation to travel and competition.

Dual functions of Lactobacillus acidophilus NCFM as protection against rotavirus diarrhea

OBJECTIVE

The aim of the study was to examine the dose effects of Lactobacillus acidophilus (LA) NCFM strain on rotavirus-specific antibody and B-cell responses in gnotobiotic pigs vaccinated with an oral attenuated human rotavirus (AttHRV).

METHODS

Pigs were inoculated with AttHRV vaccine in conjunction with high-dose LA (14 doses, total 2.2 × 10(6) colony-forming units [CFU]), intermediate-dose LA (MidLA) (9 doses, total 3.2 × 10(9) CFU), low-dose LA (LoLA) (5 doses, total 2.1 × 10(6) CFU), or without LA feeding. Protection against rotavirus shedding and diarrhea was assessed upon challenge with a virulent HRV. Rotavirus-specific immunoglobulin A (IgA) and IgG antibodies in serum and rotavirus-specific IgA and IgG antibody-secreting cells (ASCs) and memory B cells in ileum, spleen, and blood of the pigs were measured and compared among treatment groups.

RESULTS

The MidLA, but not high-dose LA or LoLA, significantly reduced rotavirus diarrhea (MidLA-only group) and significantly improved the protection conferred by AttHRV vaccine (MidLA + AttHRV group). Associated with the increased protection, MidLA significantly enhanced rotavirus-specific antibody, ASCs, and memory B-cell responses to AttHRV vaccine. High-dose LA or LoLA did not enhance virus-specific antibody and ASC responses, and hence did not improve the vaccine efficacy.

CONCLUSIONS

These findings highlight the importance of dose selection and indicate that certain specific lactobacilli strains at the appropriate dose have the dual function of reducing rotavirus diarrhea and enhancing the immunogenicity and protective efficacy of rotavirus vaccines.

Immunomodulatory effects of a probiotic drink containing Lactobacillus casei Shirota in healthy older volunteers

PURPOSE

There is growing evidence that probiotics confer health benefits to the host by modulating immune function, especially in older people, where immunosenescence is a feature even of healthy ageing. The aim of this study was to investigate the effect of a probiotic drink containing Lactobacillus casei Shirota (LcS) on immune function in a healthy non-immunocompromised older population.

METHODS

Thirty healthy old volunteers were recruited into a randomized placebo-controlled, single-blind crossover study. The volunteers were supplemented with the probiotic drink containing 1.3 × 10(10) CFU LcS or skimmed milk per day for 4 weeks, followed by 4 weeks of washout and were crossed over to the other treatment. Peripheral blood and saliva samples were collected at baseline and end of each treatment.

RESULTS

Probiotic consumption was associated with a significant increase in natural killer (NK) cell activity relative to baseline and a significant decrease in the mean fluorescence intensity of CD25 expression in the resting T cells compared with placebo. Additionally, there was a trend towards an increased ratio of IL-10 to IL-12 relative to baseline after LcS intake.

CONCLUSIONS

Consumption of a probiotic drink containing LcS improved NK cell activity and tended to produce a more anti-inflammatory cytokine profile in an older population.

Are vaccination models suitable to determine whether probiotics have beneficial health effects in the general population?

The European Food Safety Authority (EFSA) has indicated that stimulation of protective antibody titers from vaccination could be used to substantiate a supplement or food health claim on the function of the immune system related to defense against pathogens in healthy individuals. Vaccination allows exposure of the immune system to controlled quantities of antigen and also for assessment of median antibody responses and percentage of responders/non-responders, which provides indication of an integrated immune response to challenge. Probiotic vaccination studies have shown enhanced antibody titers, lower percentages of non-seroconverters and greater percentages reaching minimum cut-off titer values in healthy adults, elderly and children. These results indicate that probiotics are a good candidate to stimulate responses to vaccines and thus, according to EFSA, enhance the function of the immune system related to defense against infection. However, animal research has recently indicated that Foxp3+ T-regulatory cells, recognized suppressors of immune activity, were paradoxically associated with reduced respiratory viral morbidity without compromising viral clearance. These effects conflict with vaccine research findings, which suggest a depletion of Foxp3+ T-regs enhances the immune response. Many probiotics exert anti-inflammatory influence on the immune system and induce T-regs. Given this, caution regarding the applicability of the vaccination model as indicated by EFSA must be exercised. Induction of T-cell immune modulatory pathways may also explain the reduced duration of respiratory illness observed in probiotic clinical studies.

