An update on the use and investigation of probiotics in health and disease

Fungal Signature in the Gut Microbiota of Pediatric Patients With Inflammatory Bowel Disease

BACKGROUND

Inflammatory bowel disease (IBD) involves dysregulation of mucosal immunity in response to environmental factors such as the gut microbiota. The bacterial microbiota is often altered in IBD, but the connection to disease is not fully clarified and gut fungi have recently been suggested to play a role as well. In this study, we compared microbes from all 3 domains of life-bacteria, archaea, and eukaryota-in pediatric patients with IBD and healthy controls.

METHODS

A stool sample was collected from patients with IBD (n = 32) or healthy control subjects (n = 90), and bacterial, archaeal, and fungal communities were characterized by deep sequencing of rRNA gene segments specific to each domain.

RESULTS

Patients with IBD (Crohn's disease or ulcerative colitis) had lower bacterial diversity and distinctive fungal communities. Two lineages annotating as Candida were significantly more abundant in patients with IBD (P = 0.0034 and P = 0.00038, respectively), whereas a lineage annotating as Cladosporium was more abundant in healthy subjects (P = 0.0025). There were no statistically significant differences in archaea, which were rare in pediatric samples compared with those from adults.

CONCLUSIONS

Pediatric IBD is associated with reduced diversity in both fungal and bacterial gut microbiota. Specific Candida taxa were found to be increased in abundance in the IBD samples. These data emphasize the potential importance of fungal microbiota signatures as biomarkers of pediatric IBD, supporting their possible role in disease pathogenesis.

The administration of probiotics and synbiotics in immune compromised adults: is it safe?

This study aimed to systematically evaluate safety of probiotics and synbiotics in immune compromised adults (≥18 years). Safety was analysed using the Common Terminology Clinical Adverse Events (CTCAE version 4.0) classification, thereby providing an update on previous reports using the most recent available clinical data (2008-2013). Safety aspects are represented and related to number of participants per probiotic strain/culture, study duration, dosage, clinical condition and selected afflictions. Analysis of 57 clinical studies indicates that probiotic and/or synbiotic administration in immune compromised adults is safe with regard to the current evaluated probiotic strains, dosages and duration. Individuals were considered immune compromised if HIV-infected, critically ill, underwent surgery or had an organ- or an autoimmune disease. There were no major safety concerns in the study, as none of the serious adverse events (AE)s were related, or suspected to be related, to the probiotic or synbiotic product and the study products were well tolerated. Overall, AEs occurred less frequent in immune compromised subjects receiving probiotics and/or synbiotics compared to the control group. In addition, the results demonstrated a flaw in precise reporting and classification of AE in most studies. Furthermore, generalisability of conclusions are greatly limited by the inconsistent, imprecise and potentially incomplete reporting as well as the variation in probiotic strains, dosages, administration regimes, study populations and reported outcomes. We argue that standardised reporting on adverse events (CTCAE) in 'food' studies should be obligatory, thereby improving reliability of data and re-enforcing the safety profile of probiotics.

Attenuation of Colitis by Lactobacillus casei BL23 Is Dependent on the Dairy Delivery Matrix

The role of the food delivery matrix in probiotic performance in the intestine is not well understood. Because probiotics are often provided to consumers in dairy products, we investigated the contributions of milk to the health-benefiting performance of Lactobacillus casei BL23 in a dextran sulfate sodium (DSS)-induced murine model of ulcerative colitis. L. casei BL23 protected against the development of colitis when ingested in milk but not in a nutrient-free buffer simulating consumption as a nutritional supplement. Consumption of (acidified) milk alone also provided some protection against weight loss and intestinal inflammation but was not as effective as L. casei and milk in combination. In contrast, L. casei mutants deficient in DltD (lipoteichoic acid d-alanine transfer protein) or RecA (recombinase A) were unable to protect against DSS-induced colitis, even when consumed in the presence of milk. Mice fed either L. casei or milk contained reduced quantities of colonic proinflammatory cytokines, indicating that the L. casei DltD(-) and RecA(-) mutants as well as L. casei BL23 in nutrient-free buffer were effective at modulating immune responses. However, there was not a direct correlation between colitis and quantities of these cytokines at the time of sacrifice. Identification of the cecal microbiota by 16S rRNA gene sequencing showed that L. casei in milk enriched for Comamonadaceae and Bifidobacteriaceae; however, the consumption of neither L. casei nor milk resulted in the restoration of the microbiota to resemble that of healthy animals. These findings strongly indicate that probiotic strain efficacy can be influenced by the food/supplement delivery matrix.

The Role of Intestinal Microbiota in Acute Graft-versus-Host Disease

The mammalian intestinal microbiota is a complex ecosystem that plays an important role in host immune responses. Recent studies have demonstrated that alterations in intestinal microbiota composition are linked to multiple inflammatory diseases in humans, including acute graft-versus-host disease (aGVHD). aGVHD is one of the major obstacles in allogeneic hematopoietic stem cell transplantation (allo-HSCT), characterized by tissue damage in the gastrointestinal (GI) tract, liver, lung, and skin. Here, we review the current understanding of the role of intestinal microbiota in the control of immune responses during aGVHD. Additionally, the possibility of using probiotic strains for potential treatment or prevention of aGVHD will be discussed.

Capability of exopolysaccharide-producing Lactobacillus paraplantarum BGCG11 and its non-producing isogenic strain NB1, to counteract the effect of enteropathogens upon the epithelial cell line HT29-MTX

The putative protective role of the exopolysaccharide (EPS)-producing Lactobacillus paraplantarum BGCG11, and its non-EPS-producing isogenic strain NB1, was tested upon HT29-MTX monolayers challenged with seven opportunistic pathogens. The probiotic strain Lactobacillus rhamnosus LMG18243 (GG) was used as a reference bacterium. Tested lactobacilli were able to efficiently reduce the attachment to HT29-MTX of most pathogens. Lb. paraplantarum NB1 and Lb. rhamnosus GG were more efficient reducing the adhesion of Clostridium difficile or Yersinia enterocolitica than Lb. paraplantarum BGCG11, while strain BGCG11 reduced, to a greater extent, the adhesion of Escherichia coli and Listeria monocytogenes. The detachment and cell lysis of HT29-MTX monolayers in the presence of pathogens alone and co-incubated with lactobacilli or purified EPS was followed. L. monocytogenes induced the strongest cell detachment among the seven tested pathogens and this effect was prevented by addition of purified EPS-CG11. The results suggest that this EPS could be an effective macromolecule in protection of HT29-MTX cells from the pathogen-induced lysis. Regarding innate intestinal barrier, the presence of C. difficile induced the highest IL-8 production in HT29-MTX cells and this capability was reinforced by the co-incubation with Lb. paraplantarum NB1 and Lb. rhamnosus GG. However, the increase in IL-8 production was not noticed when C. difficile was co-incubated with EPS-producing Lb. paraplantarum BGCG11 strain or its purified EPS-CG11 polymer, thus indicating that the polymer could hinder the contact of bacteria with the intestinal epithelium. The measurement of mucus secreted by HT29-MTX and the expression of muc1, muc2, muc3B and muc5AC genes in the presence of pathogens and lactobacilli suggested that all lactobacilli strains are weak "co-adjuvants" helping some pathogens to slightly increase the secretion of mucus by HT29-MTX, while purified EPS-CG11 did not induce mucus secretion. Taking altogether, Lb. paraplantarum BGCG11 could act towards the reinforcement of the innate mucosal barrier through the synthesis of a physical-protective EPS layer which could make difficult the contact of the pathogens with the epithelial cells.

