Immunological and trophical effects of Saccharomyces boulardii on the small intestine in healthy human volunteers

The potential role of yeasts in the mitigation of health issues related to beer consumption

Food consumption of healthier products has become an essential trend in the food sector. This is also the case in beer, a biochemical process of transformation performed by yeast cells. More and more studies proclaim the need to reduce ethanol content in alcoholic drinks, certainly the most important health issue of beer consumption. In this review we gather key health issues related to beer consumption and the last advances regarding the use of yeast to attenuate those health problems. Furthermore, we have included the latest findings about the general positive impact of yeast in health as a consequence of its ability to biotransform polyphenolic compounds present in the wort, producing healthy compounds as hydroxytyrosol or melatonin, and its ability to perform as a probiotic driver. Besides, a group of population with chronic diseases as diabetes or celiac disease could take advantage of low carbohydrate or gluten-free beers, respectively. The role of yeast in beer production has been traditionally associated to its fermentative power. But here we have found a change in this dogma in the last years toward yeasts being a main driver to enhance healthy aspects of beer. The key findings are discussed and possible future directions are proposed.

Probiotic Yeast Saccharomyces: Back to Nature to Improve Human Health

Saccharomyces cerevisiae var. boulardii is best known for its treatment efficacy against different gastrointestinal diseases. This probiotic yeast can significantly protect the normal microbiota of the human gut and inhibit the pathogenicity of different diarrheal infections. Several clinical investigations have declared S. cerevisiae var. boulardii a biotherapeutic agent due to its antibacterial, antiviral, anti-carcinogenic, antioxidant, anti-inflammatory and immune-modulatory properties. Oral or intramuscular administration of S. cerevisiae var. boulardii can remarkably induce health-promoting effects in the host body. Different intrinsic and extrinsic factors are responsible for its efficacy against acute and chronic gut-associated diseases. This review will discuss the clinical and beneficial effects of S. cerevisiae var. boulardii in the treatment and prevention of different metabolic diseases and highlight some of its health-promising properties. This review article will provide fundamental insights for new avenues in the fields of biotherapeutics, antimicrobial resistance and one health.

From Birth and Throughout Life: Fungal Microbiota in Nutrition and Metabolic Health

The human gastrointestinal tract is home to a vibrant, diverse ecosystem of prokaryotic and eukaryotic microorganisms. The gut fungi (mycobiota) have recently risen to prominence due to their ability to modulate host immunity. Colonization of the gut occurs through a combination of vertical transmission from the maternal mycobiota and environmental and dietary exposure. Data from human and animal studies demonstrate that nutrition strongly affects the mycobiota composition and that changes in the fungal communities can aggravate metabolic diseases. The mechanisms pertaining to the mycobiota's influence on host health, pathology, and resident gastrointestinal communities through intrakingdom, transkingdom, and immune cross talk are beginning to come into focus, setting the stage for a new chapter in microbiota-host interactions. Herein, we examine the inception, maturation, and dietary modulation of gastrointestinal and nutritional fungal communities and inspect their impact on metabolic diseases in humans.

Saccharomyces boulardii: What Makes It Tick as Successful Probiotic?

Saccharomyces boulardii is a probiotic yeast often used for the treatment of GI tract disorders such as diarrhea symptoms. It is genetically close to the model yeast Saccharomyces cerevisiae and its classification as a distinct species or a S. cerevisiae variant has long been discussed. Here, we review the main genetic divergencies between S. boulardii and S. cerevisiae as a strategy to uncover the ability to adapt to the host physiological conditions by the probiotic. S. boulardii does possess discernible phenotypic traits and physiological properties that underlie its success as probiotic, such as optimal growth temperature, resistance to the gastric environment and viability at low pH. Its probiotic activity has been elucidated as a conjunction of multiple pathways, ranging from improvement of gut barrier function, pathogen competitive exclusion, production of antimicrobial peptides, immune modulation, and trophic effects. This review summarizes the participation of S. boulardii in these mechanisms and the multifactorial nature by which this yeast modulates the host microbiome and intestinal function.

Diversity of Saccharomyces boulardii CNCM I-745 mechanisms of action against intestinal infections

The yeast Saccharomyces boulardii CNCM I-745 is one of the probiotics recommended for the prevention of antibiotic-associated diarrhea. Studies conducted in vivo and in vitro demonstrated that in the case of infectious diseases there are two potential sites of action of Saccharomyces boulardii CNCM I-745: (1) An action on enteropathogenic microorganisms (adhesion of bacteria and their elimination or an effect on their virulence factors: Toxins, lipopolysaccharide, etc.); and (2) a direct action on the intestinal mucosa (trophic effects, effects on epithelial reconstitution, anti-secretory effects, anti-inflammatory, immunomodulators). Oral administration of Saccharomyces boulardii CNCM I-745 to healthy subjects does not alter their microbiota. However, in the case of diseases associated with the use of antibiotics or chronic diarrhea, Saccharomyces boulardii CNCM I-745 can restore the intestinal microbiota faster. The interaction of Saccharomyces boulardii CNCM I-745 with the innate immune system have been recently demonstrated thus opening up a new therapeutic potential of this yeast in the case of diseases associated with intestinal infections but also other pathologies associated with dysbiosis such as inflammatory diseases.

[Saccharomyces boulardii CNCM I-745 - the medicinal yeast improves intestinal enzyme function]

BACKGROUND

Saccharomyces boulardii CNCM I-745 is a probiotic medicinal yeast used in the prevention and treatment of diarrhea. It has numerous effects, i. a. immunological and antitoxin effects, it binds pathogens and has a beneficial effect on the intestinal microbiota. In addition, pronounced trophic effects were detected.

METHOD

The focus of this review is on the effects of S. boulardii CNCM I-745 on digestive enzymes located in the brush border membrane. An important role in this context is attributed to polyamines which are synthesized and secreted by S. boulardii CNCM I-745.