Effect of Lactobacillus rhamnosus LGG® and Bifidobacterium animalis ssp. lactis BB-12® on health-related quality of life in college students affected by upper respiratory infections

College students are susceptible to upper respiratory infections (URI) due to inadequate sleep, stress and close living quarters. Certain probiotic strains modulate immune function and may improve health-related quality of life (HRQL) during URI. The present study recruited apparently healthy college students and assessed the effect of probiotics on HRQL outcomes (i.e. self-reported duration, symptom severity and functional impairment of URI) in those who developed URI. Missed school and work days due to URI were also considered. Subjects (n 231) were apparently healthy college students living on campus in residence halls at the Framingham State University (Framingham, MA, USA), and were randomised to receive placebo (n 117) or probiotic-containing powder (daily dose of minimum 1 billion colony-forming units of each Lactobacillus rhamnosus LGG® (LGG®) and Bifidobacterium animalis ssp. lactis BB-12® (BB-12®); n 114) for 12 weeks. Subjects completed The Wisconsin Upper Respiratory Symptom Survey-21 to assess HRQL during URI. The final analyses included 198 subjects (placebo, n 97 and probiotics, n 101). The median duration of URI was significantly shorter by 2 d and median severity score was significantly lower by 34% with probiotics v. placebo (P,0·001), indicating a higher HRQL during URI. Number of missed work days was not different between groups (P=0·429); however, the probiotics group missed significantly fewer school days (mean difference = 0·2 d) compared to the placebo group (P=0·002). LGG® and BB-12® may be beneficial among college students with URI for mitigating decrements in HRQL. More research is warranted regarding mechanisms of action associated with these findings and the cost-benefit of prophylactic supplementation.

The effect of bifid triple viable on immune function of patients with ulcerative colitis

Objective. To study effect and its mechanism of Bifid Triple Viable for initially treating ulcerative colitis with 5-aminosalicylic acid. Methods. 82 patients, who were firstly diagnosed as ulcerative colitis, were randomized into experiment group (41 cases, treated with Bifid Triple Viable and Etiasa) and control group (41 cases, treated with Etiasa). The clinic symptom score, colon mucosa inflammation score, and some immune indices were detected and compared between two groups before and two months after treatment. Results. Two months after treatment, the clinical symptom score, colon mucosa inflammation score, and IL-1β expression in colon mucosa decreased significantly (P < 0.01), and IL-10 and IgA expressions in colon mucosa increased significantly (P < 0.01). Those differences were more marked in experiment group than control group (P < 0.05). However, peripheral blood T cell subgroup, immunoglobulins, and complements had no significant difference between two groups two months after treatment, but the ratio of peripheral blood CD4+ T cell to CD8+ T cell in experiment group increased more than that in control group (P < 0.05). Conclusion. Bifid Triple Viable contributed to Etiasa to treat ulcerative colitis in inducing remission period, which was perhaps related to affecting the patient's immune function.

Probiotics and Immune Response to Exercise

Probiotics are live microorganisms present in several foods and nutritional supplements that may prevent or limit the effects of various illnesses and infections and elicit a range of health benefits in physically active individuals. The primary clinical areas of interest with probiotics include metabolism; gastrointestinal, inflammatory, and functional disorders; the respiratory system; and a range of infections and allergies. The gastrointestinal tract is a key element controlling and regulating adaptation to exercise and physical activity. Gut symptomatology such as nausea, bloating, cramping, pain, diarrhea, and bleeding occurs in some highly active individuals such as athletes, particularly in prolonged exhaustive events. A small number of studies examining probiotic supplementation in highly active individuals indicate modest clinical benefits in terms of reduced frequency, severity, and/or duration of respiratory and gastrointestinal illness. The purported mechanisms of action for probiotics include direct interaction with the gut microbiota, interaction with the gut epithelium and mucosal immune system, and via immune signaling to organs and systems including the liver, brain, and respiratory tract. Future research will identify additional biologically and clinically beneficial strains, validate multicomponent formulations, clarify dose–response issues, and inform the development of guidelines for clinicians, health care practitioners, and the general community.