Safety of probiotics and synbiotics in children under 18 years of age

This study aimed to systematically evaluate safety of probiotics and synbiotics in children ageing 0-18 years. This study is the third and final part in a safety trilogy and an update is provided using the most recent available clinical data (2008-2013) by means of the Common Terminology Clinical Adverse Events (CTCAE version 4.0) classification. Safety aspects are represented and related to number of participants per probiotic strain/culture, study duration, dosage, clinical condition and selected afflictions. Analysis of 74 clinical studies indicated that probiotic and/or synbiotic administration in children is safe with regard to the specific evaluated strains, dosages and duration. The population of children include healthy, immune compromised and obese subjects, as well as subjects with intestinal disorders, infections and inflammatory disorders. This study revealed no major safety concerns, as the adverse events (AEs) were unrelated, or not suspected to be related, to the probiotic or synbiotic product. In general the study products were well tolerated. Overall, AEs occurred more frequent in the control arm compared to children receiving probiotics and/or synbiotics. Furthermore, the results indicate inadequate reporting and classification of AEs in the majority of the studies. In addition, generalizability of conclusions are greatly limited by the inconsistent, imprecise and potentially incomplete reporting as well as the variation in probiotic strains, dosages, administration regimes, study populations and reported outcomes.

Immunomodulation properties of multi-species fermented milks

Dairy propionibacteria (PAB) are used as a ripening starter in combination with Lactic acid bacteria (LAB) for dairy products such as Swiss-type cheese. LAB and PAB have also been studied for their probiotic properties but little is still known about their individual and/or synergistic beneficial effects within dairy matrices. In the context of a rising incidence of Inflammatory Bowel Diseases, it has become crucial to evaluate the immunomodulatory potential of bacteria ingested in large numbers via dairy products. We therefore selected different strains and combinations of technological LAB and PAB. We determined their immunomodulatory potential by IL-10 and IL-12 induction, in human peripheral blood mononuclear cells, on either single or mixed cultures, grown on laboratory medium or directly in milk. Milk was fermented with selected anti-inflammatory strains of LAB or PAB/LAB mixed cultures and the resulting bacterial fractions were also evaluated for these properties, together with starter viability and optimum technological aspects. The most promising fermented milks were evaluated in the context of TNBS- or DSS-induced colitis in mice. The improvement in inflammatory parameters evidenced an alleviation of colitis symptoms as a result of fermented milk consumption. This effect was clearly strain-dependent and modulated by growth within a fermented dairy product. These findings offer new tools and perspectives for the development of immunomodulatory fermented dairy products for targeted populations.

Functional dynamics of the gut microbiome in elderly people during probiotic consumption

A mechanistic understanding of the purported health benefits conferred by consumption of probiotic bacteria has been limited by our knowledge of the resident gut microbiota and its interaction with the host. Here, we detail the impact of a single-organism probiotic, Lactobacillus rhamnosus GG ATCC 53103 (LGG), on the structure and functional dynamics (gene expression) of the gut microbiota in a study of 12 healthy individuals, 65 to 80 years old. The analysis revealed that while the overall community composition was stable as assessed by 16S rRNA profiling, the transcriptional response of the gut microbiota was modulated by probiotic treatment. Comparison of transcriptional profiles based on taxonomic composition yielded three distinct transcriptome groups that displayed considerable differences in functional dynamics. The transcriptional profile of LGG in vivo was remarkably concordant across study subjects despite the considerable interindividual nature of the gut microbiota. However, we identified genes involved in flagellar motility, chemotaxis, and adhesion from Bifidobacterium and the dominant butyrate producers Roseburia and Eubacterium whose expression was increased during probiotic consumption, suggesting that LGG may promote interactions between key constituents of the microbiota and the host epithelium. These results provide evidence for the discrete functional effects imparted by a specific single-organism probiotic and challenge the prevailing notion that probiotics substantially modify the resident microbiota within nondiseased individuals in an appreciable fashion.

Probiotic bacteria have been used for over a century to promote digestive health. Many individuals report that probiotics alleviate a number of digestive issues, yet little evidence links how probiotic microbes influence human health. Here, we show how the resident microbes that inhabit the healthy human gut respond to a probiotic. The well-studied probiotic Lactobacillus rhamnosus GG ATCC 53103 (LGG) was administered in a clinical trial, and a suite of measurements of the resident microbes were taken to evaluate potential changes over the course of probiotic consumption. We found that LGG transiently enriches for functions to potentially promote anti-inflammatory pathways in the resident microbes.

The infant gut microbiome: evidence for obesity risk and dietary intervention

Increasing globally, particularly in children, obesity is a serious public health issue and risk factor for overweight and metabolic disease in later life. Both in experimental animal and human studies, advances in gene sequencing technologies have yielded intriguing possibilities for the role of the gut microbiome in later development of overweight status. Before translating study findings into practice, we must first reconcile inconsistencies between animal experimentation, and human adult and infant studies. Recent evidence for associations with gut microbiota and infant weight gain or child weight status, implicate Bacteroides and Lactobacillus species. Dietary manipulation with human milk and pre/probiotic formulations holds promise for preventing obesity.

Effects of ex-vivo and in-vivo treatment with probiotics on the inflammasome in dogs with chronic enteropathy

Inflammasomes coordinate the maturation of IL-1β and IL-18 in response to danger signals. They are vital for maintenance of intestinal homeostasis and have been linked to chronic intestinal inflammation in humans. Probiotics have been advocated as treatment in intestinal inflammation. So far, no study has investigated the role of the inflammasome in canine chronic enteropathy (CE). In this study the intestinal expression of inflammasome components was assessed in CE dogs compared to controls, when treated with probiotic Enterococcus faecium (EF) ex-vivo and in-vivo. RNA extraction from endoscopic biopsies and reverse-transcriptase quantitative PCR was performed for NLRP3, casp-1, IL-1β and IL-18. Immunohistochemistry was performed to investigate protein expression in tissues. Gene expression of casp-1 and NLRP3 was lower in CE samples than controls. Ex-vivo treatment with EF reduced NLRP3 expression in control samples. Treatment of CE dogs with EF alongside dietary intervention had no effect on gene expression. In contrast, IL-1β protein expression in CE decreased with dietary treatment (but not with probiotics). The results of this study suggest that the inflammasome or its components may be partially involved in the inflammatory process seen in CE, but distinct from intestinal inflammation in humans.

Implication of fructans in health: immunomodulatory and antioxidant mechanisms

Previous studies have shown that fructans, a soluble dietary fiber, are beneficial to human health and offer a promising approach for the treatment of some diseases. Fructans are nonreducing carbohydrates composed of fructosyl units and terminated by a single glucose molecule. These carbohydrates may be straight or branched with varying degrees of polymerization. Additionally, fructans are resistant to hydrolysis by human digestive enzymes but can be fermented by the colonic microbiota to produce short chain fatty acids (SCFAs), metabolic by-products that possess immunomodulatory activity. The indirect role of fructans in stimulating probiotic growth is one of the mechanisms through which fructans exert their prebiotic activity and improve health or ameliorate disease. However, a more direct mechanism for fructan activity has recently been suggested; fructans may interact with immune cells in the intestinal lumen to modulate immune responses in the body. Fructans are currently being studied for their potential as “ROS scavengers” that benefit intestinal epithelial cells by improving their redox environment. In this review, we discuss recent advances in our understanding of fructans interaction with the intestinal immune system, the gut microbiota, and other components of the intestinal lumen to provide an overview of the mechanisms underlying the effects of fructans on health and disease.

