Probiotics

Intrinsic and inducible resistance to hydrogen peroxide in Bifidobacterium species

Interest in, and use of, bifidobacteria as a probiotic delivered in functional foods has increased dramatically in recent years. As a result of their anaerobic nature, oxidative stress can pose a major challenge to maintaining viability of bifidobacteria during functional food storage. To better understand the oxidative stress response in two industrially important bifidobacteria species, we examined the response of three strains of B. longum and three strains of B. animalis subsp. lactis to hydrogen peroxide (H₂O₂). Each strain was exposed to a range of H₂O₂ concentrations (0-10 mM) to evaluate and compare intrinsic resistance to H₂O₂. Next, strains were tested for the presence of an inducible oxidative stress response by exposure to a sublethal H₂O₂ concentration for 20 or 60 min followed by challenge at a lethal H₂O₂ concentration. Results showed B. longum subsp. infantis ATCC 15697 had the highest level of intrinsic H₂O₂ resistance of all strains tested and B. animalis subsp. lactis BL-04 had the highest resistance among B. lactis strains. Inducible H₂O₂ resistance was detected in four strains, B. longum NCC2705, B. longum D2957, B. lactis RH-1, and B. lactis BL-04. Other strains showed either no difference or increased sensitivity to H₂O₂ after induction treatments. These data indicate that intrinsic and inducible resistance to hydrogen peroxide is strain specific in B. longum and B. lactis and suggest that for some strains, sublethal H₂O₂ treatments might help increase cell resistance to oxidative damage during production and storage of probiotic-containing foods.

Preventive effect of probiotics and α-tocopherol on ethanol-induced gastric mucosal injury in rats

The protective effect of a probiotic mixture of 13 different bacteria and α-tocopherol on 98% ethanol-induced gastric mucosal injury was evaluated. Levels of gastric mucosal pro- and anti-inflammatory cytokines, malondialdehyde, and secretory immunglobulin A were measured. Rats were allocated into four groups: control, ethanol, probiotic, and α-tocopherol. The control and ethanol groups received skim milk for 14 days. Probiotic and α-tocopherol groups were administered probiotic mixture suspended in skim milk and 100 mg/kg α-tocopherol, respectively, by daily gavage for 14 days. On Day 15, gastric lesions were induced by administration of ethanol 98% (1 mL) to all rats except those in the control group. Probiotic, but not α-tocopherol, seemed to inhibit ethanol-induced gastric mucosal tumor necrosis factor-α, interferon-γ, and interleukin-2 production (P > .05). Ethanol caused the elevation of mucosal interleukin-4 level (compared to the control, P < .05). Probiotic pretreatment significantly suppressed the ethanol-induced increase of gastric mucosal interleukin-4 levels. Pretreatment with either probiotic or α-tocopherol inhibited the ethanol-induced increase of mucosal malondialdehyde concentration (P < .01 and P < .05, respectively). Probiotic pretreatment enhanced the gastric mucosal secretory immunoglobulin A concentration (P < .001). In conclusion, probiotic mixture and α-tocopherol reduced ethanol-induced gastric mucosal lipid peroxidation, suggesting that they may be beneficial for gastric lesions induced by lower ethanol concentration.

Role of natural killer and dendritic cell crosstalk in immunomodulation by commensal bacteria probiotics

A cooperative dialogue between natural killer (NK) cells and dendritic cells (DCs) has been elucidated in the last years. They help each other to acquire their complete functions, both in the periphery and in the secondary lymphoid organs. Thus, NK cells' activation by dendritic cells allows the killing of transformed or infected cells in the periphery but may also be important for the generation of adaptive immunity. Indeed, it has been shown that NK cells may play a key role in polarizing a Th1 response upon interaction with DCs exposed to microbial products. This regulatory role of DC/NK cross-talk is of particular importance at mucosal surfaces such as the intestine, where the immune system exists in intimate association with commensal bacteria such as lactic acid bacteria (LAB). We here review NK/DC interactions in the presence of gut-derived commensal bacteria and their role in bacterial strain-dependent immunomodulatory effects. We particularly aim to highlight the ability of distinct species of commensal bacterial probiotics to differently affect the outcome of DC/NK cross-talk and consequently to differently influence the polarization of the adaptive immune response.

