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PubMed2003

Probiotics: Isolated bacteria strain or mixtures of different strains? Two different approaches in the use of probiotics as therapeutics.

Probiotics are cultures of beneficial bacteria from the healthy gut microflora that improve the balance of the intestinal milieu by modifying the intestinal microflora and suppressing enhanced inflammatory responses. Probiotics are currently the subject of intense and widespread research as functional foods since they are known to induce health benefits, may be used as pharmaceutical preparations, and have achieved a "generally recognized as safe" (GRAS) status. Lactobacillus strains can also be genetically engineered for use in oral immunotherapeutic applications, such as vaccination and delivery of immunoregulatory substances. In the present review we evaluate the two different approaches to the therapeutic use of probiotics. We also focus on recent findings in the field of molecular biology and genetics of the intestinal immune response related to the microflora and intestinal ecology, in order to understand the mechanisms of action of probiotics and their present indications in gastrointestinal diseases. Finally, with a view to future perspectives we provide some examples of probiotics that are being assessed and have great potential in improving the health of animals and man.

Adjuvants, Immunologic↗
PubMed1998

Probiotics reinforce mucosal degradation of antigens in rats: implications for therapeutic use of probiotics.

The effects of probiotics, administered with different diets, i.e., unhydrolyzed or hydrolyzed dietary antigens, on macromolecular degradation in the gut mucosa were studied. Rat pups were divided into five feeding groups at the age of 14 d. In addition to maternal milk, the milk group was gavaged daily with cows' milk and the hydrolysate group with extensively hydrolyzed whey formula, while controls received sterile saline. In addition to these diets, the milk-GG group and the hydrolysate-GG group were given probiotic bacteria, Lactobacillus GG ATCC 53103 (10(10) colony-forming units per day). At 21 d, the absorption of macromolecules, horseradish peroxidase and beta-lactoglobulin across patch-free jejunal segments was studied in Ussing chambers. The degree of macromolecular degradation was studied by means of HPLC gel filtration. The absorption rate of intact horseradish peroxidase differed among the feeding groups (P = 0.038). This was due to the high median (interquartile range) absorption of intact horseradish peroxidase (ng x h-1 x cm-2) in the milk group [255 (14-1332)] and supplementation with L. GG in the milk-GG group [35 (8-233)] restoring the status to the control level [22 (0-116)]. A parallel effect was seen in the hydrolysate group [100 (9-236)] vs. the hydrolysate-GG group [1 (0- 13)]. A gel filtration study confirmed that larger molecules were absorbed across the mucosa in the milk group compared to the other groups. The absorption of degraded horseradish peroxidase differed between the feeding groups (P = 0. 005). L. GG had a distinct effect when administered with unhydrolyzed, native protein vs. hydrolyzed protein: it increased absorption of degraded horseradish peroxidase in the milk-GG group [7310 (4763-8228)] vs. the milk group [3726 (2423-5915)], while reducing it in the hydrolysate-GG group [2051 (1463-2815)] vs. the hydrolysate group [4573 (3759-9620)]. Our results showed that probiotics not only restore aberrant macromolecular transport, but they also have a specific effect on mucosal degradation depending on dietary antigen: adjuvant-like properties (unhydrolyzed antigen) and immunosuppressive-like properties (hydrolyzed antigen). The antigenicity of the diet therefore should be taken into consideration, when introducing novel probiotic functional foods for the management of gastrointestinal disorders.

Animals↗
PubMed2006

Exopolysaccharides produced by probiotic strains modify the adhesion of probiotics and enteropathogens to human intestinal mucus.

Exopolysaccharides (EPSs) are exocellular polymers present in the surface of many bacteria, including Lactobacillus and Bifidobacterium. The genome sequence of several strains revealed the presence of EPS-encoding genes. However, the physiological role that EPSs play in the bacterial ecology still remains uncertain. In this study, we have assessed the effect of EPSs produced by Lactobacillus rhamnosus GG, Bifidobacterium longum NB667, and Bifidobacterium animalis IPLA-R1 on the adhesion of probiotic and enteropathogen strains to human intestinal mucus. The EPS fraction GG had no significant effect on the adhesion of L. rhamnosus GG and B. animalis IPLA-R1. However, the EPS fractions NB667 and IPLA-R1 significantly reduced the adherence of both probiotic strains. In contrast, the three EPS fractions increased the adhesion of Enterobacter sakazakii ATCC 29544 and Escherichia coli NCTC 8603. Higher adherence of Salmonella enterica serovar Typhimurium ATCC 29631 and Clostridium difficile ATCC 9689 was detected in the presence of the EPS fractions GG and NB667. In general, these effects were obtained at EPS concentrations of up to 5 mg/ml, and they were EPS dose dependent. The competitive exclusion of probiotics in the presence of EPS could suggest the involvement of these biopolymers in the adhesion to mucus. The increase in the adherence of enteropathogens could be explained if components of the pathogen surface are able to bind to specific EPSs and the bound EPSs are able to adhere to mucus. To the best of our knowledge, this is the first work reporting the effect of EPSs from probiotics on bacterial adhesion properties.