RESULTS AND CONCLUSIONS

Polyamines are essential for cell proliferation and differentiation. They enhance the expression of intestinal enzymes as well as nutrient transport systems and directly influence the nucleic acid binding capacity. S. boulardii CNCM I-745 induces signals via mitogen-activated protein kinase cascades (MAP kinase pathway) and influences the PI3 kinase signaling pathway. Furthermore, S. boulardii CNCM I-745 secretes certain enzymes that promote nutrient delivery to both the yeast itself and the host organism. The increased presence of digestive enzymes obviously contributes significantly to the clinical effect of S. boulardii CNCM I-745.

Co-culture of Bacillus coagulans and Candida utilis efficiently treats Lactobacillus fermentation wastewater

Co-culture of Bacillus coagulans and Candida utilis was firstly investigated in the efficient treatment of Lactobacillus fermentation wastewater (LFW) containing total organic carbon (TOC) of 22.0 g/L and total nitrogen (TN) of 2.4 g/L. The utilization of lactic acid by C. utilis was responsible for the relief of feedback inhibition to promote the growth of B. coagulans. The removal ratio of TOC by B. coagulans and C. utilis was only 9.1% and 22.7%, respectively, which was improved to 49.0% by co-culture. The removal ratio of TN by B. coagulans and C. utilis was merely 6.3% and 12.5%, respectively, which was also promoted to 44.6% by co-culture. Both the high growth of B. coagulans and the efficient removal of TOC and TN from LFW was achieved with the co-culture, which is not previously reported and very important in the production of probiotics with the resource utilization of LFW.

Ecological Therapeutic Opportunities for Oral Diseases

The three main oral diseases of humans, that is, caries, periodontal diseases, and oral candidiasis, are associated with microbiome shifts initiated by changes in the oral environment and/or decreased effectiveness of mucosal immune surveillance. In this review, we discuss the role that microbial-based therapies may have in the control of these conditions. Most investigations on the use of microorganisms for management of oral disease have been conducted with probiotic strains with some positive but very discrete clinical outcomes. Other strategies such as whole oral microbiome transplantation or modification of community function by enrichment with health-promoting indigenous oral strains may offer more promise, but research in this field is still in its infancy. Any microbial-based therapeutics for oral conditions, however, are likely to be only one component within a holistic preventive strategy that should also aim at modification of the environmental influences responsible for the initiation and perpetuation of microbiome shifts associated with oral dysbiosis.

Saccharomyces boulardii CNCM I-745 Improves Intestinal Enzyme Function: A Trophic Effects Review

Several properties of the probiotic medicinal yeast Saccharomyces boulardii CNCM I-745 contribute to its efficacy to prevent or treat diarrhoea. Besides immunologic effects, pathogen-binding and anti-toxin effects, as well as positive effects on the microbiota, S boulardii CNCM I-745 also has pronounced effects on digestive enzymes of the brush border membrane, known as trophic effects. The latter are the focus of this review. Literature has been reviewed after searching Medline and PMC databases. All relevant non-clinical and clinical studies are summarized. S. boulardii CNCM I-745 synthesizes and secretes polyamines, which have a role in cell proliferation and differentiation. The administration of polyamines or S. boulardii CNCM I-745 enhances the expression of intestinal digestive enzymes as well as nutrient uptake transporters. The signalling mechanisms leading to enzyme activation are not fully understood. However, polyamines have direct nucleic acid–binding capacity with regulatory impact. S. boulardii CNCM I-745 induces signalling via the mitogen-activated protein kinase pathway. In addition, effects on the phosphatidylinositol-3 kinase (PI3K) pathway have been reported. As an additional direct effect, S. boulardii CNCM I-745 secretes certain enzymes, which enhance nutrient acquisition for the yeast and the host. The increased availability of digestive enzymes seems to be one of the mechanisms by which S. boulardii CNCM I-745 counteracts diarrhoea; however, also people with certain enzyme deficiencies may profit from its administration. More studies are needed to fully understand the mechanisms of trophic activation by the probiotic yeast.

Gleaning Insights from Fecal Microbiota Transplantation and Probiotic Studies for the Rational Design of Combination Microbial Therapies

Beneficial microorganisms hold promise for the treatment of numerous gastrointestinal diseases. The transfer of whole microbiota via fecal transplantation has already been shown to ameliorate the severity of diseases such as Clostridium difficile infection, inflammatory bowel disease, and others. However, the exact mechanisms of fecal microbiota transplant efficacy and the particular strains conferring this benefit are still unclear. Rationally designed combinations of microbial preparations may enable more efficient and effective treatment approaches tailored to particular diseases. Here we use an infectious disease, C. difficile infection, and an inflammatory disorder, the inflammatory bowel disease ulcerative colitis, as examples to facilitate the discussion of how microbial therapy might be rationally designed for specific gastrointestinal diseases. Fecal microbiota transplantation has already shown some efficacy in the treatment of both these disorders; detailed comparisons of studies evaluating commensal and probiotic organisms in the context of these disparate gastrointestinal diseases may shed light on potential protective mechanisms and elucidate how future microbial therapies can be tailored to particular diseases.

Influence of Saccharomyces boulardii CNCM I-745on the gut-associated immune system

Background

The probiotic Saccharomyces boulardii CNCM I-745 (also known as Saccharomyces cerevisiae HANSEN CBS 5926; in the following S. boulardii) has proven its effectiveness in preventive and therapeutic treatment of many gastrointestinal diseases, especially diseases associated with acute diarrhea. In particular, antibiotic-associated diarrhea, Clostridium difficile-associated diarrhea, traveller’s diarrhea, as well as acute diarrhea due to common viral and bacterial infections in children and adults.

Aim

The aim of this review is to summarize the experimental studies elucidating the molecular and immunological mechanisms by which these clinically proven effects are archived, with an emphasis on the gut-associated immune system. The main focus is laid on anti-inflammatory and immune-modulatory action of S. boulardii involved in bacterial or enterotoxin-mediated diarrhea and inflammation. An attempt is made to differentiate between the effects associated with cellular versus soluble factors and between prophylactic and therapeutic effects.

Methods

A literature search was performed in PubMed/PubMed Central for the effects of S. boulardii on the gut-associated immune system (focus acute diarrhea).