Administration of probiotics reduces bacterial translocation after intestinal transplantation in rats

Bacterial translocation (BT) has been suggested to be responsible for the high incidence of infections after intestinal transplantation (IT). The purpose of this study was to examine whether a probiotic supplement after orthotopic IT ameliorated ischemia-reperfusion injury and reduced BT at 4 or 6 days postoperative (sham or IT), as mesenteric lymph nodes (MLNs), liver, and splenic tissue samples from the six groups were assessed for BT by bacterial culture, measurement of tumor necrosis factor-α (TNF-α) in MLNs by competitive reverse transcription-polymerase chain reaction, and histological evaluation by Park's classification. Oral administration of probiotics after IT did not improve short-term survival rates compared with the transplant-only groups (P > .05). However, the BT rates and levels of TNF-α in MLNs in groups with IT only were higher than the probiotic cohorts (P < .05). Histological injuries were significantly ameliorated in the group with six days of probiotic treatment compared with that in the nontreated hosts (P < .05). These data indicated that administration of probiotics after IT improved graft histology and reduced BT in rats.

Role of probiotics in management of diverticular disease

Patients with diverticular disease may experience a variety of chronic symptoms, including abdominal discomfort, bloating, and altered bowel habit. They are also at risk of complications, including hemorrhage, diverticulitis, abscess, and fistula formation. The potential role of abnormal colonic microflora in the pathogenesis of diverticular inflammation has led to investigation of novel therapies such as probiotics. Probiotics are microorganisms that may be of net benefit to humans when consumed. The rationale and safety of their use in diverticular disease is discussed and current literature is reviewed.

Study of the relationship between changes in lactic acid bacterial cell components and stimulation of IL-12 production under salt-stressed conditions

One hundred and seventeen strains of plant origin lactic acid bacteria were observed to have interleukin (IL)-12 production-inducing activities using mouse peritoneal macrophages. Pediococcus pentosaceus (KKM122) was chosen for its stable and strong IL-12 production-inducing activity. There was no significant difference in IL-12 activity induced by the KKM122 strain grown in culture conditions of 0% and 6% NaCl. The cell wall components of cells grown in 6% salt condition, however, significantly induced lower IL-12 production as compared with those of cells grown in 0% salt condition. Cell wall components enhanced IL-12 activity by removing cytoplasmic components when KKM122 strain was cultured in 0% salt condition. The immunoenhancing factor was mainly present in the cell wall components. IL-12 production-inducing activities were dependent on both the amount of bacterial cytoplasmic components and the structure of the cell wall components under the NaCl concentration in the culture medium.

Oral administration of Lactobacillus salivarius inhibits the allergic airway response in mice

Asthma is recognized throughout the world as a chronic airway inflammatory disease. In this study, we investigated the effect of probiotics in response to antigen challenge in an ovalbumin (OVA)-sensitized asthma model in BALB/c mice. Lactobacillus salivarius PM-A0006 was orally administered to mice before antigen challenge. After antigen challenge, serum OVA-specific antibody levels, airway responsiveness to methacholine, influx of inflammatory cells to the lung, and cytokine levels in bronchoalveolar lavage (BAL) fluid and splenocytes were assessed. Oral treatment with live L. salivarius PM-A0006 significantly attenuated the influx of eosinophils to the airway lumen and reduced the levels of serum OVA-specific IgE and eotaxin in BAL fluid of antigen-challenged animals. Furthermore, L. salivarius PM-A0006 also decreased allergen-induced airway hyperresponsiveness and elevated the levels of IFN-gamma. These results showed that oral treatment with L. salivarius PM-A0006 could have therapeutic potential in the treatment of allergic airway disease.