Antibiosis↗
PubMed1999

[Probiotics, prebiotics and probiotic products. Current status].

This review contains information about eubiotics, probiotics and probiotical products. Such new definitions as prebiotics, synbiotics are described. Review considers characteristics of different kinds of probiotical substances and factors which provide normalization of intestinal microbial balance and related to probiotical action.

Adjuvants, Immunologic↗
PubMed2005

Selected topics in probiotics and prebiotics: meeting report for the 2004 international scientific association for probiotics and prebiotics.

On August 29-31, 2004, 84 academic and industry scientists from 16 countries gathered in Copper Mountain, Colorado USA to discuss certain issues at the forefront of the science of probiotics and prebiotics. The format for this invitation only meeting included six featured lectures: engineering human vaginal lactobacilli to express HIV-inhibitory molecules (Peter Lee, Stanford University), programming the gut for health (Thaddeus Stappenbeck, Washington University School of Medicine), immune modulation by intestinal helminthes (Joel Weinstock, University of Iowa Hospitals and Clinics), hygiene as a cause of autoimmune disorders (G. A. Rook, University College London), prebiotics and bone health (Connie Weaver, Purdue University) and prebiotics and colorectal cancer risk (Ian Rowland, Northern Ireland Centre for Food and Health). In addition, all participants were included in one of eight discussion groups on the topics of engineered probiotics, host-commensal bacteria communication, 'omics' technologies, hygiene and immune regulation, biomarkers for healthy people, prebiotic and probiotic applications to companion animals, development of a probiotic dossier, and physiological relevance of prebiotic activity. Brief conclusions from these discussion groups are summarized in this paper.

Animals↗
PubMed2005

Effect of a probiotic infant formula on infections in child care centers: comparison of two probiotic agents.

OBJECTIVE: To investigate the effect of 2 different species of probiotics in preventing infections in infants attending child care centers. METHODS: A double-blind, placebo-controlled, randomized trial was conducted from December 1, 2000, to September 30, 2002, at 14 child care centers in the Beer-Sheva area of Israel in healthy term infants 4 to 10 months old. Infants were assigned randomly to formula supplemented with Bifidobacterium lactis (BB-12), Lactobacillus reuteri (American Type Culture Collection 55730), or no probiotics. Duration of feeding, including follow-up, for each participant was 12 weeks. All infants were fed only the assigned formula and were not breastfed due to parental decision before recruitment to the study. Probiotic or prebiotic food products or supplements were not allowed. Main outcome measures were number of days and number of episodes with fever (>38 degrees C) and number of days and number of episodes with diarrhea or respiratory illness. RESULTS: Participants (n = 201) were similar regarding gestational age, birth weight, gender, and previous breastfeeding. The controls (n = 60), compared with those fed B lactis (n = 73) or L reuteri (n = 68), had significantly more febrile episodes (mean [95% confidence interval]: 0.41 [0.28-0.54] vs 0.27 [0.17-0.37] vs 0.11 [0.04-0.18], respectively). The controls also had more diarrhea episodes (0.31 [0.22-0.40] vs 0.13 [0.05-0.21] vs 0.02 [0.01-0.05], respectively) and episodes of longer duration (0.59 [0.34-0.84] vs 0.37 [0.08-0.66] vs 0.15 [0.12-0.18] days, respectively). The L reuteri group, compared with BB-12 or controls, had a significant decrease of number of days with fever, clinic visits, child care absences, and antibiotic prescriptions. Rate and duration of respiratory illnesses did not differ significantly between groups. CONCLUSIONS: Child care infants fed a formula supplemented with L reuteri or B lactis had fewer and shorter episodes of diarrhea, with no effect on respiratory illnesses. These effects were more prominent with L reuteri, which was also the only supplement to improve additional morbidity parameters.

Bifidobacterium↗
PubMed2006

Safety and tolerance of a probiotic formula in early infancy comparing two probiotic agents: a pilot study.

