Lactobacillus plantarum 299: beneficial in vitro immunomodulation in cells extracted from inflamed human colon

Lactobacillus Persisters Formation and Resuscitation

Lactobacillus is a commonly used probiotic, and many researchers have focused on its stress response to improve its functionality and survival. However, studies on persister cells, dormant cells that aid bacteria in surviving general stress, have focused on pathogenic bacteria that cause infection, not Lactobacillus. Thus, understanding Lactobacillus persister cells will provide essential clues for understanding how Lactobacillus survives and maintains its function under various environmental conditions. We treated Lactobacillus strains with various antibiotics to determine the conditions required for persister formation using kill curves and transmission electron microscopy. In addition, we observed the resuscitation patterns of persister cells using single-cell analysis. Our results show that Lactobacillus creates a small population of persister cells (0.0001-1% of the bacterial population) in response to beta-lactam antibiotics such as ampicillin and amoxicillin. Moreover, only around 0.5-1% of persister cells are heterogeneously resuscitated by adding fresh media; the characteristics are typical of persister cells. This study provides a method for forming and verifying the persistence of Lactobacillus and demonstrates that antibiotic-induced Lactobacillus persister cells show characteristics of dormancy, sensitivity of antibiotics, same as exponential cells, multi-drug tolerance, and resuscitation, which are characteristics of general persister cells. This study suggests that the mechanisms of formation and resuscitation may vary depending on the characteristics, such as the membrane structure of the bacterial species.

What happens to Bifidobacterium adolescentis and Bifidobacterium longum ssp. longum in an experimental environment with eukaryotic cells?

BACKGROUND

The impact of probiotic strains on host health is widely known. The available studies on the interaction between bacteria and the host are focused on the changes induced by bacteria in the host mainly. The studies determining the changes that occurred in the bacteria cells are in the minority. Within this paper, we determined what happens to the selected Bifidobacterium adolescentis and Bifidobacterium longum ssp. longum in an experimental environment with the intestinal epithelial layer. For this purpose, we tested the bacteria cells' viability, redox activity, membrane potential and enzymatic activity in different environments, including CaCo-2/HT-29 co-culture, cell culture medium, presence of inflammatory inductor (TNF-α) and oxygen.

RESULTS

We indicated that the external milieu impacts the viability and vitality of bacteria. Bifidobacterium adolescentis decrease the size of the live population in the cell culture medium with and without TNF-α (p < 0.001 and p < 0.01 respectively). In contrast, Bifidobacterium longum ssp. longum significantly increased survivability in contact with the eukaryotic cells and cell culture medium (p < 0.001). Bifidobacterium adolescentis showed significant changes in membrane potential, which was decreased in the presence of eukaryotic cells (p < 0.01), eukaryotic cells in an inflammatory state (p < 0.01), cell culture medium (p < 0.01) and cell culture medium with TNF-α (p < 0.05). In contrast, Bifidobacterium longum ssp. longum did not modulate membrane potential. Instead, bacteria significantly decreased the redox activity in response to milieus such as eukaryotic cells presence, inflamed eukaryotic cells as well as the culture medium (p < 0.001). The redox activity was significantly different in the cells culture medium vs the presence of eukaryotic cells (p < 0.001). The ability to β-galactosidase production was different for selected strains: Bifidobacterium longum ssp. longum indicated 91.5% of positive cells, whereas Bifidobacterium adolescentis 4.34% only. Both strains significantly reduced the enzyme production in contact with the eukaryotic milieu but not in the cell culture media.

CONCLUSION

The environmental-induced changes may shape the probiotic properties of bacterial strains. It seems that the knowledge of the sensitivity of bacteria to the external environment may help to select the most promising probiotic strains, reduce research costs, and contribute to greater reproducibility of the obtained probiotic effects.

L. plantarum and L. lactis as a promising agent in treatment of inflammatory bowel disease and colorectal cancer

It has been understood for nearly a century that patients with intestinal inflammatory disease (IBD) have a higher risk of developing colorectal cancer (CRC). Recently, two species of lactic acid bacteria, Lactobacillus plantarum and Lactococcus lactis, have been investigated as therapeutic agents for IBD. These bacteria have been shown to survive gastric transit, to adhere and colonize in the intestinal tract of humans and modulate the intestinal microbiota and immune response. L. plantarum and L. lactis might be used as multifunctional drugs for the treatment of IBD and the prevention or treatment of CRC. This article summarizes current knowledge of L. plantarum and L. lactis as therapeutic and preventative agents for IBD and CRC, respectively.

Anti-inflammatory and Immunostimulant Therapy with Lactobacillus fermentum and Lactobacillus plantarum in COVID-19: A Literature Review

Inflammatory diseases are diseases characterized by inflammatory symptoms. Acute inflammatory disease can cause dysregulation of the inflammatory immune response, thereby inhibiting the development of protective immunity against infection. Among the acute inflammatory disease is COVID-19. The initial viral infection causes the antigen-presenting cells to detect the virus through a phagocytosis mechanism in the form of macrophage and dendritic cells. Lactobacillus fermentum and L. plantarum are gram-positive bacteria potentially serving as immunomodulators caused by inflammation and immune system response. Short-chain fatty acids (SCFA) produced by Lactobacillus can induce immune response through tolerogenic dendritic cells. This probiotic bacterium can induce the production of different cytokines or chemokines. Following the results of in vitro and in vivo tests, L. fermentum and L. plantarum can induce IL-10 release to activate regulatory T-cell and inhibit tumor necrosis factor-α (TNF-α) binding activity of nuclear factor kappa B (NF-κB). Literature review showed that dysregulation of inflammatory immune response disorders due to inflammatory disease could be treated using probiotic bacteria L. fermentum and L. plantarum. Therefore, it is necessary to conduct further studies on the potential of indigenous Indonesian strains of these two bacteria as anti-inflammatory and immunostimulants.

The role of synbiotics in improving inflammatory status in nasopharyngeal carcinoma patients

Nasopharyngeal carcinoma (NPC) is a malignant tumor that grows from the epithelial cells of nasopharynx. NPC has the ability to modify its metabolism and leads the patient to suffer from malnutrition and cachexia, therefore aggravates the occurrence of impaired inflammatory response. Currently, available treatments for NPC are chemotherapy, radiotherapy, or chemoradiotherapy. Despite of its efficacy, these regimens have been known to elicit various inflammation-related side effects including infection, diarrhea, and mucositis. It has long been established that increased activity of inflammatory response is associated to low survival rate in both early and advanced stage of cancer. Furthermore, uncontrolled and dysregulated inflammatory response are significantly correlated with malignant progression of cancer. Considering how pivotal inflammation to malignancy progression, there is a need for effective strategies to modulate inflammatory response. Various strategies have been proposed to improve immune response in NPC patients including dietary supplementation of synbiotics. Synbiotics refers to the manipulation of both probiotics and prebiotics to provide a synergistic benefit to the host by promoting the growth of beneficial bacteria while inhibiting the growth of pathogenic bacteria. There is a growing number of evidences related to the potential of synbiotics in modulating the pro-inflammatory response and improve immune systems in a variety of conditions, including cancer. In this study, we will discuss the immunomodulatory effects of synbiotics in the nasopharyngeal carcinoma occurrences.