Effects of Lactobacillus acidophilus NCFM on insulin sensitivity and the systemic inflammatory response in human subjects

According to animal studies, intake of probiotic bacteria may improve glucose homeostasis. We hypothesised that probiotic bacteria improve insulin sensitivity by attenuating systemic inflammation. Therefore, the effects of oral supplementation with the probiotic bacterium Lactobacillus acidophilus NCFM on insulin sensitivity and the inflammatory response were investigated in subjects with normal or impaired insulin sensitivity. In a double-blinded, randomised fashion, forty-five males with type 2 diabetes, impaired or normal glucose tolerance were enrolled and allocated to a 4-week treatment course with either L. acidophilus NCFM or placebo. L. acidophilus was detected in stool samples by denaturating gradient gel electrophoresis and real-time PCR. Separated by the 4-week intervention period, two hyperinsulinaemic-euglycaemic clamps were performed to estimate insulin sensitivity. Furthermore, the systemic inflammatory response was evaluated by subjecting the participants to Escherichia coli lipopolysaccharide injection (0·3 ng/kg) before and after the treatment course. L. acidophilus NCFM was detected in 75 % of the faecal samples after treatment with the probiotic bacterium. Insulin sensitivity was preserved among volunteers in the L. acidophilus NCFM group, whereas it decreased in the placebo group. Both baseline inflammatory markers and the systemic inflammatory response were, however, unaffected by the intervention. In conclusion, intake of L. acidophilus NCFM for 4 weeks preserved insulin sensitivity compared with placebo, but did not affect the systemic inflammatory response.

Evaluation of the intestinal colonization by microencapsulated probiotic bacteria in comparison with the same uncoated strains

BACKGROUND

Beneficial findings concerning probiotics are increasing day by day. However, one of the most important parameter which affects the probiotic activity of a microorganism is its survival during the gastroduodenal transit. Some microencapsulation techniques could be applied to bacterial cells to improve this parameter.

METHODS

A comparison between the intestinal colonization by microencapsulated bacteria and the same not microencapsulated strains has been conducted in a double blind, randomized, cross-over study. The study (April to July 2005) involved 44 healthy volunteers. In particular, participants were divided into 2 groups: group A (21 participants) received a mix of probiotic strains Lactobacillus plantarum LP01 (LMG P-21021) and Bifidobacterium breve BR03 (DSM 16604) in an uncoated form, group B (23 participants) was given the same strains microencapsulated with a gastroresistant material. The not microencapsulated strains were administered at 5 x 10(9) colony forming units/strain/d for 21 days, whereas the microencapsulated bacteria were given at 1 x 10(9) colony forming units/strain/d for 21 days. At the end of the first period of treatment with probiotics a 3 weeks washout phase has been included in the study protocol. At the end of the washout period the groups were crossed: in detail, group A had the microencapsulated and group B the uncoated bacteria. The administered amounts of each strain were the same as the first treatment. The quantitative evaluation of intestinal colonization by strains microencapsulated or not microencapsulated was made by fecal samples examination at the beginning of the clinical trial, after 10 and 21 days of each treatment period. In particular, fecal heterofermentative Lactobacilli and Bifidobacteria have been counted.

RESULTS

A statistically significant increase in the fecal amounts of Lactobacilli and Bifidobacteria was recorded in both groups at the end of each treatment compared with d0 or d42 (P<0.0001 and P<0.0001 at d21, P<0.0001 and P<0.0001 at d63 for Lactobacilli and Bifidobacteria, respectively), confirming the ability of the 2 strains to colonize the human gut, either in a gastroprotected form or not. Participants treated with the microencapsulated bacteria reported a kinetics of intestinal colonization quite similar to participants who received not coated strains.

CONCLUSIONS

Probiotics are able to exert many different beneficial effects on the human host. These effects are mediated by the number of viable cells which reach the gut. The microencapsulation technique used in this study is a valid strategy to significantly improve gastroresistance of strains, thus enhancing their probiotic activity and allowing the use of a 5 times lower amount.

Lactobacillus plantarum prevents the upregulation of adhesion molecule expression in an experimental colitis model

BACKGROUND

Lactobacillus consumption has been shown to attenuate the severity of experimental colitis. Whether the effects of Lactobacillus on colitis are related to modulation of leukocyte recruitment into the inflamed intestine is unclear.

AIMS

To investigate the effect of Lactobacillus plantarum daily intragastric administration on lymphocyte homing and intestinal inflammation in interleukin 10 (IL-10) knockout mice, an experimental model of colitis.