OBJECTIVE: To compare the safety and tolerance of two formulas, supplemented with different probiotic agents, in early infancy. DESIGN: Prospective randomized placebo-controlled trial. SETTING: Clinics of a University Medical Center. SUBJECTS: Full-term healthy infants aged less than 4 months. INTERVENTION: Infants were randomly assigned for 4 weeks to a standard milk-based formula supplemented with either Bifidobacterium lactis (BB-12), Lactobacillus reuteri (ATCC 55730) or a probiotics-free formula. MEASURES OF OUTCOME: Growth parameters, daily characteristics of feeding, stooling and behavior, and side effects. RESULTS: Fifty-nine infants, aged 3-65 days, were included. Subjects in all three groups were similar at entry in terms of gestational age, birth weight, sex, growth parameters and breast feeding rate prior to the study. The supplemented formulas were well accepted and did not reveal any adverse effects. A comparison of growth parameters, and variables of feeding, stooling and crying and irritability did not reveal any significant differences between groups. CONCLUSIONS: The use of formula supplemented with either Lactobacillus reuteri or Bifidobacterium lactis in early infancy, was safe, well tolerated and did not adversely affect growth, stooling habits or infant behavior.

Analysis of Variance↗
PubMed2001

Probiotics, prebiotics, and synbiotics--approaching a definition.

Definitions of different pro-, pre-, and synbiotics suggested by different investigators are critically discussed. On the basis of this analysis, the probiotic concept is confined to effects exerted by viable microorganisms but is applicable independent of the site of action and route of administration. It therefore may include sites such as the oral cavity, the intestine, the vagina, and the skin.

Dairy Products↗
PubMed2006

The survival and persistence in the human gastrointestinal tract of five potential probiotic lactobacilli consumed as freeze-dried cultures or as probiotic sausage.

Among five lactobacilli (L. plantarum MF1291, MF1298, DC13, L. pentosus MF1300 and L. salivarius DC5) which were administrated as freeze-dried cultures for 17 volunteers, MF1298 and DC13 were the most frequently reisolated strains in faeces demonstrating the human gastric survival of these strains. Furthermore, MF1298 and DC13 persisted in the same volunteer after ended intake, suggesting host-specific persistence behaviour. When MF1298 was administrated as sausage fermented with this strain, the number of volunteers harbouring MF1298 increased from 4 to 10 indicating that the sausage matrix protects the survival through the gastrointestinal tract (GIT).

Adult↗
PubMed2004

Toll-like receptor 9 signaling mediates the anti-inflammatory effects of probiotics in murine experimental colitis.

BACKGROUND & AIMS: We tested whether the attenuation of experimental colitis by live probiotic bacteria is due to their immunostimulatory DNA, whether toll-like receptor (TLR) signaling is required, and whether nonviable probiotics are effective. METHODS: Methylated and unmethylated genomic DNA isolated from probiotics (VSL-3), DNAse-treated probiotics and Escherichia coli (DH5 alpha) genomic DNA were administered intragastrically (i.g.) or subcutaneously (s.c.) to mice prior to the induction of colitis. Viable or gamma-irradiated probiotics were administered i.g. to wild-type mice and mice deficient in different TLR or in the adaptor protein MyD88, 10 days prior to administration of dextran sodium sulfate (DSS) to their drinking water and for 7 days thereafter. RESULTS: Intragastric and s.c. administration of probiotic and E. coli DNA ameliorated the severity of DSS-induced colitis, whereas methylated probiotic DNA, calf thymus DNA, and DNase-treated probiotics had no effect. The colitis severity was attenuated to the same extent by i.g. delivery of nonviable gamma-irradiated or viable probiotics. Mice deficient in MyD88 did not respond to gamma-irradiated probiotics. The severity of DSS-induced colitis in TLR2 and TLR4 deficient mice was significantly decreased by i.g. administration of gamma-irradiated probiotics, whereas, in TLR9-deficient mice, gamma-irradiated probiotics had no effect. CONCLUSIONS: The protective effects of probiotics are mediated by their own DNA rather than by their metabolites or ability to colonize the colon. TLR9 signaling is essential in mediating the anti-inflammatory effect of probiotics, and live microorganisms are not required to attenuate experimental colitis because nonviable probiotics are equally effective.

Absorption↗
PubMed2003

Fecal shedding of enterohemorrhagic Escherichia coli in weaned calves following treatment with probiotic Escherichia coli.