Effect of Fluidized Bed Drying, Matrix Constituents and Structure on the Viability of Probiotic Lactobacillus paracasei ATCC 55544 during Storage at 4 °C, 25 °C and 37 °C

The stabilization of probiotics for application in non-refrigerated food products is a challenging task. In the present study, probiotic Lactobacillus paracasei (Lacticaseibacillus paracasei) ATCC 55544 cells were immobilized in a dairy matrix comprising of whole milk powder, skim milk powder, or milk protein isolate using fluidized bed drying technology. The samples were taken out at different drying stages, with an apparent water activity (a_w) of a_w 0.5, a_w 0.4, and a_w 0.3, respectively, and vacuum-packed to maintain the a_w and stored at three different temperatures of 4 °C, 25 °C, and 37 °C. The study evaluated the impact of matrix constituents, milk fat, protein, and carbohydrate on the viability of encapsulated probiotic L . paracasei ATCC 55544 during storage for 1 month. The whole milk powder matrix provided superior protection to the bacteria. Confocal Laser Scanning Microscopy (CLSM) was used to investigate the structure of the immobilizing matrix and the location of the probiotic L. paracasei cells embedded within the matrix. The CLSM study revealed that the probiotic bacterial cells are mostly embedded as clusters beneath the top layer. We hypothesize that the biofilm-like structure, together with the protective whole milk powder matrix, helps to retain the superior viability of probiotic cells during storage at non-refrigerated storage conditions of 25 °C and 37 °C.

Lactiplantibacillus plantarum 299v (LP299V®): three decades of research

This review aims to provide a comprehensive overview of the in vitro, animal, and clinical studies with the bacterial strain Lactiplantibacillus plantarum 299v (L. plantarum 299v; formerly named Lactobacillus plantarum 299v) published up until June 30, 2020. L. plantarum 299v is the most documented L. plantarum strain in the world, described in over 170 scientific publications out of which more than 60 are human clinical studies. The genome sequence of L. plantarum 299v has been determined and is available in the public domain (GenBank Accession number: NZ_LEAV01000004). The probiotic strain L. plantarum 299v was isolated from healthy human intestinal mucosa three decades ago by scientists at Lund University, Sweden. Thirty years later, a wealth of data coming from in vitro, animal, and clinical studies exist, showing benefits primarily for gastrointestinal health, such as reduced flatulence and abdominal pain in patients with irritable bowel syndrome (IBS). Moreover, several clinical studies have shown positive effects of L. plantarum 299v on iron absorption and more recently also on iron status. L. plantarum 299v is safe for human consumption and does not confer antibiotic resistance. It survives the harsh conditions of the human gastrointestinal tract, adheres to mannose residues on the intestinal epithelial cells and has in some cases been re-isolated more than ten days after administration ceased. Besides studying health benefits, research groups around the globe have investigated L. plantarum 299v in a range of applications and processes. L. plantarum 299v is used in many different food applications as well as in various dietary supplements. In a freeze-dried format, L. plantarum 299v is robust and stable at room temperature, enabling long shelf-lives of consumer healthcare products such as capsules, tablets, or powder sachets. The strain is patent protected for a wide range of indications and applications worldwide as well as trademarked as LP299V^®.

Diet supporting therapy for inflammatory bowel diseases

PURPOSE

Non-specific inflammatory bowel diseases (IBD) include Crohn's disease and ulcerative colitis. More and more often attention is paid to the possibility of dietary support for inflammatory bowel diseases.

METHODS

The following review article considers the role of dietary components in the treatment of IBD as: pteridines, probiotics, bovine immunoglobulin, vitamin D, omega-3, flavonoids, polyphenols, curcumin and phosphatidylcholine. The article also discusses plant raw materials of arjuna, soy protein and nettles, trying to summarize their effect on quenching the inflammatory process within the intestines. This review focuses on the possibilities of dietary components and supplementation use to improve the pharmacotherapy response as well as the general clinical patients' condition.

RESULTS

The mechanism of action of supportive therapy is based on reduction in oxidative stress, maintaining the adequate balance between Th1 and Th2 lymphocytes by affecting cytokines, increasing riboflavin supply for macrophages, increasing expression of vitamin D receptor, regulation by decreasing the expression of NF-κB in liver cells and ability to inhibit the COX2 entrance and inactivate prostaglandins that are involved in the inflammatory process and 12-lipoxygenase pathway inhibition.

CONCLUSION

Considering clinical researches, it seems that the use of the above-mentioned ingredients in the diet of patients suffering IBD may positively influence the treatment process and maintenance of remission.

The role of the skin microbiota in the modulation of cutaneous inflammation-Lessons from the gut

Inflammation is a vital defense mechanism used to protect the body from invading pathogens, but dysregulation can lead to chronic inflammatory disorders such as psoriasis and atopic dermatitis. Differences in microbiota composition have been observed in patients with inflammatory skin conditions compared with healthy individuals, particularly within lesions. There is also increasing evidence accumulating to support the notion that the microbiome contributes to the onset or modulates the severity of inflammatory diseases. Despite the known protective effects of orally administered lactic acid bacteria against inflammation, few studies have investigated the potential protective effects of topical application of bacteria on skin health and even fewer have looked at the potential anti-inflammatory effects of skin commensals. If lack of diversity and reduction in the abundance of specific commensal strains is observed in inflammatory skin lesions, and it is known that commensal bacteria can produce anti-inflammatory compounds, we suggest that certain members of the skin microbiota have anti-inflammatory properties that can be harnessed for use as topical therapeutics in inflammatory skin disorders.

Probiotics, Prebiotics, and Synbiotics: Implications and Beneficial Effects against Irritable Bowel Syndrome

Irritable bowel syndrome (IBS) is still a common functional gastrointestinal disease that presents chronic abdominal symptoms but with a pathophysiology that is not yet fully elucidated. Moreover, the use of the synergistic combination of prebiotics and probiotics, known as synbiotics, for IBS therapy is still in the early stages. Advancements in technology led to determining the important role played by probiotics in IBS, whereas the present paper focuses on the detailed review of the various pathophysiologic mechanisms of action of probiotics, prebiotics, and synbiotics via multidisciplinary domains involving the gastroenterology (microbiota modulation, alteration of gut barrier function, visceral hypersensitivity, and gastrointestinal dysmotility) immunology (intestinal immunological modulation), and neurology (microbiota–gut–brain axis communication and co-morbidities) in mitigating the symptoms of IBS. In addition, this review synthesizes literature about the mechanisms involved in the beneficial effects of prebiotics and synbiotics for patients with IBS, discussing clinical studies testing the efficiency and outcomes of synbiotics used as therapy for IBS.