Gut Balance, a synbiotic supplement, increases fecal Lactobacillus paracasei but has little effect on immunity in healthy physically active individuals

Synbiotic supplements, which contain multiple functional ingredients, may enhance the immune system more than the use of individual ingredients alone. A double blind active controlled parallel trial over a 21 d exercise training period was conducted to evaluate the effect of Gut Balance™, which contains Lactobacillus paracasei subsp. paracasei (L. casei 431®), Bifidobacterium animalis ssp. lactis (BB-12®), Lactobacillus acidophilus (LA-5®), Lactobacillus rhamnosus (LGG®), two prebiotics (raftiline and raftilose) and bovine whey derived lactoferrin and immunoglobulins with acacia gum on fecal microbiota, short chain fatty acids (SCFA), gut permeability, salivary lactoferrin and serum cytokines. All subjects randomized were included in the analysis. There was a 9-fold (1.2-fold to 64-fold; 95% confidence intervals p = 0.03) greater increase in fecal L. paracasei numbers with Gut Balance™ compared with acacia gum supplementation. Gut Balance™ was associated with a 50% (-12% to 72%; p = 0.02) smaller increase in the concentration of serum IL-16 in comparison to acacia gum from pre- to post-study. No substantial effects of either supplement were evident in fecal SCFA concentrations, measures of mucosal immunity or GI permeability. Clinical studies are now required to determine whether Gut Balance™ may exert beneficial GI health effects by increasing the recovery of fecal L. paracasei. Both supplements had little effect on immunity. Twenty two healthy physically active male subjects (mean age = 33.9 ± 6.5y) were randomly allocated to either daily prebiotic or synbiotic supplementation for 21 d. Saliva, blood, urine and fecal samples were collected pre-, mid and post-intervention. Participants recorded patterns of physical activity on a self-reported questionnaire.

Consumption of Galactooligosaccharides together with Probiotics Stimulates the In Vitro Peripheral Blood Mononuclear Cell Proliferation and IFNγ Production in Healthy Men

Probiotics and prebiotics modify the intestinal environment and could have immunomodulatory effects. The proliferation of spontaneous and phytohemagglutinin-stimulated peripheral blood mononuclear cells (PBMCs) and their production of interleukin-4, interleukin-5, transforming growth factor-β1, and interferon-γ (IFNγ) were determined in eighteen men at the baseline and during a 2-week period of probiotics (mixture of Lactobacillus rhamnosus GG, Lactobacillus rhamnosus LC705, Propionibacterium freudenreichii ssp. shermanii JS, and Bifidobacterium breve Bb99) and galactooligosaccharides (GOSs) (3.8 g/day). The spontaneous and stimulated proliferation of PBMC increased from the baseline during probiotics+GOS (P<0.001). The secretion of IFNγ, but not other cytokines, by stimulated PBMC increased during the same period (P<0.05). In conclusion, the consumption of this probiotic mixture including GOS appears to increase the capacity of PBMC to proliferate and release IFNγ selectively in healthy men.

Prevention and treatment of urinary tract infection with probiotics: Review and research perspective

The spiralling costs of antibiotic therapy, the appearance of multiresistant bacteria and more importantly for patients and clinicians, unsatisfactory therapeutic options in recurrent urinary tract infection (RUTI) calls for alternative and advanced medical solutions. So far no sufficient means to successfully prevent painful and disabling RUTI has been found. Even though long-term oral antibiotic treatment has been used with some success as a therapeutic option, this is no longer secure due to the development of bacterial resistance. One promising alternative is the use of live microorganisms (probiotics) to prevent and treat recurrent complicated and uncomplicated urinary tract infection (UTI).

The human normal bacterial flora is increasingly recognised as an important defence to infection. Since the advent of antibiotic treatment five decades ago, a linear relation between antibiotic use and reduction in pathogenic bacteria has become established as medical conventional wisdom. But with the use of antibiotics the beneficial bacterial flora hosted by the human body is destroyed and pathogenic bacteria are selectively enabled to overgrow internal and external surfaces. The benign bacterial flora is crucial for body function and oervgrowth with pathogenic microorganisms leads to illness. Thus the concept of supporting the human body's normal flora with live microorganisms conferring a beneficial health effect is an important medical strategy.

