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PubMed2002

Effect of probiotic Lactobacillus strains in young children hospitalized with acute diarrhea.

BACKGROUND: Oral bacteriotherapy promotes recovery from acute childhood diarrhea, but few strains have been shown to have therapeutic potentials. We examined the effect of two newly identified probiotic Lactobacillus strains in acute childhood diarrhea. METHODS: Sixty-nine children were randomized during hospitalization for acute diarrhea to receive a mixture of Lactobacillus rhamnosus 19070-2 and Lactobacillus reuteri DSM 12246, 10(10) colony-forming units of each strain or placebo twice daily for 5 days. Before selection of these stains their potential probiotic characteristics were demonstrated in vitro and in healthy volunteers. RESULTS: In patients receiving probiotics, the diarrheal phase was reduced by 20%. The duration of diarrhea was 82 h in the treatment group vs. 101 h in the control group (not significant, P = 0.07). However, 3 of 30 patients from the treatment group vs. 13 of 39 from the control group still had loose stools at the end of the study period (P = 0.03). In patients with diarrhea for <60 h before start of treatment (early intervention), a clear effect of the probiotics was demonstrated (80 h in the treatment group vs. 130 h in the control group, P = 0.003). After early intervention, the length of hospitalization was reduced by 48% (3.5 vs. 1.7 days, P = 0.03). At the end of the intervention, rotavirus antigen was found in 12% of patients from the treatment group vs. 46% from the control group (P = 0.02). CONCLUSIONS: The two probiotics, L. rhamnosus 19070-2 and L. reuteri DSM 12246, ameliorated acute diarrhea in hospitalized children and reduced the period of rotavirus excretion. Oral bacteriotherapy was associated with a reduced length of hospital stay. The beneficial effects were most prominent in children treated early in the diarrheal phase.

Acute Disease↗

PubMed2002

Variable response to probiotics in two models of experimental colitis in rats.

BACKGROUND AND AIM: Clinical and experimental data suggest an important role for intestinal microflora in the pathogenesis of inflammatory bowel disease, and probiotics have been shown to ameliorate pouchitis. We evaluated the effect of different preparations of probiotic bacteria on experimental colitis in rats. METHODS: Rats were treated daily intragastrically with two probiotic preparations, VSL#3 or strain GG (LGG), 7 days before induction of colitis and for another week thereafter. Colitis was induced by intracolonic administration of either dinitrobenzene sulfonic acid (DNBS) or iodoacetamide. Rats were killed 7 days after induction of colitis, the colon isolated, washed, weighed, lesion area measured, and mucosa processed for determination of myeloperoxidase (MPO) and nitric oxide synthase (NOS) activities and prostaglandin E2 (PGE2) generation. RESULTS: In rats cotreated with VSL#3 or LGG and iodoacetamide, there was a significant decrease in the lesion area, 98 +/- 37 mm and 142 +/- 43 mm, respectively, as compared with 342 +/- 66 mm in the control group. Colonic wet weight significantly decreased to 1.3 +/- 0.1 g/10 cm and 1.4 +/- 0.1 g/10 cm, respectively, as compared with 1.7 +/- 0.1 g/10 cm. There was also a significant decrease in PGE2 generation, MPO, and NOS activities in the VSL#3 and LGG treatment groups. Presence of VSL#3 bacteria in the rat's colon was confirmed by culture and polymerase chain reaction (PCR) amplification. Neither probiotic preparation had an effect on the extent of colonic damage in DNBS-induced colitis. CONCLUSION: Both VSL#3 and LGG significantly ameliorated colitis induced by the sulfhydryl-blocker iodoacetamide, but had no effect on the immune-mediated DNBS-induced colitis. The results suggest a possible role for sulfhydryl compounds in the protective effect of probiotic bacteria, and support their use in patients with inflammatory bowel disease.

Alkylating Agents↗

PubMed2006

Probiotics and their use in diverticulitis.