Probiotic and Functional Properties of Limosilactobacillus reuteri INIA P572

Limosilactobacillus reuteri INIA P572 is a strain able to produce the antimicrobial compound reuterin in dairy products, exhibiting a protective effect against some food-borne pathogens. In this study, we investigated some probiotic properties of this strain such as resistance to gastrointestinal passage or to colonic conditions, reuterin production in a colonic environment, and immunomodulatory activity, using different in vitro and in vivo models. The results showed a high resistance of this strain to gastrointestinal conditions, as well as capacity to grow and produce reuterin in a human colonic model. Although the in vitro assays using the RAW 264.7 macrophage cell line did not demonstrate direct immunomodulatory properties, the in vivo assays using a Dextran Sulphate Sodium (DSS)-induced colitic mice model showed clear immunomodulatory and protective effects of this strain.

Immunomodulation of J774A.1 Murine Macrophages by Lactiplantibacillus plantarum Strains Isolated From the Human Gastrointestinal Tract and Fermented Foods

Lactobacillus plantarum species (recently re-named Lactiplantibacillus (Lpb.) plantarum subsp. plantarum) can be isolated from both either the mammalian gut or specific fermented foods where they may be present at high concentrations. Whilst Lpb. plantarum strains have been proposed as potential probiotic candidates, the ability of resident strains consumed in fermented foods to interact with the host is unclear. The main objective of this study was to investigate the cellular location and ability of three different food-borne Lpb. plantarum strains isolated from different sources (table olives and cheese) to modulate the immune response of a murine macrophage-like cell line (J774A.1). For that purpose, macrophages were exposed to the three different Lpb. plantarum strains for 24 h and the expression of a panel of genes involved in the immune response, including genes encoding pattern-recognition receptors (TLRs and NLRs) and cytokines was evaluated by qRT-PCR. We also utilized chemical inhibitors of intracellular pathways to gain some insight into potential signaling mechanisms. Results showed that the native food strains of Lpb. plantarum were able to modulate the response of J774A.1 murine macrophages through a predominately NOD signaling pathway that reflects the transient intracellular location of these strains within the macrophage. The data indicate the capacity of food-dwelling Lpb. plantarum strains to influence macrophage-mediated host responses if consumed in sufficient quantities.

Probiotics Ameliorate Stool Consistency in Patients with Chronic Constipation: A Randomized, Double-Blind, Placebo-Controlled Study

BACKGROUND/AIMS

The efficacy of probiotics for improving clinical symptoms, altering the fecal microbiota, and regulating serum immune cytokine levels was investigated in patients with irritable bowel syndrome-constipation (IBS-C) or functional constipation (FC).

METHODS

A randomized, double-blind, placebo-controlled trial was conducted at Kyung Hee University Hospital between October 2016 and February 2017. Consecutive 18-75-year-old patients with diagnosis of IBS-C or FC (based on Rome IV criteria) consumed probiotics (3.0 × 10⁸ CFU/g Streptococcus thermophilus MG510 and 1.0 × 10⁸ CFU/g Lactobacillus plantarum LRCC5193) or a placebo daily for 4 weeks (weeks 1-4) and were followed up for a 4-week washout period without intervention (weeks 5-8). The primary outcomes of the study were Bristol Stool Form Scale and Complete Spontaneous Bowel Movements (CSBM). Efficacy was assessed by per protocol.

RESULTS

Stool consistency measured by the Bristol Stool Form Scale was significantly better in the probiotic group (n = 88) than in the placebo group (n = 83) at 4 and 8 weeks (3.7 ± 1.1 vs. 3.1 ± 1.1 at 8 weeks, P = 0.002). No significant difference was found in CSBM. The quality of life was significantly better in the probiotic group than in the placebo group at 4 weeks (P = 0.044) and 8 weeks (P = 0.049). The relative abundance of L. plantarum among the fecal microbiomes was significantly greater in the probiotic group than in the placebo group at 4 weeks (P = 0.029). However, the levels of other microbiomes and of serum cytokines (IL-10/IL-12 ratio and TNF-α) did not differ significantly between the two groups.

CONCLUSIONS

Probiotics significantly ameliorated stool consistency in patients with chronic constipation. In addition, the beneficial effect of L. plantarum on stool consistency remained after the probiotic supplementation was discontinued. The mechanism whereby probiotics benefit patients with chronic constipation should be clarified in further studies.

Efficacy of Lactobacillus plantarum in prevention of inflammatory bowel disease

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L. plantarum have effects on inflammation for the prevention and management IBD.

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The mechanisms of action of L. plantarum on IBD are complex.

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Further clinical studies are needed to validate its potential use in IBD in humans.

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L. plantarum are considered safe overall for use as feed additives and humans.

The incidence of inflammatory bowel disease (IBD) is increasing globally. Altered gut bacteria and bacterial metabolic pathways are two important factors in the initiation and progression of IBD. Lactobacillus plantarum is distributed in a variety of ecological niches, has a proven ability to survive gastric transit, and can colonize the intestinal tract of human and other mammals. Several studies have described the effects of L. plantarum consumption on human physiology. This review summarizes the safety and the effects of L. plantarum in vitro and in animal models for the prevention and management of IBD. L. plantarum modulates the ratio of Th1 and Th2 cells by stimulating the production of different inflammatory cytokines such as tumor necrosis factor-alpha, interleukin (IL)-1β, IL-6, IL-10, IL-12, and interferon-gamma. The blocking of cyclooxygenase-2 in Th1 also is an apoptotic inhibition mechanism. This overview of the molecular studies addresses the activity of L. plantarum in the human gut environment and its’ potential for remission of IBD.

The influence of prebiotic or probiotic supplementation on antibody titers after influenza vaccination: a systematic review and meta-analysis of randomized controlled trials

Background

Influenza infection is a common disease with a huge disease burden. Influenza vaccination has been widely used, but concerns regarding vaccine efficacy exist, especially in the elderly. Probiotics are live microorganisms with immunomodulatory effects and may enhance the immune responses to influenza vaccination.

Methods

We conducted a systematic review and meta-analysis to determine the influence of prebiotics/probiotics/synbiotics supplementation on vaccine responses to influenza vaccination. Studies were systematically identified from electronic databases up to July 2017. Information regarding study population, influenza vaccination, components of supplements, and immune responses were extracted and analyzed. Twelve studies, investigating a total of 688 participants, were included in this review.

Results

Patients with prebiotics/probiotics supplements were found to have higher influenza hemagglutination inhibition antibody titers after vaccination (for A/H1N1, 42.89 vs 35.76, mean difference =7.14, 95% CI =2.73, 11.55, P=0.002; for A/H3N2, 105.4 vs 88.25, mean difference =17.19, 95% CI =3.39, 30.99, P=0.01; for B strain, 34.87 vs 30.73, mean difference =4.17, 95% CI =0.37, 7.96, P=0.03).

Conclusion

Supplementation with prebiotics or probiotics may enhance the influenza hemagglutination inhibition antibody titers in all A/H1N1, A/H3N2, and B strains (20%, 19.5%, and 13.6% increases, respectively). Concomitant prebiotics or probiotics supplementation with influenza vaccination may hold great promise for improving vaccine efficacy. However, high heterogeneity was observed and further studies are warranted.