Gut microbiome, gut function, and probiotics: Implications for health

New insights from a rapidly developing field of research have ushered in a new era of understanding of the complexity of host-microbe interactions within the human body. The paradigm shift from culturing to metagenomics has provided an insight into the complex diversity of the microbial species that we harbor, revealing the fact that we are in fact more microbes than human cells. The largest consortium of these microbes resides in the gut and is called the gut microbiota. This new science has expanded the ability to document shifts in microbial populations to an unparalleled degree. It is now understood that signals from the microbiota provide trophic, nutritional, metabolic, and protective effects for the development and maintenance of the host digestive, immune, and neuroendocrine system. Evidence linking changes in the gut microbiota to gastrointestinal and extraintestinal disorders like irritable bowel syndrome, inflammatory bowel disease, obesity, diabetes, and celiac disease have begun to emerge recently. Probiotics act through diverse mechanisms positively affecting the composition and/or function of the commensal microbiota and alter host immunological responses. Well-controlled intervention trials, systematic reviews, and meta-analysis provide convincing evidence for the benefit of probiotics in prevention and treatment of gastrointestinal as well as extraintestinal disorders.

Allergy in children in hand versus machine dishwashing

BACKGROUND AND OBJECTIVE

The hygiene hypothesis stipulates that microbial exposure during early life induces immunologic tolerance via immune stimulation, and hence reduces the risk of allergy development. Several common lifestyle factors and household practices, such as dishwashing methods, may increase microbial exposure. The aim of this study was to investigate if such lifestyle factors are associated with allergy prevalence.

METHODS

Questionnaire-based study of 1029 children aged 7 to 8 years from Kiruna, in the north of Sweden, and Mölndal, in the Gothenburg area on the southwest coast of Sweden. Questions on asthma, eczema, and rhinoconjunctivitis were taken from the International Study of Asthma and Allergies in Childhood questionnaire.

RESULTS

Hand dishwashing was associated with a reduced risk of allergic disease development (multivariate analysis, odds ratio 0.57; 95% confidence interval: 0.37-0.85). The risk was further reduced in a dose-response pattern if the children were also served fermented food and if the family bought food directly from farms.

CONCLUSIONS

In families who use hand dishwashing, allergic diseases in children are less common than in children from families who use machine dishwashing. We speculate that a less-efficient dishwashing method may induce tolerance via increased microbial exposure.

VSL#3 probiotic treatment decreases bacterial translocation in rats with carbon tetrachloride-induced cirrhosis

BACKGROUND & AIMS

Probiotics can prevent pathological bacterial translocation in cirrhosis by modulating intestinal microbiota and improving gut barrier and immune disturbances. To evaluate the effect of probiotic VSL#3 on bacterial translocation, intestinal microbiota, gut barrier and inflammatory response in rats with experimental cirrhosis.

METHODS

Forty-six Sprague-Dawley rats with CCl4 -induced cirrhosis were randomized into two groups: VSL#3 group (n = 22) that received VSL#3 in drinking water, and water group (n = 24) that received water only. Treatment began at week 6 of cirrhosis induction and continued until laparotomy, performed 1 week after development of ascites or at week 20. A control group included 11 healthy rats. At this study end, we evaluated bacterial translocation, intestinal flora, intestinal barrier (ileal claudin-2 and 4, β-defensin-1, occludin and malondialdehyde as index of oxidative damage) and serum cytokines.

RESULTS

Mortality during this study was similar in the VSL#3 group (10/22, 45%) and the water group (10/24, 42%) (P = 1). The incidence of bacterial translocation was 1/12 (8%) in the VSL#3 group, 7/14 (50%) in the water group (P = 0.03 vs. VSL#3 group) and 0/11 in the control group (P = 0.008 vs. water group). The concentration of ileal and caecal enterobacteria and enterococci was similar in the two groups of cirrhotic rats. The ileal occludin concentration was higher and ileal malondialdehyde and serum levels of TNF-α were lower in the VSL#3 group than in the water group (P < 0.05).

CONCLUSIONS

VSL#3 decreases bacterial translocation, the pro-inflammatory state and ileal oxidative damage and increases ileal occludin expression in rats with experimental cirrhosis.

Crohn's disease specific pancreatic antibodies: clinical and pathophysiological challenges

Crohn's disease (CrD) and ulcerative colitis (UC) are the main inflammatory bowel diseases (IBD). IBD-specific humoral markers of autoimmunity in the form of autoantibodies have been reported first in the late 1950s by demonstrating the occurrence of autoimmunity in UC, while humoral autoimmunity in CrD can be traced back to the 1970s. Ever since, the pathophysiological role of autoimmune responses in IBDs has remained poorly understood. Notwithstanding, autoreactive responses play a major role in inflammation leading to overt IBD. In CrD, approximately 40% of patients and <20% of patients with UC demonstrate loss of tolerance to antigens of the exocrine pancreas. Glycoprotein 2 (GP2) has been identified as a major autoantigenic target of the so-called pancreatic antibodies. The previously unsolved contradiction of pancreatic autoreactivity and intestinal inflammation in IBD was elucidated by demonstrating the expression of GP2 at the site thereof. Intriguingly, GP2 has been reported to be a receptor on microfold cells of intestinal Peyer's patches, which are believed to represent the origin of CrD inflammation. The development of immunoassays for the detection of antibodies to GP2 has paved the way to investigate the association of such antibodies with the clinical phenotype in CrD. Given the recently discovered immunomodulating role of GP2 in innate and adaptive intestinal immunity, this association can shed further light on the pathophysiology of IBD. In this context, the association of anti-GP2 autoantibodies as novel CrD-specific markers with the clinical phenotype in CrD will be discussed in this review.

Gut microbes and the brain: paradigm shift in neuroscience

The discovery of the size and complexity of the human microbiome has resulted in an ongoing reevaluation of many concepts of health and disease, including diseases affecting the CNS. A growing body of preclinical literature has demonstrated bidirectional signaling between the brain and the gut microbiome, involving multiple neurocrine and endocrine signaling mechanisms. While psychological and physical stressors can affect the composition and metabolic activity of the gut microbiota, experimental changes to the gut microbiome can affect emotional behavior and related brain systems. These findings have resulted in speculation that alterations in the gut microbiome may play a pathophysiological role in human brain diseases, including autism spectrum disorder, anxiety, depression, and chronic pain. Ongoing large-scale population-based studies of the gut microbiome and brain imaging studies looking at the effect of gut microbiome modulation on brain responses to emotion-related stimuli are seeking to validate these speculations. This article is a summary of emerging topics covered in a symposium and is not meant to be a comprehensive review of the subject.

Gut microbes and the brain: paradigm shift in neuroscience

The discovery of the size and complexity of the human microbiome has resulted in an ongoing reevaluation of many concepts of health and disease, including diseases affecting the CNS. A growing body of preclinical literature has demonstrated bidirectional signaling between the brain and the gut microbiome, involving multiple neurocrine and endocrine signaling mechanisms. While psychological and physical stressors can affect the composition and metabolic activity of the gut microbiota, experimental changes to the gut microbiome can affect emotional behavior and related brain systems. These findings have resulted in speculation that alterations in the gut microbiome may play a pathophysiological role in human brain diseases, including autism spectrum disorder, anxiety, depression, and chronic pain. Ongoing large-scale population-based studies of the gut microbiome and brain imaging studies looking at the effect of gut microbiome modulation on brain responses to emotion-related stimuli are seeking to validate these speculations. This article is a summary of emerging topics covered in a symposium and is not meant to be a comprehensive review of the subject.