Probiotics are live microorganisms that when ingested affect the intestinal microbial flora and benefit the health of the host. Probiotics have been shown to have a positive effect on various gastrointestinal and other conditions; however, the beneficial effect of probiotics on treating diverticulitis and diverticular disease has not yet been clearly demonstrated. In this paper, the theoretical framework for using probiotics to prevent or treat diverticular disease is reviewed, and two preliminary studies on the use of probiotics for maintenance of remission of uncomplicated diverticular disease are briefly summarized.

Disease Progression↗

PubMed2006

Probiotic treatment of collagenous colitis: a randomized, double-blind, placebo-controlled trial with Lactobacillus acidophilus and Bifidobacterium animalis subsp. Lactis.

BACKGROUND: Probiotic treatment may be effective in diseases involving gut microflora and intestinal inflammation. In collagenous colitis (CC), a potential pathogenic role of the gut microflora has been proposed. The effect of probiotic treatment in CC is unknown. Our aim was to investigate the clinical effect of treatment with Lactobacillus acidophilus LA-5 and Bifidobacterium animalis subsp. lactis BB-12 (AB-Cap-10) in patients with CC. MATERIALS AND METHODS: Patients with CC and diarrhea were in a double-blind placebo-controlled study randomized (2:1) to AB-Cap-10 or placebo for 12 weeks. The primary end point was reduction in bowel frequency per week of >or=50%. Secondary end points were changes in bowel frequencies, stool consistency, stool weight, histopathology, and abdominal bloating and pain. RESULTS: Twenty-nine patients were randomized: 21 to probiotics and 8 to placebo. Reduction in bowel frequency per week of >or=50% occurred in 6 of 21 (29%) and in 1 of 8 (13%) patients receiving probiotic and placebo, respectively (P = 0.635). No differences between treatments were observed regarding the secondary end points. Post hoc analysis showed a median reduction in bowel frequency per week from 32 (range 18-84) to 23 (range 11-56; P < 0.005), a reduction in number of days with liquid stools per week from 6 days (range 0-7 days) to 1 day (range 0-7 days; P < 0.005), and an increase in number of days with solid stools per week (P < 0.05) in the AB-Cap-10 group. CONCLUSIONS: AB-Cap-10 had no significant effect on the chosen end points. Post hoc analysis demonstrated amelioration of clinical symptoms in the AB-Cap-10 group, indicating that probiotic treatment may potentially influence the disease course of CC.

Adult↗

PubMed2005

Effects of probiotics on the gastrointestinal tract.

PURPOSE OF REVIEW: This review summarizes recent developments in our understanding of what gastrointestinal disorders probiotics can be of benefit for, focussing on conditions associated with infection or disruption of the normal gut flora. New insights into the effects administered strains can have in the gut, their safety, and potential for future development, will also be discussed. RECENT FINDINGS: Recent clinical studies have shown that probiotics can protect young children from diarrhoeal illness, including antibiotic-associated diarrhoea. They may also protect neonates from necrotizing enterocolitis. In adults, they can help prevent or reduce the severity of diarrhoeal illness, and ameliorate side-effects for those undergoing antibiotic therapy for infection. Researchers are looking at combining probiotics with prebiotics to enhance anti-inflammatory effects and restore colonization resistance of the commensal flora. New technologies are elucidating complex effects on gene expression in the gut, the probiotic, and bacterial pathogens. Recombinant strains capable of binding bacterial toxins are being developed as novel therapeutics against gastrointestinal infection. SUMMARY: Considering the clinical trial evidence of therapeutic benefit, probiotics are an underused treatment modality for prevention and amelioration of diarrhoeal illness. Better understanding of strain-specific effects, dosing regimens and any contraindications should help resolve this.

Gastrointestinal Diseases↗

PubMed2006

Probiotics and neonatal intestinal infection.