The fecal shedding and pathogenicity of enterohemorrhagic E. coli (EHEC) O26:H11, EHEC O111:NM, and EHEC O157:H7 in weaned calves (8 to 10 weeks of age) were compared with and without treatment with a three-strain mixture of probiotic bacteria (competitive-exclusion E. coli). Three groups of 12 calves were each perorally given a five-strain mixture of one of the EHEC serotypes (10(10) CFU of total bacteria per calf). Seventy-two hours later, six calves from each group were each administered 10(10) CFU of probiotic bacteria. None of the EHEC serotypes caused significant clinical disease, although a few calves developed mild transient diarrhea or pyrexia. Gross or microscopic lesions attributable to EHEC were not detected in control or probiotic-treated calves at necropsy. For probiotic-treated calves given E. coli O157:H7 and for probiotic-treated calves given E. coli O111:NM, fecal shedding was reduced compared with that for untreated calves. For the probiotic-treated calves given E. coli O157:H7, the reductions in fecal shedding on days 8, 12, 14, 16, 20, 22, 28, and 30 after peroral administration were statistically significant (P<0.05). For probiotic-treated calves given E. coli O111:NM, there were statistically significant reductions (P<0.05) in fecal shedding on days 6, 8, 10, and 12. In contrast, there was no reduction in fecal shedding for calves administered E. coli O26:H11 and treated with the probiotic bacteria. In fact, calves in both the treated and the nontreated groups continued to shed large populations of E. coli O26:H11 throughout the 32-day trial. At necropsy, E. coli O157:H7 was isolated from five of six untreated calves and from only two of six probiotic-treated calves. E. coli O111:NM was isolated from four of six untreated calves at necropsy and from two of six probiotic-treated calves. However, E. coli O26:H11 was isolated from five of six untreated calves and from all six probiotic-treated calves. The results obtained in this study indicate that probiotic E. coli substantially reduced or eliminated fecal shedding of E. coli O157:H7 and E. coli O111:NM 8 to 30 days and 6 to 12 days after the administration of the probiotic culture, respectively, and reduced the persistence of E. coli O157:H7 in the gastrointestinal tract at necropsy (31 to 33 days after the administration of the probiotic culture). The probiotic E. coli did not reduce fecal shedding or gastrointestinal persistence of E. coli O26:H11.

Animals↗
PubMed2006

Influences of enteral nutrition combined with probiotics on gut microflora and barrier function of rats with abdominal infection.

AIM: To investigate the influences of enteral, parenteral nutrition and probiotics delivered by gut on intestinal microecology, epithelial tight junctions, immune and barrier function of rats with abdominal infection. METHODS: Rat abdominal infection models established with cecal ligation and perforation method, were divided into three groups: parenteral nutrition (PN group, n = 7), PN+enteral nutrition (EN group, n = 7) and PN + EN + probiotics (probiotics group, n = 7) via the needle jejunostomy and neck vein for five days. The total nutritional supplement of the three groups was isonitrogenic and isocaloric. Probiotics was delivered by jejunostomy 10 mL/d (1 x 10(8) cfu/mL). The rats were killed on the sixth day. The feces in the cecum were cultured for anaerobic bacterial growth and analyzed with bacterial group DNA fingerprint profile with random amplified polymorphic DNA. The transmembrane binding proteins (occludin) and IgA level in plasma cells of intestine epithelium in colon and terminal ileum were measured by an immunohistochemistry method. The ultrastructure of intestinal epithelial tight junctions in colon and small intestine was observed by electron-microscopy. Vena cava blood and the homogenated tissue of liver, lung and mesenteric lymph nodes were cultured to determine the bacterial translocations, and endotoxin in the blood from portal vein was detected. RESULTS: (1) The amount of bacteria of gut species in EN group and probiotic group was higher than that in PN group. The DNA-profiles in EN group and probiotic group were similar to that of normal rats. The number of DNA-profiles in probiotics group was much more than that in PN group and EN group. Moreover, there were strange stripes in PN group. (2) The expression of occludin and IgA in the small and large intestine in EN group (2.309 +/- 0.336, 15.440 +/- 2.383) and probiotic group (2.938 +/- 0.515, 16.230 +/- 3.183) was improved as compared with PN group (1.207 +/- 0.587, P < 0.05, 11.189 +/- 2.108, P < 0.01). The expression of occludin in probiotic group (intestine: 2.93 +/- 0.515; cecum: 3.40 +/- 0.617) was higher than that in EN group (intestine: 2.309 +/- 0.336; cecum: 2.076 +/- 0.670; P < 0.05). The expression of IgA, especially in EN group (intestine: 15.440 +/- 2.383) and probiotic EN group (large intestine: 12.516 +/- 1.542) significantly increased as compared with PN group (intestine: 11.189 +/- 2.108; cecum: 10.160 +/- 1.643; P<0.01). The intestinal epithelial tight junctions and microvilli of the probiotic group were more intact than those in the PN group. (3) The bacterial translocations in blood, liver, lung and mesenteric lymph nodes, and the levels of endotoxin were significantly reduced in probiotic (0.082 +/- 0.029) and EN (0.125 +/- 0.040) groups as compared with PN group (0.403 +/- 0.181, P < 0.05). CONCLUSION: Application of EN combined with probiotics could improve the expression of transmembrane binding proteins (occludin) and IgA, correct the intestinal flora disturbance, maintain gut barrier functions and tight junctions, and reduce the occurrence of gut bacterial translocation.