Manipulating the gut microbiota to maintain health and treat disease

BACKGROUND

The intestinal microbiota composition varies between healthy and diseased individuals for numerous diseases. Although any cause or effect relationship between the alterations in the gut microbiota and disease is not always clear, targeting the intestinal microbiota might offer new possibilities for prevention and/or treatment of disease.

OBJECTIVE

Here we review some examples of manipulating the intestinal microbiota by prebiotics, probiotics, and fecal microbial transplants.

RESULTS

Prebiotics are best known for their ability to increase the number of bifidobacteria. However, specific prebiotics could potentially also stimulate other species they can also stimulate other species associated with health, like Akkermansia muciniphila, Ruminococcus bromii, the Roseburia/Enterococcus rectale group, and Faecalibacterium prausnitzii. Probiotics have beneficial health effects for different diseases and digestive symptoms. These effects can be due to the direct effect of the probiotic bacterium or its products itself, as well as effects of the probiotic on the resident microbiota. Probiotics can influence the microbiota composition as well as the activity of the resident microbiota. Fecal microbial transplants are a drastic intervention in the gut microbiota, aiming for total replacement of one microbiota by another. With numerous successful studies related to antibiotic-associated diarrhea and Clostridium difficile infection, the potential of fecal microbial transplants to treat other diseases like inflammatory bowel disease, irritable bowel syndrome, and metabolic and cardiovascular disorders is under investigation.

CONCLUSIONS

Improved knowledge on the specific role of gut microbiota in prevention and treatment of disease will help more targeted manipulation of the intestinal microbiota. Further studies are necessary to see the (long term) effects for health of these interventions.

Effects of the gut microbiota on bone mass

The gut microbiota (GM), the commensal bacteria living in our intestine, performs numerous useful functions, including modulating host metabolism and immune status. Recent studies demonstrate that the GM is also a regulator of bone mass and it is proposed that the effect of the GM on bone mass is mediated via effects on the immune system, which in turn regulates osteoclastogenesis. Under normal conditions, the skeleton is constantly remodeled by bone-forming osteoblasts (OBs) and bone-resorbing osteoclasts (OCLs), and imbalances in this process may lead to osteoporosis. Here we review current knowledge on the possible role for the GM in the regulation of bone metabolism and propose that the GM might be a novel therapeutic target for osteoporosis and fracture prevention.

TLR signaling modulates side effects of anticancer therapy in the small intestine

Intestinal mucositis represents the most common complication of intensive chemotherapy, which has a severe adverse impact on quality of life of cancer patients. However, the precise pathophysiology remains to be clarified, and there is so far no successful therapeutic intervention. In this study, we investigated the role of innate immunity through TLR signaling in modulating genotoxic chemotherapy-induced small intestinal injury in vitro and in vivo. Genetic deletion of TLR2, but not MD-2, in mice resulted in severe chemotherapy-induced intestinal mucositis in the proximal jejunum with villous atrophy, accumulation of damaged DNA, CD11b(+)-myeloid cell infiltration, and significant gene alterations in xenobiotic metabolism, including a decrease in ABCB1/multidrug resistance (MDR)1 p-glycoprotein (p-gp) expression. Functionally, stimulation of TLR2 induced synthesis and drug efflux activity of ABCB1/MDR1 p-gp in murine and human CD11b(+)-myeloid cells, thus inhibiting chemotherapy-mediated cytotoxicity. Conversely, TLR2 activation failed to protect small intestinal tissues genetically deficient in MDR1A against DNA-damaging drug-induced apoptosis. Gut microbiota depletion by antibiotics led to increased susceptibility to chemotherapy-induced mucosal injury in wild-type mice, which was suppressed by administration of a TLR2 ligand, preserving ABCB1/MDR1 p-gp expression. Findings were confirmed in a preclinical model of human chemotherapy-induced intestinal mucositis using duodenal biopsies by demonstrating that TLR2 activation limited the toxic-inflammatory reaction and maintained assembly of the drug transporter p-gp. In conclusion, this study identifies a novel molecular link between innate immunity and xenobiotic metabolism. TLR2 acts as a central regulator of xenobiotic defense via the multidrug transporter ABCB1/MDR1 p-gp. Targeting TLR2 may represent a novel therapeutic approach in chemotherapy-induced intestinal mucositis.

Synbiotic containing Bacillus coagulans and fructo-oligosaccharides for functional abdominal pain in children

AIM

We evaluated the effectiveness of a synbiotic in the treatment of childhood functional abdominal pain (FAP).

BACKGROUND

Probiotics are effective in the treatment of functional gastrointestinal disorders in adult patients, but there is lack of information in children.

PATIENTS AND METHODS

Children with FAP, based on the Rome III criteria (n = 115, aged 6-18 years), were randomized to receive either synbiotic (Bacillus coagulans, Unique IS-2, 150 million spore plus FOS, 100 mg) twice daily or placebo for four weeks. Treatment response was defined as ≥ 2-point reduction in the 6-point self-rated pain scale or "no pain". Physician-rated global severity and improvement were also evaluated. Patients were followed for a total of 12 weeks.

RESULTS

Eighty-eight patients completed the trial (45 with synbiotic). Response rate was higher with synbiotic than placebo after medication (60% vs. 39.5%, P = 0.044), but was not different between the two groups at week 12 (64.4% vs. 53.4%, P = 0.204). Difference between the two groups regarding the physician-rated global severity over the study period was not statistically significant (z = -1.87, P = 0.062). There was no significant difference between the two groups in physician-rated global improvement (week 4, P = 0.437; week 12, P = 0.111). Receiving synbiotic (OR 2.608, 95% CI: 1.01-6.68) and baseline pain score (OR 2.21, 95% CI: 1.19-4.10) were predictors of treatment response after medication.

CONCLUSION

The synbiotic containing Bacillus coagulans and FOS seems to be effective in the treatment of childhood FAP. Further trials are recommended in this regard.

Implication of fructans in health: immunomodulatory and antioxidant mechanisms

Previous studies have shown that fructans, a soluble dietary fiber, are beneficial to human health and offer a promising approach for the treatment of some diseases. Fructans are nonreducing carbohydrates composed of fructosyl units and terminated by a single glucose molecule. These carbohydrates may be straight or branched with varying degrees of polymerization. Additionally, fructans are resistant to hydrolysis by human digestive enzymes but can be fermented by the colonic microbiota to produce short chain fatty acids (SCFAs), metabolic by-products that possess immunomodulatory activity. The indirect role of fructans in stimulating probiotic growth is one of the mechanisms through which fructans exert their prebiotic activity and improve health or ameliorate disease. However, a more direct mechanism for fructan activity has recently been suggested; fructans may interact with immune cells in the intestinal lumen to modulate immune responses in the body. Fructans are currently being studied for their potential as "ROS scavengers" that benefit intestinal epithelial cells by improving their redox environment. In this review, we discuss recent advances in our understanding of fructans interaction with the intestinal immune system, the gut microbiota, and other components of the intestinal lumen to provide an overview of the mechanisms underlying the effects of fructans on health and disease.