Results and conclusion

S. boulardii exhibits its positive effect by the direct effects on pathogens or their toxins as well as by influencing the host’s infection-induced signaling cascades and its innate and adaptive immune system. The combination of these mechanisms results in a reduction of the pathogens’ ability for adhesion or colonization and an attenuation of the overreacting inflammatory immune response. Thereby, the integrity of the intestinal epithelial cell layer is preserved or restored, and the diarrheic leakage of fluids into the intestinal lumen is attenuated.

Effect of Saccharomyces boulardii in Children with Acute Gastroenteritis and Its Relationship to the Immune Response

We evaluated the effect of Saccharomyces boulardii administration in otherwise healthy children aged between 6 months and 10 years who were admitted for acute diarrhoea (15 males, 12 females). The patients were randomized into two groups: group 1 ( n = 16) received 250 mg S. boulardii dissolved in 5 ml of water orally twice daily for 7 days and group 2 ( n = 11) received placebo. Clinical and laboratory assessments were performed on admission and on day 7 of follow-up. Both groups experienced reduced daily stool frequency, the decrease being significantly greater in group 1 on days 3 and 4 compared with group 2. Group 1 demonstrated significant increases in serum immunoglobulin A and decreases in C-reactive protein levels on day 7. The percentage of CD8 lymphocytes on day 7 was significantly higher in group 1 than group 2. This study confirmed the efficacy of S. boulardii in paediatric acute gastroenteritis and the findings suggest that S. boulardii treatment enhances the immune response.

Characterization of the Probiotic Yeast Saccharomyces boulardii in the Healthy Mucosal Immune System

The probiotic yeast Saccharomyces boulardii has been shown to ameliorate disease severity in the context of many infectious and inflammatory conditions. However, use of S. boulardii as a prophylactic agent or therapeutic delivery vector would require delivery of S. boulardii to a healthy, uninflamed intestine. In contrast to inflamed mucosal tissue, the diverse microbiota, intact epithelial barrier, and fewer inflammatory immune cells within the healthy intestine may all limit the degree to which S. boulardii contacts and influences the host mucosal immune system. Understanding the nature of these interactions is crucial for application of S. boulardii as a prophylactic agent or therapeutic delivery vehicle. In this study, we explore both intrinsic and immunomodulatory properties of S. boulardii in the healthy mucosal immune system. Genomic sequencing and morphological analysis of S. boulardii reveals changes in cell wall components compared to non-probiotic S. cerevisiae that may partially account for probiotic functions of S. boulardii. Flow cytometry and immunohistochemistry demonstrate limited S. boulardii association with murine Peyer’s patches. We also show that although S. boulardii induces a systemic humoral immune response, this response is small in magnitude and not directed against S. boulardii itself. RNA-seq of the draining mesenteric lymph nodes indicates that even repeated administration of S. boulardii induces few transcriptional changes in the healthy intestine. Together these data strongly suggest that interaction between S. boulardii and the mucosal immune system in the healthy intestine is limited, with important implications for future work examining S. boulardii as a prophylactic agent and therapeutic delivery vehicle.

The Biological Fight Against Pathogenic Bacteria and Protozoa

The animal gastrointestinal tract is a tube with two open ends; hence, from the microbial point of view it constitutes an open system, as opposed to the circulatory system that must be a tightly closed microbial-free environment. In particular, the human intestine spans ca. 200 m² and represents a massive absorptive surface composed of a layer of epithelial cells as well as a paracellular barrier. The permeability of this paracellular barrier is regulated by transmembrane proteins known as claudins that play a critical role in tight junctions.

Saccharomyces boulardii CNCM I-745 supports regeneration of the intestinal microbiota after diarrheic dysbiosis - a review

The probiotic medicinal yeast Saccharomyces cerevisiae HANSEN CBS 5926 (Saccharomyces boulardii CNCM I-745) is used for the prevention and treatment of diarrhea. Its action is based on multiple mechanisms, including immunological effects, pathogen-binding and antitoxinic effects, as well as effects on digestive enzymes. Correlated with these effects, but also due to its inherent properties, S. boulardii is able to create a favorable growth environment for the beneficial intestinal microbiota, while constituting extra protection to the host mucus layer and mucosa. This review focuses on the positive influence of S. boulardii on the composition of the intestinal microbiota. In a dysbiosis, as during diarrhea, the main microbial population (especially Lachnospiraceae, Ruminococcaceae, Bacteroidaceae, and Prevotellaceae) is known to collapse by at least one order of magnitude. This gap generally leads to transient increases in pioneer-type bacteria (Enterobacteriaceae, Bifidobacteriaceae, and Clostridiaceae). Several human studies as well as animal models demonstrate that treatment with S. boulardii in dysbiosis leads to the faster reestablishment of a healthy microbiome. The most relevant effects of S. boulardii on the fecal composition include an increase of short chain fatty acid-producing bacteria (along with a rise in short chain fatty acids), especially of Lachnospiraceae and Ruminococcaceae, as well as an increase in Bacteroidaceae and Prevotellaceae. At the same time, there is a suppression of pioneer bacteria. The previously observed preventive action of S. boulardii, eg, during antibiotic therapy or regarding traveler’s diarrhea, can be explained by several mechanisms, including a stabilizing effect on the healthy microbiota as well as possibly on the mucus layer. Several different dysbiotic situations could profit from the effects of S. boulardii CNCM I-745. Its additional potential lies in a general stabilization of the gut flora for at-risk populations. More studies are needed to explore the full potential of this versatile probiotic yeast.

