What is the evidence for the use of probiotics in the treatment of inflammatory bowel disease?

Investigation of the effects of probiotic, Bacillus subtilis on stress reactions in laying hens using infrared thermography

The goal of the study was to assess whether tonic immobility (TI)-induced stress reactions in laying hens can be reduced by probiotic supplementation and if the changes in body surface temperature, as a stress indicator, are genetically dependent and can be detected using infrared thermography (IRT). Seventy-one white and 70 brown hens were used. Hens were randomly assigned to three treatments at 1-day-old: beak trimmed and fed a regular diet; non-beak trimmed and fed a regular diet; and non-beak trimmed and fed a diet supplemented with probiotics, Bacillus subtilis. At 40 weeks of age, hens were tested for TI reactions. Eye and face temperatures were measured with IRT immediately before and after TI testing. Results revealed that the probiotic supplementation did not affect hens' stress responses to TI testing; the left and right eye temperatures increased by 0.26s°C and 0.15°C, respectively, while right face temperature tended to increase following TI testing. However, the right eye (32.60°C for white, and 32.35°C for brown) and face (39.51°C for white, and 39.36°C for brown) temperatures differed significantly among genetic lines. There was a positive correlation between TI duration and the changes of the left and right eye temperatures after TI testing in white hens. Based on these results, hens experienced TI-induced surface temperature changes that were detectable using IRT. White hens experienced greater stress reactions in response to TI than brown hens. However, supplementation with Bacillus subtilis did not attenuate hens' reaction to TI testing.

Alteration of Gut Microbiota in Inflammatory Bowel Disease (IBD): Cause or Consequence? IBD Treatment Targeting the Gut Microbiome

Inflammatory bowel disease (IBD) is a chronic complex inflammatory gut pathological condition, examples of which include Crohn’s disease (CD) and ulcerative colitis (UC), which is associated with significant morbidity. Although the etiology of IBD is unknown, gut microbiota alteration (dysbiosis) is considered a novel factor involved in the pathogenesis of IBD. The gut microbiota acts as a metabolic organ and contributes to human health by performing various physiological functions; deviation in the gut flora composition is involved in various disease pathologies, including IBD. This review aims to summarize the current knowledge of gut microbiota alteration in IBD and how this contributes to intestinal inflammation, as well as explore the potential role of gut microbiota-based treatment approaches for the prevention and treatment of IBD. The current literature has clearly demonstrated a perturbation of the gut microbiota in IBD patients and mice colitis models, but a clear causal link of cause and effect has not yet been presented. In addition, gut microbiota-based therapeutic approaches have also shown good evidence of their effects in the amelioration of colitis in animal models (mice) and IBD patients, which indicates that gut flora might be a new promising therapeutic target for the treatment of IBD. However, insufficient data and confusing results from previous studies have led to a failure to define a core microbiome associated with IBD and the hidden mechanism of pathogenesis, which suggests that well-designed randomized control trials and mouse models are required for further research. In addition, a better understanding of this ecosystem will also determine the role of prebiotics and probiotics as therapeutic agents in the management of IBD.

Effects of a high fat diet on intestinal microbiota and gastrointestinal diseases

Along with the rapid development of society, lifestyles and diets have gradually changed. Due to overwhelming material abundance, high fat, high sugar and high protein diets are common. Numerous studies have determined that diet and its impact on gut microbiota are closely related to obesity and metabolic diseases. Different dietary components affect gut microbiota, thus impacting gastrointestinal disease occurrence and development. A large number of related studies are progressing rapidly. Gut microbiota may be an important intermediate link, causing gastrointestinal diseases under the influence of changes in diet and genetic predisposition. To promote healthy gut microbiota and to prevent and cure gastrointestinal diseases, diets should be improved and supplemented with probiotics.

