Effect of probiotic administration on the intestinal microbiota, current knowledge and potential applications

Effect of Mixed Probiotics on Ovalbumin-Induced Atopic Dermatitis in Juvenile Mice

Atopic dermatitis is one of the most common dermatologic problems, especially in children. Given the ability of symbiotic microorganisms in modulating the immune system, probiotics administration has been studied in previous research in the management of atopic dermatitis. However, there are conflicting results between studies. In this study, we aimed to assess the effectiveness of mixed probiotics as a treatment option for atopic dermatitis induced by ovalbumin. BALB/c juvenile mice were classified and divided into the ovalbumin group, mixed probiotic group (ovalbumin + LK), and control group. Except for the control group, all mice were sensitized with ovalbumin to establish a model of atopic dermatitis. The mixed probiotics were given by gavage for 14 days. Mice body weight, skin lesions, skin inflammation, ovalbumin-specific Ig, the number of Treg and CD103+DC, and the expression level of PD-1/PD-L1 were examined. The results showed that mixed probiotics can improve body weight and alleviate skin symptoms. Mixed probiotics reduced serum Th2 inflammatory factors, eosinophils, mast cell degranulation, mast cell count, and the expression of ovalbumin-specific immunoglobulin E/G1 and increased the anti-inflammatory cytokine interleukin-10, Treg cells, CD103+DC cells, and the expression level of PD-1/PD-L1. These findings suggest that mixed probiotics could be a viable treatment option for atopic dermatitis and provide insight into the underlying mechanisms involved.

Intestinal Delivery of Probiotics: Materials, Strategies, and Applications

Probiotics with diverse and crucial properties and functions have attracted broad interest from many researchers, who adopt intestinal delivery of probiotics to modulate the gut microbiota. However, the major problems faced for the therapeutic applications of probiotics are the viability and colonization of probiotics during their processing, oral intake, and subsequent delivery to the gut. The challenges of simple oral delivery (stability, controllability, targeting, etc.) have greatly limited the use of probiotics in clinical therapies. Nanotechnology can endow the probiotics to be delivered to the intestine with improved survival rate and increased resistance to the adverse environment. Additionally, the progress in synthetic biology has created new opportunities for efficiently and purposefully designing and manipulating the probiotics. In this article, a brief overview of the types of probiotics for intestinal delivery, the current progress of different probiotic encapsulation strategies, including the chemical, physical, and genetic strategies and their combinations, and the emerging single-cell encapsulation strategies using nanocoating methods, is presented. The action mechanisms of probiotics that are responsible for eliciting beneficial effects are also briefly discussed. Finally, the therapeutic applications of engineered probiotics are discussed, and the future trends toward developing engineered probiotics with advanced features and improved health benefits are proposed.

Hermetia illucens Fermented with Lactobacillus plantarum KCCM12757P Alleviates Dextran Sodium Sulfate-Induced Colitis in Mice

Inflammatory bowel disease (IBD) can severely affect humans and animals and is difficult to treat. Black soldier fly (Hermetia illucens; Hi) larvae (BSFL) are a sustainable source of protein. However, no studies exist on the antioxidant and anti-inflammatory functions of BSFL or fermented BSFL with respect to IBD. In this study, riboflavin-producing Lactobacillus plantarum KCCM12757P was isolated from a fish farm tank, and in conjunction with hot water-extracted Hi (HeHi) (termed HeHi_Lp), was used to determine optimal fermentation conditions to increase vitamin B2 concentration. This in vivo study investigated the therapeutic effects and mechanistic role of HeHi_Lp in chronic colitis-induced murine models. Histological changes, inflammatory cytokine levels, and intestinal barrier function were explored. Gut microbial communities and gene expression in the nuclear factor (NF)-κB signaling pathway were also studied. HeHi_Lp remarkably reduced the disease activity index, inflammatory cytokine (inducible nitric oxide synthase, cyclooxygenase 2, tumor necrosis factor α, interleukin (IL-6 and IL-1β) levels, and increased body weight and colon length. HeHi_Lp administration significantly raised zonula occludens 1, occludin and claudin 1 and improved the composition of the gut microbiota and beneficial intestinal bacteria. These results suggest that HeHi_Lp can be used as a dietary supplement in pet food to alleviate colitis.

Might Gut Microbiota Be a Target for a Personalized Therapeutic Approach in Patients Affected by Atherosclerosis Disease?

In recent years, the increasing number of studies on the relationship between the gut microbiota and atherosclerosis have led to significant interest in this subject. The gut microbiota, its metabolites (metabolome), such as TMAO, and gut dysbiosis play an important role in the development of atherosclerosis. Furthermore, inflammation, originating from the intestinal tract, adds yet another mechanism by which the human ecosystem is disrupted, resulting in the manifestation of metabolic diseases and, by extension, cardiovascular diseases. The scientific community must understand and elucidate these mechanisms in depth, to gain a better understanding of the relationship between atherosclerosis and the gut microbiome and to promote the development of new therapeutic targets in the coming years. This review aims to present the knowledge acquired so far, to trigger others to further investigate this intriguing topic.

The Crosstalk between Gut Microbiota and Nervous System: A Bidirectional Interaction between Microorganisms and Metabolome

Several studies have shown that the gut microbiota influences behavior and, in turn, changes in the immune system associated with symptoms of depression or anxiety disorder may be mirrored by corresponding changes in the gut microbiota. Although the composition/function of the intestinal microbiota appears to affect the central nervous system (CNS) activities through multiple mechanisms, accurate epidemiological evidence that clearly explains the connection between the CNS pathology and the intestinal dysbiosis is not yet available. The enteric nervous system (ENS) is a separate branch of the autonomic nervous system (ANS) and the largest part of the peripheral nervous system (PNS). It is composed of a vast and complex network of neurons which communicate via several neuromodulators and neurotransmitters, like those found in the CNS. Interestingly, despite its tight connections to both the PNS and ANS, the ENS is also capable of some independent activities. This concept, together with the suggested role played by intestinal microorganisms and the metabolome in the onset and progression of CNS neurological (neurodegenerative, autoimmune) and psychopathological (depression, anxiety disorders, autism) diseases, explains the large number of investigations exploring the functional role and the physiopathological implications of the gut microbiota/brain axis.

Assessing the efficacy of probiotics in augmenting bovine reproductive health: an integrated in vitro, in silico, and in vivo study

The aim of this study was to isolate and characterize bovine-vaginal probiotics genotypically and phenotypically using in silico and evaluate their in vivo performance in buffaloes with endometritis. For the in vitro isolation and characterization, vaginal swabs were collected from 34 cows and 17 buffaloes, and 709 primary bacterial isolates with probiotic activity were obtained using MRS agar media. Two isolates Lactiplantibacillus plantarum KUGBRC (LPKUGBRC) and Pediococcus pentosaceus GBRCKU (PPGBRCKU) demonstrated optimum in vitro probiotic activities as compared to Lacticaseibacillus rhamnosus GG including, acid production, secretion of fatty acids and exopolysaccharide, cell surface hydrophobicity, self-aggregating and co-aggregating capacity with pathogens, anti-microbial activity and bacteriocin-like compounds against pathogens Escherichia coli and Staphylococcus aureus in cell-free supernatant and absence of hemolytic activity. Their phenotypic capacity was confirmed by analyzing the whole genome sequencing data and identifying genes and pathways associated with probiotic properties. These probiotic isolates have shown no virulence genes were discovered in their genomic study. In vivo study of 92 buffaloes suffering from clinical endometritis with purulent cervico-vaginal mucus (CVM) were randomly allocated 40 × 10⁸ CFU/ml LPKUGBRC and PPGBRCKU and 40 ml Normal saline. The LPKUGBRC reduced the duration between administration of probiotic to induction of healthy estrus significantly. However, no effect was observed on pregnancy rate. These results suggest that LPKUGBRC and PPGBRCKU probiotic bacteria demonstrate probiotic efficiency and adaptability. Further sourced from the same niche as the targeted infection, they offer a distinct advantage in targeting the specific microbial population associated with endometritis. The findings of this study highlight the potential of LPKUGBRC and PPGBRCKU probiotics in treating endometritis and suggest further exploration of their clinical applications.