Saccharomyces boulardii administration changes gut microbiota and reduces hepatic steatosis, low-grade inflammation, and fat mass in obese and type 2 diabetic db/db mice

Growing evidence shows that gut microbes are key factors involved in the regulation of energy homeostasis, metabolic inflammation, lipid metabolism, and glucose metabolism. Therefore, gut microbiota modulations caused by selectively fermented oligosaccharides or probiotic bacteria constitute an interesting target in the physiopathology of obesity. However, to date, no probiotic yeast has been investigated in this context. Therefore, our study aimed to evaluate the impact of the most-studied probiotic yeast (i.e., Saccharomyces boulardii Biocodex) on obesity and associated metabolic features, such as fat mass development, hepatic steatosis, and low-grade inflammation, in obese mice. S. boulardii was administered daily by oral gavage to leptin-resistant obese and type 2 diabetic mice (db/db) for 4 weeks. We found that S. boulardii-treated mice exhibited reduced body weight, fat mass, hepatic steatosis, and inflammatory tone. Interestingly, these effects of S. boulardii on host metabolism were associated with local effects in the intestine. S. boulardii increased cecum weight and cecum tissue weight but also induced dramatic changes in the gut microbial composition at the phylum, family, and genus levels. These gut microbiota changes in response to S. boulardii may also be correlated with the host metabolism response. In conclusion, this study demonstrates for the first time that S. boulardii may act as a beneficial probiotic treatment in the context of obesity and type 2 diabetes.

To date, no probiotic yeast have been investigated in the context of obesity and type 2 diabetes. Here we found that type 2 diabetic and obese mice (db/db) treated with Saccharomyces boulardii exhibited reduced body weight, fat mass, hepatic steatosis, and inflammatory tone. These effects on host metabolism were associated with local effects in the intestine. Importantly, by using pyrosequencing, we found that S. boulardii treatment induces changes of the gut microbiota composition at the phylum, family, and genus levels. Moreover, we found that gut microbiota changes in response to S. boulardii were correlated with several host metabolism responses.

Development of microencapsulation delivery system for long-term preservation of probiotics as biotherapeutics agent

The administration of probiotic bacteria for health benefit has rapidly expanded in recent years, with a global market worth $32.6 billion predicted by 2014. The oral administration of most of the probiotics results in the lack of ability to survive in a high proportion of the harsh conditions of acidity and bile concentration commonly encountered in the gastrointestinal tract of humans. Providing probiotic living cells with a physical barrier against adverse environmental conditions is therefore an approach currently receiving considerable interest. Probiotic encapsulation technology has the potential to protect microorganisms and to deliver them into the gut. However, there are still many challenges to overcome with respect to the microencapsulation process and the conditions prevailing in the gut. This review focuses mainly on the methodological approach of probiotic encapsulation including biomaterials selection and choice of appropriate technology in detailed manner.

Efficacy and safety of the probiotic Saccharomyces boulardii for the prevention and therapy of gastrointestinal disorders

Several clinical trials and experimental studies strongly suggest a place for Saccharomyces boulardii as a biotherapeutic agent for the prevention and treatment of several gastrointestinal diseases. S. boulardii mediates responses resembling the protective effects of the normal healthy gut flora. The multiple mechanisms of action of S. boulardii and its properties may explain its efficacy and beneficial effects in acute and chronic gastrointestinal diseases that have been confirmed by clinical trials. Caution should be taken in patients with risk factors for adverse events. This review discusses the evidence for efficacy and safety of S. boulardii as a probiotic for the prevention and therapy of gastrointestinal disorders in humans.

Interaction of Saccharomyces boulardii with intestinal brush border membranes: key to probiotic effects?

The probiotic Saccharomyces boulardii exerts beneficial effects in humans, which include trophic effects, anti-inflammatory effects, antisecretory effects, inhibition of toxins, immunostimulatory effects, and resistance to bacterial overgrowth. This short communication discusses the interactions of the probiotic with brush border membrane (BBM) constituents because most of these effects are BBM mediated. The use of bacterial and yeast probiotics has increased dramatically in more and more clinical states, but their exact mechanisms of action remain largely unknown. The present communication focuses on the interactions of a confirmed yeast probiotic (S boulardii) on the constituents of BBMs.

Systematic review and meta-analysis of Saccharomyces boulardii in adult patients

This article reviews the evidence for efficacy and safety of Saccharomyces boulardii (S. boulardii) for various disease indications in adults based on the peer-reviewed, randomized clinical trials and pre-clinical studies from the published medical literature (Medline, Clinical Trial websites and meeting abstracts) between 1976 and 2009. For meta-analysis, only randomized, blinded controlled trials unrestricted by language were included. Pre-clinical studies, volunteer studies and uncontrolled studies were excluded from the review of efficacy and meta-analysis, but included in the systematic review. Of 31 randomized, placebo-controlled treatment arms in 27 trials (encompassing 5029 study patients), S. boulardii was found to be significantly efficacious and safe in 84% of those treatment arms. A meta-analysis found a significant therapeutic efficacy for S. boulardii in the prevention of antibiotic-associated diarrhea (AAD) (RR = 0.47, 95% CI: 0.35-0.63, P < 0.001). In adults, S. boulardii can be strongly recommended for the prevention of AAD and the traveler's diarrhea. Randomized trials also support the use of this yeast probiotic for prevention of enteral nutrition-related diarrhea and reduction of Helicobacter pylori treatment-related symptoms. S. boulardii shows promise for the prevention of C. difficile disease recurrences; treatment of irritable bowel syndrome, acute adult diarrhea, Crohn's disease, giardiasis, human immunodeficiency virus-related diarrhea; but more supporting evidence is recommended for these indications. The use of S. boulardii as a therapeutic probiotic is evidence-based for both efficacy and safety for several types of diarrhea.

Probiotic yeasts: Anti-inflammatory potential of various non-pathogenic strains in experimental colitis in mice

AIM: To evaluate the in vitro immunomodulation capacity of various non-pathogenic yeast strains and to investigate the ability of some of these food grade yeasts to prevent experimental colitis in mice.

METHODS: In vitro immunomodulation was assessed by measuring cytokines [interleukin (IL)-12p70, IL-10, tumor necrosis factor and interferon γ] released by human peripheral blood mononuclear cells after 24 h stimulation with 6 live yeast strains (Saccharomyces ssp.) and with bacterial reference strains. A murine model of acute 2-4-6-trinitrobenzene sulfonic acid (TNBS)-colitis was next used to evaluate the distinct prophylactic protective capacities of three yeast strains compared with the performance of prednisolone treatment.