METHODS

Two groups of ten IL-10 knockout mice were fed phosphate buffered saline containing Lactobacillus plantarum 1258 or unmodified vehicle for 4 weeks. Two groups of ten wild-type mice were used as controls. At killing, the bowels were histologically scored and evaluated by transmission electron microscopy. Mucosal addressin cell adhesion molecule 1 (MAdCAM-1) and intercellular adhesion molecule 1 (ICAM-1) expression were determined by immunohistochemistry. The levels of proinflammatory cytokines, tumor necrosis factor alpha (TNF-alpha), and interferon gamma (IFN-gamma) were determined by ELISA. In addition, levels of CD3, alpha4beta7, ICAM-1, and MAdCAM-1 were determined by reverse-transcription polymerase chain reaction and Western blot.

RESULTS

L. plantarum treatment improved the histological damage score in KO mice compared to untreated KO mice. L. plantarum significantly attenuated the expression of MAdCAM-1, ICAM-1, CD3, and alpha4beta7, but did not affect the levels of TNF-alpha and IFN-gamma when treated KO mice were compared to untreated KO mice.

CONCLUSIONS

L. plantarum interfered with the upregulation of adhesion molecules observed in IL-10 knockout mice compared to wild-type mice, attenuating the symptoms of colitis.

Durable alteration of the colonic microbiota by the administration of donor fecal flora

GOALS

To determine whether fecal bacteriotherapy results in a durable beneficial change in the colonic microbiota of patients with flora-related disorders.

BACKGROUND

Earlier studies have implicated the colonic microbiota in a number of conditions. Administration of a fecal suspension from a healthy individual to an ill individual (fecal bacteriotherapy) can cure Clostridium difficile infection and potentially other diseases. Oral probiotics do not work in this condition, yet there has been no study to determine whether fecal bacteriotherapy results in prolonged implantation.

STUDY

Fecal samples were collected from 10 patients undergoing fecal bacteriotherapy. Patients completed an antibiotic schedule and bowel lavage before the infusion of healthy donor feces. Using a molecular approach, the bacterial populations in patient fecal samples were followed from pretreatment to 24 weeks post-initial infusion and compared with the initial infused donor fecal suspension.

RESULTS

At intervals of 4, 8, and 24 weeks after the procedure, the bacterial populations in the patients' fecal samples consisted predominantly of bacteria derived from the healthy donor samples. Comparisons of similarity at 4, 8, and 24 week samples to the donor-infused sample were made and each recipient's baseline sample was statistically significant with Friedman test.

CONCLUSIONS

This study demonstrates a durable beneficial change in the patients' bacterial populations of the colon to represent those of the healthy donor's microbiota. Manipulation of the colonic microbiota to improve its protective and beneficial role represents a promising field of new therapeutic strategies for the treatment of gastrointestinal conditions.

The use of probiotics in healthy volunteers with evacuation disorders and hard stools: a double-blind, randomized, placebo-controlled study

BACKGROUND

Evacuation disorders and hard stools are common in industrialized countries, affecting on average 12% to 17% of the adult healthy population at any age. Dietary supplementation with probiotic microorganisms may be useful in reducing the disorder.

METHODS

We performed a double-blind, randomized, placebo-controlled study to evaluate the effectiveness of 2 different probiotic blends, either mixed Lactobacillus plantarum LP01 (LMG P-21021) and Bifidobacterium breve BR03 (DSM 16604) or Bifidobacterium animalis subspecies lactis BS01 (LMG P-21384), in the management of evacuation disorders and intestinal discomfort. In a period of 5 years (2003 to 2008), the study involved 300 healthy volunteers (151 males and 149 females; age 24 to 71 y) with evacuation disorders and hard stools. In particular, subjects were divided into 3 groups: 80 subjects in the group A received placebo, 110 subjects in the group B received mixed L. plantarum LP01 and B. breve BR03 (2.5 x 10 colony-forming units/d of each strain), and 110 subjects in the group C received B. animalis subsp. lactis BS01 (5 x 10 colony-forming units/d) for 30 days. At the beginning of the observational study, the healthy status of volunteers was evaluated by a complete, laboratory and ultrasound study of the abdomen. The physical examination was repeated after 15 and 30 days. In particular, the main troubles typically associated with evacuation disorders and hard stools as well as abdominal bloating were considered as parameters of interest. Exclusion criteria were items of gastrointestinal diseases and antibiotics intake.