Persistence of probiotic strains in the gastrointestinal tract when administered as capsules, yoghurt, or cheese

Most clinical studies of probiotics use freeze-dried, powdered bacteria or bacteria packed in capsules. However, probiotics are commercially available in various food matrices, which may affect their persistence in the gastrointestinal tract. The objective of the study was to compare oral and faecal recovery during and after administration of a combination of Lactobacillus rhamnosus GG and LC705, Propionibacterium freudenreichii subsp. shermanii JS, and Bifidobacterium animalis subsp. lactis Bb12 as capsules, yoghurt, or cheese. This randomized, parallel-group, open-label trial (n=36) included a 4-week run-in, 2-week intervention, and 3-week follow-up period. Participants consumed 10(10)cfu/day of probiotic combination and provided saliva and faecal samples before, during, and after the intervention. Strain-specific real-time PCR was used to quantify the strains. L. rhamnosus GG was the only probiotic strain regularly recovered in saliva samples. During the intervention period it was recovered in the saliva of 88% of the volunteers at least once. No difference was found between the yoghurt and cheese groups. At the end of the intervention, L. rhamnosus GG and LC705 counts were high in faecal samples of all product groups (8.08 and 8.67log(10) genome copies/g, respectively). There was no matrix effect on strain quantity in faeces or the recovery time after ceasing the intervention. For P. freudenreichii subsp. shermanii JS and B. animalis subsp. lactis Bb12, a matrix effect was found at the end of the intervention (P<0.01 and P<0.001, respectively) and in the recovery time during follow-up (P<0.05 for both). Yoghurt yielded the highest faecal quantity of JS and Bb12 strains (8.01 and 9.89log(10) genome copies/g, respectively). The results showed that the administration matrix did not influence the faecal quantity of lactobacilli, but affected faecal counts of propionibacteria and bifidobacteria that were lower when consumed in cheese. Thus, the consumption of probiotics in yoghurt matrix is highly suitable for studying potential health benefits and capsules provide a comparable means of administration when the viability of the strain in the capsule product is confirmed.

Genomic insights into bifidobacteria

Since the discovery in 1899 of bifidobacteria as numerically dominant microbes in the feces of breast-fed infants, there have been numerous studies addressing their role in modulating gut microflora as well as their other potential health benefits. Because of this, they are frequently incorporated into foods as probiotic cultures. An understanding of their full interactions with intestinal microbes and the host is needed to scientifically validate any health benefits they may afford. Recently, the genome sequences of nine strains representing four species of Bifidobacterium became available. A comparative genome analysis of these genomes reveals a likely efficient capacity to adapt to their habitats, with B. longum subsp. infantis exhibiting more genomic potential to utilize human milk oligosaccharides, consistent with its habitat in the infant gut. Conversely, B. longum subsp. longum exhibits a higher genomic potential for utilization of plant-derived complex carbohydrates and polyols, consistent with its habitat in an adult gut. An intriguing observation is the loss of much of this genome potential when strains are adapted to pure culture environments, as highlighted by the genomes of B. animalis subsp. lactis strains, which exhibit the least potential for a gut habitat and are believed to have evolved from the B. animalis species during adaptation to dairy fermentation environments.

Probiotics and immunity

Probiotics are defined as live microorganisms that, when administered in adequate amounts, confer a health benefit on the host, including the gastrointestinal tract. While this beneficial effect was originally thought to stem from improvements in the intestinal microbial balance, there is now substantial evidence that probiotics can also provide benefits by modulating immune functions. In animal models, probiotic supplementation is able to provide protection from spontaneous and chemically induced colitis by downregulating inflammatory cytokines or inducing regulatory mechanisms in a strain-specific manner. In animal models of allergen sensitization and murine models of asthma and allergic rhinitis, orally administered probiotics can strain-dependently decrease allergen-specific IgE production, in part by modulating systemic cytokine production. Certain probiotics have been shown to decrease airway hyperresponsiveness and inflammation by inducing regulatory mechanisms. Promising results have been obtained with probiotics in the treatment of human inflammatory diseases of the intestine and in the prevention and treatment of atopic eczema in neonates and infants. However, the findings are too variable to allow firm conclusions as to the effectiveness of specific probiotics in these conditions.

Different effects of probiotic species/strains on infections in preschool children: A double-blind, randomized, controlled study

Treatment and prevention of pediatric infectious diseases of three commercial probiotic products were evaluated by a double-blind, randomized, controlled trial. Test subjects under age 5, 1062 in total, were distributed randomly into four groups. This investigation showed that L. casei rhamnosus can control bacterial, viral and respiratory infections; a multi-species probiotic reduced gastrointestinal disease significantly. Long-term consumption of L. rhamnosus T cell-1 decreased the incidence of bacterial infection.