Epigenomics and the microbiota

The mammalian gastrointestinal tract is home to trillions of commensal microorganisms that collectively make up the intestinal microbiota. These microbes are important environmental factors that regulate homeostasis, and alterations in the composition of the microbiota have been associated with several diseases, including inflammatory bowel disease, diabetes, and cancer. New research is beginning to uncover epigenomic pathways that may regulate this relationship with the microbiota. Epigenomic modifications alter the structure of the chromatin and therefore regulate the transcriptional program of a cell. These modifications are maintained by the dynamic activity of various modifying and demodifying enzymes, the activities of which can be influenced by metabolites and other environmental cues. Histone deacetylases (HDACs) are a class of epigenomic-modifying enzymes that are regulated by both endogenous and exogenous factors, and recent studies have suggested that host HDAC expression is important for regulating communication between the intestinal microbiota and mammalian host cells.

[Correlation of the microbiota and intestinal mucosa in the pathophysiology and treatment of irritable bowel, irritable eye, and irritable mind syndrome]

Accumulating clinical evidence supports co-morbidity of irritable bowel, irritable eye and irritable mind symptoms. Furthermore, perturbation of the microbiota-host symbiosis (dysbiosis) is considered a common pathogenic mechanism connecting gastrointestinal, ocular and neuropsychiatric symptoms. Consequently, maintaining or restoring microbiota-host symbiosis represents a new approach to treat these symptoms or to prevent their relapses. Current treatment approach assigned a primary role to live probiotics alone or in combination with prebiotics to enhance colonization of beneficial bacteria and to strengthen the symbiosis. However, several papers showed major benefits of heat-killed probiotics as compared to their live counterparts on both intestinal and systemic symptoms. Recently, in addition to killing probiotics, in a proof of concept study lysates (fragments) of probiotics in combination with vitamins A, B, D and omega 3 fatty acids were successfully tested. These findings suggested a conceptual change in the approach addressed to both the microbiota and host as targets for intervention.

Altered duodenal microbiota composition in celiac disease patients suffering from persistent symptoms on a long-term gluten-free diet

OBJECTIVES

A significant fraction of celiac disease patients suffer from persistent symptoms despite a long-term gluten-free diet (GFD) and normalized small bowel mucosa. The commonly suggested reasons, such as inadvertent gluten-intake or presence of other gastrointestinal disease, do not explain the symptoms in all these patients. Recently, alterations in intestinal microbiota have been associated with autoimmune disorders, including celiac disease. This led us to test a hypothesis that abnormal intestinal microbiota may be associated with persisting gastrointestinal symptoms in treated celiac disease patients.

METHODS

Duodenal microbiota was analyzed in 18 GFD-treated patients suffering from persistent symptoms and 18 treated patients without symptoms by 16S rRNA gene pyrosequencing. The celiac disease patients had been following a strict GFD for several years and had restored small bowel mucosa and negative celiac autoantibodies. Their symptoms on GFD were assessed with Gastrointestinal Symptom Rating Scale.

RESULTS

The results of several clustering methods showed that the treated celiac disease patients with persistent symptoms were colonized by different duodenal microbiota in comparison with patients without symptoms. The treated patients with persistent symptoms had a higher relative abundance of Proteobacteria (P=0.04) and a lower abundance of Bacteroidetes (P=0.01) and Firmicutes (P=0.05). Moreover, their microbial richness was reduced. The results indicated intestinal dysbiosis in patients with persistent symptoms even while adhering to a strict GFD.

CONCLUSIONS

Our findings indicate that dysbiosis of microbiota is associated with persistent gastrointestinal symptoms in treated celiac disease patients and open new possibilities to treat this subgroup of patients.

Probiotic supplementation in systemic nickel allergy syndrome patients: study of its effects on lactic acid bacteria population and on clinical symptoms

AIMS

The study aimed to evaluate the effects of probiotic Lactobacillus reuteri DSM 17938 strain supplementation in patients suffering from systemic nickel allergy syndrome, in terms of modulation of faecal LAB population linked to a reduction of GI and cutaneous symptoms and to an increase of patient's quality of life.

METHODS AND RESULTS

A preliminary double-blind randomized placebo-controlled study was planned and a culture-independent method based on denaturing gradient gel electrophoresis (DGGE) analysis coupled to the 16S rRNA gene sequencing was applied to investigate on the dynamics of faecal LAB communities before and during a low-Ni diet, supplemented with the probiotic strain. Moreover, the severity and the frequency of GI and cutaneous reactions as well as patient's clinical condition perception (VAS scores) were estimated by statistical analysis. PCR-DGGE fingerprinting obtained using LAB-specific primers revealed significant shift in faecal community with an increase in biodiversity in patients supplemented with probiotic Lact. reuteri strain. In addition, GI reactions such as symptoms related to meals and type of stools significantly improved only in patients treated with Lact. reuteri, while severity and frequency of cutaneous symptoms (urticaria, itch and eczema) and recurrent abdominal pain (RAP) as well as VAS scores statistically decreased in both groups.

CONCLUSIONS

Our preliminary findings suggest that probiotic Lact. reuteri could be a useful supplementation during a low-Ni diet of patients with SNAS, to increase LAB population diversity, which could contribute to restore the intestinal homoeostasis conditions.

SIGNIFICANCE AND IMPACT OF THE STUDY

To date, no information is available on probiotics application and on their effects, in terms of intestinal microbiota modulation, on patients suffering from SNAS. Therefore, the identification of dominant LAB community and the study of its shift during the probiotic supplementation could enhance the knowledge of the SNAS syndrome.

The probiotic Escherichia coli Nissle 1917 inhibits propagating colonic contractions in the rat isolated large intestine

The objective of this research was to test an in vitro motility model by investigating whether a probiotic that reduces diarrhea in humans would reduce motility in the rat colon in vitro. The probiotic Escherichia coli Nissle 1917 (EcN) the active ingredient in Mutaflor® was used as an example probiotic because it is effective for treating infectious diarrheal diseases. The effect of EcN on motility was compared in two colonic preparations. In distal colon segments EcN extract decreased the tension of spontaneous contractions by 74% and frequency by 46% compared with pre-treatment controls. In the whole large intestine the number of synchronized spontaneous propagating contractions decreased by 86% when EcN extract was applied externally and 69% when applied via the lumen compared with pre-treatment. From the inhibition produced by EcN extract in the distal colon segment a myogenic action was inferred and in the whole large intestine neural involvement was implicated. Both are consistent with its anti-diarrheal effect in humans.

Migraine associated with gastrointestinal disorders: review of the literature and clinical implications

Recent studies suggest that migraine may be associated with gastrointestinal (GI) disorders, including irritable bowel syndrome (IBS), inflammatory bowel syndrome, and celiac disease. Here, an overview of the associations between migraine and GI disorders is presented, as well as possible mechanistic links and clinical implications. People who regularly experience GI symptoms have a higher prevalence of headaches, with a stronger association with increasing headache frequency. Children with a mother with a history of migraine are more likely to have infantile colic. Children with migraine are more likely to have experienced infantile colic compared to controls. Several studies demonstrated significant associations between migraine and celiac disease, inflammatory bowel disease, and IBS. Possible underlying mechanisms of migraine and GI diseases could be increased gut permeability and inflammation. Therefore, it would be worthwhile to investigate these mechanisms further in migraine patients. These mechanisms also give a rationale to investigate the effects of the use of pre- and probiotics in migraine patients.