Effect of probiotics (Lactobacillus plantarum 299 plus Bifidobacterium Cure21) in patients with poor ileal pouch function: a randomised controlled trial

OBJECTIVE

Poor pouch function after restorative proctocolectomy for ulcerative colitis is a considerable problem. Pouchitis and functional disorders are the most common reasons. Probiotics seem to have a beneficial effect in pouchitis but have not been assessed in functional pouch disorders. The aim was to analyse the effects of probiotics in patients with poor pouch function.

METHODS

Thirty-three patients were randomized to probiotics (Lactobacillus plantarum 299 and Bifidobacterium infantis Cure 21) or placebo in a double blinded, 1:1 fashion. The treatment effect was assessed by the pouch functional score (PFS; 0-15, 15 worst), pouchitis disease activity index (PDAI; 0-18, 18 worst), and levels of four faecal biomarkers of inflammation (calprotectin, lactoferrin, myeloperoxidase [MPO] and eosinophilic cationic protein [ECP]).

RESULTS

Thirty-two patients were included (probiotics = 17, placebo = 16). There was no difference in change in the PFS from before to after treatment between the groups (median difference: -1.00, 95% C.I. -3.00 to 0.00, p = 0.119). Furthermore, probiotics had no effect on PDAI (median difference: 0.00, 95% C.I. 0.00-1.00, p = 0.786), or on faecal biomarkers. Significant correlations were observed between PDAI and each of the faecal biomarkers at study start. There were no correlations between PFS or PDAI symptom subscore and the biomarkers. PDAI endoscopic and histologic subscores correlated significantly to each of the biomarkers.

CONCLUSION

The hypothesis that probiotics improves pouch-related dysfunction was not confirmed. Faecal biomarkers could play a future role in the management of pouch patients.

Immunomodulatory Effects of Lactobacillus plantarum Lp62 on Intestinal Epithelial and Mononuclear Cells

Probiotic lactic acid bacteria are known for their ability to modulate the immune system. They have been shown to inhibit inflammation in experiments with animal models, cell culture, and clinical trials. The objective of this study was to elucidate the anti-inflammatory potential of Lactobacillus plantarum Lp62, isolated from cocoa fermentation, in a cell culture model. Lp62 inhibited IL-8 production by Salmonella Typhi-stimulated HT-29 cells and prevented the adhesion of pathogens to these epithelial cells. The probiotic strain was able to modulate TNF-α, IL1-β, and IL-17 secretion by J774 macrophages. J774 activation was reduced by coincubation with Lp62. PBMC culture showed significantly higher levels of CD4⁺CD25⁺ T lymphocytes following treatment with Lp62. Probiotics also induced increased IL-10 secretion by mononuclear cells. L. plantarum Lp62 was able to inhibit inflammatory stimulation in epithelial cells and macrophages and activated a tolerogenic profile in mononuclear cells of healthy donors. These results indicate this strain for a possible application in the treatment or prevention of inflammatory diseases.

Long-term effects of early life microbiota disturbance on adaptive immunity in laying hens

Due to an interplay between intestinal microbiota and immune system, disruption of intestinal microbiota composition during immune development may have consequences for immune responses later in life. The present study investigated the effects of antibiotic treatment in the first weeks of life on the specific antibody response later in life in chickens. Layer chicks received an antibiotic cocktail consisting of vancomycin, neomycin, metronidazole, and amphotericin-B by oral gavage every 12 h, and ampicillin and colistin in drinking water for the first week of life. After the first week of life, chicks received ampicillin and colistin in drinking water for two more weeks. Control birds received no antibiotic cocktail and plain drinking water. Fecal microbiota composition was determined during antibiotic treatment (d 8 and 22), two weeks after cessation of antibiotic treatment (d 36), and at the end of the experimental period at d 175 using a 16S ribosomal RNA gene targeted microarray, the Chicken Intestinal Tract Chip (ChickChip). During antibiotic treatment fecal microbiota composition differed strongly between treatment groups. Fecal microbiota of antibiotic treated birds consisted mainly of Proteobacteria, and in particular E.coli, whereas fecal microbiota of control birds consisted mainly of Firmicutes, such as lactobacilli and clostridia. Two weeks after cessation of antibiotic treatment fecal microbiota composition of antibiotic treated birds had recovered and was similar to that of control birds. On d 105, 12 weeks after cessation of antibiotic treatment, chicks of both treatment groups received an intra-tracheal lipopolysaccharide (LPS)/human serum albumin (HuSA) challenge. Antibody titers against LPS and HuSA were measured 10 days after administration of the challenge. While T cell independent antibody titers (LPS) were not affected by antibiotic treatment, antibiotic treated birds showed lower T cell dependent antibody titers (HuSA) compared with control birds. In conclusion, intestinal microbial dysbiosis early in life may still have effects on the specific antibody response months after cessation of antibiotic treatment and despite an apparent recovery in microbiota composition.

Immunomodulatory effects of Lactobacillus strains: emphasis on their effects on cancer cells

Lactobacilli are a group of normal microbiota whose immunomodulatory effects have been known for a long time. Recently, they have gained more attention for their direct and indirect effects on cancer cells. Several cell line experiments, animal model studies as well as clinical trials have indicated their inhibitory effects on cancer initiation and progression. Different lactobacilli strains could modulate innate and adoptive immune system. Such effects have been documented in modulation of function of T cells, dendritic cells and macrophages as well as cytokine production. In this review, the various immunomodulatory effects of lactobacilli on tumor cells as well as their direct cytotoxic effects on cancer cells are discussed.

Effects of 12 weeks of probiotic supplementation on quality of life in colorectal cancer survivors: a double-blind, randomized, placebo-controlled trial

BACKGROUND

Probiotics may help resolve bowel symptoms and improve quality of life. We investigated the effects of 12 weeks of probiotics administration in colorectal cancer patients.

METHODS

We conducted a double-blind, randomized, placebo-controlled trial. The participants took probiotics (Lacidofil) or placebo twice a day for 12 weeks. The cancer-related quality of life (FACT), patient's health-9 (PHQ-9), and bowel symptom questionnaires were completed by each participant.

RESULTS

We obtained data for 32 participants in the placebo group and 28 participants in the probiotics group. The mean ages of total participants were 56.18 ± .86 years and 58.3% were male. Administration of probiotics significantly decreased the proportion of patients suffering from irritable bowel symptoms (0 week vs. 12 week; 67.9% vs. 45.7%, p=0.03), improved colorectal cancer-related FACT (baseline vs. 12 weeks: 19.79 ± 4.66 vs. 21.18 ± 3.67, p=0.04) and fatigue-related FACT (baseline vs. 12 weeks: 43.00 (36.50-45.50) vs. 44.50 (38.50-49.00), p=0.02) and PHQ-9 scores (0 weeks vs. 12 weeks; 3.00 (0-8.00) vs. 1.00 (0-3.00), p=0.01). We found significant differences in changes of the proportion of patients with bowel symptoms (p<0.05), functional well-being scores (p=0.04) and cancer-related FACT scores (p=0.04) between the two groups.

CONCLUSION

Probiotics improved bowel symptoms and quality of life in colorectal cancer survivors.

