Probiotics and prebiotics in gastrointestinal disorders

Postbiotics Production of Candidate-Probiotic Lactiplantibacillus plantarum AC131 with Renewable Bio Resources

Lactiplantibacillus plantarum is a versatile specie, well known as a producer of lactic acid (LA) and other metabolites with biotechnological significance. The present work characterizes growth and lactic acid production of the candidate-probiotic strain L. plantarum AC131, from Bulgarian white brined cheeses. Different nutritional media with ingredients from renewable resources-reduced sugars from dried distillers' grains with soluble (DDGS) and waste waters from the water-vapor distillation of Bulgarian Rosa alba L. and Rosa damascena Mill. essential oil-were assessed. The results obtained showed significant LA production (up to 95% conversion) in modified MRS broth with reducing sugars from DDGS hydrolysates. The addition of R. alba L. and R. damascena Mill. distillation effluents stimulated the growth and biological activity of postbiotics produced by L. plantarum AC131. In both experimental approaches, a statistically significant inhibition (from 20 to 60%) of E. coli HB 101 growth was found during 24 h exposure and a variable effect on the biofilm formed. In conclusion, reducing sugars from DDGS hydrolysates can be successfully used as a carbon source for lactic acid production. In the case of fermentation without pH control, the process is product inhibited, while with pH control, nearly full conversion was achieved. Postbiotics produced during the process of fermentation showed a variety of biological activity and inhibitory effects on the growth of Escherichia coli HB 101.

Modulatory Effect of Beneficial Enterococci and Their Enterocins on the Blood Phagocytes in Murine Experimental Trichinellosis

Bacteriocins (enterocins) represent a new therapeutic strategy in various intestinal and non-intestinal infections. In antiparasitic defence, an oxidative inflammation of phagocytes is effective in destroying new-born Trichinella spiralis larvae. The strains Enterococcus faecium CCM8558 and E. durans ED26E/7 and their enterocins, enterocin M and a durancin-like enterocin, respectively, were administered daily, and mice were then infected with T. spiralis larvae on the seventh day of treatment. Phagotest and Bursttest kits were used to detect the phagocytosis and respiratory burst in blood leukocytes. T. spiralis infection inhibited phagocytosis from day 11 post-infection (dpi) during the migration of new-born larvae into the muscles. E. faecium CCM8558, E. durans ED26E/7, and the durancin-like enterocin increased phagocytic activity from day 11 dpi. Both strains and their enterocins (enterocin M and durancin-like) stimulated the ingestion capability of phagocytes from 18 to 32 dpi. Enterococci/enterocins therapy prevented a reduction in cells with respiratory burst caused by T. spiralis infection from 11 dpi. The enzymatic activity of phagocytes was stimulated on 18 and 25 dpi, particularly by E. faecium CCM8558 and enterocin M. Enterocin M and the durancin-like enterocin were as effective in stimulating phagocytosis as the bacterial strains that produce them. The stimulation of phagocytosis could contribute to decreased larval migration and reduced parasite burden in the host.

Metabolic-Associated Fatty Liver Disease and the Gut Microbiota

As an important sequela of the burgeoning global obesity problem, metabolic-associated fatty liver disease (MAFLD) has gained increasing prominence recently. The gut-liver axis (GLA) provides a direct conduit to the liver for the gut microbiota and their metabolic by-products (including secondary bile acids, ethanol, and trimethylamine). These GLA-related factors, including the host inflammatory response and integrity of the gut mucosal wall, likely contribute to the pathogenesis of MAFLD. Accordingly, these GLA-related factors are targets for possible preventive and treatment strategies for MAFLD, and include probiotics, prebiotics, bile acids, short-chain fatty acids, fecal microbiota transplantation, carbon nanoparticles, and bacteriophages.

Dietary Sodium Butyrate Improves Intestinal Health of Triploid Oncorhynchus mykiss Fed a Low Fish Meal Diet

This study aimed to determine the effects of dietary sodium butyrate (NaB) on the growth and gut health of triploid Oncorhynchus mykiss juveniles (8.86 ± 0.36 g) fed a low fish meal diet for 8 weeks, including the inflammatory response, histomorphology, and the composition and functional prediction of microbiota. Five isonitrogenous and isoenergetic practical diets (15.00% fish meal and 21.60% soybean meal) were supplemented with 0.00% (G1), 0.10% (G2), 0.20% (G3), 0.30% (G4), and 0.40% NaB (G5), respectively. After the feeding trial, the mortality for G3 challenged with Aeromonas salmonicida for 7 days was lower than that for G1 and G5. The optimal NaB requirement for triploid O. mykiss based on weight gain rate (WGR) and the specific growth rate (SGR) was estimated to be 0.22% and 0.20%, respectively. The activities of intestinal digestive enzymes increased in fish fed a NaB diet compared to G1 (p < 0.05). G1 also showed obvious signs of inflammation, but this inflammation was significantly alleviated with dietary NaB supplementation. In comparison, G3 exhibited a more complete intestinal mucosal morphology. Dietary 0.20% NaB may play an anti-inflammatory role by inhibiting the NF-κB-P65 inflammatory signaling pathway. Additionally, the relative abundance of probiotics was altered by dietary NaB. In conclusion, dietary 0.20% NaB improved the intestinal health of triploid O. mykiss fed a low fish meal diet.

IL-22 and Lactobacillus delbrueckii mitigate alcohol-induced exacerbation of DSS-induced colitis

Ulcerative colitis (UC) is characterized by cycles of active disease flare and inactive disease remission. During UC remission, IL-22 is up-regulated, acting as a hallmark of entrance into UC remission. Recently, we found that in our mouse model of binge alcohol and dextran sodium sulfate (DSS)-induced colitis, alcohol increases severity of UC pathology. In this study, we assessed not only whether alcohol influenced IL-22 expression and thereby perpetuates UC, but also whether recombinant IL-22 (rIL-22) or treatment with a probiotic could alleviate exacerbated symptoms of UC. Levels of large intestine IL-22 were significantly decreased ∼6.9-fold in DSS ethanol compared with DSS vehicle. Examination of lamina propria (LP) cells in the large intestine revealed IL-22+ γδ T cells in DSS vehicle-treated mice were significantly increased, while IL-22+ γδ T cells in DSS ethanol mice were unable to mount this IL-22 response. We administered rIL-22 and found it restored weight loss of DSS ethanol-treated mice. Colonic shortening and increased Enterobacteriaceae were also attenuated. Administration of Lactobacillus delbrueckii attenuated weight loss (p < 0.01), colon length (p < 0.001), mitigated increases in Enterobacteriaceae, increased levels of IL-22, and increased levels of p-STAT3 back to that of DSS vehicle group in DSS ethanol mice. In contrast, sole administration of L. delbrueckii supernatant was not sufficient to reduce UC exacerbation following alcohol. Our findings suggest L. delbrueckii contributes to repair mechanisms by increasing levels of IL-22, resulting in phosphorylation of STAT3, thus attenuating the alcohol-induced increases in intestinal damage after colitis.