PURPOSE OF REVIEW: Necrotizing enterocolitis remains an enigmatic and potentially devastating condition with high morbidity and mortality. This review explores ways in which bacterial pathogens, together with gut microflora, influence the pathophysiology of necrotizing enterocolitis. Specifically, it examines the role of gut microbial colonization and its 'normalization' with probiotics vis a vis its contribution to intestinal bacterial invasion. RECENT FINDINGS: Recent studies have demonstrated that prophylactic administration of probiotics to preterm neonates decreases both the incidence and severity of subsequent necrotizing enterocolitis. SUMMARY: Probiotics represent a therapeutic effort to bolster natural host defenses via the 'normalization' of abnormal gut microflora of the premature infant at risk, thereby reducing the subsequent threat of necrotizing enterocolitis. The appeal of probiotics in neonatology is threefold. First, their safety record renders them an attractive alternative to many of the more aggressive therapeutic options; second, they represent a simple, noninvasive attempt to recreate a natural or normal flora rather than a disruption of nature. Third, probiotics are used mainly for disease prevention and are naturally occurring. As such, they are not considered to be drugs, but rather food supplements. To date, very few other strategies have been proven definitively to be efficacious in decreasing the incidence of necrotizing enterocolitis.

Enterocolitis, Necrotizing↗

PubMed2005

Probiotic amelioration of azotemia in 5/6th nephrectomized Sprague-Dawley rats.

The present study was to test the hypothesis that, selected bacteria instilled into the gastrointestinal tract could help in converting nitrogenous wastes accumulated due to renal insufficiency into non-toxic compounds; thereby, ameliorating the biochemical imbalance. Herein we describe a prospective, blinded, placebo controlled pilot-study, using 5/6th nephrectomized Sprague Dawley rat, as a chronic renal failure model. The study group consisted of 36 nephrectomized and 7 non-nephrectomized (control) rats. After two-week nephrectomy stabilization, cohorts of six nephrectomized rats were fed casein-based diet plus one of the following regimens: (A) Control, (B) Placebo (casein-based diet without probiotics), (C) Bacillus pasteurii, (D) Sporolac(R), (E) Kibow cocktail, (F) CHR Hansen Cocktail, and (G) ECONORM. Subsequently, blood (retro-orbital) and urine (collected for measurements of blood urea-nitrogen and creatinine respectively), body weight and bacterial counts (feces) were obtained at regular intervals. The study end-points were to determine if any of the probiotic dietary supplements facilitated, (1) decreased blood concentrations of uremic toxins, (2) altered renal function, and (3) prolonged survival. After 16 weeks of treatment, regimens C and D significantly prolonged the life span of uremic rats, in addition to showing a reduction in blood urea-nitrogen levels, concluding that supplementation of probiotic formulation to uremic rats slows the progression of azotemia, which may correlate with prolonged life span of uremic rats. Derivative trials of probiotic treatment of larger animals and humans will further assess the potential role of probiotic formulations in delaying the onset and clinical severity of clinical illness at different stages of renal failure.

Animals↗

PubMed2005

Maintenance therapy with a probiotic in antibiotic-dependent pouchitis: experience in clinical practice.

BACKGROUND: Management of antibiotic-dependent pouchitis is often challenging. Oral bacteriotherapy with probiotics (such as VSL #3) as maintenance treatment has been shown to be effective in relapsing pouchitis in European trials. However, this agent has not been studied in the US, and its applicability in routine clinical practice has not been evaluated. AIM: To determine compliance and efficacy of probiotic treatment in patients with antibiotic-dependent pouchitis. METHODS: Thirty-one patients with antibiotic-dependent pouchitis were studied. VSL #3 is a patented probiotic preparation of live freeze-dried bacteria. All patients received 2 weeks of ciprofloxacin 500 mg b.d. followed by VSL #3 6 g/day for 8 months. Baseline Pouchitis Disease Activity Index scores were calculated. Patients' symptoms were reassessed at week 3 when VSL #3 therapy was initiated and at the end of the 8-month trial. Some patients underwent repeat pouch endoscopy at the end of the trial. RESULTS: All 31 patients responded to the 2-week ciprofloxacin trial with resolution of symptoms and they were subsequently treated with VSL #3. The mean duration of follow-up was 14.5+/-5.3 months (range: 8-26 months). At the 8-month follow-up, six patients were still on VSL #3 therapy, and the remaining 25 patients had discontinued the therapy due to either recurrence of symptoms while on treatment or development of adverse effects. All six patients who completed the 8-month course with a mean treatment period of 14.3+/-7.2 months (range: 8-26 months) had repeat clinical and endoscopic evaluation as out-patients. At the end of 8 months, these six patients had a mean Pouchitis Disease Activity Index symptom score of 0.33+/-0.52 and a mean Pouchitis Disease Activity Index endoscopy score of 1.83+/-1.72, which was not statistically different from the baseline Pouchitis Disease Activity Index endoscopy score of 2.83+/-1.17 (P=0.27). CONCLUSION: This study was conducted to evaluate bacteriotherapy in routine care. The use of probiotics has been adopted as part of our routine clinical practice with only anecdotal evidence of efficacy. Our review of patient outcome from the treatment placebo showed that only a minority of patients with antibiotic-dependent pouchitis remained on the probiotic therapy and in symptomatic remission after 8 months.