Microbiota- Brain-Gut-Axis Relevance to Parkinson's Disease: Potential Therapeutic Effects of Probiotics

Parkinson's disease (PD) is the second most common type of neurogenerative disease among middleaged and older people, characterized by aggregation of alpha-synuclein and dopaminergic neuron loss. The microbiota- gut-brain axis is a dynamic bidirectional communication network and is involved in the pathogenesis of PD. The aggregation of misfolded protein alpha-synuclein is a neuropathological characteristic of PD, originates in the gut and migrates to the central nervous system (CNS) through the vagus nerve and olfactory bulb. The change in the architecture of gut microbiota increases the level short-chain fatty acids (SCFAs) and other metabolites, acting on the neuroendocrine system and modulating the concentrations of gamma-Aminobutyric acid (GABA), serotonin, and other neurotransmitters. It also alters the vagus and intestinal signalling, influencing the brain and behaviour by activating microglia and systemic cytokines. Both experimental and clinical reports indicate the role of intestinal dysbiosis and microbiota host interaction in neurodegeneration. Probiotics are live microorganisms that modify the gut microbiota in the small intestine to avoid neurological diseases. Probiotics have been shown in clinical and preclinical studies to be effective in the treatment of PD by balancing the gut microbiota. In this article, we described the role of gut-microbiota in the pathogenesis of PD. The article aims to explore the mechanistic strategy of the gut-brain axis and its relation with motor impairment and the use of probiotics to maintain gut microbial flora and prevent PD-like symptoms.

The role of probiotic supplementation on insulin resistance in obesity associated diabetes: A mini review

Obesity and diabetes are two metabolic disorders linked by an inflammatory process named insulin resistance (IR). Various research on the role of gut microbiota in developing obesity and its associated disorders has led to the growing interest in probiotic supplementation. Considering the life-threatening complications of diabesity this mini review explored the effects of probiotic supplementation on IR in obesity associated diabetes. This review is based on recent articles from 2005-2020, studying the role of probiotic supplementation on glucose and insulin parameters in healthy and diabetic mouse model. Probiotic supplementation altered the gut microbiota composition, increased short chain fatty acid production, and decreased pro inflammatory cytokines. Additionally, they decreased intestinal permeability, circulating lipopolysaccharides and metabolic endotoxemia, hence improved insulin sensitivity and reduced obesity. Although multi-strain probiotic supplementation showed greater benefits than single strain interventions, variations in the concentration of probiotics used and the duration of treatment also influenced the results.  Probiotic supplementation could manipulate the gut microbiota by reducing intestinal permeability, inflammation and ameliorate IR and obesity associated diabetes in animal models which requires further long-term clinical studies in humans. 

Lactobacillus plantarum strains attenuated DSS-induced colitis in mice by modulating the gut microbiota and immune response

Gut microbiota has become a new therapeutic target in the treatment of inflammatory Bowel Disease (IBD). Probiotics are known for their beneficial effects and have shown good efficacy in the clinical treatment of IBD and animal models of colitis. However, how these probiotics contribute to the amelioration of IBD is largely unknown. In the current study, the DSS-induced mouse colitis model was treated with oral administration of Lactobacillus plantarum strains to investigate their effects on colitis. The results indicated that the L. plantarum strains improved dysbiosis and enhanced the abundance of beneficial bacteria related to short-chain fatty acids (SCFAs) production. Moreover, L. plantarum strains decreased the level of pro-inflammatory cytokines, i.e., IL-17A, IL-17F, IL-6, IL-22, and TNF-α and increased the level of anti-inflammatory cytokines, i.e., TGF-β, IL-10. Our result suggests that L. plantarum strains possess probiotic effects and can ameliorate DSS colitis in mice by modulating the resident gut microbiota and immune response.

Oxidative Stress in the Pathogenesis of Aorta Diseases as a Source of Potential Biomarkers and Therapeutic Targets, with a Particular Focus on Ascending Aorta Aneurysms

Aorta diseases, such as ascending aorta aneurysm (AsAA), are complex pathologies, currently defined as inflammatory diseases with a strong genetic susceptibility. They are difficult to manage, being insidious and silent pathologies whose diagnosis is based only on imaging data. No diagnostic and prognostic biomarkers or markers of outcome have been known until now. Thus, their identification is imperative. Certainly, a deep understanding of the mechanisms and pathways involved in their pathogenesis might help in such research. Recently, the key role of oxidative stress (OS) on the pathophysiology of aorta disease has emerged. Here, we describe and discuss these aspects by revealing some OS pathways as potential biomarkers, their underlying limitations, and potential solutions and approaches, as well as some potential treatments.

Bifidobacterium animalis subsp. lactis HN019 Effects on Gut Health: A Review

Optimal gut motility is central to bowel function and gut health. The link between the gut dysmotility related disorders and dysfunctional-intestinal barriers has led to a hypothesis that certain probiotics could help in normalizing gut motility and maintain gut health. This review investigates the roles of Bifidobacterium animalis subsp. lactis HN019 (B. lactis HN019™) on gut health, and its mechanisms of action in various pre-clinical and clinical studies. Research supports the hypothesis that B. lactis HN019™ has a beneficial role in maintaining intestinal barrier function during gastrointestinal infections by competing and excluding potential pathogens via different mechanisms; maintaining normal tight junction function in vitro; and regulating host immune defense toward pathogens in both in vitro and human studies. This has been observed to lead to reduced incidence of diarrhea. Interestingly, B. lactis HN019™ also supports normal physiological function in immunosenescent elderly and competes and excludes potential pathogens. Furthermore, B. lactis HN019™ reduced intestinal transit time and increased bowel movement frequency in functional constipation, potentially by modulating gut–brain–microbiota axis, mainly via serotonin signaling pathway, through short chain fatty acids derived from microbial fermentation. B. lactis HN019™ is thus a probiotic that can contribute to relieving gut dysmotility related disorders.

Effects of Probiotics, Prebiotics, and Synbiotics on Uremic Toxins, Inflammation, and Oxidative Stress in Hemodialysis Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

The dysbiosis of gut microbiota may cause many complications in patients with end-stage renal disease, which may be alleviated by probiotic, prebiotic, and synbiotic supplementation. The aim of this systematic review and meta-analysis was to assess the effects of these supplementations on circulatory uremic toxins, biomarkers of inflammation, and oxidative stress in hemodialysis patients. We searched the EMBASE, MEDLINE, Web of Science, and Cochrane Library databases until 8 August 2021. Randomized controlled trials evaluating adult patients receiving hemodialysis were included. The pooled results from 23 studies with 931 hemodialysis patients indicated that interventions significantly decreased the circulating levels of p-cresyl sulfate (standardized mean difference (SMD): 0.38; 95% CI: -0.61, -0.15; p = 0.001), endotoxins (SMD: -0.58; 95% CI: -0.99, -0.18; p = 0.005), malondialdehyde (SMD: -1.16; 95% CI: -1.81, -0.52; p = 0.0004), C-reactive proteins (CRP) (SMD: -0.61; 95% CI: -0.99, -0.23; p = 0.002), and interleukin 6 (SMD: -0.92; 95% CI: -1.51, -0.33; p = 0.002), and improved the total antioxidant capacity (SMD: 0.89; 95% CI: 0.49, 1.30; p < 0.0001) and glutathione (SMD: 0.40; 95% CI: 0.14, 0.66; p = 0.003) when compared to the placebo group. Our results suggest that treatment with probiotics, prebiotics, and synbiotics may help alleviate uremic toxin levels, oxidative stress, and the inflammatory status in hemodialysis patients.