In Vitro Production of Galactooligosaccharides by a Novel β-Galactosidase of Lactobacillus bulgaricus

β-galactosidase is an enzyme with dual activity and important industrial application. As a hydrolase, the enzyme eliminates lactose in milk, while as a trans-galactosidase it produces prebiotic galactooligosaccharides (GOS) with various degrees of polymerization (DP). The aim of the present study is the molecular characterization of β-galactosidase from a Bulgarian isolate, Lactobacillus delbrueckii subsp. bulgaricus 43. The sequencing of the β-gal gene showed that it encodes a new enzyme with 21 amino acid replacements compared to all other β-galactosidases of this species. The molecular model revealed that the new β-galactosidase acts as a tetramer. The amino acids D207, H386, N464, E465, Y510, E532, H535, W562, N593, and W980 form the catalytic center and interact with Mg²⁺ ions and substrate. The β-gal gene was cloned into a vector allowing heterologous expression of E. coli BL21(DE3) with high efficiency, as the crude enzyme reached 3015 U/mL of the culture or 2011 U/mg of protein. The enzyme's temperature optimum at 55 °C, a pH optimum of 6.5, and a positive influence of Mg²⁺, Mn²⁺, and Ca²⁺ on its activity were observed. From lactose, β-Gal produced a large amount of GOS with DP3 containing β-(1→3) and β-(1→4) linkages, as the latter bond is particularly atypical for the L. bulgaricus enzymes. DP3-GOS formation was positively affected by high lactose concentrations. The process of lactose conversion was rapid, with a 34% yield of DP3-GOS in 6 h, and complete degradation of 200 g/L of lactose for 12 h. On the other hand, the enzyme was quite stable at 55 °C and retained about 20% of its activity after 24 h of incubation at this temperature. These properties expand our horizons as regards the use of β-galactosidases in industrial processes for the production of lactose-free milk and GOS-enriched foods.

Biological activity of galacto-oligosaccharides: A review

Galacto-oligosaccharides (GOS) are oligosaccharides formed by β-galactosidase transgalactosylation. GOS is an indigestible food component that can pass through the upper gastrointestinal tract relatively intact and ferment in the colon to produce short-chain fatty acids (SCFAs) that further regulate the body’s intestinal flora. GOS and other prebiotics are increasingly recognized as useful food tools for regulating the balance of colonic microbiota-human health. GOS performed well compared to other oligosaccharides in regulating gut microbiota, body immunity, and food function. This review summarizes the sources, classification, preparation methods, and biological activities of GOS, focusing on the introduction and summary of the effects of GOS on ulcerative colitis (UC), to gain a comprehensive understanding of the application of GOS.

Update of Probiotics in Human World: A Nonstop Source of Benefactions till the End of Time

Lactic acid bacteria (LAB) are known for their biotechnological potential. Moreover, LAB are distinguished by amazing criteria: Adjusting the intestinal environment, inhibiting pathogenic microbes in the gastrointestinal tract, ability to reduce pathogen adhesion activity, improving the balance of the microbiota inside the intestine, capabilities of regulating intestinal mucosal immunity, and maintaining intestinal barrier function. The escalating number of research and studies about beneficial microorganisms and their impact on promoting health has attracted a big interest in the last decades. Since antiquity, various based fermented products of different kinds have been utilized as potential probiotic products. Nevertheless, the current upsurge in consumers' interest in bioalternatives has opened new horizons for the probiotic field in terms of research and development. The present review aims at shedding light on the world of probiotics, a continuous story of astonishing success in various fields, in particular, the biomedical sector and pharmaceutical industry, as well as to display the importance of probiotics and their therapeutic potential in purpose to compete for sturdy pathogens and to struggle against diseases and acute infections. Shadows and future trends of probiotics use are also discussed.

Prebiotics Fructo-, Galacto-, and Mannan-Oligosaccharide Do Not Protect against 5-Fluorouracil-Induced Intestinal Mucositis in Rats

BACKGROUND

Prebiotics selectively stimulate the growth of beneficial bacteria within the gastrointestinal tract, and have been investigated in human and animal studies for their capacity to improve intestinal health.

OBJECTIVE

We investigated the prebiotics fructo-oligosaccharide (FOS), galacto-oligosaccharide (GOS), and mannan-oligosaccharide (MOS) for their potential to alleviate intestinal damage in rats.

METHODS

Female Dark Agouti rats (6-8 wk old, 110-150 g) were allocated to 1 of the following treatment groups (n = 8/group): saline/water, saline/FOS, saline/GOS, saline/MOS, 5-fluorouracil (5FU)/water, 5FU/FOS, 5FU/GOS, and 5FU/MOS. Rats were pretreated with either 5% GOS, MOS, or FOS or vehicle (water) from day -12 to day 0. On day 0, rats received a single intraperitoneal injection of saline or 5FU. Metabolic data were recorded daily and all rats were killed on day 3. Histopathology was quantified in hematoxylin and eosin-stained sections. Intestinal sucrase and myeloperoxidase activity were quantified by biochemical assay. Fecal SCFAs-acetic, propionic, and butyric acid-were also measured. Statistical analysis was by repeated-measures, 2-factor ANOVA or Kruskal-Wallis and Mann-Whitney U test; P < 0.05 was considered statistically significant.

RESULTS

Body weight was significantly decreased in all treatment groups after 5FU injection, with no change in body weight observed in any prebiotic treatment group. Total food intake was lower by ≥7% in the GOS treatment group pre-5FU than in all other groups (P < 0.05). Ileal villus height was 18% higher in GOS-treated rats pre-5FU than in respective water controls (P < 0.05). Jejunal and ileal villus height and crypt depth were significantly decreased in all treatment groups after 5FU injection, with no prebiotic effect observed. SCFAs were differentially increased in prebiotic treatment groups compared with water-only controls (P < 0.05).

CONCLUSIONS

FOS, GOS, and MOS have differential effects in modifying small intestinal pathology and SCFA profiles in rats with healthy and damaged small intestinal mucosa.

Prebiotics: A Potential Treatment Strategy for the Chemotherapy-damaged Gut?

Mucositis, characterized by ulcerative lesions along the alimentary tract, is a common consequence of many chemotherapy regimens. Chemotherapy negatively disrupts the intestinal microbiota, resulting in increased numbers of potentially pathogenic bacteria, such as Clostridia and Enterobacteriaceae, and decreased numbers of "beneficial" bacteria, such as Lactobacilli and Bifidobacteria. Agents capable of restoring homeostasis in the bowel microbiota could, therefore, be applicable to mucositis. Prebiotics are indigestible compounds, commonly oligosaccharides, that seek to reverse chemotherapy-induced intestinal dysbiosis through selective colonization of the intestinal microbiota by probiotic bacteria. In addition, evidence is emerging that certain prebiotics contribute to nutrient digestibility and absorption, modulate intestinal barrier function through effects on mucin expression, and also modify mucosal immune responses, possibly via inflammasome-mediated processes. This review examines the known mechanisms of prebiotic action, and explores their potential for reducing the severity of chemotherapy-induced mucositis in the intestine.

Treatment of in vitro enterohemorrhagic Escherichia coli infection using phage and probiotics

AIMS

To assay the combination of phage and probiotics against EHEC in vitro on infected Hep-2 cells.

METHODS AND RESULTS

Phage and probiotics treatments on EHEC O157:H7-infected Hep-2 cells were assayed individually or combined. The effect of freeze-drying on phage and probiotic antimicrobial activity was also studied. While treatment with phage alone increased cell detachment caused by EHEC infection, the treatments with MM alone or in combination with phage proved to effectively diminish cell damage caused by EHEC infection. Combined treatment showed a decrease in apoptotic cell count of 57·3% and a reduction in EHEC adhesion to cell monolayer of 1·2 log CFU. The simultaneous use of phage and probiotics showed no antagonistic effect, and freeze-drying did not affect their antipathogenic activity.

