The mechanism of action of probiotics

Effects of Probiotic Enterococcus faecium from Yak on the Intestinal Microflora and Metabolomics of Mice with Salmonella Infection

Salmonella spp. are pathogenic bacteria that cause diarrhea, abortion, and death in yak and severely harm livestock breeding. Therefore, it is vital to identify a probiotic that effectively antagonizes Salmonella. To the best of our knowledge, few prior studies have investigated the efficacy of Enterococcus faecium against Salmonella. Here, we evaluated the enteroprotective mechanism of E. faecium in a mouse Salmonella infection model using hematoxylin-eosin (H&E) staining, quantitative real-time polymerase chain reaction (Q-PCR) technology, microbial diversity sequencing, and metabonomics. Enterococcus faecium inhibited the proinflammatory cytokines IL-1β, IL-6, TNF-α, and IFN-γ and promoted the anti-inflammatory cytokine IL-10. The Firmicutes/Bacteroidota (F/B) ratio and the abundances of Firmicutes and Akkermansia were significantly higher in the E. faecium than in the Salmonella group. Metabonomics and microbial diversity sequencing disclosed five different metabolites with variable importance in the projection (VIP) > 3 that were characteristic of both the Salmonella and E. faecium groups. Combined omics revealed that Lactobacillus and Bacteroides were negatively and positively correlated, respectively, with cholic acid, while Desulfovibrio was positively correlated with lipids in both the control and Salmonella groups. Desulfovibrio was also positively correlated with lipids in both the Salmonella and E. faecium groups. Enterococcus faecium antagonizes Salmonella by normalizing the abundance of the intestinal microorganisms and modulating their metabolic pathways. Hence, it may efficaciously protect the host intestine against Salmonella infection.

Lactobacilli Probiotics Modulate Antibacterial Response Gene Transcription of Dendritic Cells Challenged with LPS

Probiotics are beneficial bacteria that may modulate the immune response by altering the maturation and function of antigen-presenting cells, such as dendritic cells. This study aimed to evaluate the antibacterial gene expression of dendritic cells challenged with LPS and probiotics. Immature dendritic cells were obtained from human CD14+ monocytes and challenged with E. coli LPS and probiotics Lacticaseibacillus rhamnosus (LR-32) and Lactobacillus acidophilus (LA-5) at a ratio DC:bacteria of 1:10. The analysis of gene expression was performed by RT-qPCR using the Kit RT2 human antibacterial response. In the supernatant, the cytokines secretion was determined by ELISA. Tukey post-ANOVA with p at 5% was used for statistical analysis. LPS showed the higher upregulation of 29 genes compared with the groups where probiotics were added to LPS, including genes related to an inflammatory response like BIRC3, CASP1, CCL5, CXCL1, IL12B, IL18, MYD88, NLRP3, RIPK1, and TIRAP. Similarly, LPS increased the transcription of genes enrolled with apoptosis such as CARD6, CASP1, IRF5, MAP2K1, MAP2K4, MAPK1, MYD88, NLRP3, RIPK2, TNF, TNFRSF1A, and XIAP when compared to probiotics groups (p < 0.05). Although probiotics decrease several genes upregulated by LPS, the transcription of encoded cytokines IL12A, IL12B, IL1B, IL6, CXCL8, and TNF genes was maintained upregulated by probiotics, except for IL18, which was downregulated by LA-5. LA-5 led to a higher transcription of IL1B, IL6, and CXCL-8 which was followed by the secretion of these proteins by ELISA. The results suggest that probiotics attenuate the transcription of inflammatory and immune response genes caused by LPS.

Antioxidant Effects and Probiotic Properties of Latilactobacillus sakei MS103 Isolated from Sweet Pickled Garlic

Fermented vegetable-based foods, renowned for their unique flavors and human health benefits, contain probiotic organisms with reported in vitro antioxidative effects. This study investigates the probiotic properties of Latilactobacillus sakei MS103 (L. sakei MS103) and its antioxidant activities using an in vitro oxidative stress model based on the hydrogen peroxide (H2O2)-induced oxidative damage of RAW 264.7 cells. L. sakei MS103 exhibited tolerance to extreme conditions (bile salts, low pH, lysozyme, H2O2), antibiotic sensitivity, and auto-aggregation ability. Moreover, L. sakei MS103 co-aggregated with pathogenic Porphyromonas gingivalis cells, inhibited P. gingivalis-induced biofilm formation, and exhibited robust hydrophobic and electrostatic properties that enabled it to strongly bind to gingival epithelial cells and HT-29 cells for enhanced antioxidant effects. Additionally, L. sakei MS103 exhibited other antioxidant properties, including ion-chelating capability and the ability to effectively scavenge superoxide anion free radicals, hydroxyl, 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid, and 2,2-diphenyl-1-picrylhydrazyl. Furthermore, the addition of live or heat-killed L. sakei MS103 cells to H2O2-exposed RAW 264.7 cells alleviated oxidative stress, as reflected by reduced malondialdehyde levels, increased glutathione levels, and the up-regulated expression of four antioxidant-related genes (gshR2, gshR4, Gpx, and npx). These findings highlight L. sakei MS103 as a potential probiotic capable of inhibiting activities of P. gingivalis pathogenic bacteria and mitigating oxidative stress.