RESULTS

Subjects treated with the mixed probiotic strains L. plantarum LP01 and B. breve BR03 or B. animalis subsp. lactis BS01 reported a significant improvement in the number of weekly bowel movements and in the main troubles associated with evacuations, particularly consistency of feces and ease of expulsion. Discomfort items such as abdominal bloating and anal itching, burning, or pain also registered a relevant improvement in the active groups receiving probiotics.

CONCLUSIONS

The intake of an effective amount of mixed L. plantarum LP01 and B. breve BR03 or B. animalis subsp. lactis BS01 for 30 days is able to significantly relieve the evacuation disorders and hard stools, thus providing a useful tool for the management of such condition, which is particularly widespread in industrialized countries at any age.

Lactic acid bacteria efficiently protect human and animal intestinal epithelial and immune cells from enteric virus infection

This study aimed to examine the potential antiviral activity of lactic acid bacteria (LAB) using animal and human intestinal and macrophage cell line models of non tumor origin. To this end, LAB strains selected on the basis of previous in vitro trials were co-incubated with cell line monolayers, which were subsequently challenged with rotavirus (RV) and transmissible gastroenteritis virus (TGEV). In order to elucidate the possible mechanism responsible for the antiviral activity, the induction of reactive oxygen species (ROS) release as well as the attachment ability of LAB on the cell lines was investigated. Various strains were found to exhibit moderate to complete monolayer protection against viral RV or TGEV disruption. Highest protection effects were recorded with the known probiotics Lactobacillus rhamnosus GG and Lactobacillus casei Shirota against both RV and TGEV, while notable antiviral activity was also attributed to Enterococcus faecium PCK38, Lactobacillus fermentum ACA-DC179, Lactobacillus pentosus PCA227 and Lactobacillus plantarum PCA236 and PCS22, depending on the cell line and virus combination used. A variable increase (of up to 50%) on the release of NO(-) and H(2)O(2) (ROS) was obtained when LAB strains were co-incubated with the cell lines, but the results were found to be LAB strain and cell line specific, apart from a small number of strains which were able to induce strong ROS release in more than one cell line. In contrast, the ability of the examined LAB strains to attach to the cell line monolayers was LAB strain but not cell line specific. Highest attachment ability was observed with L. plantarum ACA-DC 146, L. paracasei subsp. tolerans ACA-DC 4037 and E. faecium PCD71. Clear indications on the nature of the antiviral effect were evident only in the case of the L. casei Shirota against TGEV and with L. plantarum PCA236 against both RV and TGEV. In the rest of the cases, each interaction was LAB-cell line-virus specific, barring general conclusions. However, it is probable that more than one mechanism is involved in the antiviral effect described here. Further investigations are required to elucidate the underlying mode of action and to develop a cell line model as a system for selection of probiotic strains suited for farm animal applications.

Lactobacillus plantarum DSM 2648 is a potential probiotic that enhances intestinal barrier function

The aim of this research was to identify bacterial isolates having the potential to improve intestinal barrier function. Lactobacillus plantarum strains and human oral isolates were screened for their ability to enhance tight junction integrity as measured by the transepithelial electrical resistance (TEER) assay. Eight commercially used probiotics were compared to determine which had the greatest positive effect on TEER, and the best-performing probiotic strain, Lactobacillus rhamnosus HN001, was used as a benchmark to evaluate the isolates. One isolate, L. plantarum DSM 2648, was selected for further study because it increased TEER 135% more than L. rhamnosus HN001. The ability of L. plantarum DSM 2648 to tolerate gastrointestinal conditions and adhere to intestinal cells was determined, and L. plantarum DSM 2648 performed better than L. rhamnosus HN001 in all the assays. Lactobacillus plantarum DSM 2648 was able to reduce the negative effect of Escherichia coli [enteropathogenic E. coli (EPEC)] O127:H6 (E2348/69) on TEER and adherence by as much as 98.75% and 80.18%, respectively, during simultaneous or prior coculture compared with EPEC incubation alone. As yet, the precise mechanism associated with the positive effects exerted by L. plantarum DSM 2648 are unknown, and may influence its use to improve human health and wellness.