Probiotic intervention has strain-specific anti-inflammatory effects in healthy adults

AIM: To evaluate the effects of three potentially anti-inflammatory probiotic bacteria from three different genera on immune variables in healthy adults in a clinical setting based on previous in vitro characterization of cytokine responses.

METHODS: A total of 62 volunteers participated in this randomized, double-blind and placebo-controlled parallel group intervention study. The volunteers were randomized to receive a milk-based drink containing either Lactobacillus rhamnosus GG (LGG), Bifidobacterium animalis ssp. lactis Bb12 (Bb12), or Propionibacterium freudenreichii ssp. shermanii JS (PJS) or a placebo drink for 3 wk. Venous blood and saliva samples were taken at baseline and on d 1, 7 and 21. Fecal samples were collected at baseline and at the end of intervention.

RESULTS: The serum hsCRP expressed as the median AUC_0-21 (minus baseline) was 0.018 mg/L in the placebo group, -0.240 mg/L in the LGG group, 0.090 mg/L in the Bb12 group and -0.085 mg/L in the PJS group (P = 0.014). In vitro production of TNF-α from in vitro cultured peripheral blood mononuclear cells (PBMC) was significantly lower in subjects receiving LGG vs placebo. IL-2 production from PBMC in the Bb12 group was significantly lower compared with the other groups.

CONCLUSION: In conclusion, probiotic bacteria have strain-specific anti-inflammatory effects in healthy adults.

Immunomodulatory effects of probiotics in different stages of life

The immunomodulatory properties of lactic acid bacteria (LAB) and foods containing them (e.g., fermented milks) is a topic currently under investigation. Individuals could potentially benefit from the inclusion of LAB in the diet at different times during the life cycle. One of the most accepted specific uses of probiotic bacteria is the prevention of atopic eczema in infants with family history of the disease who receive the probiotic bacteria early, through supplementation of the gestating mother and orally after birth. Immune enhancing effects have also been suggested to be beneficial in diarrhoea treatment, especially in children infected with rotavirus and in malnourished patients, infants and adolescents, whose capacity to produce IFN-gamma can be increased after LAB-containing yoghurt intake. Regarding young people and adults, investigations have been conducted exploring the immunomodulation by LAB in subjects under stressful situations, in the prevention of urinary tract infections in fertile women and in the treatment of allergy. However, the beneficial effects of probiotics in these conditions remain controversial and the scientific evidence provided so far is not considered to be conclusive. The elderly population has been the focus of investigations aimed at identifying the capacity of probiotics to counteract the immunosenescence process by increasing phagocytic and natural killer (NK) cell activities and to protect against infection. The mechanisms involved in the different effects attributed to LAB remain to be clarified. Moreover, considering that the immunomodulatory properties are strain-specific, defining the optimal dose of a certain bacteria or combination of bacteria strains and the duration of treatment for a desired effect in a target population group is essential in order to substantiate health claims.

Probiotic lactobacilli and VSL#3 induce enterocyte beta-defensin 2

Recent evidence suggests that probiotic bacteria may stabilize gut barrier function via induction of anti-microbial peptides such as defensins. This study aimed to elucidate the induction mechanism of the human beta defensin-2 (hBD-2) gene by different probiotic lactobacillus strains. The expression of hBD-2 mRNA peaked at 6 h of incubation upon treatment of Caco-2 cells and increased with higher dosage of various probiotic bacteria. Deletion of nuclear factor (NF)-kappaB and activator protein-1 (AP-1) binding sites on the hBD-2 promoter resulted in a complete abrogation of promoter activation by probiotics. As revealed by the use of specific mitogen-activated protein kinase (MAPK) inhibitors the hBD-2 induction was dependent on the MAPK extracellular regulated kinase (ERK 1/2), p38 and c-Jun N-terminal kinase (JNK), although to varying degrees. Several Lactobacillus strains and VSL#3, a probiotic cocktail of four lactobacilli, three bifidum and one streptococcus species, induced the secretion of the hBD-2 peptide into the culture media as shown by enzyme-linked immunosorbent assay (ELISA). Thus, the present study suggests that lactobacilli and the VSL#3 bacterial mixture strengthen intestinal barrier functions through the up-regulation of hBD-2 via induction of proinflammatory pathways including NF-kappaB and AP-1 as well as MAPKs.