Adult↗

PubMed2006

Systematic review: are probiotics useful in controlling gastric colonization by Helicobacter pylori?

Helicobacter pylori is a highly prevalent pathogen considered as an aetiological factor for gastroduodenal ulcers, and a risk factor for gastric adenocarcinoma and lymphoma in humans. Most subjects colonized by this micro-organism are asymptomatic and remain untreated. In symptomatic patients, the antibiotic treatment has a high cost and is not 100% effective because of resistance to antibiotics and to moderate patient compliance. This review discusses the role of probiotics as alternative solutions to assist in the control of H. pylori colonization in at-risk populations. The evidence that some strains of Lactobacillus and Bifidobacterium are able to inhibit H. pylori growth through the release of bacteriocins or organic acids, and may also decrease its adhesion to epithelial cells, is reviewed. In addition, probiotics have a possible role in the stabilization of the gastric barrier function and the decrease of mucosal inflammation. Other aspects that are considered are the contribution of probiotics to the healing of the gastric mucosa linked to their antioxidant and anti-inflammatory properties. Clinical trials in colonized adults and children are reviewed, and suggest that probiotics do not eradicate H. pylori but maintain lower levels of this pathogen in the stomach; in combination with antibiotics, probiotics may increase eradication rate and/or decrease adverse effects. Papers suggesting similar effects on H. pylori by foodstuffs such as berry juice and some milk proteins are quoted. Regular intake of these and other dietary products might constitute a low-cost, large-scale alternative solution applicable for populations at-risk for H. pylori colonization.

Anti-Bacterial Agents↗

PubMed2006

Is the effect of probiotics on atopic dermatitis confined to food sensitized children?

BACKGROUND: Probiotics have previously been shown to reduce the severity of atopic dermatitis (AD) in infants and children. OBJECTIVE: To examine the effect of two probiotics (Lactobacillus rhamnosus and Bifidobacteria lactis) on established AD in children. SUBJECTS AND METHODS: Atopic children with current dermatitis received 2 x 10(10) colony forming units/g of probiotic (n=29) or placebo (n=30). Both were given daily as a powder mixed with food or water. SCORing Atopic Dermatitis (SCORAD; developed by the European Task Force on Atopic Dermatitis) a measure of the extent and severity of AD, was assessed at baseline, 2 and 12 weeks after starting treatment and 4 weeks after treatment was discontinued. RESULTS: SCORAD geometric mean score at baseline was 26.0 (21.9-30.8) in the probiotic group and 35.1 (28.9-42.8) in the placebo group (P=0.02). After adjustment for these between-group baseline differences there was no significant improvement in AD at 12 weeks, SCORAD geometric mean ratio: 0.80 (95% confidence level (CI) 0.62-1.04, P=0.10). Among the food sensitized children, there was an improvement in those treated with probiotics, SCORAD geometric mean ratio: 0.73 (95% CI 0.54-1.00, P=0.047). CONCLUSION: In this study a combination of Lactobacillus rhamnosus and Bifidobacteria lactis improved AD only in food sensitized children.