Modulating Composition and Metabolic Activity of the Gut Microbiota in IBD Patients

The healthy intestine represents a remarkable interface where sterile host tissues come in contact with gut microbiota, in a balanced state of homeostasis. The imbalance of gut homeostasis is associated with the onset of many severe pathological conditions, such as inflammatory bowel disease (IBD), a chronic gastrointestinal disorder increasing in incidence and severely influencing affected individuals. Despite the recent development of next generation sequencing and bioinformatics, the current scientific knowledge of specific triggers and diagnostic markers to improve interventional approaches in IBD is still scarce. In this review we present and discuss currently available and emerging therapeutic options in modulating composition and metabolic activity of gut microbiota in patients affected by IBD. Therapeutic approaches at the microbiota level, such as dietary interventions alone or with probiotics, prebiotics and synbiotics, administration of antibiotics, performing fecal microbiota transplantation (FMT) and the use of nematodes, all represent a promising opportunities towards establishing and maintaining of well-being as well as improving underlying IBD symptoms.

Highly Heterogeneous Probiotic Lactobacillus Species in Healthy Iranians with Low Functional Activities

Background

Lactic acid bacteria (LAB) have been considered as potentially probiotic organisms due to their potential human health properties. This study aimed to evaluate both in vitro and in vivo, the potential probiotic properties of Lactobacillus species isolated from fecal samples of healthy humans in Iran.

Methods and Results

A total of 470 LAB were initially isolated from 53 healthy individual and characterized to species level. Of these, 88 (86%) were Lactobacillus species. Biochemical and genetic fingerprinting with Phene-Plate system (PhP-LB) and RAPD-PCR showed that the isolates were highly diverse consisted of 67(76.1%) and 75 (85.2%) single types (STs) and a diversity indices of 0.994 and 0.997, respectively. These strains were tested for production of adhesion to Caco-2 cells, antibacterial activity, production of B12, anti-proliferative effect and interleukin-8 induction on gut epithelial cell lines and antibiotic resistance against 9 commonly used antibiotics. Strains showing the characteristics consistent with probiotic strains, were further tested for their anti-inflammatory effect in mouse colitis model. Only one L. brevis; one L. rhamnosus and two L. plantarum were shown to have significant probiotic properties. These strains showed shortening the length of colon compared to dextran sulfate sodium and disease activity index (DAI) was also significantly reduced in mouse.

Conclusion

Low number of LAB with potential probiotic activity as well as high diversity of lactobacilli species was evident in Iranian population. It also suggest that specific strains of L. plantarum, L. brevis and L. rhamnosus with anti-inflammatory effect in mouse model of colitis could be used as a potential probiotic candidate in inflammatory bowel disease to decrease the disease activity index.

Can inflammatory bowel disease be permanently treated with short-term interventions on the microbiome?

Inflammatory bowel disease, which includes Crohn's disease and ulcerative colitis, is a chronic, relapsing and remitting set of conditions characterized by an excessive inflammatory response leading to the destruction of the gastrointestinal tract. While the exact etiology of inflammatory bowel disease remains unclear, increasing evidence suggests that the human gastrointestinal microbiome plays a critical role in disease pathogenesis. Manipulation of the gut microbiome has therefore emerged as an attractive alternative for both prophylactic and therapeutic intervention against inflammation. Despite its growing popularity among patients, review of the current literature suggests that the adult microbiome is a highly stable structure resilient to short-term interventions. In fact, most evidence to date demonstrates that therapeutic agents targeting the microflora trigger rapid changes in the microbiome, which then reverts to its pre-treatment state once the therapy is completed. Based on these findings, our ability to treat inflammatory bowel disease through short-term manipulations of the human microbiome may only have a transient effect. Thus, this review is intended to highlight the use of various therapeutic options, including diet, pre- and probiotics, antibiotics and fecal microbiota transplant, to manipulate the microbiome, with specific attention to the alterations made to the microflora along with the duration of impact.

Stimulation of duodenal biopsies and whole blood from dogs with food-responsive chronic enteropathy and healthy dogs with Toll-like receptor ligands and probiotic Enterococcus faecium