Cytotoxicity of probiotics from Philippine commercial dairy products on cancer cells and the effect on expression of cfos and cjun early apoptotic-promoting genes and Interleukin-1 β and Tumor Necrosis Factor-α proinflammatory cytokine genes

This study determined cytotoxicity of probiotic Lactobacillus spp. from Philippine dairy products on cancer cells and normal fibroblasts and their effects on expression of early apoptotic-promoting cfos, cjun and proinflammatory cytokine IL-1β, TNF-α genes. Cultures were from Yakult, Bear Brand Probiotic Drink, Nido3+ Powdered Milk. Filter-sterilized supernatants from cultures of Lactobacillus spp. were evaluated for cytotoxicity to colon cancer cells (HT-29 and HCT116), leukemia cells (THP-1), and normal human dermal fibroblasts (HDFn) using PrestoBlue. Bleomycin was the positive control. Absolute quantification of transcript levels was conducted using qRT-PCR. Cytotoxicity index profiles on HDFn, THP-1 of all probiotic supernatants and negative controls suggest nontoxicity to the cells when compared to bleomycin, whereas all probiotic supernatants were found to be cytotoxic to HT-29 and HCT-116 colon cancer cell lines. Expression of cfos, cjun transcripts was significantly upregulated in HT-29 and HCT116 cells treated with probiotic supernatants compared to untreated baseline levels (P < 0.05). Expression of IL-1β and TNF-α by lipopolysaccharide-treated macrophages was significantly downregulated in cells with probiotic supernatants compared to those exposed to MRS medium (P < 0.05). Results provide strong support for the role of Lactobacillus spp. studied in anticancer therapy and in prevention of inflammation that may act as precursor to carcinogenesis.

Randomized clinical trial: effect of Lactobacillus plantarum 299 v on symptoms of irritable bowel syndrome

OBJECTIVES

Irritable bowel syndrome (IBS) is a common diagnosis in gastroenterology. Its etiology is unknown and therapeutic options limited. Trials suggest probiotics may be beneficial. The aim of this study was to assess the symptomatic efficacy of Lactobacillus plantarum 299 v (L. plantarum 299 v) for the relief of abdominal pain in patients with IBS fulfilling Rome II criteria.

METHODS

This study was conducted in a referral hospital. Trial participants were randomized to receive either two capsules of L. plantarum 299 v at a dosage of 5 × 10(9) cfu per capsule or placebo daily for 8 wk. Severity of abdominal pain was assessed using a visual analog scale at each visit and a quality-of-life IBS (QoL-IBS) questionnaire was also completed.

RESULTS

There was no significant difference in abdominal pain relief between the study and placebo groups (P = 0.800). There was also no difference in QoL- IBS scores between the groups (P = 0.687). Both groups had a significant improvement in abdominal pain scores over the study period, from an average of 251.55 to 197.90 (P < 0.0001) indicating a large placebo effect.

CONCLUSION

An 8-wk treatment with L. plantarum 299 v did not provide symptomatic relief, particularly of abdominal pain and bloating, in patients fulfilling the Rome II criteria.

Effect of korean herbal medicine combined with a probiotic mixture on diarrhea-dominant irritable bowel syndrome: a double-blind, randomized, placebo-controlled trial

Introduction. Although combination therapy with herbal medicine and probiotics is gaining popularity for controlling diarrhea-dominant irritable bowel syndrome (D-IBS) symptoms, few studies have investigated its clinical effects. Materials and Methods. Fifty-three patients with D-IBS were randomly allocated into 1 of the following 4 groups: herbal medicine (Gwakhyangjeonggisan; GJS) plus probiotics (Duolac7S; DUO), GJS plus placebo DUO, placebo GJS plus DUO, and placebo GJS plus placebo DUO. The study period consisted of a 2-week run-in, 8 weeks of administration, and 2 weeks of follow-up. The primary outcomes were weekly adequate relief (AR) of overall IBS symptoms and the proportion of responders (PR) during the administration period. The secondary outcomes included individual IBS symptoms, stool assessment, and quality of life. Changes of intestinal microbiota and intestinal permeability were also analyzed. Results and Discussion. Weekly AR was not different among the 4 groups throughout the treatment period. However, the 3 treatment groups exhibited significant improvements in PR compared to the findings in the placebo group. In the intestinal microbiota assessment, herbal medicine and probiotics synergistically increased beneficial bacteria counts. Conclusion. Combination therapy with herbal medicine and probiotics appears to relieve overall IBS symptoms by synergistically increasing beneficial intestinal microbe counts.

Lactobacillus plantarum MYL26 induces endotoxin tolerance phenotype in Caco-2 cells

BACKGROUND

Crohn's disease and ulcerative colitis are the major types of chronic inflammatory bowel disease occurring in the colon and small intestine. A growing body of research has proposed that probiotics are able to attenuate the inflammatory symptoms of these diseases in vitro and in vivo. However, the mechanism of probiotic actions remains unclear.

RESULTS

Our results suggested Lactobacillus plantarum MYL26 inhibited inflammation in Caco-2 cells through regulation of gene expressions of TOLLIP, SOCS1, SOCS3, and IκBα, rather than SHIP-1 and IRAK-3.

CONCLUSIONS

We proposed that live/ heat-killed Lactobacillus plantarum MYL26 and bacterial cell wall extract treatments impaired TLR4-NFκb signal transduction through Tollip, SOCS-1 and SOCS-3 activation, thus inducing LPS tolerance. Our findings suggest that either heat-killed probiotics or probiotic cell wall extracts are able to attenuate inflammation through pathways similar to that of live bacteria.

Probiotics can generate FoxP3 T-cell responses in the small intestine and simultaneously inducing CD4 and CD8 T cell activation in the large intestine

Most studies on probiotics aim to restore intestinal homeostasis to reduce immune-pathology in disease. Of equal importance are studies on how probiotics might prevent or delay disease in healthy individuals. However, knowledge on mechanisms of probiotic actions in healthy individuals is scarce. To gain more insight in how different bacterial strains may modulate the healthy intestinal immune system, we investigated the effect of the food derived bacterial strains L. plantarum WCFS1, L. salivarius UCC118, and L. lactis MG1363, on the intestinal regulatory immune phenotype in healthy mice. All three bacterial strains induced an upregulation of activity and numbers of CD11c⁺ MHCII⁺ DCs in the immune-sampling Peyer’s Patches. Only L. salivarius UCC118 skewed towards an immune regulatory phenotype in the small intestinal lamina propria (SILP). The effects were different in the large intestine lamina propria. L. salivarius UCC118 induced activation in both CD4 and CD8 positive T-cells while L. plantarum WCFS1 induced a more regulatory phenotype. Moreover, L. plantarum WCFS1 decreased the Th1/Th2 ratio in the SILP. Also L. lactis MG1363 had immunomodulatory effects. L. lactis MG1363 decreased the expression of the GATA-3 and T-bet in the SILP. As our data show that contradictory effects may occur in different parts of the gut, it is recommended to study effects of probiotic in different sites in the intestine. Our strain-specific results suggest that unspecified application of probiotics may not be very effective. Our data also indicate that selection of specific probiotic strain activities on the basis of responses in healthy mice may be a promising strategy to specifically stimulate or suppress immunity in specific parts of the intestine.