Enteric microbiota leads to new therapeutic strategies for ulcerative colitis

Ulcerative colitis (UC) is a leading form of inflammatory bowel disease that involves chronic relapsing or progressive inflammation. As a significant proportion of UC patients treated with conventional therapies do not achieve remission, there is a pressing need for the development of more effective therapies. The human gut contains a large, diverse, and dynamic population of microorganisms, collectively referred to as the enteric microbiota. There is a symbiotic relationship between the human host and the enteric microbiota, which provides nutrition, protection against pathogenic organisms, and promotes immune homeostasis. An imbalance of the normal enteric microbiota composition (termed dysbiosis) underlies the pathogenesis of UC. A reduction of enteric microbiota diversity has been observed in UC patients, mainly affecting the butyrate-producing bacteria, such as Faecalibacterium prausnitzii, which can repress pro-inflammatory cytokines. Many studies have shown that enteric microbiota plays an important role in anti-inflammatory and immunoregulatory activities, which can benefit UC patients. Therefore, manipulation of the dysbiosis is an attractive approach for UC therapy. Various therapies targeting a restoration of the enteric microbiota have shown efficacy in treating patients with active and chronic forms of UC. Such therapies include fecal microbiota transplantation, probiotics, prebiotics, antibiotics, helminth therapy, and dietary polyphenols, all of which can alter the abundance and composition of the enteric microbiota. Although there have been many large, randomized controlled clinical trials assessing these treatments, the effectiveness and safety of these bacteria-driven therapies need further evaluation. This review focuses on the important role that the enteric microbiota plays in maintaining intestinal homeostasis and discusses new therapeutic strategies targeting the enteric microbiota for UC.

The future of probiotics for disorders of the brain-gut axis

Probiotics, or at the very least products that might have probiotic properties, have been with us for decades, if not centuries, but it has only been in recent years that they have been subjected to serious scientific study. This surge in interest in probiotics has coincided with the era of the microbiome; as more and more is understood about the gut microbiota in health and disease, the therapeutic option of modulating the microbiota through the administration of probiotics has gained a more secure foundation. Regrettably, while a vast literature attests to the beneficial impact of probiotics in a variety of animal models and the mechanisms underlying such positive effects have been dissected in great detail, the data base on probiotics in man remains pretty slender.To make progress, a number of basic issues need to be addressed: strain characterization and other aspects of quality control need to be rigorously applied and additional steps such as dose optimization, definition of desired site of effect and tailoring of formulation accordingly accomplished before large scale trials, based on appropriately selected study endpoints and employing a clinically meaningful study duration, are embarked upon. Meantime, it is to be hoped that the regulatory climate will have been clarified and appropriate guidelines for the evaluation of probiotics, whether as food or drug, developed. Ultimately, the current terminology may have to be abandoned as evidence for biological and clinical activity for dead bacteria, bacterial components and bacterial products accumulates.

Intestinal microbiota in health and disease: Role of bifidobacteria in gut homeostasis

The pool of microbes inhabiting our body is known as “microbiota” and their collective genomes as “microbiome”. The colon is the most densely populated organ in the human body, although other parts, such as the skin, vaginal mucosa, or respiratory tract, also harbour specific microbiota. This microbial community regulates some important metabolic and physiological functions of the host, and drives the maturation of the immune system in early life, contributing to its homeostasis during life. Alterations of the intestinal microbiota can occur by changes in composition (dysbiosis), function, or microbiota-host interactions and they can be directly correlated with several diseases. The only disease in which a clear causal role of a dysbiotic microbiota has been demonstrated is the case of Clostridium difficile infections. Nonetheless, alterations in composition and function of the microbiota have been associated with several gastrointestinal diseases (inflammatory bowel disease, colorectal cancer, or irritable bowel syndrome), as well as extra-intestinal pathologies, such as those affecting the liver, or the respiratory tract (e.g., allergy, bronchial asthma, and cystic fibrosis), among others. Species of Bifidobacterium genus are the normal inhabitants of a healthy human gut and alterations in number and composition of their populations is one of the most frequent features present in these diseases. The use of probiotics, including bifidobacteria strains, in preventive medicine to maintain a healthy intestinal function is well documented. Probiotics are also proposed as therapeutic agents for gastrointestinal disorders and other pathologies. The World Gastroenterology Organization recently published potential clinical applications for several probiotic formulations, in which species of lactobacilli are predominant. This review is focused on probiotic preparations containing Bifidobacterium strains, alone or in combination with other bacteria, which have been tested in human clinical studies. In spite of extensive literature on and research into this topic, the degree of scientific evidence of the effectiveness of probiotics is still insufficient in most cases. More effort need to be made to design and conduct accurate human studies demonstrating the efficacy of probiotics in the prevention, alleviation, or treatment of different pathologies.

Screening of different probiotic strains for their in vitro ability to metabolise oxalates: any prospective use in humans?

BACKGROUND

Oxalate is the salt-forming ion of oxalic acid and can generate oxalate salts combining with various cations, such as sodium, potassium, magnesium, and calcium. Approximately 75% of all kidney stones are composed primarily of calcium oxalate (CaOx) and hyperoxaluria, a condition involving high urinary oxalate concentration, is considered a primary risk factor for kidney stone formation, known as nephrolithiasis. Current therapeutic strategies often fail in their compliance or effectiveness, and CaOx stone recurrence is still common. After an initial stone, there is a 50% chance of forming a second stone within 7 years if the condition is left untreated. The potential therapeutic application of some probiotics, mainly lactobacilli and bifidobacteria, in reducing hyperoxaluria in vivo through intestinal oxalate degrading activity is compelling and initial reports are promising. This study was undertaken to screen different Lactobacillus and Bifidobacterium strains for their capacity to degrade oxalate in vitro using reverse-phase high-performance liquid chromatography (HPLC).

METHODS

The oxalate-degrading activity of 13 lactobacilli and 5 bifidobacteria was tested using a novel HPLC method after growth in a broth culture added with 10 mM ammonium oxalate. Experiments were repeated 3 times. Oxalobacter formigenes (DSM 4420) was used as positive reference to validate HPLC oxalate-degrading capability assays.

RESULTS

Lactobacillus strains were more efficient than bifidobacteria in degrading oxalates. L. paracasei LPC09 (DSM 24243) gave the best result, as 68.5% of ammonium oxalate was converted at the end of incubation, whereas the following best converters belong to the L. gasseri and L. acidophilus species. The relatively low conversion rate observed for most bifidobacteria can probably be attributed to intrinsic oxalate toxicity toward this genus.

CONCLUSIONS

Humans lack the enzymes needed to directly metabolise oxalate, and this potentially toxic compound is, therefore, managed using alternative pathways. As oxalate-degrading bacteria are present in the endogenous microbiota of the human intestine, although with significant individual differences, it is possible to hypothesise that the administration of selected oxalate-degrading probiotics could be an alternative and innovative approach to reducing the intestinal absorption of oxalate and the resulting urinary excretion.

Short-chain fructo-oligosaccharide and inulin modulate inflammatory responses and microbial communities in Caco2-bbe cells and in a mouse model of intestinal injury

BACKGROUND

Few studies have focused on the ability of prebiotics to prevent pathogen-induced cellular changes or alter the composition of the intestinal microbiota in complimentary relevant cell and animal models of inflammatory bowel disease.