Probiotics and Trained Immunity

The characteristics of innate immunity have recently been investigated in depth in several research articles, and original findings suggest that innate immunity also has a memory capacity, which has been named “trained immunity”. This notion has revolutionized our knowledge of the innate immune response. Thus, stimulation of trained immunity represents a therapeutic alternative that is worth exploring. In this context, probiotics, live microorganisms which when administered in adequate amounts confer a health benefit on the host, represent attractive candidates for the stimulation of trained immunity; however, although numerous studies have documented the beneficial proprieties of these microorganisms, their mechanisms of action are not yet fully understood. In this review, we propose to explore the putative connection between probiotics and stimulation of trained immunity.

In Vivo Implications of Potential Probiotic Lactobacillus reuteri LR6 on the Gut and Immunological Parameters as an Adjuvant Against Protein Energy Malnutrition

The present study investigated the impact of probiotic Lactobacillus reuteri LR6 on the gut and systemic immunity using protein energy malnourished (PEM) murine model. Thirty male Swiss albino mice were divided into five groups: control (C), malnourished (M), probiotic fermented milk (PFM), skim milk (SM), and bacterial suspension (BS) with six mice per group. Group C was fed with conventional diet throughout the study while the other groups were fed with protein calorie restricted diet until the development of malnutrition. After development of malnutrition, group M was continued with the restricted diet while other groups were fed with re-nourished diet supplemented with PFM, SM, and BS for 1 week, respectively. Thereafter, mice were sacrificed and different histological, microbiological, and immunological parameters were studied. Probiotics feeding in PEM model as fermented product or bacterial suspension improved the intestinal health in terms of intact morphology of colonic crypts, normal goblet cells, and intact lamina propria with no inflammation in large intestine, absence of fibrosis, and no inflammation in spleen. The number of secretory IgA⁺ cells was significantly higher in group PFM and BS. Also, increase in the phagocytic percentage of the macrophages and bone marrow derived dendritic cells (DCs) were observed in the PFM and BS group in comparison to the group M. In comparison to the group M and SM, lactobacilli, bifidobacteria, and Firmicutes counts were significantly higher in the group PFM and BS. This study concludes that probiotic supplementation to re-nutrition diet could emerge as wonder therapeutics against PEM.

Biogenic selenium nanoparticles produced by Lactobacillus casei ATCC 393 inhibit colon cancer cell growth in vitro and in vivo

Selenium compounds exhibit excellent anticancer properties but have a narrow therapeutic window. Selenium nanoparticles, however, are less toxic compared to other selenium forms, and their biogenic production leads to improved bioavailability. Herein, we used the probiotic strain Lactobacillus casei ATCC 393, previously shown to inhibit colon cancer cell growth, to synthesize biogenic selenium nanoparticles. We examined the anticancer activity of orally administered L. casei, L. casei-derived selenium nanoparticles and selenium nanoparticle-enriched L. casei, and investigated their antitumor potential in the CT26 syngeneic colorectal cancer model in BALB/c mice. Our results indicate that L. casei-derived selenium nanoparticles and selenium nanoparticle-enriched L. casei exert cancer-specific antiproliferative activity in vitro. Moreover, the nanoparticles were found to induce apoptosis and elevate reactive oxygen species levels in cancer cells. It is noteworthy that, when administered orally, selenium nanoparticle-enriched L. casei attenuated the growth of colon carcinoma in mice more effectively than the isolated nanoparticles or L. casei, suggesting a potential additive effect of the nanoparticles and the probiotic. To the best of our knowledge this is the first comparative study examining the anticancer effects of selenium nanoparticles synthesized by a microorganism, the selenium nanoparticle-enriched microorganism and the sole microorganism.

The storage stability of Bacillus subtilis spore displaying cysteine protease of Clonorchis sinensis and its effect on improving the gut microbiota of mice

Bacillus subtilis (B. subtilis) spore can serve as an ideal vehicle for expressing heterologous antigens, and elicit specific immune responses by oral administration. In previous studies, we successfully constructed the recombinant B. subtilis spores expressing cysteine protease of Clonorchis sinensis (C. sinensis, B.s-CsCP), and confirmed that oral administration of B.s-CsCP could elicit good protective immune responses in mice. In this study, Gram staining was used to observe the morphology of B.s-CsCP in different form, and the storage of liquid spores and lyophilized spores at different temperatures was compared. The mice were orally immunized with three different doses of spores (2×10⁸, 1×10⁹, and 5×10⁹ CFU/day) for three times in total at biweekly interval. Then, antibody levels of mice were measured, the safety of spores was evaluated, and the changes of gut microbiota after oral gavage of spores (1×10⁹ dose) were investigated. Results showed that B. subtilis was a typical Gram-positive bacterium, and its spore had good resistance to chemical dye. Liquid B. subtilis spores resuspended in sterile water could be stored for a long time at 4 °C or below, while lyophilized spores could be well stored even at RT and better at lower temperatures. Oral administration of B. subtilis spores to mice could stimulate both local mucosal and systemic immune responses in a dose-dependent manner without toxic side effects. Besides, beneficial bacteria producing butyrate such as Odoribacter were increased, while potential pathogens such as Escherichia-Shigella were decreased in mice intestine. Therefore, our work further confirmed that B. subtilis spores expressing CsCP could be a promising oral vaccine against C. sinensis with the advantages of stability, safety, easy storage, and promotion of intestinal health.Key Points• Recombinant CsCP B. subtilis spores could be easily preserved in either liquid or freeze-dried state.• Oral immunization of recombinant spores in mice could increase both local and system immune levels in a dose-dependent manner.• Oral administration of recombinant spores increased the number of beneficial bacteria and reduced the number of harmful bacteria in the intestinal tract of mice.

Effect of Probiotic, Prebiotic, and Synbiotic Supplementation on Cardiometabolic and Oxidative Stress Parameters in Patients With Chronic Kidney Disease: A Systematic Review and Meta-analysis

PURPOSE

Chronic kidney disease (CKD) is a major health problem worldwide. Evidence supporting the use of probiotic, prebiotic, and synbiotic supplementation in the management of CKD is mixed, although some studies suggest they may be useful. A systematic review and meta-analysis was performed to evaluate the effectiveness of probiotic, prebiotic, and synbiotic supplementation for improving cardiometabolic and oxidative stress parameters in patients with CKD.

METHODS

A comprehensive key word search was performed in EMBASE, Medline, Scopus, Cochrane Central, and Web of Science until April 2020. Randomized controlled trials investigating the effectiveness of probiotic, synbiotic, and prebiotic supplementation for the management of adults with CKD were included. Primary outcomes were measures of cardiometabolic parameters such as cholesterol and fasting blood glucose. Secondary outcomes were measures of oxidative stress (eg, malondialdehyde levels) and body mass index. Random effects meta-analyses were used to estimate mean treatment effects. Results are reported as standardized mean differences (SMDs) and 95% CIs.

FINDINGS

Fourteen articles were included. In patients with CKD, probiotic, prebiotic, and synbiotic supplementation significantly reduced total cholesterol (SMD, -0.25; 95% CI, -0.46 to -0.04; I² = 00.0%), fasting blood glucose (SMD, -0.41; 95% CI, -0.65 to -0.17; I² = 00.0%), homeostatic model assessment of insulin resistance (SMD, -0.63; 95% CI, -0.95 to -0.30; I² = 43.3%), insulin levels (SMD, -0.49; 95% CI, -0.90 to -0.08; I² = 65.2%), high-sensitivity C-reactive protein levels (SMD, -0.52; 95% CI, -0.81 to -0.22; I² = 52.7%), and malondialdehyde levels (SMD, -0.79; 95% CI, -1.22 to -0.37; I² = 69.8%) compared with control interventions. Supplementation significantly increased the quantitative insulin sensitivity check index (SMD, 0.78; 95% CI, 0.51 to 1.05; I² = 00.0%), total antioxidant capacity (SMD, 0.42; 95% CI, 0.18 to 0.66; I² = 00.0%), and glutathione levels (SMD, 0.52; 95% CI, 0.19 to 0.86; I² = 37.0%).