CONCLUSIONS

The combination of phage and probiotics has great potential for reducing the number of pathogens adhered to epithelial cells during EHEC O157:H7 infection and attenuating the cytotoxic effect derived from it. Further in vivo assays are needed for assessing the actual effectiveness of the treatment.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study presents a freeze-dried formulation of phage and probiotics capable of controlling EHEC infections and reducing epithelial cell damage in vitro.

Safety and long-term effect of the probiotic FK-23 in patients with hepatitis C virus infection

A clinical trial was conducted on 39 adult HCV-positive subjects to determine the safety and long-term effect of the probiotic FK-23 (heat-treated Enterococcus faecalis strain FK-23). Asymptomatic anti-HCV positive adults who fulfilled the selection criteria and gave voluntary consent were recruited from attendees of the Hepatitis Carrier Clinic, Department of Medical Research (Lower Myanmar). Each subject was given 2,700 mg of FK-23 per day by oral route. Blood samples were taken at enrollment and every 3 months and tested for alanine aminotransferase (ALT) and aspartate transaminase (AST). Viral load, urea, total protein, hemoglobin and platelet count were determined every 6 months. Among the subjects, 23 completed 36 months, 31 completed 24 months, 35 completed 12 months and 37 completed 6 months of probiotic therapy. Significant decreases in mean ALT levels were observed at 3 months (34. 9 ± 15.1 IU/l) as compared with the initial level (64.8 ± 17.5 IU/l) and persisted up to 36 months (43.7 ± 25.2 IU/l). Decrease of AST was detected after 9 months (46.2 ± 21.7 IU/l) of probiotic therapy as compared with the initial level (64.3 ± 28.7 IU/l). FK-23 was safe based on the stable levels of biochemical and hematological parameters and the absence of untoward side effects. The FK-23 preparation was well tolerated and accepted by the subjects.

Allergic diseases among children: nutritional prevention and intervention

Allergic diseases comprise a genetically heterogeneous group of chronic, immunomediated diseases. It has been clearly reported that the prevalence of these diseases has been on the rise for the last few decades, but at different rates, in various areas of the world. This paper discusses the epidemiology of allergic diseases among children and their negative impact on affected patients, their families, and societies. These effects include the adverse effects on quality of life and economic costs. Medical interest has shifted from tertiary or secondary prevention to primary prevention of these chronic diseases among high-risk infants in early life. Being simple, practical, and cost-effective are mandatory features for any candidate methods delivering these strategies. Dietary therapy fits this model well, as it is simple, practical, and cost-effective, and involves diverse methods. The highest priority strategy is feeding these infants breast milk. For those who are not breast-fed, there should be a strategy to maintain beneficial gut flora that positively influences intestinal immunity. We review the current use of probiotics, prebiotics, and synbiotics, and safety and adverse effects. Other dietary modalities of possible potential in achieving this primary prevention, such as a Mediterranean diet, use of milk formula with modified (hydrolyzed) proteins, and the role of micronutrients, are also explored. Breast-feeding is effective in reducing the risk of asthma, allergic rhinitis, and atopic eczema among children. In addition, breast milk constitutes a major source of support for gut microbe colonization, due to its bifidobacteria and galactooligosaccharide content. The literature lacks consensus in recommending the addition of probiotics to foods for prevention and treatment of allergic diseases, while prebiotics may prove to be effective in reducing atopy in healthy children. There is insufficient evidence to support soy formulas or amino acid formulas for prevention of allergic disease. A healthy diet, such as the Mediterranean diet, may have a protective effect on the development of asthma and atopy in children. In children with asthma and allergic diseases, vitamin D deficiency correlates strongly with asthma, allergic rhinitis, and wheezing.

Personalized Medicine for Sepsis

Sepsis is a complex syndrome triggered by infection and characterized by systemic deregulation of immune and inflammatory pathways. It is a major cause of death worldwide and results in the widespread use of antibiotics and substantial health care costs. In a vicious circle, sepsis treatment promotes the emergence of highly virulent and resistant pathogens and devastating nosocomial infections. Sepsis is a heterogeneous disease affecting many people worldwide. Because individual patients have different inflammatory responses and unique profiles of immune activation against pathogens, the most effective way to advance the treatment of sepsis is probably through a tailored approach. The advent of high-throughput technologies and the remarkable progress in the field of bioinformatics has allowed the subclassification of many pathological conditions. This has potential to provide better understanding of life-threatening infections in people. The study of host factors, however, needs to be integrated with studies on bacterial signaling in both symbiotic and pathogenic bacteria. Sepsis is certainly the sum of multiple host-microbial interactions and the metagenome should be extensively investigated. Personalized medicine is probably the only strategy able to deconstruct and reassemble our knowledge about sepsis, and its use should allow us to understand and manipulate sepsis as a wide, interconnected phenomenon with myriad variables and peculiarities. In this study, the recent advances in this area, the major challenges that remain, and the reasons why the septic patient should be approached as a superorganism are discussed.

The multiple roles of sucrase-isomaltase in the intestinal physiology

Osmotic diarrhea and abdominal pain in humans are oftentimes associated with carbohydrate malabsorption in the small intestine due to loss of function of microvillar disaccharidases. Disaccharidases are crucial for the digestion and the subsequent absorption of carbohydrates. This review focuses on sucrase-isomaltase as the most abundant intestinal disaccharidase and the primary or induced pathological conditions that affect its physiological function. Congenital defects are primary factors which directly influence the transport and function of sucrase-isomaltase in a healthy epithelium. Based on the mutation type and the pattern of inheritance, a mutation in the sucrase-isomaltase gene may exert a variety of symptoms ranging from mild to severe. However, structure and function of wild type sucrase-isomaltase can be also affected by secondary factors which influence its structure and function either specifically via certain inhibitors and therapeutic agents or generally as a part of intestinal pathogenesis, for example in the inflammatory responses. Diagnosis of sucrase-isomaltase deficiency and discriminating it from other gastrointestinal intolerances can be latent in the patients because of common symptoms observed in all of these cases.

Here, we summarize the disorders that implicate the digestive function of sucrase-isomaltase as well as the diagnostic and therapeutic strategies utilized to restore normal intestinal function.

Efficacy of Synbiotics for Treatment of Bacillary Dysentery in Children: A Double-Blind, Randomized, Placebo-Controlled Study

Bacillary dysentery is a major cause of children's admission to hospitals. To assess the probiotic and prebiotic (synbiotics) effects in children with dysentery in a randomized clinical trial, 200 children with dysentery were studied in 2 groups: the synbiotic group received 1 tablet/day of synbiotic for 3-5 days and the placebo group received placebo tablets (identical tablet form like probiotics). The standard treatment was administered for all patients. Duration of hospitalization, dysentery, fever, and the weight loss were assessed in each group. It was concluded that there was no significant difference in both groups in the baseline characteristics. The mean duration of dysentery reduced (P < 0.05). The mean duration of fever has been significantly reduced in the synbiotic group (1.64 ± 0.87 days) in comparison to the placebo group (2.13 ± 0.94 days) (P < 0.001). Average amount of weight loss was significantly lower in the synbiotic group in comparison to that in the placebo group (129.5 ± 23.388 grams and 278 ± 28.385 grams, resp.; P < 0.001). There was no significant difference in the mean duration of hospitalization in both groups (P > 0.05). The use of synbiotics as an adjuvant therapy to the standard treatment of dysentery significantly reduces the duration of dysentery, fever, and rate of weight losses. The trial is registered with IRCT201109267647N1.