RESULTS: The six yeast strains all showed similar non-discriminating anti-inflammatory potential when tested on immunocompetent cells in vitro. However, although they exhibited similar colonization patterns in vivo, some yeast strains showed significant anti-inflammatory activities in the TNBS-induced colitis model, whereas others had weaker or no preventive effect at all, as evidenced by colitis markers (body-weight loss, macroscopic and histological scores, myeloperoxidase activities and blood inflammatory markers).

CONCLUSION: A careful selection of strains is required among the biodiversity of yeasts for specific clinical studies, including applications in inflammatory bowel disease and other therapeutic uses.

Beneficial effects of probiotic and food borne yeasts on human health

Besides being important in the fermentation of foods and beverages, yeasts have shown numerous beneficial effects on human health. Among these, probiotic effects are the most well known health effects including prevention and treatment of intestinal diseases and immunomodulatory effects. Other beneficial functions of yeasts are improvement of bioavailability of minerals through the hydrolysis of phytate, folate biofortification and detoxification of mycotoxins due to surface binding to the yeast cell wall.

Characterization of alpha,alpha-trehalase released in the intestinal lumen by the probiotic Saccharomyces boulardii

OBJECTIVE

Trehalose intolerance due to alpha,alpha-trehalase deficiency has scarcely been studied. The purpose of this study was to measure alpha,alpha-trehalase activity in intestinal biopsy samples from 200 consecutive patients over a period of 6 months, and to characterize alpha,alpha-trehalase released by the probiotic Saccharomyces boulardii (S. boulardii).

MATERIAL AND METHODS

Enzyme activities were measured in human and rat intestinal mucosal samples using the micromethod of Messer & Dalqvist. alpha,alpha-trehalase from S. boulardii was immunoprecipitated and Western blotted using an IgG purified antibody raised against a 23 amino acid peptide of alpha,alpha-trehalase of S. cerevisiae.

RESULTS

Among 200 patients, most of whom complained of abdominal symptoms and diarrhoea, 18 (9%) had total alpha,alpha-trehalase deficiency (0-12 U/g mucosa) and 39 had partial deficiency (3-12 U/g mucosa). Only 4 patients (2%) presented selective alpha,alpha-trehalase deficiency with otherwise normal disaccharidases. Expressed per gram of powder, alpha,alpha-trehalase from S. boulardii delivered in vitro an activity 175 times higher than that of human trehalase per gram of intestinal mucosa. V(max) (22+/-0.43 micromol) and K(m) (5 mM) were close to that of the human enzyme, whereas Western blot revealed a signal of two subunits of 82 kDa. Finally, treatment of rats with S. boulardii resulted in increases in alpha,alpha-trehalase activities of 25 to 45% (p<0.01) in endoluminal fluid and intestinal mucosa compared with in controls.

CONCLUSIONS

Our data suggest that alpha,alpha-trehalase deficiency is more common than is believed and that oral administration of S. boulardii could be beneficial in patients with digestive symptoms caused by trehalose intolerance.

The effect of Saccharomyces boulardii on reducing irinotecan-induced intestinal mucositis and diarrhea

To investigate the efficiency of Saccharomyces boulardii on irinotecan-induced mucosal damage and diarrhea in rats, fifty rats were randomized into three groups with 20 rats in two study groups and 10 rats in the control group. Control group did not receive any treatment. Irinotecan (60 mg/kg) alone was administered intravenously once a day for four consecutive days to the rats of Group A. Throughout the experiment, Group B rats were additionally given Saccharomyces boulardii (800 mg/kg) for 3 days before administration of irinotecan and 7 days throughout the experiment. Delayed diarrhea was more severe in Group A than Group B (P = 0.009). The weight loss was 34.7 +/- 3.8 mg for Group A, while it was 17.4 +/- 1.7 mg for Group B (P < 0.001). Findings of mucositis most clearly appeared in the jejunum. Regarding edema (P = 0.003), leukocyte migration (P = 0.038), and inflammation (P = 0.006) significant recovery was detected in the mucosa of rats receiving Saccharomyces boulardii. Villous thickness was significantly greater in Group A than Group B (P < 0.001). The results indicate that Saccharomyces boulardii provided significant improvement in irinotecan-induced diarrhea and mucositis.

Review article: yeast as probiotics -- Saccharomyces boulardii

BACKGROUND

Probiotics are defined as live micro-organisms which confer a health benefit on the host. Although most probiotics are bacteria, one strain of yeast, Saccharomyces boulardii, has been found to be an effective probiotic in double-blind clinical studies.

AIMS

To compare the main properties that differentiates yeast from bacteria and to review the properties of S. boulardii explaining its potential benefits as a probiotic.

METHODS

The PubMed and Medline databases were searched using the keywords 'probiotics', 'yeast', 'antibiotic associated diarrhea', 'Saccharomyces boulardii','bacterial diarrhea' and 'inflammatory bowel disease' in various combinations.

RESULTS

Several clinical studies have been conducted with S. boulardii in the treatment and prevention of various forms of diarrhoea. Promising research perspectives have been opened in terms of maintenance treatment of inflammatory bowel diseases. The mechanism of S. boulardii's action has been partially elucidated.

CONCLUSION

Saccharomyces boulardii is a strain of yeast which has been extensively studied for its probiotic effects. The clinical activity of S. boulardii is especially relevant to antibiotic-associated diarrhoea and recurrent Clostridium difficile intestinal infections. Experimental studies clearly demonstrate that S. boulardii has specific probiotic properties, and recent data has opened the door for new therapeutic uses of this yeast as an 'immunobiotic'.

Influence of long-term administration of lactulose and Saccharomyces boulardii on the colonic generation of phenolic compounds in healthy human subjects

OBJECTIVE

Proteins are degraded in the colon by bacterial fermentation into potentially toxic metabolites such as phenolic compounds. The aim of the present study was to investigate whether long-term administration of lactulose or Saccharomyces boulardii cells would result in a lower protein degradation. In addition, the influence of a long-term dietary intake on different gastrointestinal parameters was investigated.

METHODS

The effect of long-term intervention of the substrates was evaluated in a randomized, cross-over study in 43 healthy volunteers. At the start of the study and at the end of each 4-week treatment period, urine was collected during 48 h in different fractions and faeces during 72 h. Breath test samples and blood samples were taken to study gastrointestinal parameters.