IMPLICATIONS

Probiotic, prebiotic, and synbiotic supplementation seems to be a promising intervention for improving cardiometabolic and oxidative stress parameters in patients with CKD.

Modern concept of probiotics and principles of development of new-generation symbiotic preparations

The purpose of this work is to review data on the biological effectiveness of probiotics, their mechanisms of action, and the prospects for the development of new-generation preparations. Scientific and practical justification of symbiotic drugs of a new generation – metabiotics as a continuation of the probiotic concept is given. The authors discuss the literature data and their own results, which allow them to propose new approaches to the creation of symbiotic drugs. The authors scientifically substantiate the main scientific provisions of the probiotic concept for the development of new-generation symbiotic drugs:

Lactobacillus plantarum inhibited the inflammatory response induced by enterotoxigenic Escherichia coli K88 via modulating MAPK and NF-κB signalling in intestinal porcine epithelial cells

AIMS

To investigate the effects of Lactobacillus plantarum on inflammatory responses induced by ETEC K88 and explore the underlying molecular mechanisms.

METHODS AND RESULTS

Intestinal porcine cells (IPEC-1) were incubated with 0 or 1 × 10⁸  CFU per well L. plantarum for 4 h, and then these cells were challenged with 0 or 1 × 10⁸  CFU per well ETEC K88 for 2 h. The results showed that pre-treatment of IPEC-1 cells with L. plantarum prevented the increases in the transcript abundance of interleukin-1α (IL-1α), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumour necrosis factor-α (TNF-α) (P < 0·05) caused by ETEC K88. Additionally, L. plantarum inhibited the reduction in peroxisome proliferator-activated receptor-γ (PPAR-γ) expression caused by ETEC K88 (P < 0·05). Moreover, L. plantarum pre-treatment downregulated the phosphorylation levels of c-Jun N-terminal kinase (JNK), extracellular regulated protein kinases 1 and 2 (ERK1/2) and p38 and the nuclear concentration of nuclear factor kappa B p65 (NF-κB p65) (P < 0·05) compared with ETEC K88 group. Silencing experiment further supported that the protective effect of L. plantarum P might mediated by suppression of ETEC-provoked activation of MAPK and NF-κB signalling pathways.

CONCLUSIONS

Lactobacillus plantarum inhibited the inflammatory response induced by ETEC K88 in IPEC-1 cells via modulating MAPK and NF-κB signalling.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study elucidated the underlying mechanism in which probiotics protect against intestinal inflammation caused by ETEC K88.

Current status of probiotics for prevention and management of gastrointestinal cancers

INTRODUCTION

Gastrointestinal cancers contribute to a significant number of cancer- associated mortality. The gastrointestinal tract harbors a multitude of microorganisms, known as the microbiota. Recently, the microbiota is considered to be an accessory organ resulting in several health benefits. The microbiota is involved in almost all aspects of an individual ranging from managing behavior to controlling metabolism, immune status and the response to a disease. Researchers are observing the modulation of microbiota in almost every disease, including cancer. Probiotics are microorganisms that can help to alter the host microbiota toward a healthy state thus providing benefits from many diseases including cancer.

AREAS COVERED

We explored the current status of the use of probiotics in cancer patients. Although probiotic bacteria can provide significant benefits to individuals suffering from cancer, the number of cancer-specific clinical products containing probiotics is not comparable to research studies showing their benefits. The lack of available products is due to several factors including a lack of risk assessment data of beneficial probiotics in cancer patients.

EXPERT OPINION

Laboratory investigations indicate a huge potential of probiotics for the prevention and management of gastrointestinal cancer, but more clinical studies are required to support their application in clinical settings.

Cell-free extracts of Lactobacillus acidophilus and Lactobacillus delbrueckii display antiproliferative and antioxidant activities against HT-29 cell line

Many beneficial effects of probiotic Lactobacilli on cancer prevention and therapy were previously presented. So finding probiotics with proapoptotic activities is a promising approach for cancer drug discovery. Here, the antiproliferative and antioxidant activities of cell-free extracts of Lactobacillus acidophilus and Lactobacillus delbrueckii on HT-29 cell line were evaluated employing MTT and DPPH assays. The induction of apoptosis was assessed by Hoechst staining and flow cytometry analysis which was further confirmed by expression analysis of BCL-2, BAX, caspase-3, caspase-8, and caspase-9 genes using real-time quantitative PCR. Caspase-3 activity was also analyzed. Results showed that cell viability was significantly reduced to 42.2 ± 0.01% and 19.40 ± 0.01% by 5 and 8 mg ml^-1 of L. acidophilus and L. delbrueckii extracts, respectively. Apoptosis induction was shown with both bacterial extracts. Caspase-9 and caspase-3 overexpression as well as Bax/Bcl-2 ratio increase revealed the ability of both probiotics to induce intrinsic pathway-dependent apoptosis. The extrinsic pathway was also activated by L. acidophilus. At the concentration of 198 µg ml^-1, L. acidophilus and L. delbrueckii had a DPPH scavenging activity of 59.37 ± 3.97% and 71.19 ± 3.64%, respectively. Taken together, these findings provide evidence for antiproliferative, proapoptotic, and antioxidant effects driven by these probiotic lactic acid bacteria (LAB) strains.

Antioxidant protection enzyme activity in the blood serum and large intestinal mucosa of rats with prolonged gastric hypochlorhydria and given multiprobiotics

The activity of antioxidant protection enzymes in the blood serum and colon mucosa in rats was studied under the conditions of 28-days administration of omeprazole on its own and omeprazole together with multiprobiotics "Symbiter" and "Apibact". Physiological and biochemical study methods were applied. It was found that after omeprazole administration, the activity of superoxide dismutase in the blood serum decreased, and the activity of catalase increased compared to the control. With the co-administration of omeprazole and multiprobiotics, the activity of superoxide dismutase increased compared to the group of rats that received omeprazole only during the same time, but remained less compared to the control group. The content of reduced glutathione in the blood serum of rats after administration of omeprazole decreased, the activity of glutathione peroxidase and glutathione transferase increased, and the activity of glutathione reductase decreased compared to the control. With co-administration of omeprazole and multiprobiotics, the serum RG content was at the control level, the activity of glutathione reductase exceeded the control values. The activity of glutathione reductase decreased compared to the group receiving omeprazole only. The activity of glutathione reductase increased and did not differ from the control values. In the colon mucosa, superoxide dismutase and catalase activity decreased compared to control. With the combined administration of omeprazole and multiprobiotics, superoxide dismutase and catalase activity increased and even exceeded the control values. With the administration of omeprazole, the reduced glutathione content in the colon mucosa was lower than that in the control. The activity of glutathione peroxidase increased and glutathione transferase and activity of glutathione reductase decreased compared to the control. With co-administration of omeprazole and multiprobiotics to rats, the reduced glutathione content increased compared to the group of rats administered omeprazole only, and even exceeded that in the control.

A metabolomics footprint approach to understanding the benefits of synbiotics in functional foods and dietary therapeutics for health, communicable and non-communicable diseases

Gut microbiota have been shown to affect various cellular and host response elements such as immunological, neurological, energy, storage, etc. In recent years, this has led to rapid expansion in dietary products containing probiotics, prebiotics and combination thereof in synbiotics. While benefits of consuming functional foods derived from probiotics strains have been demonstrated for various metabolites, a detailed analysis of the biochemical footprints and their benefits remain under-studied. Herein, using a combination of NMR metabolomics, microbial techniques and cell-culture assays, we have characterized metabolite profiles of probiotic viz. Lactobacillus delbruekii ATCC 9649, Lactobacillus casei ATCC 335, Lactobacillus plantarum NRC 716 and Bacillus coagulans ATCC 12425 cultures in fermented milk. We identified predominance of sugars, small chain fatty acids, organic acids and branched chain amino acids from natural abundance ¹³C NMR studies. Additionally, we identified myriad metabolites and their respective pathways using ¹H NMR spectroscopy. Based on our findings, synbiotic fermented dairy products were customized with co-cultures and complemented with pro- and pre- biotics. Furthermore, we demonstrate epithelial cell interaction and anti-microbial activity of L. plantarum based ferment against a range of bacterial pathogens highlighting possible biochemical mechanisms for anti-microbial activity, quorum sensing, gut colonization and other beneficial factors that may be crucial. Furthermore, we propose plausible explanation against non-communicable diseases such as tumor-inhibitory, anti-proliferative and pro-apoptotic effects which has direct implications for dietary therapeutics.