Bifidobacterium↗

PubMed2006

No effects of probiotics on atopic dermatitis in infancy: a randomized placebo-controlled trial.

BACKGROUND: Studies have been performed suggesting that administration of probiotics may have therapeutic and/or preventive benefits in the development of sensitization and atopic disease, particularly in infants with atopic dermatitis (AD). OBJECTIVE: The purpose of this study was to evaluate the clinical and immunological effects of supplementation of a hydrolysed formula with two probiotic strains of bacteria on symptoms of AD in infancy. METHODS: We conducted a randomized, double-blind, placebo-controlled study. After 4-6 weeks of baseline and double-blind, placebo-controlled challenges for diagnosis of cow's milk allergy (CMA), infants less than 5 months old with AD received a hydrolysed whey-based formula as placebo (n = 17), or supplemented with either Lactobacillus rhamnosus (n = 17) or Lactobacillus GG (n = 16) for 3 months. Before, during and after intervention, the clinical severity of AD was evaluated using SCORing index Atopic Dermatitis (SCORAD). Allergic sensitization was evaluated by measurement of total IgE and a panel of food-specific IgEs as well as skin prick testing for cow's milk. Inflammatory parameters were blood eosinophils, eosinophil protein X in urine, fecal alpha-1-antitrypsin and production of IL-4, IL-5 and IFN-gamma by peripheral blood mononuclear cells after polyclonal stimulation. RESULTS: No statistically significant effects of probiotic supplementation on SCORAD, sensitization, inflammatory parameters or cytokine production between groups were found. Only four infants were diagnosed with CMA. CONCLUSION: We found no clinical or immunological effect of the probiotic bacteria used in infants with AD. Our results indicate that oral supplementation with these probiotic bacterial strains will not have a significant impact on the symptoms of infantile AD.

Cytokines↗

PubMed2004

Comparative survival of probiotic lactobacilli spray-dried in the presence of prebiotic substances.

AIMS: Probiotic milk-based formulations were spray-dried with various combinations of prebiotic substances in an effort to generate synbiotic powder products. METHODS AND RESULTS: To examine the effect of growth phase and inclusion of a prebiotic substance in the feed media on probiotic viability during spray-drying, Lactobacillus rhamnosus GG was spray-dried in lag, early log and stationary phases of growth in reconstituted skim milk (RSM) (20% w/v) or RSM (10% w/v), polydextrose (PD) (10% w/v) mixture at an outlet temperature of 85-90 degrees C. Stationary phase cultures survived best (31-50%) in both feed media and were the most stable during powder storage at 4-37 degrees C over 8 weeks, with 30-140-fold reductions in cell viability at 37 degrees C in RSM and PD/RSM powders, respectively. Stationary phase Lact. rhamnosus GG was subsequently spray-dried in the presence of the prebiotic inulin in the feed media, composed of RSM (10% w/v) and inulin (10% w/v), and survival following spray-drying was of the order 7.1-43%, while viability losses of 20,000-90,000-fold occurred in these powders after 8 weeks' storage at 37 degrees C. Survival of the Lactobacillus culture after spray-drying in powders produced using PD (20% w/v) or inulin (20% w/v) as the feed media was only 0.011-0.45%. To compare different probiotic lactobacilli during spray-drying, stationary phase Lact. rhamnosus E800 and Lact. salivarius UCC 500 were spray-dried using the same parameters as for Lact. rhamnosus GG in either RSM (20% w/v) or RSM (10% w/v) and PD (10% w/v). Lact. rhamnosus E800 experienced approx. 25-41% survival, yielding powders containing approximately 10(9) CFU g(-1), while Lact. salivarius UCC 500 performed poorly, experiencing over 99% loss in viability during spray-drying in both feed media. In addition to the superior survival of Lact. rhamnosus GG after spray-drying, both strains experienced higher viability losses (570-700-fold) during storage at 37 degrees C over 8 weeks compared with Lact. rhamnosus GG. CONCLUSIONS: Stationary phase cultures were most suitable for the spray-drying process, while lag phase was most susceptible. The presence of the prebiotics PD and inulin did not enhance viability during spray-drying or powder storage. SIGNIFICANCE AND IMPACT OF THE STUDY: High viability (approximately 10(9) CFU g(-1)) powders containing probiotic lactobacilli in combination with prebiotics were developed, which may be useful as functional food ingredients for the manufacture of probiotic foods.