Molecular and cellular characterization of immunity conferred by lactobacilli against necrotic enteritis in chickens

Necrotic enteritis is an important enteric disease of poultry that can be controlled with in-feed antibiotics. However, with the concerns over antimicrobial resistance, there is an increased interest in the use of alternatives. Probiotics are one of the alternatives that have gained considerable attention due to their antimicrobial and immunomodulatory activities. Therefore, in the present study, we evaluated the effects of two different Lactobacillus species alone or as a cocktail on prevention of necrotic enteritis. Day-old male broiler chickens were divided into five groups and on days 1, 8, 15, and 22, birds in groups 2 and 3 received 1×108 colony forming units (CFU) of L. johnsonii and L. reuteri, respectively. Group 4 received probiotic cocktails containing both bacteria (108 CFU/bird) and the negative and positive control groups did not receive any lactobacilli. Starting on day 23 post-hatch, birds in all groups (except the negative control group) were orally challenged twice per day with 3×108 CFU of a pathogenic C. perfringens strain for 3 days. Tissue and cecal samples were collected before and after challenge to assess gene expression, lymphocyte subsets determination, and microbiome analysis. On day 26 of age, lesion scoring was performed. The results demonstrated that the group that received the lactobacilli cocktail had significantly reduced lesion scores compared to the positive control group. In addition, the expression of interleukin (IL)-12 in the jejunum and CXC motif chemokine ligand 8 (CXCL8), IL-13, and IL-17 in the ileum were downregulated in the group that received the lactobacilli cocktail when compared to the positive control. Treating chickens with the lactobacilli cocktail prior to challenge enhanced the percentage of CD3-CD8+ cells and Bu-1+IgY+ B cells in the ileum and increased the frequency of monocyte/macrophages, CD3-CD8+ cells, Bu-1+IgM+, and Bu-1+IgY+ B cells in the jejunum. Treatment with the lactobacilli cocktail reduced the relative expression of Gamma-Protobacteria and Firmicutes compared to the positive control group. In conclusion, the results presented here suggest that treatment with the lactobacilli cocktail containing L. johnsonii and L. reuteri reduced necrotic enteritis lesions in the small intestine of chickens, possibly through the modulation of immune responses.

Highlights on two decades with microbiota and inflammatory bowel disease from etiology to therapy

Inflammatory Bowel diseases (IBDs) constitute a complex panel of disorders characterized with chronic inflammation affecting the alimentary canal along with extra intestinal manifestations. Its exact etiology is still unknown; however, it seems to be the result of uncharacterized environmental insults in the intestine and their immunological consequences along with dysbiosis, in genetically predisposed individuals. It was the main target of our team since 2002 to explore the etiology of IBD and the related role of bacteria. For almost two decades, our laboratory, among others, has been involved in the reciprocal interaction between the host gastrointestinal lining and the homing microbiota. In the first decade, the attention of scientists focused on the possible role of enteropathogenic E. coli and its relationship to the mechanistic pathways involved in IBD induced in both rats and mice by chemicals like Iodoacetamide, Dextran Sodium Sulfate, Trinitrobenzene, thus linking microbial alteration to IBD pathology. A thorough characterization of the various models was the focus of research in addition to exploring how to establish an active homeostatic composition of the commensal microbiota, including its wide diversity by restoration of gut microbiota by probiotics and moving from dysbiosis to eubiosis. In the last six years and in order to effectively translate such findings into clinical practice, it was critical to explore their relationship to colorectal cancer CRC both in solid tumors and chemically induced CRC. It was also critical to explore the degree of intestinal dysbiosis and linking to IBD, CRC and diabetes. Remarkably, the active mechanistic pathways were proposed as well as the role of microbiota or bacterial metabolites involved. This review covers two decades of investigations in our laboratory and sheds light on the different aspects of the relationship between microbiota and IBD with an emphasis on dysbiosis, probiotics and the multiple mechanistic pathways involved.