OBJECTIVE

The objective of this study was to determine if pretreatment with inulin and a short-chain fructo-oligosaccharide (sc-FOS) prevents enterohemorrhagic Escherichia coli (EHEC) O157:H7 infection in Caco2-bbe epithelial cells and what effect 10% wt:v sc-FOS or inulin has on C57BL/6 mice under sham conditions or pretreatment with prebiotics before Citrobacter rodentium infection (10(8) colony-forming units).

METHODS

Actin rearrangement and tight junction protein (zona occludin-1) were examined with immunofluorescence. Barrier function was assessed by a fluorescent probe and by measuring transepithelial electrical resistance (TER). Alterations in cytokine gene expression and microbiome were assessed with quantitative reverse transcriptase-polymerase chain reaction and fluorescence in situ hybridization. Short-chain fatty acids (SCFAs) were measured by GC.

RESULTS

sc-FOS added to monolayers altered actin polymerization without affecting TER or permeability to a fluorescein isothiocyanate (FITC) probe, whereas inulin increased TER (P < 0.005) and altered actin arrangement without affecting FITC permeability. Neither prebiotic attenuated EHEC-induced decreases in barrier function. Prebiotics increased interleukin 10 (Il10) and transforming growth factor-β (Tgfβ) cytokine responses alone (P < 0.05) or with EHEC O157:H7 infection (P < 0.05) in vitro. Increases in tumor necrosis factor-α (Tnfα) (P < 0.05) and decreases in chemokine CXC motif ligand 8 (Cxcl8) (P < 0.05) expression were observed with prebiotic treatment prior to EHEC infection. No differences were noted in barrier function or cytokine responses in the absence or presence of C. rodentium in vivo. Alterations in microbiome were evident at 6 d and 10 d postinfection in treatment groups, but a change in C. rodentium load was not observed. Inulin and sc-FOS (P < 0.05) increased fecal SCFAs in the absence of infection.

CONCLUSION

This study provides new insights as to how prebiotics act in complementary in vitro and in vivo models of intestinal injury.

Four types of Bifidobacteria trigger autophagy response in intestinal epithelial cells

OBJECTIVES

To investigate the influence of gut microbiota on autophagy activation in intestinal epithelial cells (IEC) and to evaluate the IEC autophagy response to different types of Bifidobacteria.

METHODS

IEC-18 cells were treated with lipopolysaccharide (LPS) derived from enteropathogenic Escherichia coli (EPEC) O127:B8 and culture medium supernatants of four types of Bifidobacteria. Transepithelial electrical resistance (TEER) was measured using an epithelial voltohmmeter. Autophagy was determined by transmission electron microscopy (TEM), the ratio of LC3-II to LC3-I and the persistence of both green fluorescent protein (GFP) and mCherry signals using a tandem mCherry-GFP-LC3 construct. The expression of Atg12-Atg5-Atg16 complex was measured by quantitative real-time polymerase chain reaction.

RESULTS

EPEC-LPS significantly diminished the TEER of IEC compared with untreated controls by 45-55%. This reduction was not observed after treated with Bifidobacteria at all time points. Bifidobacteria could initiate the activation of autophagy in IEC, based on both the ratio of LC3-II to LC3-I and TEM. There was no difference in the influence of the four types of Bifidobacteria on the autophagy response. Compared with Bifidobacteria, IEC reacted to EPEC-LPS much more intensively by autophagy accumulation. More mCherry(+) LC3 autophagic puncta and increased expressions of autophagy genes Atg5, Atg12 and Atg16 could be detected after being treated with Bifidobacteria and EPEC-LPS.

CONCLUSIONS

Bifidobacteria initiate autophagy activation in IEC. The Atg12-Atg5-Atg16 multimeric complex might participate in the activation of Bifidobacteria-induced cell autophagy.

Gut microbiota and inflammatory bowel disease: the role of antibiotics in disease management

Imbalances in the composition and number of bacteria in the gut microbiota have been implicated in inflammatory bowel disease (IBD), and modulation of the gut microbiota by probiotics and antibiotics in IBD has been an active area of research, with mixed results. This narrative review summarizes the findings of relevant publications identified using the PubMed database. Although antibiotics have been associated with an increased risk of IBD development and flares, several meta-analyses demonstrate that antibiotics are efficacious for the induction of remission and treatment of flares in patients with IBD. Data supporting their use include a large number of antibiotic studies in Crohn's disease and evidence suggests antibiotics are efficacious in both Crohn's disease and ulcerative colitis, although there are fewer studies of the latter. For Crohn's disease, antibiotics have been shown to be useful for the induction of remission and in the postoperative management of patients undergoing surgery. Additionally, patients with fistulizing disease, particularly perianal, can benefit from antibiotics administered short term. Both antimicrobials and probiotics have been shown to be useful for the treatment of pouchitis. Additional randomized controlled trials are needed to further elucidate the role of bacteria in IBD and to better inform clinicians about appropriate antibiotic therapies.

Effect of Probiotic Lactobacillus salivarius UBL S22 and Prebiotic Fructo-oligosaccharide on Serum Lipids, Inflammatory Markers, Insulin Sensitivity, and Gut Bacteria in Healthy Young Volunteers: A Randomized Controlled Single-Blind Pilot Study

This study investigated the effect of 6-week supplementation of a probiotic strain Lactobacillus salivarius UBL S22 with or without prebiotic fructo-oligosaccharide (FOS) on serum lipid profiles, immune responses, insulin sensitivity, and gut lactobacilli in 45 healthy young individuals. The patients were divided into 3 groups (15/group), that is, placebo, probiotic, and synbiotic. After 6 weeks, a significant reduction (P < .05) in total cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides and increase in high-density lipoprotein cholesterol was observed in the probiotic as well as in the synbiotic group when compared to placebo; however, the results of total cholesterol and LDL-cholesterol were more pronounced in the synbiotic group. Similarly, when compared to the placebo group, the serum concentrations of inflammatory markers such as high sensitivity C-reactive protein, interleukin (IL) 6, IL-1β, and tumor necrosis factor α were significantly (P < .05) reduced in both the experimental groups, but again the reduction in the synbiotic group was more pronounced. Also, an increase (P < .05) in the fecal counts of total lactobacilli and a decrease (P < .05) in coliforms and Escherichia coli was observed in both the experimental groups after 6 weeks of ingestion. Overall, the combination of L salivarius with FOS was observed to be more beneficial than L salivarius alone, thereby advocating that such synbiotic combinations could be therapeutically exploited for improved health and quality of life.

Probiotics against neoplastic transformation of gastric mucosa: Effects on cell proliferation and polyamine metabolism

Gastric cancer is still the second leading cause of cancer death worldwide, accounting for about 10% of newly diagnosed neoplasms. In the last decades, an emerging role has been attributed to the relations between the intestinal microbiota and the onset of both gastrointestinal and non-gastrointestinal neoplasms. Thus, exogenous microbial administration of peculiar bacterial strains (probiotics) has been suggested as having a profound influence on multiple processes associated with a change in cancer risk. The internationally accepted definition of probiotics is live microorganisms that, when administered in adequate amounts, confer a health benefit on the host. The possible effects on the gastrointestinal tract following probiotic administration have been investigated in vitro and in animal models, as well as in healthy volunteers and in patients suffering from different human gastrointestinal diseases. Although several evidences are available on the use of probiotics against the carcinogen Helicobacter pylori, little is still known about the potential cross-interactions among probiotics, the composition and quality of intestinal flora and the neoplastic transformation of gastric mucosa. In this connection, a significant role in cell proliferation is played by polyamines (putrescine, spermidine, and spermine). These small amines are required in both pre-neoplastic and neoplastic tissue to sustain the cell growth and the evidences here provided suggest that probiotics may act as antineoplastic agents in the stomach by affecting also the polyamine content and functions. This review will summarize data on the most widely recognized effects of probiotics against neoplastic transformation of gastric mucosa and in particular on their ability in modulating cell proliferation, paying attention to the polyamine metabolism.