The role of functional foods, nutraceuticals, and food supplements in intestinal health

New eating habits, actual trends in production and consumption have a health, environmental and social impact. The European Union is fighting diseases characteristic of a modern age, such as obesity, osteoporosis, cancer, diabetes, allergies and dental problems. Developed countries are also faced with problems relating to aging populations, high energy foods, and unbalanced diets. The potential of nutraceuticals/functional foods/food supplements in mitigating health problems, especially in the gastrointestinal (GI) tract, is discussed. Certain members of gut microflora (e.g., probiotic/protective strains) play a role in the host health due to its involvement in nutritional, immunologic and physiological functions. The potential mechanisms by which nutraceuticals/functional foods/food supplements may alter a host's health are also highlighted in this paper. The establishment of novel functional cell models of the GI and analytical tools that allow tests in controlled experiments are highly desired for gut research.

Probiotic properties of Lactobacillus salivarius and closely related Lactobacillus species

Lactobacillus salivarius has been frequently isolated from the mammalian digestive tract and has been studied as a candidate probiotic. Research to date has described the immunomodulatory properties of the species in cell-lines, mice, rats and humans for the alleviation of intestinal disease and the promotion of host well-being. The ability of L. salivarius to inhibit pathogens and tolerate host antimicrobial defenses demonstrates the adaptation of this species to the gastrointestinal niche. L. salivarius is the best characterized of 25 species in the L. salivarius clade of the genus Lactobacillus. Several other species of this clade are candidate probiotics; however, their probiotic potential has not yet been exploited. This review summarizes the research defining the probiotic nature of L. salivarius, by focusing in particular on L. salivarius UCC118 as a representative strain. The emergent research detailing the probiotic potential of other species in this phylogenetic clade will also be discussed.

Bifidobacterium septicemia associated with postoperative probiotic therapy in a neonate with omphalocele

We report the one case of sepsis caused by Bifidobacterium breve administered as probiotic therapy. Probiotics can be a potential cause of an invasive disease and should be used with care in vulnerable patients.

[An evidence based Iberic-Latin American guideline for acute gastroenteritis management in infants and prescholars]

Acute gastroenteritis (AG) morbidity and mortality rates in infants and prescholars continue to be high in developing countries. Authors want to develop an evidence-based document that supports decision making regarding AG therapy in infants and children younger than 5 y/o. A systematic review of the literature was performed (May, 2008). Evidence grading was established according to Oxford guidelines and Latin American experts submitted their opinions on the recommendations generated. Oral rehydration solutions are the threatment's keystone for children with AG, showing lesser complications due to therapy than IV fluids. AG is no contraindication of a normal diet. Racecadotril, zinc and smectite can contribute to AG treatment, as well as Lactobacillus GG and Saccharomycces boulardii. No other drugs are recommended. It is recommended to treat children presenting AG with oral rehydration solutions among racecadotril, zinc or smectite as well as some probiotics.

Balsalazide in treating colonic diseases

Balsalazide is the newer 5-aminosalicylic acid (5-ASA) prodrug which releases active 5-ASA only into the colon with minimal systemic absorption. The onset of action of this drug is variable, and it may take at least some days to reach clinical effectiveness. Clinical studies found balsalazide faster than mesalazine in the induction of remission, but balsalazide has no benefit compared with mesalazine in preventing relapse in the population selected. However, the high number of pills to take may affect the adherence to the treatment. This 5-ASA prodrug may be effectively used also in patients unable to tolerate other mesalamine compounds for non-hypersensitivity reasons. The costs of balsalazide capsules seem to be lower for the health system, both considering total direct healthcare costs and better outcomes, compared with patients treated with oral mesalazine. Finally, there is also some recent evidence that balsalazide may be effectively used, in combination with probiotics, in treating acute uncomplicated diverticulitis is the colon.

Diverticular disease: A therapeutic overview

Formation of colonic diverticula, via herniation of the colonic wall, is responsible for the development of diverticulosis. When diverticulosis becomes symptomatic, it becomes diverticular disease. Diverticular disease is common in Western and industrialized countries, and it is associated with numerous abdominal symptoms (including pain, bloating, nausea, diarrhea, and constipation). Standard medical therapies with antibiotics are currently recommended for patients affected by diverticular disease. However, changing concepts on the pathophysiology of the disease suggest that diverticular disease may share many of the hallmarks of inflammatory bowel diseases. On this basis, the addition of therapies using mesalazine and probiotics may enhance treatment efficacy by shortening the course of the disease and preventing recurrences.