RESULTS

No influence of long-term administration of both substrates was found on GE, OCTT and serum lipids. A significant decrease in small intestinal permeability was found after long-term dietary intervention with lactulose. Long-term administration of lactulose significantly decreased urinary p-cresol excretion, but did not lower fecal p-cresol excretion. No significant effects were observed after S. boulardii intake.

CONCLUSION

The results obtained in present study have indicated that colonic amino acid fermentation can be reduced by the administration of lactulose as a fermentable carbohydrate.

Saccharomyces cerevisiae strain 905 reduces the translocation of Salmonella enterica serotype Typhimurium and stimulates the immune system in gnotobiotic and conventional mice

Previous results in the laboratory of the authors showed that Saccharomyces cerevisiae strain 905, isolated during 'cachaça' production, was able to colonize and survive in the gastrointestinal tract of germ-free and conventional mice, and to protect these animals against oral challenge with Salmonella enterica serotype Typhimurium or Clostridium difficile. In the present work, the effects of S. cerevisiae 905 on the translocation of Salm. Typhimurium (mesenteric lymph nodes, Peyer's patches, spleen, liver) as well as on the immune system (number of Küpffer cells, immunoglobulin production, clearance of Escherichia coli B41) were evaluated in gnotobiotic and/or conventional mice. The treatment with the yeast reduced significantly the translocation of Salm. Typhimurium to liver in gnotobiotic animals and to all the organs tested in conventional mice. The number of Küpffer cells per 100 hepatocytes in liver was significantly higher (P<0.05) in yeast mono-associated mice (52.9+/-15.7) than in germ-free controls (38.1+/-9.0). Probably as a consequence, clearance of E. coli B41 from the bloodstream was more efficient in yeast mono-associated animals when compared to germ-free mice. Higher levels (P<0.05) of secretory IgA in intestinal content and of IgA and IgM in serum were observed in yeast mono-associated mice when compared to germ-free group. Concluding, the protection against pathogenic bacteria observed in a previous study was probably due to a modulation of both local and systemic immunity of mice treated with S. cerevisiae 905.

Molecular monitoring of the fecal microbiota of healthy human subjects during administration of lactulose and Saccharomyces boulardii

Diet is a major factor in maintaining a healthy human gastrointestinal tract, and this has triggered the development of functional foods containing a probiotic and/or prebiotic component intended to improve the host's health via modulation of the intestinal microbiota. In this study, a long-term placebo-controlled crossover feeding study in which each subject received several treatments was performed to monitor the effect of a prebiotic substrate (i.e., lactulose), a probiotic organism (i.e., Saccharomyces boulardii), and their synbiotic combination on the fecal microbiota of three groups of 10 healthy human subjects differing in prebiotic dose and/or intake of placebo versus synbiotic. For this purpose, denaturing gradient gel electrophoresis (DGGE) analysis of 16S rRNA gene amplicons was used to detect possible changes in the overall bacterial composition using the universal V(3) primer and to detect possible changes at the subpopulation level using group-specific primers targeting the Bacteroides fragilis subgroup, the genus Bifidobacterium, the Clostridium lituseburense group (cluster XI), and the Clostridium coccoides-Eubacterium rectale group (cluster XIVa). Although these populations remained fairly stable based on DGGE profiling, one pronounced change was observed in the universal fingerprint profiles after lactulose ingestion. Band position analysis and band sequencing revealed that a band appearing or intensifying following lactulose administration could be assigned to the species Bifidobacterium adolescentis. Subsequent analysis with real-time PCR (RT-PCR) indicated a statistically significant increase (P < 0.05) in total bifidobacteria in one of the three subject groups after lactulose administration, whereas a similar but nonsignificant trend was observed in the other two groups. Combined RT-PCR results from two subject groups indicated a borderline significant increase (P = 0.074) of B. adolescentis following lactulose intake. The probiotic yeast S. boulardii did not display any detectable universal changes in the DGGE profiles, nor did it influence the bifidobacterial levels. This study highlighted the capacity of an integrated approach consisting of DGGE analysis and RT-PCR to monitor and quantify pronounced changes in the fecal microbiota of healthy subjects upon functional food administration.

Saccharomyces boulardii and infection due to Giardia lamblia

Therapy with metronidazole is the recommended option in giardiasis. However, some clinical trial reports suggest the appearance of drug resistance to explain therapeutic failure. Several investigations have been carried out on the effect of probiotic microorganisms for preventing or treating gastrointestinal diseases, but little is known about their efficacy against protozoal infections. The principal objective of our study was to evaluate the efficacy of Saccharomyces boulardii against Giardia lamblia infections. A double-blind, placebo-controlled study was carried out on adult patients with giardiasis. Group 1 (30 patients) included metronidazole 750 mg 3 times daily along with S. boulardii capsules (250 mg b.i.d. orally) for 10 d while group 2 (35 patients) was treated with metronidazole 750 mg 3 times daily and with empty capsules as placebo for 10 d. Patients were re-examined at 2 and 4 weeks after treatment, and stool examinations were performed. At week 2, G. lamblia cysts were detected in 6 cases (17.1%) of group 2 and none in group 1. At the end of the fourth week, presence of the cysts continued in the same 6 cases in group 2 (control group). These findings indicated that S. boulardii may be effective in treating giardiasis when combined with metronidazole therapy.

Effects of Saccharomyces boulardii on intestinal mucosa

Saccharomyces boulardii (S. boulardii) is a non-pathogenic biotherapeutic agent, widely prescribed in a lyophilized form in many countries over the world. S. boulardii acts as a shuttle liberating effective enzymes, proteins and trophic factors during its intestinal transit that improve host immune defenses, digestion, and absorption of nutrients. In addition, S. boulardii secretes during its intestinal transit polyamines, mainly spermine and spermidine that regulate gene expression and protein synthesis. In this review, we will focus on the interactions of the yeast with the host intestinal mucosa.