The composition of the microbiome plays a significant role in the pathogenesis of inflammatory bowel disease (IBD) in humans and chronic enteropathies (CE) in dogs. The administration of probiotic micro-organisms is one way of modulating the microbiome, but experiments elucidating mechanisms of action of probiotics in the intestine of healthy and CE dogs are lacking. The aim of our study was to investigate the effects of different Toll-like receptor (TLR) ligands and Enterococcus faecium (EF) on ex vivo cultured duodenal samples and whole blood (WB) from dogs with food-responsive chronic enteropathy (FRE) when compared to healthy dogs. Biopsy stimulation was performed in 17 FRE and 11 healthy dogs; WB stimulation was performed in 16 FRE and 16 healthy dogs. Expression of TLR2, 4, 5 and 9, IL-17A, IL-22, IFNy, TNFα, IL-4, IL-10, TGFβ and PPARy was determined in biopsies by quantitative polymerase chain reaction (PCR). In addition, production of TNFα, IL-10, IFNy and IL-17A protein in WB and biopsy supernatants was assessed by ELISA. Treatment with individual TLR ligands or EF induced a variety of changes in the expression of different TLRs and cytokines, but not necessarily a consistent change with a single stimulating agent. Even though cytokine protein could not be detected in supernatants from ex vivo stimulated biopsies, we found TNFα protein responses in blood to be opposite of the transcriptional responses seen in the biopsies. Stimulation of canine duodenal biopsies with TLR ligands can potentially induce anti-inflammatory gene expression, especially in healthy tissue, whereas the effects of EF were limited.

The probiotic mixture VSL#3 mediates both pro- and anti-inflammatory responses in bone marrow-derived dendritic cells from C57BL/6 and BALB/c mice

Probiotic bacteria express a wide range of molecular structures that bind to receptors on innate immune cells and mediate health-promoting effects in the host. We have recently demonstrated in a colitis model that favourable effects of the probiotic mixture VSL#3 may in part be due to the suppression of intestinal chemokine expression. To obtain more insights into the underlying mechanisms, in the present study, we analysed the modulation of bone marrow-derived dendritic cells (BM-DC) from BALB/c (T helper (Th)2 biased) v. C57BL/6 (Th1 biased) mice. Our findings showed that VSL#3 differed from pure Toll-like receptor (TLR) ligands by inducing the production of various cytokines, including IL-12 p70 subunit (IL-12p70), IL-23 and IL-10. Dedicated TLR arrays were employed to profile mRNA from BM-DC cultured with lipopolysaccharide (LPS), VSL#3, or a combination of both. This approach led to the identification of (1) a cluster of genes that were up- or down-regulated, irrespective of the stimulus, (2) a cluster of genes that were synergistically up-regulated by LPS and VSL#3 in BM-DC from C57BL/6 mice, but not in those from BALB/c mice, and (3) a cluster of LPS-induced genes that were suppressed by VSL#3, in particular chemokine genes. These data show that this probiotic mixture has both pro- and anti-inflammatory effects on BM-DC and suggest that their immune-modulating properties in vivo may depend on the genetic background of the host.

Temporal bacterial community dynamics vary among ulcerative colitis patients after fecal microbiota transplantation

OBJECTIVES

Fecal microbiota transplantation (FMT) from healthy donors, which is an effective alternative for treatment of Clostridium difficile-associated disease, is being considered for several disorders such as inflammatory bowel disease, irritable bowel syndrome, and metabolic syndrome. Disease remission upon FMT is thought to be facilitated by an efficient colonization of healthy donor microbiota, but knowledge of the composition and temporal stability of patient microbiota after FMT is lacking.

METHODS

Five patients with moderately to severely active ulcerative colitis (Mayo score ≥6) and refractory to standard therapy received FMT via nasojejunal tube and enema. In addition to clinical activity and adverse events, the patients' fecal bacterial communities were monitored at multiple time points for up to 12 weeks using 16S rRNA gene-targeted pyrosequencing.

RESULTS

FMT elicited fever and a temporary increase of C-reactive protein. Abundant bacteria from donors established in recipients, but the efficiency and stability of donor microbiota colonization varied greatly. A positive clinical response was observed after 12 weeks in one patient whose microbiota had been effectively augmented by FMT. This augmentation was marked by successive colonization of donor-derived phylotypes including the anti-inflammatory and/or short-chain fatty acid-producing Faecalibacterium prausnitzii, Rosebura faecis, and Bacteroides ovatus. Disease severity (as measured by the Mayo score) was associated with an overrepresentation of Enterobacteriaceae and an underrepresentation of Lachnospiraceae.