The effect of a multi-strain probiotic on growth performance, non-specific immune response, and intestinal health of juvenile turbot, Scophthalmus maximus L

Probiotic is well known because of its health benefit on the host, including improve growth, treat disease, and enhance immunity. Currently, probiotic has been widely used in aquaculture. However, there is little information about the effect of probiotic on turbot. Therefore, an effort was made to explore the effect of a multi-strain probiotic on growth performance, non-specific immune response, and intestinal health of juvenile turbot, Scophthalmus maximus L. One hundred eighty juvenile turbot (20.04 ± 0.23 g) were randomly divided into three groups (T0, T1, T2), and fed diet were formulated to contain 0%, 1%, and 5% multi-strain probiotic, respectively. Sixty days after the feeding experiment, the growth performance, body composition, enzyme activities, and intestinal microorganism of turbot were analyzed. T2 and T1 showed better growth performance and significant higher (P < 0.05) enzyme activities than T0 (except lysozyme). Moreover, the IV (intestinal villus), IW (intestinal wall), and GC (goblet cell) were well modulated in probiotic treatments. Furthermore, Lactobacillus was found colonized in the intestine of the group fed with 5% multi-strain probiotic. These results suggested adding dietary multi-strain probiotic could positively affect for turbot aquaculture.

Abincol® (Lactobacillus plantarum LP01, Lactobacillus lactis subspecies cremoris LLC02, Lactobacillus delbrueckii LDD01), an oral nutraceutical, pragmatic use in patients with chronic intestinal disorders

Chronic intestinal disorders (CID), including inflammatory bowel disease (IBD), such as ulcerative colitis and Crohn's disease, irritable bowel syndrome (IBS), and diverticular disease (DD), are diseases that relapse episodes. There is evidence that patients with CID have intestinal dysbiosis, so probiotics may counterbalance the impaired microbiota. Therefore, the current survey evaluated the efficacy and safety of Abincol®, an oral nutraceutical containing a probiotic mixture with Lactobacillus plantarum LP01 (1 billion of living cells), Lactobacillus lactis subspecies cremoris LLC02 (800 millions of living cells), and Lactobacillus delbrueckii LDD01 (200 millions of living cells), in 3,460 outpatients (1,660 males and 1,800 females, mean age 55 years) with chronic intestinal disorders. Patients took 1 stick/daily for 8 weeks. Abincol® significantly diminished the presence and the severity of intestinal symptoms and improved stool form. In conclusion, the current survey suggests that Abincol® may be considered an effective and safe therapeutic option in the management of patients with chronic intestinal disorders.

Effects of Lactic Acid Bacteria-Fermented Soymilk on Isoflavone Metabolites and Short-Chain Fatty Acids Excretion and Their Modulating Effects on Gut Microbiota

Lactobacillus rhamnosus strain ASCC 1520 with high soy isoflavone transformation ability was used to ferment soymilk and added to the diet of mice. The impact of L. rhamnosus fermentation on soy isoflavone metabolites and intestinal bacterial community, in conjunction with fecal enzyme activity and short-chain fatty acids (SCFA) excretion was evaluated. Antibiotics intervention resulted in a decrease in fecal enzyme activities and SCFA. Although long-term intake of soymilk or L. rhamnosus-fermented soymilk did not affect the fecal β-glucuronidase and β-galactosidase activities, it improved the β-glucosidase activity when antibiotics were concomitantly administered. Soymilk or fermented soymilk administration increased the isoflavone metabolites (O-DMA and equol) excreted in urine. Antibiotics decreased the daidzein excretion and its metabolites but showed little effect on glycitein and genistein excretion. Principal coordinates analysis (PCoA) of the 16s rRNA gene sequencing data found a remarkable shift in gut microbiota after soymilk administration and antibiotics treatment. Matastats test of the relative abundance of bacterial taxa revealed Odoribacter (Bacteroidales family), Lactobacillus (Lactobacillales order), and Alistipes (Rikenellaceae family) were enriched in soymilk while bacterial taxa from Bacteroides and Lactobacillus were enriched in L. rhamnosus-fermented soymilk. Furthermore, there was less decrease in bacterial taxa with fermented soymilk group even when antibiotics were concomitantly administered. Overall, this study revealed that the gut microbiota of a healthy host is enough for the whole isoflavone metabolism under normal conditions. Feeding mice with L. rhamnosus-fermented soymilk improved fecal enzyme activity and kept the balance of the gut mirobiota when antibiotics were used. PRACTICAL APPLICATION: Feeding mice with L. rhamnosus-fermented soymilk improved fecal enzyme activity and kept the balance of the gut mirobiota when antibiotics were used.

Complete Genome Sequence of Lactobacillus reuteri PNW1, a Promising Probiotic Candidate

This study reports the whole-genome sequence of Lactobacillus reuteri PNW1 isolated from gastrointestinal tracts of weaned piglets of the indigenous South African Windsnyer pig breed. A total of 5.2 GB data comprising 8,209,104 paired-end reads were generated.

This study reports the whole-genome sequence of Lactobacillus reuteri PNW1 isolated from gastrointestinal tracts of weaned piglets of the indigenous South African Windsnyer pig breed. A total of 5.2 GB data comprising 8,209,104 paired-end reads were generated. The assembled genome is 2,430,215 bp long in 420 contigs with 39% G+C content.

In vivo screening of multiple bacterial strains identifies Lactobacillus rhamnosus Lb102 and Bifidobacterium animalis ssp. lactis Bf141 as probiotics that improve metabolic disorders in a mouse model of obesity

Given the growing evidence that gut dysfunction, including changes in gut microbiota composition, plays a critical role in the development of inflammation and metabolic diseases, the identification of novel probiotic bacteria with immunometabolic properties has recently attracted more attention. Herein, bacterial strains were first isolated from dairy products and human feces and then screened in vitro for their immunomodulatory activity. Five selected strains were further analyzed in vivo, using a mouse model of diet-induced obesity. C57BL/6 mice were fed a high-fat high-sucrose diet, in combination with 1 of 3 Lactobacillus strains (Lb38, L. plantarum; L79, L. paracasei/casei; Lb102, L. rhamnosus) or Bifidobacterium strains (Bf26, Bf141, 2 different strains of B. animalis ssp. lactis species) administered for 8 wk at 10⁹ colony-forming units/d. Whereas 3 strains showed only modest (Lb38, Bf26) or no (L79) effects, Lb102 and Bf141 reduced diet-induced obesity, visceral fat accretion, and inflammation, concomitant with improvement of glucose tolerance and insulin sensitivity. Further analysis revealed that Lb102 and Bf141 enhanced intestinal integrity markers in association with selective changes in gut microbiota composition. We have thus identified 2 new potential probiotic bacterial strains with immunometabolic properties to alleviate obesity development and associated metabolic disturbances.-Le Barz, M., Daniel, N., Varin, T. V., Naimi, S., Demers-Mathieu, V., Pilon, G., Audy, J., Laurin, E., Roy, D., Urdaci, M. C., St-Gelais, D., Fliss, I, Marette, A. In vivo screening of multiple bacterial strains identifies Lactobacillus rhamnosus Lb102 and Bifidobacterium animalis ssp. lactis Bf141 as probiotics that improve metabolic disorders in a mouse model of obesity.