In Vitro Evaluation of the Most Active Probiotic Strains Able to Improve the Intestinal Barrier Functions and to Prevent Inflammatory Diseases of the Gastrointestinal System

Background: The integrity of the intestinal barrier is fundamental to gut health and homeostasis; its damage can increase intestinal permeability, with translocation of bacteria and/or endotoxins from gut, and the onset of various intestinal diseases. Lactobacillus spp. is one of the most common probiotics normally found in fermented foods and dairy products and is known for its anti-inflammatory and immunomodulatory properties and for its ability to protect and enhance the intestinal barrier functions. The aim of this work was to evaluate the ability of different strains of Lactobacillus spp. to improve in vitro the integrity of the intestinal barrier, to exert anti-inflammatory and immunomodulatory activity and to prevent Salmonella Typhimurium and enteroinvasive Escherichia coli (EIEC) infections. Methods: We analyzed the cellular expression of tight junctions, antimicrobial peptide HBD-2, pro-inflammatory cytokines and the inhibition of pathogens adhesion and invasion in a model of co-cultured epithelial cells treated with Lactobacillus spp. Results: L. brevis, L. reuteri and L. rhamnosus proved to be more effective in protecting the intestinal epithelium. Conclusions: These in vitro studies can help select strains particularly active in their intended use to obtain consortia formulations that can have as much maximum yield as possible in terms of patient benefit.

Effects of Treatment with Lactobacilli on Necrotic Enteritis in Broiler Chickens

Growth promoter antibiotics have been commonly used for the control of necrotic enteritis (NE) in broilers for decades. However, due to a ban on the use of these antibiotics, alternatives such as probiotics have been tested widely for NE control. The present study tested the efficacy of four different species of lactobacilli (two isolates of Lactobacillus johnsonii and one of Ligilactobacillus (L.) salivarius, Limosilactobacillus (L.) reuteri, and L. crispatus) against NE. Day-old male broiler chickens were divided into six groups and orally inoculated with 1 × 10⁷ or 1 × 10⁸ colony-forming units (CFU) of lactobacilli on 1, 7, 14, and 20 days of age. While negative and positive control groups did not receive lactobacilli, the latter was challenged with Clostridium perfringens (CP). Chickens, at 21 days old, were challenged for 3 days with 3 × 10⁸ CFU of a virulent strain of CP. Tissues were collected for immune system gene expression, immunophenotyping, intestinal histomorphometry, and microbiota analysis. Lactobacilli inoculation conferred partial protection in chickens against NE, marked by lowered lesion scores and improved villus:crypt ratio. Immunomodulatory effects were demonstrated by the significant alteration of interferon (IFN)-γ, interleukin (IL)-1β, IL-2, IL-12p35, IL-17, and transforming growth factor beta (TGF-β) gene transcription in the duodenum and jejunum as well as subtle changes in the frequency of CD8 + T cells and B cells in the cecal tonsil of the treated chickens. Microbiota analysis showed increased levels of some bacterial phyla including Actinobacteria, Lactobacillaceae, and Firmicutes. In conclusion, these findings suggest that the use of certain lactobacilli can reduce NE severity and modulate immune responses and intestinal microbiota composition in chickens.

Fecal Iron Measurement in Studies of the Human Intestinal Microbiome

Iron is an essential micronutrient for humans and their intestinal microbiota. Host intestinal cells and iron-dependent bacteria compete for intraluminal iron, so the composition and functions of the gut microbiota may influence iron availability. Studies of the effects of the microbiota or probiotic interventions on host iron absorption may be particularly relevant to settings with high burdens of iron deficiency and gastrointestinal infections, since inflammation reduces iron bioavailability and unabsorbed intraluminal iron may modify the composition of the microbiota. The quantification of stool iron content may serve as an indicator of the amount of intraluminal iron to which the intestinal microbiota is exposed, which is particularly relevant for studies of the effect of iron on the intestinal microbiome, where fecal samples collected for purposes of microbiome characterization can be leveraged for stool iron analysis. However, few studies are available to guide researchers in the selection and implementation of stool iron assays, particularly because cross-comparison of available methods is limited in literature. This review aims to describe the available stool iron quantification methods and highlight their potential application in studies of iron-microbiome relationships, with a focus on pediatric research. MS-based methods offer high sensitivity and precision, but the need for expensive equipment and the high per-sample and maintenance costs may limit their widespread use. Conversely, colorimetric assays offer lower cost, ease of use, and rapid turnaround times but have thus far been optimized primarily for blood-derived matrices rather than stool. Further research efforts are needed to validate and standardize methods for stool iron assessment and to determine if the incorporation of such analyses in human microbiome studies 1) yields insights into the interactions between intestinal microbiota and iron and 2) contributes to the development of interventions that mitigate iron deficiency and promote a healthy microbiome.