Screening of the equine intestinal microflora for potential probiotic organisms

REASONS FOR PERFORMING STUDY

Probiotics have not been demonstrated to provide any beneficial health effects in horses, possibly because of improper selection of probiotic organisms. This study was designed to identify lactic acid bacteria of equine origin with predetermined beneficial properties which might make them useful as therapeutic probiotics.

HYPOTHESIS

A small percentage of lactic acid bacteria that are native to the intestinal tract of horses possess properties that may be useful in the treatment and/or prevention of gastrointestinal disease in horses.

METHODS

Faecal samples were collected from healthy mature horses and foals. Lactic acid bacteria were isolated and tested for the ability to grow in acid and bile environments, aerotolerance and in vitro inhibition of enteropathogens. One isolate that possessed these properties was administered orally to healthy mature horses and foals and gastrointestinal survival was assessed.

RESULTS

Of the 47 tested organisms, 18 were deemed to be adequately acid- and bile-tolerant. All were aerotolerant. Four organisms markedly inhibited Salmonella spp. One isolate, Lactobacillus pentosus WE7, was subjectively superior and chosen for further study. It was also inhibitory against E. coli, moderately inhibitory against S. zooepidemicus and C. difficile and mildly inhibitory against C. perfringens. After oral administration, this isolate was recovered from the faeces of 8/9 (89%) foals and 7/8 (87.5%) mature horses.

CONCLUSIONS

Lactobacillus pentosus WE7 possesses in vitro and in vivo properties that may be useful for the prevention and treatment of enteric disease in horses.

POTENTIAL RELEVANCE

The beneficial in vitro and in vivo properties that L. pentosus WE7 possesses indicate that randomised, blinded, placebo-controlled efficacy studies are warranted.

Bacillus polyfermenticus ameliorates colonic inflammation by promoting cytoprotective effects in colitic mice

Although human consumption of Bacillus polyfermenticus provides several health benefits, the probiotic effect of this bacterium against colonic inflammation has not yet, to our knowledge, been studied. Therefore, we induced colitis in mice by oral or intrarectal administration of dextran sodium sulfate (DSS) or trinitrobenzenosulfonic acid (TNBS), respectively, and investigated the effect of B. polyfermenticus on colitis. We found that mice treated with DSS or TNBS along with B. polyfermenticus had reduced mortality and severity of colitis (weight loss, diarrhea, and mucosal damages) than mice treated with DSS or TNBS alone. B. polyfermenticus also reduced the expression of inflammatory molecules, including chemokine (C-X-C motif) ligand 1, intercellular adhesion molecule, and tumor necrosis factor-alpha, but enhanced the expression of the antiinflammatory cytokine interleukin-10 in the inflamed mouse colon. Moreover, B. polyfermenticus suppressed apoptosis both in vivo in inflamed colonic mucosa and in vitro in colonic epithelial cells stimulated with apoptosis-inducing agents (FasL or Clostridium difficile Toxin A) when the apoptotic response was determined by a terminal deoxynucleotidyl transferase dUTP nick end labeling assay and cleavage of poly(ADP-ribose) polymerase or caspase-3, respectively. Treating colonic epithelial cells with B. polyfermenticus-conditioned medium (BPCM) enhanced cell proliferation and induced the phosphoinositide 3-kinases/Akt signaling pathway, suggesting that this bacterium can promote epithelial cell proliferation. BPCM also promoted the migration of colonic epithelial cells. These data suggest that B. polyfermenticus ameliorates colonic inflammation by suppressing apoptosis and promoting epithelial cell proliferation and migration.

Review article: the current and evolving treatment of colonic diverticular disease

BACKGROUND

Formation of colonic diverticula, via herniation of the colonic wall, is responsible for the development of diverticulosis and consequently diverticular disease. Diverticular disease can be associated with numerous debilitating abdominal and gastrointestinal symptoms (including pain, bloating, nausea, constipation and diarrhoea).