Oral Dysbiosis in Pancreatic Cancer and Liver Cirrhosis: A Review of the Literature

The human body is naturally colonized by a huge number of different commensal microbial species, in a relatively stable equilibrium. When this microbial community undergoes dysbiosis at any part of the body, it interacts with the innate immune system and results in a poor health status, locally or systemically. Research studies show that bacteria are capable of significantly influencing specific cells of the immune system, resulting in many diseases, including a neoplastic response. Amongst the multiple different types of diseases, pancreatic cancer and liver cirrhosis were significantly considered in this paper, as they are major fatal diseases. Recently, these two diseases were shown to be associated with increased or decreased numbers of certain oral bacterial species. These findings open the way for a broader perception and more specific investigative studies, to better understand the possible future treatment and prevention. This review aims to describe the correlation between oral dysbiosis and both pancreatic cancer and liver cirrhotic diseases, as well as demonstrating the possible diagnostic and treatment modalities, relying on the oral microbiota, itself, as prospective, simple, applicable non-invasive approaches to patients, by focusing on the state of the art. PubMed was electronically searched, using the following key words: "oral microbiota" and "pancreatic cancer" (PC), "liver cirrhosis", "systemic involvement", and "inflammatory mediators". Oral dysbiosis is a common problem related to poor oral or systemic health conditions. Oral pathogens can disseminate to distant body organs via the local, oral blood circulation, or pass through the gastrointestinal tract and enter into the systemic circulation. Once oral pathogens reach an organ, they modify the immune response and stimulate the release of the inflammatory mediators, this results in a disease. Recent studies have reported a correlation between oral dysbiosis and the increased risk of pancreatic and liver diseases and provided evidence of the presence of oral pathogens in diseased organs. The profound impact that microbial communities have on human health, provides a wide domain towards precisely investigating and clearly understanding the mechanism of many diseases, including cancer. Oral microbiota is an essential contributor to health status and imbalance in this community was correlated to oral and systemic diseases. The presence of elevated numbers of certain oral bacteria, particularly P. gingivalis, as well as elevated levels of blood serum antibodies, against this bacterial species, was associated with a higher risk of pancreatic cancer and liver cirrhosis incidence. Attempts are increasingly directed towards investigating the composition of oral microbiome as a simple diagnostic approach in multiple diseases, including pancreatic and liver pathosis. Moreover, treatment efforts are concerned in the recruitment of microbiota, for remedial purposes of the aforementioned and other different diseases. Further investigation is required to confirm and clarify the role of oral microbiota in enhancing pancreatic and liver diseases. Improving the treatment modalities requires an exertion of more effort, especially, concerning the microbiome engineering and oral microbiota transplantation.

Probiotic Bacillus enhance the intestinal epithelial cell barrier and immune function of piglets

Bacillus is widely used in the livestock industry. This study was designed to evaluate the effects of probiotic Bacillus amyloliquefaciens SC06 (Ba), originally isolated from soil, in piglets diet as an alternative to antibiotics (aureomycin), mainly on intestinal epithelial barrier and immune function. Ninety piglets were divided into three groups: G1 (containing 150 mg/kg aureomycin in the diet); G2 (containing 75 mg/kg aureomycin and 1×108 cfu/kg Ba in the diet); G3 (containing 2×108 cfu/kg Ba in the diet without any antibiotics). The results showed that, compared with the antibiotic group (G1), villus length, crypt depth and villus length/crypt depth ratio of intestine significantly increased in the G2 and G3 groups. In addition, intestinal villi morphology, goblet-cell number, mitochondria structure and tight junction proteins of intestinal epithelial cells in G2 and G3 were better than in G1. The relative gene expression of intestinal mucosal defensin-1, claudin3, claudin4, and human mucin-1 in G3 was significantly lower, while the expression of villin was significantly higher than in the antibiotic group. Probiotic Ba could significantly decrease serum interferon (IFN)-α, IFN-γ, interleukin (IL)-1β, and IL-4 levels, whereas increase tumour necrosis factor (TNF)-α and IL-6 secretion. Ba could also significantly decrease cytokines TNF-α, IFN-γ, IL-1β, and IL-4 level in liver, whereas it significantly increased IFN-α. Furthermore, replacing antibiotics with Ba also significantly down-regulated gene expression of TNF and IL-1α in intestinal mucosa, but up-regulated IL-6 and IL-8 transcription. Dietary addition of Ba could significantly reduce the gene expression of nuclear factor kappa beta (NFκB)-p50 and Toll-like receptor (TLR)6, while there was no significant difference for that of myeloid differentiation primary response 88, TNF receptor-associated factor-6, nucleotide-binding oligomerisation domain-containing protein 1, TLR2, TLR4, and TLR9. Taken together, our findings demonstrated that probiotic Ba could increase the intestinal epithelial cell barrier and immune function by improving intestinal mucosa structure, tight junctions and by activating the TLRs signalling pathway.

Influence of the microbiota and probiotics in obesity

Gut microbiota plays a key role in the control of body weight. In the present review the different ways in which it can modify the energy homeostasis of the host are exposed, based on its capacity to modify the metabolism of the individual and its contribution in the energy consumption regulation. With the current evidence, it is not clear what microbiota profile is associated with the presence of obesity, although in animal models it seems to be related to a higher proportion of bacteria of the Firmicutes phylum, to the detriment of those of the Bacteroidetes phylum. Other factors clearly involved would be the diversity in the gut microbiota or its possible functional changes. More studies in humans are needed to clarify how dysbiosis can influence weight control. On the other hand, probiotics directly affect the gut microbiota, modulating its composition and, possibly, its functionality. A large number of studies in humans have evaluated the impact of probiotics on obesity. Although this intervention may have a potentially beneficial effect, more effort is needed to clarify which strains of probiotics should be recommended, at what dose and for how long.

Effect of riboflavin-producing bacteria against chemically induced colitis in mice

AIM

To assess the anti-inflammatory effect associated with individual probiotic suspensions of riboflavin-producing lactic acid bacteria (LAB) in a colitis murine model.

METHODS AND RESULTS

Mice intrarectally inoculated with trinitrobenzene sulfonic acid (TNBS) were orally administered with individual suspensions of riboflavin-producing strains: Lactobacillus (Lact.) plantarum CRL2130, Lact. paracasei CRL76, Lact. bulgaricus CRL871 and Streptococcus thermophilus CRL803; and a nonriboflavin-producing strain or commercial riboflavin. The extent of colonic damage and inflammation and microbial translocation to liver were evaluated. iNOs enzyme was analysed in the intestinal tissues and cytokine concentrations in the intestinal fluids. Animals given either one of the four riboflavin-producing strains showed lower macroscopic and histologic damage scores, lower microbial translocation to liver, significant decreases of iNOs+ cells in their large intestines and decreased proinflammatory cytokines, compared with mice without treatment. The administration of pure riboflavin showed similar benefits. Lact. paracasei CRL76 accompanied its anti-inflammatory effect with increased IL-10 levels demonstrating other beneficial properties in addition to the vitamin production.

CONCLUSION

Administration of riboflavin-producing strains prevented the intestinal damage induced by TNBS in mice.

SIGNIFICANCE AND IMPACT OF THE STUDY

Riboflavin-producing phenotype in LAB represents a potent tool to select them for preventing/treating IBD.

The effects of probiotic supplement on hemoglobin in chronic renal failure patients under hemodialysis: A randomized clinical trial

Background:

Chronic inflammation is one of the causes of anemia in chronic renal failure patients under hemodialysis. Probiotics probably establish a balance between pro- and anti-inflammatory cytokines. The study was conducted to determine the effects of probiotic supplementation on hemoglobin (Hb) in hemodialysis patients.

Materials and Methods:

A parallel clinical trial was conducted in which patients were randomly allocated into two groups. The intervention group (n = 18) was given a 500 mg probiotic supplement (a capsule) every day whereas the control group (n = 18) received placebo (a capsule), both for 3 months. Hb levels and C-reactive protein (CRP) levels were measured for three periods. The data were analyzed in SPSS-16 using statistical tests including the t-test and repeated-measures ANOVA.