Oligosaccharides in infant formula: more evidence to validate the role of prebiotics

The gastrointestinal (GI) microbiota differs between breast-fed and classic infant formula-fed infants. Breast milk is rich in prebiotic oligosaccharides (OS) and may also contain some probiotics, but scientific societies do not recommend the addition of prebiotic OS or probiotics to standard infant formula. Nevertheless, many infant formula companies often add one or the other or both. Different types of prebiotic OS are used in infant formula, including galacto-oligosaccharide, fructo-oligosaccharide, polydextrose and mixtures of these OS, but none adds human milk OS. There is evidence that the addition of prebiotics to infant formula brings the GI microbiota of formula-fed infants closer to that of breast-fed infants. Prebiotics change gut metabolic activity (by decreasing stool pH and increasing SCFA), have a bifidogenic effect and bring stool consistency and defecation frequency closer to those of breast-fed infants. Although there is only limited evidence that these changes in GI microbiota induce a significant clinical benefit for the immune system, interesting positive trends have been observed in some markers. Additionally, adverse effects are extremely seldom. Prebiotics are added to infant formula because breast milk contains human milk OS. Because most studies suggest a trend of beneficial effects and because these ingredients are very safe, prebiotics bring infant formula one step closer to the golden standard of breast milk.

Probiotics prophylaxis in infants with primary vesicoureteral reflux

BACKGROUND

In this era of increasing bacterial resistance to antimicrobial therapy, probiotics have great potential and yet they are a harmless alternative approach. This study is a prospective randomized uncontrolled trial to investigate the preventive effect of probiotic prophylaxis in infants with primary vesicoureteral reflux (VUR) and frequently recurring urinary tract infection (UTI) during the first follow-up year.

METHODS

One hundred and twenty-eight infants (aged 1 week to 12 months) with primary VUR were prospectively randomized into a probiotic (n = 64, Lactobacillus acidophilus, 1.0 × 10(8) CFU/g) or antibiotic (n = 64, trimethoprim/sulfamethoxazole, 2/10 mg/kg) group.

RESULTS

The incidence of recurrent UTI in the probiotic group was slightly lower than in the antibiotic group without statistical significance (32.8 % [21 out of 64] vs 40.6 % [26/64]) (P = 0.348). Causative organisms of recurrent UTI, resolution rate of VUR, and development of renal scarring were not different between the probiotic and antibiotic prophylaxis groups. The incidences of antibiotic resistance of causative organisms in recurrent UTI were significantly lower in the probiotic group than in the antibiotic group.

CONCLUSIONS

Probiotics could be considered a natural alternative regimen for prophylaxis in infants with primary VUR.

Gut microbiota and liver diseases

Several studies revealed that gut microbiota are associated with various human diseases, e.g., metabolic diseases, allergies, gastroenterological diseases, and liver diseases. The liver can be greatly affected by changes in gut microbiota due to the entry of gut bacteria or their metabolites into the liver through the portal vein, and the liver-gut axis is important to understand the pathophysiology of several liver diseases, especially non-alcoholic fatty liver disease and hepatic encephalopathy. Moreover, gut microbiota play a significant role in the development of alcoholic liver disease and hepatocarcinogenesis. Based on these previous findings, trials using probiotics have been performed for the prevention or treatment of liver diseases. In this review, we summarize the current understanding of the changes in gut microbiota associated with various liver diseases, and we describe the therapeutic trials of probiotics for those diseases.

Effects of synbiotics injected in ovo on regulation of immune-related gene expression in adult chickens

OBJECTIVE

To determine immunomodulatory effects of synbiotics administered in ovo on immune-related gene expression in adult chickens.

ANIMALS

30 Green-legged Partridgelike chickens.

PROCEDURES

On incubation day 12, eggs were injected with 3 synbiotics (Lactococcus lactis subsp lactis IBB SL1 with raffinose family oligosaccharides [RFOs; S1], Lactococcus lactis subsp cremoris IBB SC1 with RFOs [S2], and Lactobacillus acidophilus and Streptococcus faecium with lactose [S3]). Control eggs were injected with RFOs prebiotic or saline (0.9% NaCl) solution. Gene expression of 6 cytokines (interleukin [IL]-4, IL-6, IL-12p40, IL-18, interferon [IFN]-β, and IFN-γ) and 1 chemokine (IL-8) was analyzed in the cecal tonsils and spleen of 6-week-old chickens by means of reverse transcription quantitative PCR assays.

RESULTS

Gene expression for IL-4, IL-6, IFN-β, and IL-18 was significantly upregulated in the spleen of chickens in groups S2 and S3. In contrast, IL-12 expression was downregulated in group S2 and IFN-γ expression was downregulated in group S3. Expression of IL-8 did not change in chickens treated with synbiotics in ovo. Gene expression of all cytokines, except for IL-18, was downregulated in cecal tonsils.

CONCLUSIONS AND CLINICAL RELEVANCE

In ovo administration of synbiotics activated the immune system in adult chickens. The intestinal immune system (cecal tonsils) had downregulation of expression for the cytokines evaluated, which indicated an increase in oral tolerance, whereas in the peripheral part of the immune system (spleen), expression of IL-4 and IL-6 was upregulated. Evaluation of immune-related gene expression patterns may be useful when monitoring the effectiveness of synbiotic selection with respect to immunobiotic properties.

The use of probiotics in pediatric gastroenterology: a review of the literature and recommendations by Latin-American experts

OBJECTIVE

The stability and composition of intestinal flora plays a vital role in human wellbeing throughout life from as early as birth. Over the past 50 years, several studies have been conducted to evaluate the effect of probiotic administration in pediatric gastroenterology. This document aims to provide a recommendation score on probiotic utilization in pediatric gastroenterology, together with a review of current knowledge concerning its benefits, tolerability, and safety.

STUDY DESIGN

Published literature was selected without study design restriction: clinical guidelines, meta-analyses, randomized controlled trials (RCTs), cohort studies, outcomes research and case-controlled studies were selected using the following MESH-validated terms: probiotics, diarrhea, acute diarrhea, antibiotic-associated diarrhea, traveler's diarrhea, bacterial diarrhea, nosocomial diarrhea, prophylactic diarrhea, Helicobacter pylori infection, colic, infantile colic, necrotizing enterocolitis (NEC), inflammatory bowel disease, constipation, and allergy. Once the validity and the quality of results were evaluated, a recommendation score and level of evidence were assigned for pediatric gastrointestinal-related conditions, according to the updated Evidence-Based Medicine guidelines: 1a for systematic review (SR) of RCTs, 1b for individual RCT, 1c for SR and individual RCT, 2a for SR of cohort studies, 2b for individual cohort studies, 2c for outcomes research, and 3a for SR of case-control studies.