Saccharomyces boulardii produces in rat small intestine a novel protein phosphatase that inhibits Escherichia coli endotoxin by dephosphorylation

Using a polyclonal antibody raised against a highly conserved sequence of 38 amino acids containing the activation site (VTDSAAGAT) common to mammalian and yeast alkaline phosphatases (AP), we identified in decapsidated Saccharomyces boulardii a protein phosphatase detected by autoradiography as a single signal (63 kD). Using an affinity chromatography column, the protein phosphatase could be concentrated 39.1-fold and presented as a doublet of two subunits. Compared with rat and bovine purified intestinal AP, the enzyme from S. boulardii had a greater ability to dephosphorylate the lipopolysaccharide (LPS) of Escherichia coli 055B5. When tested in vivo, intraperitoneal injection of intact LPS to rats produced, after 9 h, 100 ng/mL of circulating tumor necrosis factor-alpha with inflammatory lesions and apoptotic bodies in the liver and the heart, whereas rats injected with partially dephosphorylated LPS produced only 40 ng/mL tumor necrosis factor-alpha without organic lesions. In conclusion, S. boulardii is able to inhibit toxicity of E. coli surface endotoxins by the release of a protein phosphatase exhibiting a great capacity of dephosphorylation.

Effects ofEnterococcus faeciumNCIMB 10415 as probiotic supplement on intestinal transport and barrier function of piglets

Many studies report positive effects of probiotic supplementation on the performance and health of piglets. The intention of this study was to describe the effects of Enterococcus faecium NCIMB 10415 on the transport and barrier functions of pig small intestine to improve our understanding of the underlying mechanisms of this probiotic. Ussing chamber studies were conducted with isolated jejunal epithelia of piglets at the age of 14, 28, 35 and 56 days. Jejunal tissues of the control group were compared with epithelia of piglets that had received a diet supplemented with the probiotic Enterococcus faecium NCIMB 10415. Transport properties (absorption and secretion) of the epithelia were examined by mucosal addition of glucose or L-glutamine or by serosal addition of PGE2. Electrophysiology of the epithelia was continuously recorded and the change in short circuit current (Isc) was determined. Paracellular permeability was measured by measuring the flux rates of mannitol. The increase of Isc caused by mucosal addition of glucose was, at all glucose concentrations, higher in the probiotic group compared with the control group. However, the difference (up to 100% of the control) was not significant. The increase of Isc after the mucosal addition of L-glutamine (12mmol/l) was higher in the tissues of the probiotic group but did not reach significance. Serosal PGE2 induced a significantly higher increase of Isc in tissues of the probiotic group at the age of 28 days. No consistent differences were observed in mannitol transport rates between the feeding groups. Significant age-dependent alterations of absorptive and secretory properties of the jejunal epithelium were observed; these were independent of the treatment. A probiotic supplementation seems to influence transport properties of small intestine epithelium. The increased absorption of glucose could be interpreted as a positive effect for the animal.

Screening of yeasts as probiotic based on capacities to colonize the gastrointestinal tract and to protect against enteropathogen challenge in mice

Probiotics are defined as viable microorganisms that exhibit a beneficial effect on the host's health when they are ingested. Two important criteria are used for selection of probiotic microorganisms: they must be able to survive in the gastrointestinal environment and to present at least one beneficial function (colonization resistance, immunomodulation or nutritional contribution). Generally, in vitro assays demonstrating these properties were used to select probiotics but it is unclear if the data can be extrapolated to in vivo conditions. In the present work, twelve Saccharomyces cerevisiae strains isolated from different environments (insect association, tropical fruit, cheese and "aguardente" production) and pre-selected for in vitro resistance to simulated gastrointestinal conditions were inoculated in germ-free mice to evaluate their real capacity to colonize the mammal digestive tract. Using these data, one of the yeasts (S. cerevisiae 905) was selected and tested in gnotobiotic (GN) and conventional (CV) mice for its capacity to protect against oral challenge with two enteropathogenic bacteria (Salmonella Typhimurium and Clostridium difficile). The yeast reached populational levels potentially functional in the gastrointestinal portions where the enteropathogens tested act. No antagonism against either pathogenic bacterium by the yeast was observed in the digestive tract of GN mice but, after challenge with S. Typhimurium, mortality was lower and liver tissue was better preserved in CV animals treated with the yeast when compared with a control group (p<0.05). Histopathological results of intestines showed that the yeast also presented a good protective effect against oral challenge with C. difficile in GN mice (p<0.05). In conclusion, among the 12 S. cerevisiae tested, strain 905 showed the best characteristics to be used as a probiotic as demonstrated by survival capacity in the gastrointestinal tract and protective effect of animals during experimental infections.

Efficacy of saccharomyces boulardii with antibiotics in acute amoebiasis

AIM

To compare the efficacy of antibiotics therapy alone with antibiotics and saccharomyces boulardii in treatment of acute amebiasis.

METHODS

In a double blind, random clinical trial on patients with acute intestinal amoebiasis, 57 adult patients with acute amoebiasis, diagnosed with clinical manifestations (acute mucous bloody diarrhea) and amebic trophozoites engulfing RBCs found in stool were enrolled in the study. Regimen 1 included metronidazole (750 mg Tid) and iodoquinol (630 mg Tid) for 10 days. Regimen 2 contained capsules of lyophilized saccharomyces boulardii (250 mg Tid) orally in addition to regimen 1. Patients were re-examined at two and four weeks after the treatment, and stool examination was performed at the end of week 4. Student's t-test, chi(2) and McNemar's tests were used for statistical analysis.

RESULTS

Three patients refused to participate. The other 54 patients were randomized to receive either regimen 1 or regimen 2 (Groups 1 and 2 respectively, each with 27 patients). The two groups were similar regarding their age, sex and clinical manifestations. In Group 1, diarrhea lasted 48.0+/-18.5 hours and in Group 2, 12.0+/-3.7 hours (P<0.0001). In Group 1, the durations of fever and abdominal pain were 24.0+/-8.8 and 24.0+/-7.3 hours and in Group 2 they were 12.0+/-5.3 and 12.0+/-3.2 hours, respectively (P<0.001). Duration of headache was similar in both groups. At week 4, amebic cysts were detected in 5 cases (18.5 %) of Group 1 but in none of the Group 2 (P<0.02).