Abdomen↗
PubMed2006

Exposure, health information and flavour-masking strategies for improving the sensory quality of probiotic juice.

Probiotics are live microbial food supplements, which have been shown to exert numerous health benefits. Research has identified that probiotics cause perceptible off-flavours that often contribute to consumer dissatisfaction. This research consisted of three objectives. Firstly, to confirm whether probiotics have a significant effect on the sensory quality and the consumer acceptance of juices. Secondly, to evaluate whether the addition of tropical juices masks probiotic off-flavours, thereby increasing consumer liking. Thirdly, to determine whether non-sensory factors (i.e., repeated exposure, and health information) have an impact on consumer liking. Three orange juice products were manufactured for analysis; Control juice, juice containing probiotics, and juice containing probiotics and tropical fruit juices (10% v/v). Descriptive sensory analysis using a trained panel (n=8) determined that probiotic juices possessed unique 'medicinal' characteristics. Using labelled affective magnitude scales, consumers (n=116) evaluated their 'overall liking' of the three juices in a randomised order in the laboratory. Once assigned into one of three balanced exposure groups, each consumer took home seven, 100mL bottles of one of the juices, and consumed one bottle each day for 7 days. After each in-home consumption, consumers evaluated their 'overall liking' to familiarize themselves with the juice. Furthermore, half of the consumers were provided with information about the presence and the health benefits of probiotics, while the other half of consumers received no information. After 7 days of in-home usage, consumers returned to the laboratory for post-exposure sensory testing, where they re-evaluated their 'overall liking' of the three juices in a randomised order. Results showed that tropical juices were effective in masking the off-flavours associated with probiotic ingredients, and that consumer liking for the probiotic juice containing tropical juice flavours was maintained over the 7-day exposure period. Exposure and information had significant effects on the 'overall liking' of juices containing probiotic cultures. A significant interaction between exposure and information was observed. Therefore, exposure, health information and flavour-masking techniques can have a positive effect on the hedonic qualities of probiotic juices.

Adolescent↗
PubMed2004

Monostrain, multistrain and multispecies probiotics--A comparison of functionality and efficacy.

This literature review was carried out to make a comparison of functionality and efficacy between monostrain, multistrain and multispecies probiotics. A monostrain probiotic is defined as containing one strain of a certain species and consequently multistrain probiotics contain more than one strain of the same species or, at least of the same genus. Arbitrarily, the term multispecies probiotics is used for preparations containing strains that belong to one or preferentially more genera. Multispecies probiotics were superior in treating antibiotic-associated diarrhea in children. Growth performance and particularly mortality in broilers could be improved with multistrain probiotics. Mice were better protected against S. Typhimurium infection with a multistrain probiotic. A multispecies probiotic provided the best clearance of E. coli O157:H7 from lambs. Rats challenged with S. Enteritidis showed best post-challenge weight gains when treated with a multispecies probiotic. Possible mechanisms underlying the enhanced effects of probiotic mixtures are discussed. It is also emphasized that strains used in multistrain and multispecies probiotics should be compatible or, preferably, synergistic. The design and use of multistrain and multispecies probiotics should be encouraged.

Animals↗
PubMed2001

Probiotic bacteria in fermented foods: product characteristics and starter organisms.