RESULTS AND CONCLUSIONS

The Latin American Expert group consensus recommends the use of the following probiotics for pediatric gastrointestinal conditions: prevention of acute infectious diarrhea (AID): 1b for Bifidobacterium lactis, Lactobacillus rhamnosus GG (LGG), and L. reuteri; prevention of nosocomial diarrhea: 1 b for B. lactis Bb12, B. bifidum, LGG and Streptococcus thermophiles; treatment of AID: 1a for LGG and S. boulardii, 1b for L. reuteri; prevention of antibiotic-associated diarrhea: 1b for LGG and S. boulardii; prevention of traveler's diarrhea: 1b for S. boulardii; prevention of infantile colic: 1a for L. reuteri DSM 17938; treatment of infantile colic: 1b for L. reuteri DSM 17938; prevention of NEC: 1a for B. breve, mixtures of Bifidobacterium and Streptococcus, LGG, L. acidophilus and L. reuteri DSM 17938; induction and maintenance of remission in ulcerative colitis: 1b for VSL#3; improving symptoms of irritable bowel syndrome: 2c for LGG and VSL#3.

Probiotics: an update

OBJECTIVE

Triggered by the growing knowledge on the link between the intestinal microbiome and human health, the interest in probiotics is ever increasing. The authors aimed to review the recent literature on probiotics, from definitions to clinical benefits, with emphasis on children.

SOURCES

Relevant literature from searches of PubMed, CINAHL, and recent consensus statements were reviewed.

SUMMARY OF THE FINDINGS

While a balanced microbiome is related to health, an imbalanced microbiome or dysbiosis is related to many health problems both within the gastro-intestinal tract, such as diarrhea and inflammatory bowel disease, and outside the gastro-intestinal tract such as obesity and allergy. In this context, a strict regulation of probiotics with health claims is urgent, because the vast majority of these products are commercialized as food (supplements), claiming health benefits that are often not substantiated with clinically relevant evidence. The major indications of probiotics are in the area of the prevention and treatment of gastro-intestinal related disorders, but more data has become available on extra-intestinal indications. At least two published randomized controlled trials with the commercialized probiotic product in the claimed indication are a minimal condition before a claim can be sustained. Today, Lactobacillus rhamnosus GG and Saccharomyces boulardii are the best-studied strains. Although adverse effects have sporadically been reported, these probiotics can be considered as safe.

CONCLUSIONS

Although regulation is improving, more stringent definitions are still required. Evidence of clinical benefit is accumulating, although still missing in many areas. Misuse and use of products that have not been validated constitute potential drawbacks.

Immunomodulatory effect of non-viable components of probiotic culture stimulated with heat-inactivated Escherichia coli and Bacillus cereus on holoxenic mice

Background

Competition of probiotic bacteria with other species from the intestinal microbiota involves different mechanisms that occur regardless of probiotics’ viability. The objective of this paper was to assess the cytokine serum levels in holoxenic mice after oral administration of non-viable components (NVC) of Enterococcus faecium probiotic culture stimulated with heat-inactivated Escherichia coli and Bacillus cereus in comparison to NVC of unstimulated E. faecium probiotic culture.

Methods

Probiotic E. faecium CMGb 16 culture, grown in the presence of heat-inactivated cultures of E. coli and B. cereus CMGB 102, was subsequently separated into supernatant (SN) and heat-inactivated cellular sediment (CS) fractions by centrifugation. Each NVC was orally administered to holoxenic mice (balb C mouse strain), in three doses, given at 24 hours. Blood samples were collected from the retinal artery, at 7, 14, and 21 days after the first administration of the NVC. The serum concentrations of IL-12 and tumor necrosis factor-alpha (TNF-α) interleukins were assessed by ELISA method.

Results

After the oral administration of SN component obtained from the probiotic culture stimulated with heat-inactivated cultures of B. cereus CMGB 102 and E. coli O28, the serum concentrations of IL-12 were maintained higher in the samples collected at 7 and 14 days post-administration. No specific TNF-α profile could be established, depending on stimulated or non-stimulated probiotic culture, NVC fraction, or harvesting time.

Conclusion

The obtained results demonstrate that non-viable fractions of probiotic bacteria, stimulated by other bacterial species, could induce immunostimulatory effects mediated by cytokines and act, therefore, as immunological adjuvants.

Safety assessment of the butyrate-producing Butyricicoccus pullicaecorum strain 25-3(T), a potential probiotic for patients with inflammatory bowel disease, based on oral toxicity tests and whole genome sequencing

Inflammatory bowel disease (IBD) is a chronic inflammation of the digestive tract, characterized by dysbiosis of the intestinal microbiota. Probiotics have been suggested as a strategy to reduce active disease or extend remission. We isolated and characterized the butyrate-producing strain Butyricicoccus pullicaecorum 25-3(T) and identified it as a potential probiotic for patients with IBD. To evaluate the safety of 25-3(T) for use in humans, we conducted a standard acute oral toxicity test and a 28-day repeated oral dose toxicity test. The complete genome of B. pullicaecorum 25-3(T) was sequenced to search for virulence factors and antibiotic resistance determinants. The minimum inhibitory concentration (MIC) of 21 antimicrobials was determined. Results showed no adverse effects in the oral toxicity tests. B. pullicaecorum 25-3(T) is resistant against aminoglycosides and trimethoprim. The genome of 25-3(T) contains no virulence factors, one gene related to harmful metabolites and 52 sequences with high similarity to antimicrobial and toxic compound resistance genes, that did not correspond with a resistant phenotype. This first report of a safety assessment of a butyrate-producing strain from Clostridium cluster IV shows that B. pullicaecorum 25-3(T) is a non-pathogenic strain, but carries antibiotic resistance genes with the risk of transfer, that need further investigation.

Effect of Dietary Cyclic Nigerosylnigerose on Intestinal Immune Functions in Mice

We examined the dietary effects of cyclic nigerosylnigerose (CNN), a dietary indigestible oligosaccharide with four D-glucopyranosyl residues linked by alternating alpha-(1-->3)- and alpha-(1-->6) glucosidic linkages, on the intestinal immune function of mice, and the effects were compared with those of alpha-(1-->3)-linked oligosaccharide (nigerooligosaccharides, NOS) or alpha-(1-->6)-linked oligosaccharide (isomaltooligosaccharides, IMO). BALB/c mice were fed with 1-5% CNN, 5% IMO, or 12.5% NOS for 4 weeks, and the intestinal mucosal immune responses were determined. In the 1-5% CNN fed groups, the amounts of IgA in feces increased significantly. In addition, IgA, transforming growth factor-beta1 (TGF-beta1), and interleukin-6 (IL-6) secretion by Peyer's patch (PP) cells were enhanced in CNN fed mice. In the 5% CNN group, pH in the cecum decreased, and the amounts of lactic acid and butyric acid increased. These findings were not observed in the NOS- or IMO-fed group of mice. They suggest that CNN supplementation changes the intestinal environment of microflora and indirectly enhances the immune function in the gut.