Results:

In the probiotic supplementation group, the mean Hb was 9.22 ± 1.04 mg/dl before the intervention and reached 10.85 ± 1.177 mg/dl afterward, while in the placebo group, the mean Hb level was 9.38 ± 0.97 mg/dl before the intervention and reached 10.03 ± 1.97 mg/dl afterward (P > 0.05). During the study, the placebo caused to increase of Hb temporary, but in longer term, the effect of probiotic was more manifested. Hb levels increased in both groups although the change was not statistically significant (P > 0.05). The findings showed no significant differences between the two groups in either the pre- or post-intervention CRP levels (P = 0.239).

Conclusion:

Probiotic supplementation decreased Hb fluctuations in hemodialysis patients but did not result in a significant increase in Hb levels. Similar studies are therefore recommended to be conducted with a prolonged duration of the study or an increased probiotic dose with larger sample size to complete the results of the present study.

Evidence of the Anti-Inflammatory Effects of Probiotics and Synbiotics in Intestinal Chronic Diseases

Probiotics and synbiotics are used to treat chronic diseases, principally due to their role in immune system modulation and the anti-inflammatory response. The present study reviewed the effects of probiotics and synbiotics on intestinal chronic diseases in in vitro, animal, and human studies, particularly in randomized clinical trials. The selected probiotics exhibit in vitro anti-inflammatory properties. Probiotic strains and cell-free supernatants reduced the expression of pro-inflammatory cytokines via action that is principally mediated by toll-like receptors. Probiotic administration improved the clinical symptoms, histological alterations, and mucus production in most of the evaluated animal studies, but some results suggest that caution should be taken when administering these agents in the relapse stages of IBD. In addition, no effects on chronic enteropathies were reported. Probiotic supplementation appears to be potentially well tolerated, effective, and safe in patients with IBD, in both CD and UC. Indeed, probiotics such as Bifidobacterium longum 536 improved the clinical symptoms in patients with mild to moderate active UC. Although it has been proposed that probiotics can provide benefits in certain conditions, the risks and benefits should be carefully assessed before initiating any therapy in patients with IBD. For this reason, further studies are required to understand the precise mechanism by which probiotics and synbiotics affect these diseases.

Probiotics may delay the progression of nonalcoholic fatty liver disease by restoring the gut microbiota structure and improving intestinal endotoxemia

Gut-derived bacterial lipopolysaccharide (LPS) and subsequent hepatic toll-like receptor 4 (TLR4) activation have been recognized to be involved in the onset of diet-induced nonalcoholic fatty liver disease (NAFLD), but little is known about the variation of LPS and TLR4 during the progression of NAFLD. Probiotics were able to inhibit proliferation of harmful bacteria and improve gastrointestinal barrier function. However, it's unclear whether LPS/TLR4 is involved in the protection effect of probiotics on NAFLD. In this study, we described characteristic of gut microbiota structure in the progression of NAFLD, and we also analyzed the relationship between gut microbiota and LPS/TLR4 in this process. Furthermore, we applied probiotics intervention to investigate the effect of probiotics on gut flora structure, intestinal integrity, serum LPS, liver TLR4 and liver pathology. Our results showed that serum LPS and liver TLR4 were highly increased during progression of NAFLD, with gut flora diversity and gut mircobiological colonization resistance (B/E) declining. Furthermore, probiotics could improve gut microbiota structure and liver pathology. Probiotics could also downregulate serum LPS and liver TLR4. Our results suggested that both gut flora alteration and endotoxemia may be involved in the progression of NAFLD. Probiotics may delay the progression of NAFLD via LPS/TLR4 signaling.

The immunological characteristics and probiotic function of recombinant Bacillus subtilis spore expressing Clonorchis sinensis cysteine protease

Background

Clonorchiasis, a food-borne zoonosis, is caused by Clonorchis sinensis. The intestinal tract and bile ducts are crucial places for C. sinensis metacercariae to develop into adult worms. The endospore of Bacillus subtilis is an ideal oral immunization vehicle for delivery of heterologous antigens to intestine. Cysteine protease of C. sinensis (CsCP) is an endogenous key component in the excystment of metacercariae and other physiological or pathological processes.

Methods

We constructed a fusion gene of CotC (a coat protein)-CsCP and obtained B. subtilis spores with recombinant plasmid of pEB03-CotC-CsCP (B.s-CotC-CsCP). CotC-CsCP expressed on spores’ surface was detected by Western blotting and immunofluorescence. Immunological characteristics of recombinant spore coat protein were evaluated in a mouse model. The levels of CsCP-specific antibodies were detected by ELISA. Effects of recombinant spores on mouse intestine were evaluated by histological staining. The activities of biochemical enzymes in serum were assayed by microplate. Liver sections of infected mice were evaluated by Ishak score after Masson’s trichrome.

Results

The B.s-CotC-CsCP spores displayed CsCP on their coat. Specific IgG and isotypes were significantly induced by coat proteins of B.s-CotC-CsCP spores after subcutaneous immunization. IgA levels in intestinal mucus and bile of B.s-CotC-CsCP orally treated mice significantly increased. Additionally, more IgA-secreting cells were observed in enteraden and lamina propria regions of the mouse jejunum, and an increased amount of acidic mucins in intestines were also observed. There were no significant differences in enzyme levels of serum among groups. No inflammatory injury was observed in the intestinal tissues of each group. The degree of liver fibrosis was significantly reduced after oral immunization with B.s-CotC-CsCP spores.

Conclusions

Bacillus subtilis spores maintained the original excellent immunogenicity of CsCP expressed on their surface. Both local and systemic specific immune responses were elicited by oral administration of B.s-CotC-CsCP spores. The spores effectively promoted intestinal health by inducing secretion of acidic mucins, with no other side effects to the liver or intestine. Oral administration of spores expressing CsCP could provide effective protection against C. sinensis. This study may be a cornerstone for development of antiparasitic agents or vaccines against clonorchiasis based on B. subtilis spore expressing CsCP on the surface.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1928-0) contains supplementary material, which is available to authorized users.

Anti-cancer effect of lactic acid bacteria expressing antioxidant enzymes or IL-10 in a colorectal cancer mouse model

The association between inflammatory bowel diseases and colorectal cancer is well documented. The genetic modification of lactic acid bacteria as a tool to increase the anti-inflammatory potential of these microorganisms has also been demonstrated. Thus the aim of the present work was to evaluate the anti-cancer potential of different genetically modified lactic acid bacteria (GM-LAB) producing antioxidant enzymes (catalase or superoxide dismutase) or the anti-inflammatory cytokine IL-10 (protein or DNA delivery) using a chemical induced colon cancer murine model. Dimethilhydrazine was used to induce colorectal cancer in mice. The animals received GM-LAB producing anti-oxidant enzymes, IL-10 or a mixture of different GM-LAB. Intestinal damage, enzyme activities and cytokines were evaluated and compared to the results obtained from mice that received the wild type strains from which derived the GM-LAB. All the GM-LAB assayed showed beneficial effects against colon cancer even though they exerted different mechanisms of action. The importance to select LAB with innate beneficial properties as the progenitor strain was demonstrated with the GM-LAB producing anti-oxidant enzymes. In addition, the best effects for the mixtures GM-LAB that combine different anti-inflammatory mechanism. Results indicate that mixtures of selected LAB and GM-LAB could be used as an adjunct treatment to decrease the inflammatory harmful environment associated to colorectal cancer, especially for patients with chronic intestinal inflammation who have an increased risk to develop colorectal cancer.