Metabolites of Lactobacillus plantarum 2142 prevent oxidative stress-induced overexpression of proinflammatory cytokines in IPEC-J2 cell line

Probiotics have already proven beneficial effects in the treatment of several intestinal infections, but the underlying mechanisms how the probiotics can affect responses of porcine IPEC-J2 enterocytes to oxidative stress remained to be elucidated. The immunomodulatory effect of five bacterial strains (Lactobacillus plantarum 2142, Lactobacillus casei Shirota, Bifidobacterium animalis subsp. lactis BB-12, Bacillus amyloliquefaciens CECT 5940 and Enterococcus faecium CECT 4515) on 1 mM peroxide-triggered upregulation of interleukin (IL)-8 and tumor necrosis factor alpha (TNF-α) level was screened by q RT-PCR. Our data revealed that spent culture supernatant (SCS) of L. plantarum 2142 had significant lowering effect on IL-8 and TNF-α level with concomitant promoting activity on protective Hsp70 gene expression. According to our results, lactic acid (racemic, D: - and L: -lactic acid) and acetic acid produced by lactobacilli had no protective effect in quenching upregulation of proinflammatory cytokines. Furthermore, L. plantarum 2142-specific supernatant peptides were detected by gel electrophoresis and capillary zone electrophoresis.

L. plantarum, L. salivarius, and L. lactis attenuate Th2 responses and increase Treg frequencies in healthy mice in a strain dependent manner

Many studies on probiotics are aimed at restoring immune homeostasis in patients to prevent disease recurrence or reduce immune-mediated pathology. Of equal interest is the use of probiotics in sub-clinical situations, which are characterized by reduced immune function or low-grade inflammation, with an increased risk of infection or disease as a consequence. Most mechanistic studies focus on the use of probiotics in experimental disease models, which may not be informative for these sub-clinical conditions. To gain better understanding of the effects in the healthy situation, we investigated the immunomodulatory effects of two Lactobacillus probiotic strains, i.e. L. plantarum WCFS1 and L. salivarius UCC118, and a non-probiotic lactococcus strain, i.e. L. lactis MG1363, in healthy mice. We studied the effect of these bacteria on the systemic adaptive immune system after 5 days of administration. Only L. plantarum induced an increase in regulatory CD103⁺ DC and regulatory T cell frequencies in the spleen. However, all three bacterial strains, including L. lactis, reduced specific splenic T helper cell cytokine responses after ex vivo restimulation. The effect on IFN-γ, IL5, IL10, and IL17 production by CD4⁺ and CD8⁺ T cells was dependent on the strain administered. A shared observation was that all three bacterial strains reduced T helper 2 cell frequencies. We demonstrate that systemic immunomodulation is not only observed after treatment with probiotic organisms, but also after treatment with non-probiotic bacteria. Our data demonstrate that in healthy mice, lactobacilli can balance T cell immunity in favor of a more regulatory status, via both regulatory T cell dependent and independent mechanisms in a strain dependent manner.

Role of probiotics in urogenital healthcare

Urogenital infections are one of the most common causes for a woman to visit a gynecologist or a urologist. The well-known association between abnormal vaginal microbial flora and its formidable risk in the increased incidence of urinary tract infection underscores the importance of understanding the microbial flora and the efforts needed to maintain it, for ensuring urogenital health. Surprisingly in spite of the increased incidence urogenital infections receive very less attention from the medical fraternity. Growing awareness among people and newer advances in the medical field has brought them into the limelight. The importance of replenishing these depleting commensals with ‘probiotics’ has resurfaced in a big way. As the days go by science and medicines will touch new milestones, which will include probiotics. The value of a probiotics cannot be taken at face value. Probiotics must not be considered a panacea for treating urogenital infections. However, the available data promises that it will be a strong option in improving and maintaining urogenital health.

Effect of herbal extract granules combined with probiotic mixture on irritable bowel syndrome with diarrhea: study protocol for a randomized controlled trial

Background

Irritable bowel syndrome (IBS) is a chronic gastrointestinal disorder characterized by abdominal pain and change of bowel habits without organic disease. Many patients seek alternative IBS treatments because of the limitations of conventional treatments. Gwakhyangjeonggisan (GJS), a herbal formula, has long been used for alleviating diarrhea-predominant IBS (D-IBS) in traditional medicine. Duolac7S, which comprises 7 bacterial species as probiotics, has been frequently used for D-IBS. Although GJS and Duolac7S have been administered simultaneously in many D-IBS patients, no study has investigated the effects of GJS and Duolac7S combination therapy on D-IBS.

Methods/Design

The current trial is a randomized, double-blinded, placebo-controlled, 4-arm study. After a 2-week run-in period, 60 patients with D-IBS will be randomly assigned to one of the 4 combination groups consisting of GJS (water extract granules, 3 g/pack, 3 times a day) with Duolac7S (powder form, 1 capsule, 2 times a day) or their placebos and followed up for 2 weeks. The assigned treatments will last for 8 weeks. The primary outcomes are adequate relief of IBS pain and discomfort and the proportion of responders (on a weekly basis). The secondary outcomes are visual analog scale for IBS symptoms (on a daily basis), quality of life (at 0, 8, and 10 weeks), intestinal permeability, and composition of intestinal microbiota (at 0 and 8 weeks).

Discussion

The present study is designed to examine the safety and efficacy of GJS and Duolac7S combination therapy on D-IBS. Our study provides the clinical evidence of a new therapeutic strategy for D-IBS.

Trial registration

ClinicalTrials.gov NCT01342718 .

The relative efficacy of different strain combinations of lactic acid bacteria in the reduction of populations of Salmonella enterica Typhimurium in the livers and spleens of mice

Multispecies probiotics have been reported to be more effective than monostrain probiotics in health promoting for the host. In this study, 12 lactic acid bacteria (LAB) strains were selected based on the level of induction of tumor necrosis factor (TNF)-α in RAW 264.7 macrophage cells. Their adherence to Caco-2 cells and inhibitory effects on Salmonella invasion of Caco-2 cells were compared. Strains with different probiotic properties were then combined and BALB/c mice were fed with LAB strains for 63 days; then the mice were challenged with Salmonella on day 64. For Salmonella-unchallenged mice that received a multistrain combination of LAB strains that have greater TNF-α production in macrophages, greater adherence and inhibit Salmonella invasion of Caco-2 cells to a greater extent, their peritoneal macrophages had greater phagocytic activity. For Salmonella-challenged mice, a significant reduction of Salmonella cells in the livers and spleens of the mice was observed 8 days post challenge. The addition of 12% skim milk powder together with LAB strain combinations significantly enhanced the reduction of Salmonella cells in the mice livers and spleens. In conclusion, we have shown that LAB strain combinations with particular probiotic properties when fed to mice can inhibit Salmonella invasion of the liver and spleen.

Treatment of irritable bowel syndrome in women

Irritable bowel syndrome (IBS) is a complex clinical process with multiple pathophysiologic mechanisms. There has recently been a shift in the treatment of patients with severe IBS symptoms to disease-modifying therapies as opposed to symptomatic treatment. Because pathophysiologic differences exist between men and women, so does the efficacy of treatment options. These differences could further explain gender-related differences in disease prevalence and treatment response. A brief discussion of the definition, epidemiology, and diagnostic criteria of IBS is followed by a comprehensive review of the current treatment choices and potential future therapeutic options of IBS in women.