Effects of Clostridium butyricum on growth performance, immune function, and cecal microflora in broiler chickens challenged with Escherichia coli K88

This study was conducted to investigate the effects of Clostridium butyricumon growth performance, immune function, and cecal microflora in broiler chickens challenged with Escherichia coli K88. Three hundred sixty 1-d-old broiler chickens were randomly divided into 4 treatments: negative control (NC) birds were fed a basal diet and not challenged with E. coli K88; positive control (PC) birds were fed a basal diet and challenged with E. coli K88; C. butyricum treatment (CB) birds were fed a diet containing 2 × 10(7) cfu C. butyricum/kg of diet and challenged with E. coli K88; and colistin sulfate treatment (CS) birds were fed a diet containing 20 mg of colistin sulfate/kg of diet and challenged with E. coli K88. Birds fed CB had greater (P < 0.05) BW than the PC birds from 3 to 21 d postchallenge. Birds fed CB had greater (P < 0.05) serum IgA and IgY at 14 d postchallenge, greater (P < 0.05) serum IgM at 21 d postchallenge, and greater (P < 0.05) mucosal secreted IgA at 3 and 7 d postchallenge than the PC birds. Birds fed CB had greater concentrations of serum complement component 3 at 14 d postchallenge, and greater (P < 0.05) concentrations of serum complement component 4 at 3, 7, and 14 d postchallenge than the PC birds. Birds in the CS or CB treatments had less cecal E. coli population at 3, 7, and 21 d postchallenge, and less cecal Clostridium perfringens counts at 21 d postchallenge compared with the PC birds. The CB treatment increased (P < 0.05) the population of cecal Lactobacillus at 3 d postchallenge and the number of cecal Bifidobacterium at 3, 14, and 21 d postchallenge in comparison with the PC treatment. The results indicate that dietary supplementation of CB promotes growth performance, improves immune function, and benefits the cecal microflora in Escherichia coli K88-challenged chickens.

Modeling inflammatory bowel disease: the zebrafish as a way forward

The zebrafish has proved to be an informative model of vertebrate development and, more recently, an emerging model of human disease. The realization of the full potential of the zebrafish as a disease model lies in two interdependent areas. The first is an appreciation that the often overlooked strength of this species lies in allowing the design of experiments that address the interplay of genetics and the environment in a manipulable manner. The second is in the application and further development of gene targeting approaches. These twin features will be addressed in this review in the context of modeling inflammatory bowel disease.

Probiotics and prebiotics in pediatric diarrheal disorders

INTRODUCTION

In pediatrics, prebiotics and/or probiotics are added to infant formula, mainly to prevent diseases such as diarrheal disorders. Probiotic food supplements and medication are frequently used in the treatment of diarrheal disorders. This paper reviews the recent published evidence on these topics.

AREAS COVERED

Relevant literature published using PubMed and CINAHL was collected and reviewed. Recent review papers were give special attention.

EXPERT OPINION

The addition of pre- and/or probiotics to infant formula seems not harmful, but the evidence for benefit is limited. Most probiotics are commercialized as food supplements, and therefore do not qualify for medication legislation. Worldwide, Saccharomyces boulardii is the only strain which is registered as "medication" in the majority of countries. Efficacy data can only be considered if performed with the commercialized product. Some products reduce the risk for antibiotic-associated diarrhea and reduced the duration of acute infectious diarrhea with about 24 h. Overall, data in the other indications (inflammatory bowel disease, irritable bowel syndrome) are disappointing, although there are some recent promising results. The use of food supplements as medication opens the discussion to create a category of "medical food."

Synbiotics, probiotics or prebiotics in infant formula for full term infants: a systematic review

BACKGROUND

Synbiotics, probiotics or prebiotics are being added to infant formula to promote growth and development in infants. Previous reviews (2007 to 2011) on term infants given probiotics or prebiotics focused on prevention of allergic disease and food hypersensitivity. This review focused on growth and clinical outcomes in term infants fed only infant formula containing synbiotics, probiotics or prebiotics.

METHODS

Cochrane methodology was followed using randomized controlled trials (RCTs) which compared term infant formula containing probiotics, prebiotics or synbiotics to conventional infant formula with / without placebo among healthy full term infants. The mean difference (MD) and corresponding 95% confidence intervals (CI) were reported for continuous outcomes, risk ratio (RR) and corresponding 95% CI for dichotomous outcomes. Where appropriate, meta-analysis was performed; heterogeneity was explored using subgroup and sensitivity analyses. If studies were too diverse a narrative synthesis was provided.

RESULTS

Three synbiotic studies (N = 475), 10 probiotics studies (N = 933) and 12 prebiotics studies (N = 1563) were included. Synbiotics failed to significantly increase growth in boys and girls. Use of synbiotics increased stool frequency, had no impact on stool consistency, colic, spitting up / regurgitation, crying, restlessness or vomiting. Probiotics in formula also failed to have any significant effect on growth, stool frequency or consistency. Probiotics did not lower the incidence of diarrhoea, colic, spitting up / regurgitation, crying, restlessness or vomiting. Prebiotics in formula did increase weight gain but had no impact on length or head circumference gain. Prebiotics increased stool frequency but had no impact on stool consistency, the incidence of colic, spitting up / regurgitation, crying, restlessness or vomiting. There was no impact of prebiotics on the volume of formula tolerated, infections and gastrointestinal microflora. The quality of evidence was compromised by imprecision, inconsistency of results, use of different study preparations and publication bias.

AUTHORS' CONCLUSIONS

There is not enough evidence to state that supplementation of term infant formula with synbiotics, probiotics or prebiotics does result in improved growth or clinical outcomes in term infants. There is no data available to establish if synbiotics are superior to probiotics or prebiotics.

Probiotics, prebiotics infant formula use in preterm or low birth weight infants: a systematic review

BACKGROUND

Previous reviews (2005 to 2009) on preterm infants given probiotics or prebiotics with breast milk or mixed feeds focused on prevention of Necrotizing Enterocolitis, sepsis and diarrhea. This review assessed if probiotics, prebiotics led to improved growth and clinical outcomes in formula fed preterm infants.

METHODS

Cochrane methodology was followed using randomized controlled trials (RCTs) which compared preterm formula containing probiotic(s) or prebiotic(s) to conventional preterm formula in preterm infants. The mean difference (MD) and corresponding 95% confidence intervals (CI) were reported for continuous outcomes, risk ratio (RR) and corresponding 95% CI for dichotomous outcomes. Heterogeneity was assessed by visual inspection of forest plots and a chi² test. An I² test assessed inconsistencies across studies. I²> 50% represented substantial heterogeneity.

RESULTS

Four probiotics studies (N=212), 4 prebiotics studies (N=126) were included. Probiotics: There were no significant differences in weight gain (MD 1.96, 95% CI: -2.64 to 6.56, 2 studies, n=34) or in maximal enteral feed (MD 35.20, 95% CI: -7.61 to 78.02, 2 studies, n=34), number of stools per day increased significantly in probiotic group (MD 1.60, 95% CI: 1.20 to 2.00, 1 study, n=20). Prebiotics: Galacto-oligosaccharide/Fructo-oligosaccharide (GOS/FOS) yielded no significant difference in weight gain (MD 0.04, 95% CI: -2.65 to 2.73, 2 studies, n=50), GOS/FOS yielded no significant differences in length gain (MD 0.01, 95% CI: -0.03 to 0.04, 2 studies, n=50). There were no significant differences in head growth (MD -0.01, 95% CI: -0.02 to 0.00, 2 studies, n=76) or age at full enteral feed (MD -0.79, 95% CI: -2.20 to 0.61, 2 studies, n=86). Stool frequency increased significantly in prebiotic group (MD 0.80, 95% CI: 0.48 to 1.1, 2 studies, n=86). GOS/FOS and FOS yielded higher bifidobacteria counts in prebiotics group (MD 2.10, 95% CI: 0.96 to 3.24, n=27) and (MD 0.48, 95% CI: 0.28 to 0.68, n=56).