Animals↗

PubMed2004

Identification method based on PCR combined with automated ribotyping for tracking probiotic Lactobacillus strains colonizing the human gut and vagina.

AIMS: A molecular methodology based on PCR-associated automated ribotyping was developed to specifically detect the Lactobacillus strains of two probiotic products (an orally administered lyophilized preparation and vaginal tablets) in human faeces and vaginal swabs. METHODS AND RESULTS: The 16S-23S rDNA sequences and the ribotype profiles of the probiotic lactobacilli were characterized and new species-specific primer sets were designed. The identification of faecal and vaginal lactobacilli isolated from subjects administered with the probiotic products was performed by using PCR with species-specific primers followed by strain-specific automated ribotyping. CONCLUSIONS: The PCR-ribotyping identification allowed to study the colonization patterns of the probiotic lactobacilli in the human gut and vagina evidencing the strains with the best survival capability. SIGNIFICANCE AND IMPACT OF THE STUDY: The proposed molecular method represents a powerful tool of strain-specific identification, useful for differentiating exogenous from indigenous strains in any microbial ecosystem and for rationally choosing probiotic bacteria with the best chance of survival in the host.

Colony Count, Microbial↗

PubMed2004

Stationary-phase acid and heat treatments for improvement of the viability of probiotic lactobacilli and bifidobacteria.

AIMS: To investigate whether sublethal treatments of stationary-phase probiotic cultures enhance their survival during lethal treatments and to adapt these treatments to the fermenter-scale production of probiotic cultures. METHODS AND RESULTS: Conditions for acid and heat pretreatments were screened for three Lactobacillus and two Bifidobacterium strains. Strains were sublethally treated both at laboratory scale and at fermenter scale in a strain-specific manner and exposed to a subsequent lethal treatment. At laboratory scale viability improvement was detected in each strain. However, improvement was more pronounced in the Lactobacillus than in the Bifidobacterium strains. At fermenter scale three strains were tested: for the two Lactobacillus strains a marked improvement in viability was obtained whereas for the Bifidobacterium strain the improvement was either minor or not detected. CONCLUSIONS: Development of treatments for viability enhancement of probiotic strains is feasible, but strain-specific optimization is necessary to obtain notable improvements. SIGNIFICANCE AND IMPACT OF THE STUDY: Strain-specific treatments were developed for the viability enhancement of stationary-phase probiotic cells both at laboratory and fermenter scale. These results can be utilised in the production of probiotic cultures with improved viability.

Bifidobacterium↗

PubMed2005

Probiotics and gastrointestinal diseases.

There is increasing evidence indicating health benefits by consumption of foods containing microorganisms, i.e. probiotics. A number of clinical trials have been performed to evaluate the effects in the prevention and treatment of gastrointestinal diseases caused by pathogenic microorganisms or by disturbances in the normal microflora. Gastrointestinal infections caused by Helicobacter pylori, traveller's diarrhoea, rotavirus diarrhoea, antibiotic-associated diarrhoea (AAD) and Clostridium difficile-induced diarrhoea are conditions that have been studied. There are also studies performed on the preventive effect of probiotics on radiation-induced diarrhoea and diarrhoea in tube-fed patients. Inflammatory bowel disease and irritable bowel syndrome, two idiopathic conditions where alterations in the normal microflora have been implicated as responsible for initiation, are two further areas where the use of probiotics has been regarded as promising. The results from clinical studies have not been conclusive in that the effects of probiotics have been strain-dependent and different study designs have been used. Treatment of acute diarrhoea in children and prevention of AAD are the two most justified areas for the application of probiotics.