AIMS

To review the state of treatment for diverticular disease and its complications, and briefly discuss potential future therapies.

METHODS

PubMed and recent conference abstracts were searched for articles describing the treatment of diverticular disease.

RESULTS

Many physicians will recommend alterations to lifestyle and increasing fibre consumption. Empirical antibiotics remain the mainstay of therapy for patients with diverticular disease and rifaximin seems to be the best choice. In severe or relapsing disease, surgical intervention is often the only remaining treatment option. Although novel treatment options are yet to become available, the addition of therapies based on mesalazine (mesalamine) and probiotics may enhance treatment efficacy.

CONCLUSIONS

Data suggest that diverticular disease may share many of the hallmarks of other, better-characterized inflammatory bowel diseases; however, treatment options for patients with diverticular disease are scarce, revolving around antibiotic treatment and surgery. There is a need for a better understanding of the fundamental mechanisms of diverticular disease to design treatment regimens accordingly.

Effects of the enteral administration of Bifidobacterium breve on patients undergoing chemotherapy for pediatric malignancies

PURPOSE

Probiotics are expected to be effective in prophylaxis of infection in cancer patient, since infections in neutropenics are mainly caused by endogenous flora through the intestinal mucosa. However, the experience with the use of probiotics in immunocompromised patients is limited, and precise fecal bacteria analysis has not been reported. The aim of the study was to evaluate the effects of the enteral administration of the probiotic, Bifidobacterium breve strain Yakult, on its ability to prevent infection, fecal micro flora, and intestinal environments in cancer patients on chemotherapy.

METHODS

A placebo-controlled trial was performed at Juntendo University Hospital. Patients with malignancies admitted for chemotherapy (n = 42) were randomized into two groups receiving probiotic or placebo. The effects on infectious complications, natural killer cells, fecal micro flora, fecal organic acid concentrations, and fecal pH were studied.

RESULTS

The frequency of fever and the use of intravenous antibiotics were lower in the probiotic group than the placebo group. The probiotic administration enhanced the habitation of anaerobes. Disruption of the intestinal microbiota after chemotherapy such as the increase in the population levels of Enterobacteriaceae was observed at more pronounced manner in the placebo group in comparison to the probiotic group. The concentrations of total organic acids were maintained most of the time at the normal level, which constantly maintained the pH below 7.0 only in the probiotic group.

CONCLUSION

These data, although based on a limited number of patients and samples, suggest that administration of B. breve strain Yakult could be an effective approach for achieving clinical benefits in immunocompromised hosts by improving their intestinal environments.

Effects of probiotics for the prevention and treatment of radiation-induced diarrhea

BACKGROUND AND AIMS

Probiotic supplementation seems to provide beneficial effects in the prevention and treatment of radiation-induced diarrhea. We performed a systematic review and meta-analysis to estimate the efficacy of probiotic supplementation for prevention and treatment of radiation-induced diarrhea.

METHODS

Two reviewers independently searched PubMed, EMBASE, Cochrane Library, Google Scholar and on-line clinical trials registers (up to January 2009) for randomized controlled trials that evaluated the efficacy of probiotic supplementation for the prevention and treatment of radiation-induced diarrhea. Each clinical trial was separately evaluated for study characteristics, methodologic quality and outcomes. Results of the randomized controlled trials were pooled in a meta-analysis.

RESULTS

Four randomized controlled trials were included. Three clinical trials, with a total of 632 subjects, evaluated the preventive effects of probiotic supplementation and 1 study evaluated the therapeutic role. Random effects meta-analysis of the preventive trials did not show significant differences between probiotic supplementation and control groups (odds ratio 0.47; 95% confidence interval: 0.13-1.67). However, the few available trials and the presence of significant clinical and statistical heterogeneity limited the analysis. Similarly, the therapeutic clinical trial did not show significant differences between active and placebo groups. No major adverse events owing to probiotic supplementation were reported in any study.

CONCLUSIONS

Probiotic supplementation showed beneficial effect in the prevention and treatment of radiation-induced diarrhea in experimental animal studies. Encouraging results have been observed in humans; however, the few available clinical studies do not allow firm conclusions. More well-performed, randomized placebo-controlled studies are needed.