CONCLUSIONS

There is not enough evidence to state that supplementation with probiotics or prebiotics results in improved growth and clinical outcomes in exclusively formula fed preterm infants.

Preoperative probiotics decrease postoperative infectious complications of colorectal cancer

BACKGROUND

The objective is to elucidate the effects of oral bifid triple viable probiotics among patients with colorectal cancer.

METHODS

Sixty patients undergoing radical colorectal resection were randomly assigned to 3-day (days -5 to -3) preoperative probiotics (group A, n = 30) or placebo (group B, n = 30) treatment. The alteration of intestinal flora was evaluated by fecal cultures of Escherichia coli, Bifidobacterium longum and intestinal fungi; the gut barrier function by serum endotoxins and D-lactic acids and the immune and stress responses by peripheral blood immunoglobins, interleukin-6 and C-reactive protein. Postoperative infections were documented physically, radiologically and microbiologically.

RESULTS

Inverted Bifidobacterium/Escherichia ratios were preoperatively and postoperatively present in group B (both P < 0.05). Bifidobacterium counts increased significantly, whereas Escherichia counts decreased significantly on postoperative days 3 to 5 (P < 0.05), along with reversing the Bifidobacterium/Escherichia ratio inversion until postoperative days 3 to 5 in group A. Group A also had lower levels of endotoxins, D-lactic acids, serum interleukin-6 and C-reactive protein but higher levels of serum IgG and sIgA (all P < 0.05) than group B. The incidences of postoperative infectious complications were 3.3% to 6.7% and 3.3% to 30% in groups A and B (overall, 10.0% versus 33.3%, P < 0.05), respectively.

CONCLUSION

The preoperative oral bifid triple viable probiotics minimize the postoperative occurrence of infectious complications, with possible mechanisms attributed to the maintenance of the intestinal flora and restriction of bacterial translocation from the intestine. It was representative of the enhancement of systemic/localized immunity and concurrent attenuation of systemic stress response.

Intestinal microbiota and health in childhood

Western medicine has only recently discovered that the intestinal microbiota is a major determinant of the well-being of the host. Although it would be oversimplifying to limit the benefits of breastfeeding compared to cow milk based infant formula to differences in gastrointestinal flora, the impact of the latter has been demonstrated beyond doubt. As a consequence, gastro intestinal flora manipulation with pre- and probiotics added to infant formula or food (mainly milk based products) and/or with food supplements have become a priority area of high quality research. The composition of intestinal microbiota can be manipulated with “biotics”: antibiotics, prebiotics and probiotics. Commercialised pre- and probiotic products differ in composition and dose. Major threats to the concept of developing a major role for intestinal microbiota manipulation on health are the commercialisation of products claiming health benefits that have not been validated. Legislation of food supplements and medication differs substantially and allows commercialisation of poor quality food supplements, what will result in negative experiences. Medicinal products can only be advertised for which there is scientific proof of benefit that has been demonstrated with “the same product with the same dose in the same indication”. Specificity of prebiotics and probiotics strains and product specificity are of importance, although high quality evidence for this assertion is missing. Dose-efficacy studies are urgently needed. Probiotics are “generally regarded as safe”, but side effects such as septicemia and fungemia have sometimes been reported in high-risk situations.

Will isomalto-oligosaccharides, a well-established functional food in Asia, break through the European and American market? The status of knowledge on these prebiotics

This critical review article presents the current state of knowledge on isomalto-oligosaccharides, some well known functional oligosaccharides in Asia, to evaluate their potential as emergent prebiotics in the American and European functional food market. It includes first a unique inventory of the different families of compounds which have been considered as IMOs and their specific structure. A description has been given of the different production methods including the involved enzymes and their specific activities, the substrates, and the types of IMOs produced. Considering the structural complexity of IMO products, specific characterization methods are described, as well as purification methods which enable the body to get rid of digestible oligosaccharides. Finally, an extensive review of their techno-functional and nutritional properties enables placing IMOs inside the growing prebiotic market. This review is of particular interest considering that IMO commercialization in America and Europe is a topical subject due to the recent submission by Bioneutra Inc. (Canada) of a novel food file to the UK Food Standards Agency, as well as several patents for IMO production.

Probiotics in hepatology

The paper provides a basic review of intestinal microflora and its importance in liver diseases. The intestinal microflora has many important functions, above all to maintain the microbial barrier against established as well as potential pathogens. Furthermore, it influences the motility and perfusion of the intestinal wall, stimulates the intestinal immune system and therefore also the so-called common mucosal immune system, reducing bacterial translocation and producing vitamins. Immune homeostasis at mucosal level results from a controlled response to intestinal luminal antigens. In liver cirrhosis, there are many changes in its function, mostly an increase in bacterial overgrowth and translocation. In this review, probiotics and their indications in hepatology are generally discussed. According to recent knowledge, these preparations are indicated in clinical practice only for cases of hepatic encephalopathy. Probiotics are able to decrease the permeability of the intestinal wall, and decrease bacterial translocation and endotoxemia in animal models as well as in clinical studies, which is extremely important in the prevention of complications of liver cirrhosis and infection after liver transplantation. Probiotics could limit oxidative and inflammatory liver damage and, in some situations, improve the histological state, and thus non-alcoholic steatohepatitis could be considered as another possible indication.

The immunomodulatory properties of probiotic microorganisms beyond their viability (ghost probiotics: proposal of paraprobiotic concept)

The probiotic approach represents a potentially effective and mild alternative strategy for the prevention and treatment of either inflammatory or allergic diseases. Several studies have shown that different bacterial strains can exert their probiotic abilities by influencing the host's immune system, thereby modulating immune responses. However, the emerging concern regarding safety problems arising from the extensive use of live microbial cells is enhancing the interest in non-viable microorganisms or microbial cell extracts, as they could eliminate shelf-life problems and reduce the risks of microbial translocation and infection. The purpose of this review is to provide an overview of the scientific literature concerning studies in which dead microbial cells or crude microbial cell fractions have been used as health-promoting agents. Particular attention will be given to the modulation of host immune responses. Possible mechanisms determining the effect on the immune system will also be discussed. Finally, in the light of the FAO/WHO definition of probiotics, indicating that the word 'probiotic' should be restricted to products that contain live microorganisms, and considering the scientific evidence indicating that inactivated microbes can positively affect human health, we propose the new term 'paraprobiotic' to indicate the use of inactivated microbial cells or cell fractions to confer a health benefit to the consumer.

The prophylactic use of probiotics in the prevention of radiation therapy-induced diarrhea

Cancer treatment regimens that include radiation therapy (RT) to the abdominal region for cervical, ovarian, prostate, sigmoid, or colorectal cancer potentially disturb the colonization resistance of the indigenous gut flora, causing RT-induced diarrhea, enteritis, and colitis in more than 80% of patients with cancer. One approach for the prevention of RT-induced diarrhea is the use of probiotics. Randomized clinical trials have demonstrated efficacy of probiotic preparations VSL #3 and Lactobacillus casei DN-114 001 in decreasing the incidence and grade of RT-induced diarrhea. Oncology nurses and advanced practice clinicians are in a position to interpret research findings related to RT-induced diarrhea, enteritis, and colitis and to apply evidence-based practice principles in patients with cancer receiving RT to promote positive outcomes.