Probiotic bacteria are sold mainly in fermented foods, and dairy products play a predominant role as carriers of probiotics. These foods are well suited to promoting the positive health image of probiotics for several reasons: 1) fermented foods, and dairy products in particular, already have a positive health image; 2) consumers are familiar with the fact that fermented foods contain living microorganisms (bacteria); and 3) probiotics used as starter organisms combine the positive images of fermentation and probiotic cultures. When probiotics are added to fermented foods, several factors must be considered that may influence the ability of the probiotics to survive in the product and become active when entering the consumer's gastrointestinal tract. These factors include 1) the physiologic state of the probiotic organisms added (whether the cells are from the logarithmic or the stationary growth phase), 2) the physical conditions of product storage (eg, temperature), 3) the chemical composition of the product to which the probiotics are added (eg, acidity, available carbohydrate content, nitrogen sources, mineral content, water activity, and oxygen content), and 4) possible interactions of the probiotics with the starter cultures (eg, bacteriocin production, antagonism, and synergism). The interactions of probiotics with either the food matrix or the starter culture may be even more intensive when probiotics are used as a component of the starter culture. Some of these aspects are discussed in this article, with an emphasis on dairy products such as milk, yogurt, and cheese.

Bifidobacterium↗
PubMed2002

Microencapsulation of probiotic bacteria: technology and potential applications.

In the recent past, there has been an explosion of probiotic health-based products. Many reports indicated that there is poor survival of probiotic bacteria in these products. Further, the survival of these bacteria in the human gastro-intestinal system is questionable. Providing probiotic living cells with a physical barrier against adverse environmental conditions is therefore an approach currently receiving considerable interest. The technology of micro-encapsulation of probiotic bacterial cells evolved from the immobilised cell culture technology used in the biotechnological industry. Several methods of micro-encapsulation of probiotic bacteria have been reported and include spray drying, extrusion, emulsion and phase separation. None of these reported methods however, has resulted in the large numbers of shelf-stable, viable probiotic bacterial cells necessary for use in industry for development of new probiotic products. The most commonly reported micro-encapsulation procedure is based on the calcium-alginate gel capsule formation. Kappa-carrageenan, gellan gum, gelatin and starch are also used as excipients for the micro-encapsulation of probiotic bacteria. The currently available equipment for micro-encapsulation is not able to generate large quantities of uniform sized micro or nano capsules. There is a need to design and develop equipment that will be able to generate precise and uniform micro or nano capsules in large quantities for industrial applications. The reported food vehicles for delivery of encapsulated probiotic bacteria are yoghurt, cheese, ice cream and mayonnaise. Studies need to be done on the application of micro-encapsulation of probiotic bacteria in other food systems. The number of probiotic supplements will increase in the future. More studies, however, need to be conducted on the efficacy of micro-encapsulation to deliver probiotic bacteria and their controlled or targeted release in the gastrointestinal tract.

Alginates↗
PubMed2004

Probiotics for treating infectious diarrhoea.

BACKGROUND: Probiotics are microbial cell preparations or components of microbial cells that have a beneficial effect on the health and well being of the host. Probiotics may offer a safe intervention in acute infectious diarrhoea to reduce the duration and severity of the illness. OBJECTIVES: To assess the effects of probiotics in proven or presumed infectious diarrhoea. SEARCH STRATEGY: We searched the Cochrane Infectious Diseases Group's trials register (December 2002), the Cochrane Controlled Trials Register (The Cochrane Library Issue 4, 2002), MEDLINE (1966 to 2002), EMBASE (1988 to 2002), and reference lists from studies and reviews. We also contacted organizations and individuals working in the field, and pharmaceutical companies manufacturing probiotic agents. SELECTION CRITERIA: Randomized controlled trials comparing a specified probiotic agent with placebo or no probiotic in people with acute diarrhoea that is proven or presumed to be caused by an infectious agent. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial methodological quality and extracted data. MAIN RESULTS: Twenty-three studies met the inclusion criteria with a total of 1917 participants, mainly in countries with low overall mortality rates. Trials varied in relation to the probiotic(s) tested, dosage, methodological quality, and the diarrhoea definitions and outcomes. Probiotics reduced the risk of diarrhoea at 3 days (relative risk 0.66, 95% confidence interval 0.55 to 0.77, random effects model; 15 studies) and the mean duration of diarrhoea by 30.48 hours (95% confidence interval 18.51 to 42.46 hours, random effects model, 12 studies). Subgroup analysis by probiotic(s) tested, rotavirus diarrhoea, national mortality rates, and age of participants did not fully account for the heterogeneity. REVIEWERS' CONCLUSIONS: Probiotics appear to be a useful adjunct to rehydration therapy in treating acute, infectious diarrhoea in adults and children. More research is needed to inform the use of particular probiotic regimens in specific patient groups.

Adult↗