CONCLUSIONS

This study highlights the value of characterizing temporally resolved microbiota dynamics for a better understanding of FMT efficacy and provides potentially useful diagnostic indicators for monitoring FMT success in the treatment of ulcerative colitis.

Probiotics in the management of children with allergy and other disorders of intestinal inflammation

Soon after birth, the human gastrointestinal tract quickly becomes colonised by a variety of bacterial species. Throughout life the gastrointestinal tract continues to serve as host to a complex society of nonpathological bacteria. Microorganisms, such as probiotics, have the potential to modulate mucosal immune response and reduce gastrointestinal inflammation caused by a variety of infectious and allergic events. The most widely studied genera of probiotics are lactobacilli and bifidobacteria. Lactobacillus rhamnosis strain ATC53103 (LGG) can replenish gut flora during infectious diarrhoeal episodes. This beneficial effect is carried over to traveller's diarrhoea and children experiencing antibiotic-associated diarrhoea. Furthermore, LGG can reduce the risk of respiratory tract infections in children attending daycares and hospitals. With allergic disease on the rise, probiotics have the potential to positively impact atopic dermatitis, asthma, and allergic rhinitis. LGG has been shown to decrease the severity and delay the onset of atopic dermatitis. Additionally, LGG is beneficial in the treatment of allergic colitis and necrotising entercolitis. Some strains of probiotics appear to be useful in the treatment and/or prevention of allergic disease, however, caution must be used when generalising the effectiveness of a specific strain of organism to other organisms and other disease states.

The design of probiotic studies to substantiate health claims

The EC Regulation No. 1924/2006 on Nutrition and Health claims made on foods has generated considerable debate and concern among scientists and industry. At the time of writing, the European Food Safety Authority (EFSA) has not approved any probiotic claims despite numerous human trials and meta-analyses showing evidence of beneficial effects. On 29th and 30th September 2010, ten independent, academic scientists with a documented record in probiotic research, met to discuss designs for future probiotic studies to demonstrate health benefits for gut and immune function. The expert panel recommended the following: (i) always formulate a precise and concrete hypothesis, and appropriate goals and parameters before starting a trial; (ii) ensure trials have sufficient sample size, such that they are adequately powered to reach statistically significant conclusions, either supporting or rejecting the a priori hypothesis, taking into account adjustment for multiple testing (this might necessitate more than one recruitment site); (iii) ensure trials are of appropriate duration; (iv) focus on a single, primary objective and only evaluate multiple parameters when they are hypothesis-driven. The panel agreed that there was an urgent need to better define which biomarkers are considered valuable for substantiation of a health claim. As a first step, the panel welcomed the publication on the day of the meeting of EFSA's draft guidance document on immune and gut health, although it came too late for study designs and dossiers to be adjusted accordingly. New validated biomarkers need to be identified in order to properly determine the range of physiological functions influenced by probiotics. In addition, validated biomarkers reflecting risk factors for disease, are required for article 14 claims (EC Regulation No. 1924/2006). Finally, the panel concluded that consensus among scientists is needed to decide appropriate clinical endpoints for trials.

Influence of Lactobacillus pentosus S-PT84 Ingestion on the Mucosal Immunity of Healthy and Salmonella Typhimurium-Infected Mice

Lactobacillus pentosus (L. pentosus) strain S-PT84, isolated from Kyoto pickles, enhances splenic natural killer (NK) cell activity, and has high T-helper1 (Th1) cytokine and type 1-IFN (IFN-α) inducing activity. In the present study, we investigated the influence of S-PT84 ingestion on the mucosal immunity of healthy and Salmonella Typhimurium (S. Typhimurium)-infected mice. In the S. Typhimurium infection model, numbers of S. Typhimurium in feces and the spleen were significantly decreased, and body weight loss and deterioration in the general health score of S. Typhimurium-infected mice were improved by S-PT84 ingestion. Oral administration of S-PT84 enhanced IL-5 and IL-6 production from Peyer’s patch cells in vitro, with a concomitant significant increase in IgA production from Peyer’s patch cells, which may explain the mechanism of enhanced IgA production in the small intestine in vivo. These results suggest that S-PT84 ingestion is useful for the maintenance of health or the improvement of certain symptoms during pathogen infection.