World Gastroenterology Organisation practice guideline: Probiotics and prebiotics

The human gut harbors dense and diverse microbial communities which have an impact on host's health. The symbiotic relationship between gut microbial communities and host can be optimized by pharmacological or nutritional intervention on the intestinal ecosystem using probiotics or prebiotics. Worldwide research on the use of prebiotics and probiotics in human and animal health has accelerated in recent years. However, there is lack of information about the practical use of probiotics and prebiotics in Medicine. A major area for medical applications has been the prevention or treatment of gastrointestinal diseases. Recently, a group of international experts appointed by the World Gastroenterology Organization prepared a practical guideline on the current indications of probiotics and prebiotics in Gastroenterology. The full text of the guideline is published in the current issue of our Journal. The document underscores strain-specificity of the clinical effects, and provides precise information on which specific probiotic strains or prebiotic compounds are useful for what particular clinical indications (see Table 3).

Helping patients make informed choices about probiotics: a need for research

Applications of probiotics in the treatment of gastrointestinal disorders are gaining acceptance among patients, despite evidence that probiotics can present substantial health risks, particularly for patients who are immunocompromised or seriously ill. Patients will likely formulate their attitudes and beliefs about probiotic therapies with reference to interpretive frameworks that compare probiotics with more familiar therapeutic modalities, including complementary and alternative medicines, pharmacological therapies, and gene-transfer technologies. Each of these frameworks highlights a different set of benefit-to-risk considerations regarding probiotic usage and reinforces extreme characterizations of both the therapeutic promise and peril of probiotics. Considerable effort may be required to help patients make informed choices about probiotic therapies.

Probiotics prevent enterohaemorrhagic Escherichia coli O157:H7-mediated inhibition of interferon-gamma-induced tyrosine phosphorylation of STAT-1

Enterohaemorrhagic Escherichia coli (EHEC) O157:H7 inhibits interferon (IFN)-gamma-stimulated tyrosine phosphorylation of signal transducer and activator of transcription (STAT)-1 in epithelial cells. We determined the effects of probiotics on EHEC-mediated disruption of IFN-gamma-stimulated STAT-1 activation in epithelial cell lines. Confluent Intestine 407, HEp-2 and Caco-2 epithelial cells were pre-treated (3 h) with either probiotics or surface-layer proteins derived from Lactobacillus helveticus R0052 prior to infection with EHEC O157:H7 strain CL56 (m.o.i. 100:1, 6 h, 37 degrees C in 5% CO2). Subsequently, cells were washed and stimulated with human recombinant IFN-gamma (50 ng ml(-1), 0.5 h, 37 degrees C) followed by whole-cell protein extraction and immunoblotting for tyrosine-phosphorylated STAT-1. Relative to uninfected cells, STAT-1-activation was reduced after EHEC O157:H7 infection. Pre-incubation with the probiotic L. helveticus R0052 followed by EHEC infection abrogated pathogen-mediated disruption of IFN-gamma-STAT-1 signalling. As determined using Transwell inserts, probiotic-mediated protection was independent of epithelial cell contact. In contrast, pre-incubation with boiled L. helveticus R0052, an equal concentration of viable Lactobacillus rhamnosus R0011, or surface-layer proteins (0.14 mg ml(-1)) did not restore STAT-1 signalling in EHEC-infected cells. The viable probiotic agent L. helveticus R0052 prevented EHEC O157:H7-mediated subversion of epithelial cell signal transduction responses.

Effects of dietary amines on the gut and its vasculature

Trace amines, including tyramine and β-phenylethylamine (β-PEA), are constituents of many foods including chocolate, cheeses and wines and are generated by so-called ‘friendly’ bacteria such as Lactobacillus, Lactococcus and Enterococcus species, which are found in probiotics. We therefore examined whether these dietary amines could exert pharmacological effects on the gut and its vasculature. In the present study we examined the effects of tyramine and β-PEA on the contractile activity of guinea-pig and rat ileum and upon the isolated mesenteric vasculature and other blood vessels. Traditionally, these amines are regarded as sympathomimetic amines, exerting effects through the release of noradrenaline from sympathetic nerve endings, which should relax the gut. A secondary aim was therefore to confirm this mechanism of action. However, contractile effects were observed in the gut and these were independent of noradrenaline, acetylcholine, histamine and serotonin receptors. They were therefore probably due to the recently described trace amine-associated receptors. These amines relaxed the mesenteric vasculature. In contrast, the aorta and coronary arteries were constricted, a response that was also independent of a sympathomimetic action. From these results, we propose that after ingestion, trace amines could stimulate the gut and improve intestinal blood flow. Restriction of blood flow elsewhere diverts blood to the gut to aid digestion. Thus, trace amines in the diet may promote the digestive process through stimulation of the gut and improved gastrointestinal circulation.

Applications of probiotics for neonatal enteric diseases

Probiotics are bacteria and yeast that have a beneficial effect on the maintenance of health. Probiotic microorganisms are inherently present in fermented food products. A renewed interest in probiotic therapy designed for both treatment and prevention of intestinal and extraintestinal disorders has resulted in studies in infants and children. This review focuses on the applications of probiotics in enteric conditions experienced by neonates and discusses future evaluations to develop recommendations for their use.

Nutritional modulation of antitumor efficacy and diarrhea toxicity related to irinotecan chemotherapy in rats bearing the ward colon tumor

PURPOSE

To evaluate and compare the influence of dietary elements on cancer progression, chemotherapy efficacy, and toxicity, particularly severe, late-onset diarrhea related to irinotecan (CPT-11) treatment.

EXPERIMENTAL DESIGN

We used laboratory rats fed a standardized basal diet, Ward colon tumor, and CPT-11 therapy for the study of CPT-11-induced diarrhea. Dietary interventions were selected from nutrients already established to modify other forms of colitis and which have been hypothesized to mitigate chemotherapy-induced gastrointestinal injury (glutamine, n-3 fatty acids, prebiotic oligosaccharides). Animals adapted to test diets were treated with CPT-11 at the maximum tolerated dose (125 mg/kg x 3 days) and diarrhea was followed continuously for 1 week.

RESULTS

The inclusion of n-3 fatty acids in the diet (5%, w/w of total fat) suppressed tumor growth and enhanced CPT-11's efficacy; this treatment did not affect the incidence or severity of diarrhea. By contrast, oral glutamine bolus (0.75 g/kg) administered prior to each CPT-11 treatment reduced the incidence of severe diarrhea (34.1 +/- 4.7% versus 53.8 +/- 4.2%, P < 0.005) and decreased the area under the curve of diarrhea score (16.5 +/- 1.0 versus 18.8 +/- 0.5, P < 0.05). Identical results were obtained with i.v. bolus glutamine administration. Glutamine treatment did not alter CPT-11's antitumor efficacy. The addition of prebiotic oligosaccharides to the diet (8%, w/w of diet) did not mitigate the severity of diarrhea, and it raised the activity of beta-glucuronidase in cecal contents, a key bacterial enzyme mediating CPT-11-related intestinal toxicity.

CONCLUSION

Our experiments suggest that glutamine and n-3 fatty acids might be potentially useful adjuncts to CPT-11 treatment.

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.