Maternal perspectives on the use of probiotics in infants: a cross-sectional survey

Background

Probiotic products that may modify the intestinal microbiota are becoming increasingly available and known to consumers due to their potential to prevent or treat many pediatric health conditions. As scientific knowledge of the health benefits of probiotics increases, it is important to identify factors that may prevent their successful integration into patient care as well as to ensure effective translation of research findings. The aim of this study was to describe maternal perspectives on probiotics and their use in infants.

Methods

Mothers with a child aged two years or younger enrolled in the Alberta Pregnancy Outcomes and Nutrition (APrON) study were invited by email to complete a 29 item self-administered web-based questionnaire.

Results

A total of 413 mothers of the 1327 contacted completed the questionnaire. The majority (99.3%) of respondents had heard of probiotics and were aware that they contained live bacteria (87.0%); 89.3% had used a product containing probiotics themselves but only 50.8% had given one to their infant. Most mothers indicated they believed that probiotics were beneficial (73.1%) and none thought they were harmful. Over a third of mothers did not feel informed enough to make a decision on whether probiotics were safe to use in infants (36.6%).

Conclusions

The study demonstrates that awareness and understanding of probiotics is high among mothers in Alberta, Canada. However, there is still uncertainty regarding the benefit of probiotics as well as safety in infants which could be important factors determining therapeutic use in the future. Further studies that demonstrate beneficial effects and safety of probiotics in healthy infants as well as targeted knowledge translation should help to address these potential concerns.

Gut microbiota, the pharmabiotics they produce and host health

A healthy gut microbiota plays many crucial functions in the host, being involved in the correct development and functioning of the immune system, assisting in the digestion of certain foods and in the production of health-beneficial bioactive metabolites or 'pharmabiotics'. These include bioactive lipids (including SCFA and conjugated linoleic acid) antimicrobials and exopolysaccharides in addition to nutrients, including vitamins B and K. Alterations in the composition of the gut microbiota and reductions in microbial diversity are highlighted in many disease states, possibly rendering the host susceptible to infection and consequently negatively affecting innate immune function. Evidence is also emerging of microbially produced molecules with neuroactive functions that can have influences across the brain-gut axis. For example, γ-aminobutyric acid, serotonin, catecholamines and acetylcholine may modulate neural signalling within the enteric nervous system, when released in the intestinal lumen and consequently signal brain function and behaviour. Dietary supplementation with probiotics and prebiotics are the most widely used dietary adjuncts to modulate the gut microbiota. Furthermore, evidence is emerging of the interactions between administered microbes and dietary substrates, leading to the production of pharmabiotics, which may directly or indirectly positively influence human health.

Pouchitis: prevention and treatment

PURPOSE OF REVIEW

Pouchitis, representing a spectrum of disease phenotypes, is the most common long-term complication in patients who have undergone restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA). Its management and prevention are challenging.

RECENT FINDINGS

Treatment modalities vary according to phenotypes of pouchitis. The medical therapy of pouchitis remains largely empiric and antibiotic-based. However, patients may develop de-novo chronic antibiotic-refractory pouchitis (CARP) or progress from acute antibiotic-responsive phenotype. Patients with CARP often require alternative medical approaches to routine antibiotics, including the use of oral or topical mesalazine, corticosteroids, and sometimes immunomodulators or biological agents against tumour necrosis factor. There are two strategies to prevent pouchitis, the primary (i.e., the prevention of the initial episode) and secondary (i.e., the prevention of recurrent episodes) prophylaxis. There are scant data in the literature on nutritional aspects.

SUMMARY

We evaluated the efficacy of current strategies of prevention and treatments of pouchitis and propose algorithms, including attention to nutrition wherein data exist.

Use of probiotics to correct dysbiosis of normal microbiota following disease or disruptive events: a systematic review

OBJECTIVE

To assess the evidence for the claim probiotics can correct dysbiosis of the normal microbiota resulting from disease or disruptive events.

SETTING

Systematic review of published clinical trials of patients receiving a probiotic intervention for the prevention or treatment of various diseases.

DATA SOURCES

Sources searched (1985-2013): PubMed, EMBASE, Cochrane Database of Systematic Reviews, CINAHL, AMED and ISI Web of Science. Three on-line clinical trial registries were searched: Cochrane Central Register of Controlled trials, MetaRegister of Controlled Trials and National Institutes of Health.

REVIEW METHODS

Included studies were randomised clinical trials of probiotic interventions having microbiological assays. Studies were evaluated following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for specific probiotic strains. A standard data extraction form was used to collect the raw data.

OUTCOME MEASURES

The primary outcome is the degree of microbiota correction by specific probiotic strains. Secondary outcome was the association between the degree of dysbiosis correction and clinical efficacy.

RESULTS

The review of the literature found three distinct study designs: model A (restoration) assayed patients enrolled with a healthy, undisturbed microbiota and then assayed postdisruptive event and probiotic therapy; model B (alteration) assayed patients with pre-existing disrupted microbiota and then postprobiotic therapy; model C (no dysbiosis) assayed volunteers with no disruptive event prebiotic and postprobiotic. From a total of 63 trials, 83% of the probiotic products using model A restored the microbiota, 56% using model B improved the microbiota and only 21% using model C had any effect on microbiota. Clinical efficacy was more commonly associated with strains capable of restoration of the normal microbiota.

CONCLUSIONS

The ability to assess the degree of dysbiosis improvement is dependent on the enrolled population and the timing of microbiological assays. The functional claim for correcting dysbiosis is poorly supported for most probiotic strains and requires further research.

TRIAL REGISTRATION NUMBER

PROSPERO (CRD42014007224).

Practical approaches to probiotics use

Probiotics are microorganisms exerting beneficial effects on the host. They can be ingested through foods or supplements and their inclusion in these products is regulated in Canada by the Health Canada Health Products and Food Branch. The aim of this article is to summarize current evidence from randomized controlled trials and guidelines from Health Canada, the World Health Organization, and internationally recognized expert committees in the hope that it will help practitioners and professionals recommending probiotics to healthy and diseased patients, with a focus on the Canadian setting. From a general perspective, probiotics can be recommended for prevention of diseases that are associated to altered intestinal ecology. Specifically, they can be recommended for prevention of upper respiratory tract infections and pouchitis, for prevention and management of necrotizing enterocolitis, bacterial vaginosis and antibiotic associated diarrhea, including Clostridium difficile infection, and for treatment of atopic eczema in cow’s milk allergy and of infectious diarrhea. Additional substantiated probiotic benefits include prevention of hypercholesterolemia, management of constipation, reduction of recurrent urinary tract infections, improvement of irritable bowel syndrome symptoms, and reduction of antibiotics side effects in Helicobacter pylori eradication. Because probiotics are generally recognized as safe and can be removed with antimicrobial agents, their use should be considered in patients of all ages.