Evaluation of the effect of soymilk fermented by a riboflavin-producing Lactobacillus plantarum strain in a murine model of colitis

Inflammatory bowel diseases (IBD) are idiopathic diseases of the gastrointestinal tract characterised by recurrent inflammation that require lifelong treatments. It has been shown that certain strains of lactic acid bacteria (LAB) can produce specific health-promoting compounds in foods or in the gastrointestinal tract that can in turn prevent and/or treat IBD. This study was designed to evaluate the possible therapeutic potential of soymilk fermented by the riboflavin-producing strain Lactobacillus plantarum CRL 2130 in a trinitrobenzene sulfonic induced colitis mouse model. Mice that received soymilk fermented by L. plantarum CRL 2130 showed a decrease in weight loss, lower damage scores in their large intestines, lower microbial translocation to liver and decreased cytokines levels in their intestinal fluids compared to animals that received unfermented soymilk or soymilk fermented by a non-riboflavin-producing L. plantarum strain. This is the first report that demonstrates that a riboflavin-producing LAB was able to prevent experimental colitis in a murine model.

Microbiome therapeutics - Advances and challenges

The microbial community that lives on and in the human body exerts a major impact on human health, from metabolism to immunity. In order to leverage the close associations between microbes and their host, development of therapeutics targeting the microbiota has surged in recent years. Here, we discuss current additive and subtractive strategies to manipulate the microbiota, focusing on bacteria engineered to produce therapeutic payloads, consortia of natural organisms and selective antimicrobials. Further, we present challenges faced by the community in the development of microbiome therapeutics, including designing microbial therapies that are adapted for specific geographies in the body, stable colonization with microbial therapies, discovery of clinically relevant biosensors, robustness of engineered synthetic gene circuits and addressing safety and biocontainment concerns. Moving forward, collaboration between basic and applied researchers and clinicians to address these challenges will poise the field to herald an age of next-generation, cellular therapies that draw on novel findings in basic research to inform directed augmentation of the human microbiota.

Lactobacillus casei BL23 regulates Treg and Th17 T-cell populations and reduces DMH-associated colorectal cancer

BACKGROUND

Chronic intestinal inflammation alters host physiology and could lead to colorectal cancer (CRC). We have previously reported beneficial effects of the probiotic strain of Lactobacillus casei BL23 in different murine models of intestinal inflammation. In addition, there is an emerging interest on the potential beneficial effects of probiotics to treat CRC. We thus explored whether L. casei BL23 displays protective effects on CRC.

METHODS

Mice were subcutaneously injected with 1,2-dimethylhydrazine (DMH) weekly during 10 weeks and orally administered with L. casei BL23 in the drinking water until the 10th week. Multiple plaque lesions in the large intestine were observed macroscopically and counted and intestinal tissues were also histologically analyzed. Finally, T-cell populations and cytokine production were evaluated after co-incubation of L. casei BL23 with spleen cells from non-treated mice to determine the immuno-modulatory effects of this bacterium.

RESULTS

Our results show that oral treatment with this probiotic bacterium modulates host immune responses and significantly protect mice against DMH-induced CRC. This protection may be associated with the modulation of regulatory T-cells towards a Th17-biased immune response accompanied by the expression of regulatory cytokines (IL-6, IL-17, IL-10 and TGF-β), as demonstrated in L. casei BL23-treated splenocytes, but also with the colonic expression of IL-22 observed in vivo on L. casei BL23-treated mice; suggesting the induction of a fine-tune Th17-biased response.

CONCLUSIONS

Altogether our results reveal the high potential of L. casei BL23 to treat CRC and opens new frontiers for the study of immunomodulatory functions of probiotics.

Evaluation of the biosafety of recombinant lactic acid bacteria designed to prevent and treat colitis

Inflammatory bowel diseases (IBDs) affect the gastrointestinal tract and are characterized by recurrent inflammation that requires lifelong therapies. Probiotics such as lactic acid bacteria (LAB) have been proposed to complement current treatment protocols for these patients; however, their characteristics are strain dependent. In this regard, certain novel characteristics are only possible through the genetic modification of these beneficial micro-organisms. Different delivery systems, such as protein delivery of anti-oxidant enzymes and anti-inflammatory cytokines, have been shown to be effective in preventing and treating IBD in animal models. In this study, the safety of the recombinant LAB (recLAB) Streptococcus thermophilus CRL807 : CAT, S. thermophilus CRL807 : SOD, Lactococcus lactis NCDO2118 pXILCYT :  IL-10, L. lactis MG1363 pValac : IL-10 and L. lactis MG1363 pGroESL : IL-10 with proven beneficial effects was compared to their progenitor strains S. thermophilus CRL807, L. lactis NCDO2118 or L. lactis MG1363. The prolonged administration of these genetically modified strains showed that they were just as safe as the native strains from which they derive, as demonstrated by normal animal growth and relative organ weights, absence of microbial translocation from the gastrointestinal tract, normal blood parameters and intestinal histology. The results show the potential use of these recLAB in future therapeutic formulations; however, the use of modern bio-containment systems is required for the future acceptance of these recLAB by the medical community and patients with IBD.

Eluxadoline for the treatment of diarrhoea-predominant irritable bowel syndrome

INTRODUCTION

Irritable bowel syndrome (IBS) treatment is challenging physicians because of its multifactorial physiopathology. In particular, abdominal pain and diarrhea management lack one unique effective pharmacological remedy. Opioid receptors, present in the central nervous system (CNS) and the enteric nervous system (ENS), are involved in visceral sensitivity and gastrointestinal motility control. To date only a few opioid receptor modulators are currently in use for the treatment of IBS but with dosage limitations due to the early development of severe constipation.

AREAS COVERED

In this drug evaluation manuscript we review the irritable bowel syndrome therapeutic needs and chemistry, pharmacokinetics and -dynamics, clinical study results with the new opioid receptor ligand eluxadoline for the treatment of diarrhea-predominant irritable bowel syndrome (IBS-D).

EXPERT OPINION

Eluxadoline shows a peculiar pharmacological profile with μ-opioid agonism and δ-opioid antagonism actions. Its efficacy over placebo for the treatment of abdominal pain and diarrhea in IBS-D has been demonstrated in short- and long-term clinical studies in humans. Its safety has been evaluated in the same studies. Interestingly, eluxadoline showed a low rate of constipation development in IBS patients in comparison with known effects of other opioid receptor modulators. Patients with a history of acute pancreatitis should not be treated with eluxadoline.

Culture-Independent Metagenomic Surveillance of Commercially Available Probiotics with High-Throughput Next-Generation Sequencing

Millions of people consume dietary supplements either following a doctor's recommendation or at their own discretion to improve their overall health and well-being. This is a rapidly growing trend, with an associated and expanding manufacturing industry to meet the demand for new health-related products. In this study, we examined the contents and microbial viability of several popular probiotic products on the United States market. Culture-independent methods are proving ideal for fast and efficient analysis of foodborne pathogens and their associated microbial communities but may also be relevant for analyzing probiotics containing mixed microbial constituents. These products were subjected to next-generation whole-genome sequencing and analyzed by a custom in-house-developed k-mer counting method to validate manufacturer label information. In addition, the batch variability of respective products was examined to determine if any changes in their formulations and/or the manufacturing process occurred. Overall, the products we tested adhered to the ingredient claims and lot-to-lot differences were minimal. However, there were a few discrepancies in the naming of closely related Lactobacillus and Bifidobacterium species, whereas one product contained an apparent Enterococcus contaminant in two of its three lots. With the microbial contents of the products identified, we used traditional PCR and colony counting methods to comparatively assess our results and verify the viability of the microbes in these products with regard to the labeling claims. Of all the supplements examined, only one was found to be inaccurate in viability. Our use of next-generation sequencing as an analytical tool clearly demonstrated its utility for quickly analyzing commercially available products containing multiple microbes to ensure consumer safety. IMPORTANCE The rapidly growing supplement industry operates without a formal premarket approval process. Consumers rely on product labels to be accurate and true. Those products containing live microbials report both identity and viability on most product labels. This study used next-generation sequencing technology as an analytical tool in conjunction with classic culture methods to examine the validity of the labels on supplement products containing live microbials found in the United States marketplace. Our results show the importance of testing these products for identity, viability, and potential contaminants, as well as introduce a new culture-independent diagnostic approach for testing these products. Podcast: A podcast concerning this article is available.