Probiotics: contributions to oral health

Probiotics have been extensively studied for their health-promoting effects. The main field of research has been in the gastrointestinal tract. However, in the past few years probiotics have also been investigated in the oral health perspective, which is the topic of the present review. We discuss the mechanisms of bacterial adhesion, potential of probiotics in oral cavity colonization, interspecies interactions, and possible effects on immunomodulation, and means of probiotic administration. We suggest that probiotic treatment of diseases other than dental caries and periodontal disease should also be systematically investigated. In general, hardly any randomized controlled trials have been conducted in this area and the studies on probiotics vs oral health are still in their cradle. Hence, much more investigations are called for before any evidence-based conclusions can be drawn: if or not probiotic therapy can be recommended for oral health purposes.

Consumption of prebiotic inulin enriched with oligofructose in combination with the probiotics Lactobacillus rhamnosus and Bifidobacterium lactis has minor effects on selected immune parameters in polypectomised and colon cancer patients

Probiotics (PRO) modulate immunity in humans, while the effect of prebiotics (PRE) and synbiotics (SYN) on the human immune system are not well studied yet. The objective of this study was to investigate whether daily intake of a SYN modulates immune functions. In a randomised double-blind, placebo-controlled trial, thirty-four colon cancer patients who had undergone ‘curative resection’ and forty polypectomised patients participated. Subjects of the SYN group daily received encapsulated bacteria (1 × 1010 colony-forming units of Lactobacillus rhamnosus GG (LGG) and 1 × 1010 colony-forming units of Bifidobacterium lactis Bb12 (Bb12)) and 10 g of inulin enriched with oligofructose. Controls received encapsulated maltodextrin and 10 g of maltodextrin. Prior to intervention (T1), and 6 (T2) and 12 weeks after the start of the intervention (T3), phagocytic and respiratory burst activity of neutrophils and monocytes, lytic activity of natural killer cells and production of interleukin (IL)-2, IL-10 and IL-12, as well as tumour necrosis factor-α and interferon-γ (IFN-γ) by activated peripheral blood mononuclear cells (PBMC) were measured. In faeces, the concentrations of transforming growth factor-β1 and prostaglandin E2 were measured. IL-2 secretion by activated PBMC from the polyp group increased significantly between T1 or T2 and T3 (P < 0·05). In the cancer group, SYN treatment resulted in an increased capacity of PBMC to produce IFN-γ at T3 (P < 0·05). Other immunity-related parameters were not affected by SYN treatment, neither in the cancer nor in the polyp group. In conclusion, supplementation with this SYN has minor stimulatory effects on the systemic immune system of the two study groups. Further studies in humans should aim to focus on the gut-associated immune system.

Dose-response study of probiotic bacteria Bifidobacterium animalis subsp lactis BB-12 and Lactobacillus paracasei subsp paracasei CRL-341 in healthy young adults

OBJECTIVE

This study was performed to investigate the dose-response effects of supplementation with Bifidobacterium animalis subsp lactis (BB-12) and Lactobacillus paracasei subsp paracasei (CRL-431) on blood lipids, recovery from feces and bowel habits. Changes of the fecal microflora was analyzed in the 10(10) CFU/day probiotic and placebo group.

DESIGN

The study was designed as a randomized, placebo-controlled, double-blinded, parallel dose-response study.

SUBJECTS

Healthy young adults (18-40 years) were recruited by advertising in local newspapers. Of the 75 persons enrolled, 71 (46 women, 25 men, mean age 25.6 years (range 18-40 years)) completed the study.

INTERVENTION

The volunteers were randomly assigned into five groups receiving either placebo or a mixture of the two probiotics in the concentration of 10(8), 10(9), 10(10) or 10(11) CFU/day in 2 weeks run-in period, 3 weeks intervention and 2 weeks wash-out. Diary reporting bowel habits and well being (abdominal bloating, flatulence and headache) was kept for all 7 weeks and blood lipids, fecal recovery of BB-12 and CRL-431, as well as fecal microflora was tested before, immediately and 2 weeks after intervention.

RESULTS

The fecal recovery of BB-12 increased significantly (P < 0.001) with increasing dose. In the group receiving 10(11) CFU/day BB-12 was recovered from 13 out of 15 volunteers. CRL-431 was not recovered in any of the fecal samples. Supplementation with probiotics did not change the fecal bacterial composition. A significant linear increase in fecal consistency (looser stool) with increasing probiotic dose (P = 0.018) was observed. No overall dose-response effect was found on the blood lipids. High doses of probiotics were well tolerated.

CONCLUSION

A dose-related recovery of BB-12 from feces was observed.