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.

Use of probiotics in gastrointestinal disorders: what to recommend?

Perturbation of bacterial microflora of the gastrointestinal (GI) tract may play an important role in the pathophysiology of some GI disorders. Probiotics have been used as a treatment modality for over a century. They may restore normal bacterial microflora and effect the functioning of the GI tract by a variety of mechanisms. Probiotics are not currently regulated and only few randomized controlled trials exist investigating their efficacy in different GI disorders. They are available in a variety of formulations and delivery systems making interpretation and comparison of studies even more difficult. The efficacy of probiotics, either as a single strain or a combination of probiotics, has been tested in antibiotic-associated diarrhea, Clostridium difficile colitis, infectious diarrhea, ulcerative colitis, Crohn's disease, pouchitis, and irritable bowel syndrome, among other disorders. Results of the studies are reviewed in this article and recommendations for probiotic use in these disorders are made. Although probiotics appear to be generally safe in an outpatient setting, the situation may be different in immunocompromised, hospitalized patients who may be at a greater risk of developing probiotic sepsis. No studies exist addressing the issue of safety specifically. Many questions regarding use of probiotics in GI disorders remain to be answered in future studies, such as most optimal doses, duration of treatment, physiological and immunological effects, efficacy of specific probiotics in specific disease states, and safety in debilitated patients.

Review article: visceral hypersensitivity in irritable bowel syndrome: molecular mechanisms and therapeutic agents

BACKGROUND

Although development of visceral pain is an important defensive mechanism, hypersensitivity results in a significant clinical problem and is likely to be one of the major factors involved in the pathogenesis of abdominal and chest pain in functional bowel disorders (FBDs). Understanding of the molecular mechanisms involved in peripheral sensitization of visceral nociceptors has advanced as a result of the experimental studies, especially in animal models, which have led to knowledge and identification of key mediators and receptors.

AIM

To provide a comprehensive review focused on the peripheral mechanisms believed to be responsible for sensitization and potential molecular targets for a disorder which is common, distressing and has sub-optimal treatment options.

METHODS

Literature review using Ovid and Pubmed from 1966.

RESULTS

There is substantial interest in the development of new drugs for treatment of FBDs in the background of advances in understanding the molecular and physiological mechanisms of visceral hypersensitivity. The potential drug targets include TPRV1, ASICs, voltage-gated sodium channels, ATP, PAR-2, cannabinoid, prostaglandin, tachykinin and 5HT(3) receptors.

CONCLUSION

It is anticipated that with advancing molecular understanding of the basis of visceral hypersensitivity, the next decade will see accelerated development of new molecules for treatment of functional bowel diseases.

The utility of probiotics in the treatment of irritable bowel syndrome: a systematic review

OBJECTIVES

Irritable bowel syndrome (IBS) is a common disorder and available therapies have limited efficacy. Mucosal inflammation and alterations in gut microflora may contribute to the development of IBS symptoms, and researchers have hypothesized that probiotics might improve these symptoms. The aim of this study was to perform a systematic review of randomized controlled trials (RCTs) evaluating the efficacy, safety, and tolerability of probiotics in the treatment of IBS.

METHODS

Comprehensive literature searches of multiple databases were performed. Study selection criteria were as follows: (i) RCTs, (ii) adults with IBS defined by Manning or Rome II criteria, (iii) single or combination probiotic vs. placebo, and (iv) improvement in IBS symptoms and/or decrease in frequency of adverse events reported. Data about study design and results were extracted in duplicate using standardized data extraction forms. Owing to variability in outcome measures, quantitative pooling of data was not feasible.

RESULTS

A total of 16 RCTs met selection criteria. Of those, 11 studies showed suboptimal study design with inadequate blinding, inadequate trial length, inadequate sample size, and/or lack of intention-to-treat analysis. None of the studies provided quantifiable data about both tolerability and adverse events. Bifidobacterium infantis 35624 showed significant improvement in the composite score for abdominal pain/discomfort, bloating/distention, and/or bowel movement difficulty compared with placebo (P<0.05) in two appropriately designed studies. No other probiotic showed significant improvement in IBS symptoms in an appropriately designed study.

CONCLUSIONS

B. infantis 35624 has shown efficacy for improvement of IBS symptoms. Most RCTs about the utility of probiotics in IBS have not used an appropriate study design and do not adequately report adverse events. Therefore, there is inadequate data to comment on the efficacy of other probiotics. Future probiotic studies should follow Rome II recommendations for appropriate design of an RCT.

Mechanisms of action of probiotics: recent advances

The intestinal microbiota plays a fundamental role in maintaining immune homeostasis. In controlled clinical trials probiotic bacteria have demonstrated a benefit in treating gastrointestinal diseases, including infectious diarrhea in children, recurrent Clostridium difficile-induced infection, and some inflammatory bowel diseases. This evidence has led to the proof of principle that probiotic bacteria can be used as a therapeutic strategy to ameliorate human diseases. The precise mechanisms influencing the crosstalk between the microbe and the host remain unclear but there is growing evidence to suggest that the functioning of the immune system at both a systemic and a mucosal level can be modulated by bacteria in the gut. Recent compelling evidence has demonstrated that manipulating the microbiota can influence the host. Several new mechanisms by which probiotics exert their beneficial effects have been identified and it is now clear that significant differences exist between different probiotic bacterial species and strains; organisms need to be selected in a more rational manner to treat disease. Mechanisms contributing to altered immune function in vivo induced by probiotic bacteria may include modulation of the microbiota itself, improved barrier function with consequent reduction in immune exposure to microbiota, and direct effects of bacteria on different epithelial and immune cell types. These effects are discussed with an emphasis on those organisms that have been used to treat human inflammatory bowel diseases in controlled clinical trials.

Probiotic administration alters the gut flora and attenuates colitis in mice administered dextran sodium sulfate

BACKGROUND

Probiotics are used in the therapy of inflammatory bowel disease. This study aimed to determine whether prior administration of probiotic lactobacilli and bifidobacteria would prevent disease and change gut flora in an animal model of colitis.

METHODS

Swiss albino mice received a probiotic mixture (four Lactobacillus and four Bifidobacterium species) or medium (control) for a week prior to induction of colitis by oral 4% dextran sodium sulfate (DSS) for seven days. Appropriate non-colitis controls were used. Histological damage was assessed (n = 5 per group), as was expression of mRNA for tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, transforming growth factor (TGF)-beta1 and SOCS-1 in the colonic mucosa (n = 6 per group). Secretion of TNF-alpha was measured in distal colon organ culture (n = 5-6 per group). Levels of Bacteroides, Bifidobacterium, and Lactobacillus acidophilus in feces were quantified by real time polymerase chain reaction (PCR) targeting 16S rDNA.