CONCLUSION

Adding saccharomyces boulardii to antibiotics in the treatment of acute amebiasis seems to decrease the duration of clinical symptoms and cyst passage.

Inhibition of in vitro cell adherence of Clostridium difficile by Saccharomyces boulardii

The influence on the adherence of Clostridium difficile to Vero cells of the yeast Saccharomyces boulardii, the yeast fractions (cytoplasm and cell wall) and the culture supernatant was investigated in vitro. C. difficile adherence was significantly inhibited when bacteria were pre-incubated with the whole yeast and the cell wall fraction; this adherence inhibition was dose-dependent. The cell wall fraction also acts upon the target cultured cells inasmuch as the level of adherence was significantly decreased when Vero cells were preincubated with it. The same experiments carried out in the presence of an inhibitor of serine proteases resulted in no inhibition of bacterial adherence. These results suggest that the yeast could inhibit adherence of C. difficile to cells thanks to its proteolytic activity but also through steric hindrance.

Saccharomyces boulardii enhances N-terminal peptide hydrolysis in suckling rat small intestine by endoluminal release of a zinc-binding metalloprotease

Saccharomyces boulardii (S. boulardii), a biotherapeutic agent effective in acute and chronic enterocolopathies, produces trophic intestinal effects at least in part mediated by the endoluminal release of polyamines. However, the effects of the yeast on peptide hydrolysis have not yet been studied. The objectives of this study were to assess in suckling rats the endoluminal and mucosal aminopeptidase activities in response to S. boulardii treatment and to analyze their related mechanisms. Peptidase activities were assayed on yeast cells by using several L-amino acid-p-nitroanilide substrates in the pH range of 2 to 10. A marked hydrolytic activity was found for L-leucine-p-nitroanilide that peaked at pH = 8 (K(m) = 0.334 mM, V(max) = 44.7 micromol.min(-1).g(-1) protein). N-terminal peptide hydrolysis was confirmed using as substrate L-Leu-Gly-Gly (K(m) = 4.71 mM, V(max) = 18.08 micromol.min(-1).g(-1) protein). Enzyme reactions were inhibited in the presence of 1 mM Zn(2+). Oral treatment of sucklings with S. boulardii significantly enhanced jejunal and ileal mucosal leucine-aminopeptidase activities by 24 and 34%, respectively, over controls. In concordance, aminopeptidase activity was enhanced in jejunal and ileal endoluminal fluid samples by 47 and 105%, respectively. By use of an IgG-purified antibody raised against the zinc-binding domain common to metalloproteases, the yeast aminopeptidase was immunoprecipitated and detected as an heteromeric enzyme of 108 and 87-kD subunits. S. boulardii, when given orally to suckling rats, is able to significantly enhance hydrolysis of N-terminal oligopeptides in both endoluminal fluid and intestinal mucosa by the endoluminal release of a leucine aminopeptidase that appears to be a zinc-binding metalloprotease belonging to the M1 family of peptidases.

Preclinical and clinical pharmacology of biotherapeutic agents: Saccharomyces boulardii

Probiotic agents are living microorganisms that, upon ingestion, exert health benefits beyond inherent general nutrition. In this context, we must differentiate between biotherapeutics as approved drugs and dietary supplements and food products containing probiotic bacteria that are not considered drugs. At present the only biotherapeutic agent which is prescribable in some European countries, indicated to relieve specific diseases, is the yeast Saccharomyces boulardii. In this review we consider the various preclinical and clinical aspects of biotherapeutics as basic drugs and the biotherapeutic powers of their use in the treatment of some surgical enteropathies.

Short bowel syndrome

Short bowel syndrome has significant morbidity and is potentially lethal especially when intestinal loss is extensive. The pathophysiology of short bowel syndrome, its aetiology, prognosis and our understanding of the mechanisms of adaptation are reviewed. Management by a multi-disciplinary nutritional care team is advocated and should be directed to the maintenance of growth and development, the promotion of intestinal adaptation, the prevention of complications and the establishment of enteral nutrition. The choice of enteral feed, the role of drugs and the use of pro-adaptive nutrients and agents are discussed. Complications including cholestasis and catheter related sepsis are outlined with strategies to reduce them. Finally the roles of secondary surgical interventions including transplantation are discussed.

Species identification and virulence attributes of Saccharomyces boulardii (nom. inval.)

Saccharomyces boulardii (nom. inval.) has been used for the treatment of several types of diarrhea. Recent studies have confirmed that S. boulardii is effective in the treatment of diarrhea, in particular chronic or recurrent diarrhea, and furthermore that it is a safe and well-tolerated treatment. The aim of the present study was to identify strains of S. boulardii to the species level and assess their virulence in established murine models. Three strains of S. boulardii were obtained from commercially available products in France and Italy. The three S. boulardii strains did not form spores upon repeated testing. Therefore, classical methods used for the identification of Saccharomyces spp. could not be undertaken. Typing by using the restriction fragment length polymorphisms (RFLPs) of the PCR-amplified intergenic transcribed spacer regions (including the 5. 8S ribosomal DNA) showed that the three isolates of S. boulardii were not separable from authentic isolates of Saccharomyces cerevisiae with any of the 10 restriction endonucleases assessed, whereas 9 of the 10 recognized species of Saccharomyces could be differentiated. RFLP analysis of cellular DNA with EcoRI showed that all three strains of S. boulardii had identical patterns and were similar to other authentic S. cerevisiae isolates tested. Therefore, the commercial strains of S. boulardii available to us cannot be genotypically distinguished from S. cerevisiae. Two S. boulardii strains were tested in CD-1 and DBA/2N mouse models of systemic disease and showed intermediate virulence compared with virulent and avirulent strains of S. cerevisiae. The results of the present study show that these S. boulardii strains are asporogenous strains of the species S. cerevisiae, not representatives of a distinct and separate species, and possess moderate virulence in murine models of systemic infection. Therefore, caution should be advised in the clinical use of these strains in immunocompromised patients until further study is undertaken.