Acute Disease↗

PubMed2006

Probiotics and their potential health claims.

Many studies have attempted to identify specific positive health effects of probiotics. One of the challenges in generalizing health effects of probiotics is that different strains exert disparate effects on human health. As a result, the efficacy of one strain or species cannot necessarily be inferred from another. The objective of this review is to examine the current scientific literature that could be used as the basis for potential health claims. More specifically, this paper will review existing evidence of different probiotic strains to prevent and treat diarrhea, treat irritable bowel syndrome (IBS), treat inflammatory bowel disease, and prevent colon cancer. The strongest evidence is related to the use of Lactobacillus rhamnosus GG in the prevention and treatment of rotavirus-associated diarrhea. Further examination of the literature also shows promise in the treatment of some forms of IBS with probiotics. Future studies that use consistent supplementation regimes will allow more definitive conclusions to be drawn on the effects of probiotics on IBS, inflammatory bowel disease, and colon cancer.

Colonic Neoplasms↗

PubMed2005

Role of intestinal epithelial cells in immune effects mediated by gram-positive probiotic bacteria: involvement of toll-like receptors.

The mechanisms by which probiotic bacteria exert their effects on the immune system are not completely understood, but the epithelium may be a crucial player in the orchestration of the effects induced. In a previous work, we observed that some orally administered strains of lactic acid bacteria (LAB) increased the number of immunoglobulin A (IgA)-producing cells in the small intestine without a concomitant increase in the CD4(+) T-cell population, indicating that some LAB strains induce clonal expansion only of B cells triggered to produce IgA. The present work aimed to study the cytokines induced by the interaction of probiotic LAB with murine intestinal epithelial cells (IEC) in healthy animals. We focused our investigation mainly on the secretion of interleukin 6 (IL-6) necessary for the clonal expansion of B cells previously observed with probiotic bacteria. The role of Toll-like receptors (TLRs) in such interaction was also addressed. The cytokines released by primary cultures of IEC in animals fed with Lactobacillus casei CRL 431 or Lactobacillus helveticus R389 were determined. Cytokines were also determined in the supernatants of primary cultures of IEC of unfed animals challenged with different concentrations of viable or nonviable lactobacilli and Escherichia coli, previously blocked or not with anti-TLR2 and anti-TLR4. We concluded that the small intestine is the place where a major distinction would occur between probiotic LAB and pathogens. This distinction comprises the type of cytokines released and the magnitude of the response, cutting across the line that separates IL-6 necessary for B-cell differentiation, which was the case with probiotic lactobacilli, from inflammatory levels of IL-6 for pathogens.

Animals↗

PubMed2006

Probiotics stimulate production of natural antibodies in chickens.

Commensal bacteria in the intestine play an important role in the development of immune response. These bacteria interact with cells of the gut-associated lymphoid tissues (GALT). Among cells of the GALT, B-1 cells are of note. These cells are involved in the production of natural antibodies. In the present study, we determined whether manipulation of the intestinal microbiota by administration of probiotics, which we had previously shown to enhance specific systemic antibody response, could affect the development of natural antibodies in the intestines and sera of chickens. Our findings demonstrate that when 1-day-old chicks were treated with probiotics, serum and intestinal antibodies reactive to tetanus toxoid (TT) and Clostridium perfringens alpha-toxin in addition to intestinal immunoglobulin A (IgA) reactive to bovine serum albumin (BSA) were increased in unimmunized chickens. Moreover, IgG antibodies reactive to TT were increased in the intestines of probiotic-treated chickens compared to those of untreated controls. In serum, IgG and IgM reactive to TT and alpha-toxin were increased in probiotic-treated, unimmunized chickens compared to levels in untreated controls. However, no significant difference in serum levels of IgM or IgG response to BSA was observed. These results are suggestive of the induction of natural antibodies in probiotic-treated, unimmunized chickens. Elucidating the role of these antibodies in maintenance of the chicken immune system homeostasis and immune response to pathogens requires further investigation.

Animals↗