RESULTS

Compared to untreated DSS colitis, probiotic treatment significantly reduced weight loss (P < 0.05), shifted histological damage to lesser grades of severity (P < 0.001), reduced mRNA expression of TNF-alpha and TGF-beta1 (P < 0.05), and down-regulated production of TNF-alpha from distal colon explants (P < 0.05). Colitis induced a significant reduction in the relative proportions of Bifidobacterium, Bacteroides and Lactobacillus acidophilus group bacteria in feces, and these levels were significantly increased in probiotic-treated mice compared to DSS mice (P < 0.001).

CONCLUSION

Prior administration of probiotic bacteria reduced mucosal inflammation and damage in DSS-induced colitis. DSS colitis was associated with significant changes in the fecal anaerobic bacterial flora and these changes were modulated by administration of probiotic bacteria.

Probiotic Lactobacillus reuteri suppress proinflammatory cytokines via c-Jun

BACKGROUND

Differential immunoregulatory capabilities of probiotic Lactobacillus were explored in the context of pediatric Crohn's disease. Experimental strategies addressed molecular mechanisms of tumor necrosis factor (TNF) suppression in activated macrophages by transcriptional regulation.

METHODS

Secreted factors produced by probiotic Lactobacillus reuteri strains were harvested and tested with human monocytes and macrophages. Quantitative immunoassays and real-time reverse-transcriptase polymerase chain reaction (RT-PCR) were used to examine relative quantities of human cytokines and TNF mRNA, respectively, and reporter assays assessed transcriptional regulation of TNF by probiotics. DNA-protein macroarrays interrogated probiotic-mediated effects on transcription factor activation. Finally, enzyme-linked immunosorbent assays (ELISAs) and immunoblots examined the involvement of the specific transcription factor AP-1 and its components.

RESULTS

Probiotic L. reuteri strain ATCC PTA 6475 demonstrated the ability to potently suppress human TNF production by lipopolysaccharide-activated monocytes and primary monocyte-derived macrophages from children with Crohn's disease. Quantities of the chemokine MCP-1/CCL2 were also reduced by probiotic L. reuteri strain ATCC PTA 6475 in macrophages of children in remission. Quantitative real-time RT-PCR and luciferase reporter assays showed that transcriptional regulation of human TNF was a primary mechanism of probiotic-mediated immunomodulation. Probiotic L. reuteri suppressed TNF transcription by inhibiting activation of MAP kinase-regulated c-Jun and the transcription factor, AP-1.

CONCLUSIONS

Human TNF and MCP-1 suppression by probiotic L. reuteri was strain-dependent, and the activation of c-Jun and AP-1 represent primary targets for probiotic-mediated suppression of TNF transcription. This report emphasizes the clonal nature of immunoprobiosis and delineation of a specific immunomodulatory mechanism for probiotic strain selection in future inflammatory bowel disease-oriented clinical trials.

Probiotics, immunomodulation, and health benefits

Probiotics are defined as live microorganisms that, when administered in adequate amount, confer a health benefit on the host. Amongst the many benefits associated with the consumption of probiotics, modulation of the immune system has received the most attention. Several animal and human studies have provided unequivocal evidence that specific strains of probiotics are able to stimulate as well as regulate several aspects of natural and acquired immune responses. There is also evidence that intake of probiotics is effective in the prevention and/or management of acute gastroenteritis and rotavirus diarrhoea, antibiotic-associated diarrhoea and intestinal inflammatory disorders such as Crohn's disease and pouchitis, and paediatric atopic disorders. The efficacy of probiotics against bacterial infections and immunological disorders such as adult asthma, cancers, diabetes, and arthritis in humans remains to be proven. Also, major gaps exist in our knowledge about the mechanisms by which probiotics modulate immune function. Optimum dose, frequency and duration of treatment required for different conditions in different population groups also remains to be determined. Different probiotic strains vary in their ability to modulate the immune system and therefore efficacy of each strain needs to be carefully demonstrated through rigorously designed (randomised, double-blind, placebo-controlled) studies. This chapter provides an over view of the immunomodulatory effects of probiotics in health and disease, and discusses possible mechanisms through which probiotics mediate their disparate effects.

Orally administeredLactobacillus plantarumreduces pro-inflammatory interleukin secretion in sera fromListeria monocytogenesinfected mice

Lactic acid bacteria have traditionally been thought to have immunomodulating effects. To verify this property,Lactobacillus plantarumwas orally administered to mice (5 × 107colony forming units (c.f.u.)), prior to infection withListeria monocytogenesin order to evaluate the host resistance against an infectious micro-organism and to better define the influence ofL. plantarumon such responses. Balb/c mice were treated daily withL. plantarumor received PBS (sham-treated mice as controls) for 4 weeks. Subsequently, mice were intravenously infected with a clinical isolate ofL. monocytogenes. Our study revealed that the administration ofL. plantarumdid not significantly increase the survival (P = 0·13) of mice (fifteen in each group) afterL. monocytogenesinfection (106 c.f.u./ml), whereas a sub-lethal dose ofL. monocytogenes(105 c.f.u./ml) was eliminated from liver and spleen 5 d after the challenge in bothL. plantarum- and sham-treated mice (n5). Nevertheless, the levels of IL-1β and IL-6 from sera of orally administeredL. plantarumwere drastically reduced at 0, 4 (P < 0·01) and 6 d afterL. monocytogenesinfection, whereas TNF-α production was unaltered. In conclusion, administration ofL. plantarumreduced pro-inflammatory IL production after challenge withL. monocytogenes, although it did not significantly impact the survival of mice. We speculate thatL. plantarumcould exert anti-inflammatory effects, which may represent an important model to reduce inflammatory disorders. Therefore, further studies in human subjects should determine the role ofL. plantarumas an immunomodulatory micro-organism and its relationship in the host protection to pathogens.

Probiotics and prebiotics — renaissance of a therapeutic principle

Probiotics are nonpathogenic microorganisms mostly of human origin which, when administered in adequate amounts, confer a health benefit on the host and enable to prevent or improve some diseases. Probiotics may be a natural temporary constituent of the resident intestinal microflora, but their concentration is not sufficient for therapeutic purposes. The microbiota, the intestinal epithelium, and the mucosal immune system constitute the gastrointestinal ecosystem. All three components are essential for complete functional and developmental maturity of the system. The viability of intestinal microflora (including probiotic strains) requires the availability of nutritional substrates (prebiotics), i.e. various types of fiber and oligosaccharides. Prebiotics are cleaved by microbial enzymes to numerous substances (short-chain fatty acids, aminoacids, polyamines, growth factors, vitamins and antioxidants) indispensable for metabolic and functional activities of the intestinal mucosa. The principal probiotics in use include lactobacilli, bifidobacteria, some nonpathogenic strains of Escherichia coli, and Saccharomyces boulardii. These microbiota display favourable effects which qualify them for therapeutic use. For this purpose, probiotics have to fulfill a series of requirements verifying their efficacy and safety. Experimental and clinical studies examine the prerequisites for the administration of probiotics in digestive diseases, allergic and atopic affections, as well as in some extraintestinal conditions. Future goals of probiotic application include genomic analysis, controlled postnatal colonisation of the digestive tract, the use of probiotics as carriers of peroral vaccines, and recombinant probiotics with in-situ production and targeted application of therapeutic molecules.