Lacticaseibacillus rhamnosus Lcr35 Stimulates Epithelial Vaginal Defenses upon Gardnerella vaginalis Infection

Dysbiosis of the vaginal microbiome as a result of overgrowth of anaerobic bacteria, such as Gardnerella vaginalis, and low levels of "healthy" lactobacilli leads to bacterial vaginosis (BV), usually associated with a low-grade inflammatory process. Despite appropriate antibiotic treatment, G. vaginalis-associated BV is characterized by significant recurrence. The use of probiotics could be an interesting alternative therapy due to their ability to rebalance vaginal microbiota. In this study, we investigated the effects of a well-characterized probiotic strain, Lacticaseibacillus rhamnosus Lcr35, on epithelial vaginal and dendritic cell (DC) immune responses after G. vaginalis infection. In an in vitro coculture model with human monocyte-derived dendritic cells and a vaginal epithelial cell (VEC) monolayer, the Lcr35 strain induced DC activation, as evidenced by the induction of maturation and synthesis of interleukin-8 (IL-8) and CCL-20 chemokines upon apical challenge of the VECs by G. vaginalis. Analysis of the vaginal epithelial response showed that the presence of Lcr35 significantly increased the production of the proinflammatory cytokines IL-8 and IL-1β and human β-defensin 2 (HBD-2), whereas the concentration of secretory leukocyte protease inhibitor (SLPI) was decreased in G. vaginalis-infected vaginal epithelial cells. Treatment with recombinant SLPI was associated with upregulation of Lcr35-stimulated IL-8 and HBD-2 production. These results suggest that inhibition of SLPI by Lcr35 in vaginal epithelial cells contributes to the host defense response against G. vaginalis infection.

Immunomodulatory effects of the Bifidobacterium longum BL-10 on lipopolysaccharide-induced intestinal mucosal immune injury

The intestine is the largest digestive and immune organ in the human body, with an intact intestinal mucosal barrier. Bifidobacterium longum is the specific gut commensals colonized in the human gut for boosting intestinal immunity to defend against intestinal mucosal immune injury. In the LPS-induced intestinal injury model, the Bifidobacterium longum BL-10 was suggested to boost the intestinal immune. Detailly, compared with the LPS-induced mice, the BL10 group significantly reduced intestine (jejunum, ileum, and colon) tissue injury, pro-inflammatory cytokines (TNF-α, IFN-γ, IL-2, IL-6, IL-17, IL-22, and IL-12) levels and myeloperoxidase activities. Moreover, the B. longum BL-10 significantly increased the number of immunocytes (CD4+ T cells, IgA plasma cells) and the expression of tight junction protein (Claudin1 and Occludin). B. longum BL-10 regulated the body's immune function by regulating the Th1/Th2 and Th17/Treg balance, which showed a greater impact on the Th1/Th2 balance. Moreover, the results also showed that B. longum BL-10 significantly down-regulated the intestinal protein expression of TLR4, p-IκB, and NF-κB p65. The B. longum BL-10 increased the relative abundance of the genera, including Lachnospiraceae_NK4A136_group and Clostridia_UCG-014, which were related to declining the levels of intestinal injury. Overall, these results indicated that the B. longum BL-10 had great functionality in reducing LPS-induced intestinal mucosal immune injury.

Modulatory Impacts of Multi-Strain Probiotics on Rabbits’ Growth, Nutrient Transporters, Tight Junctions and Immune System to Fight against Listeria monocytogenes Infection

Simple Summary

Weaning is a crucial period associated with great stress and susceptibility to infection, implying adverse impacts on farmed rabbits’ production. Recently, probiotics have been provided as direct microbial feed supplements, which are considered the ideal antibiotic substitutes during pathogenic infections with an emphasis on promoting rabbits’ growth and modulating their immune functions. Therefore, our experiment was carried out to explore the efficacy of multi-strain probiotics (MSP) on rabbits’ growth, molecular aspects, such as nutrients transporters, cytokines, and intestinal integrity, and effectiveness against Listeria monocytogenes (L. monocytogenes) infection. Altogether, our findings proposed the beneficial consequences of MSP on rabbits’ growth, gut health, and immunity. After post-experimental infection of rabbits with L. monocytogenes, administration of MSP during the whole rearing period greatly reduced the detrimental impact of infection and consequently renovated efficient rabbits’ production.

Abstract

Multi-strain probiotics (MSP) are considered innovative antibiotics’ substitutes supporting superior gut health and immunity of farmed rabbits. The promising roles of MSP on performance, intestinal immunity, integrity and transporters, and resistance against Listeria monocytogenes (L. monocytogenes) were evaluated. In the feeding trial, 220 rabbits were fed a control diet or diet supplemented with three MSP graded levels. At 60 days of age, rabbits were experimentally infected with L. monocytogenes and the positive control, enrofloxacin, prophylactic MSP (MSPP), and prophylactic and therapeutic MSP (MSPTT) groups were included. During the growing period, MSP at the level of 1 × 10⁸ CFU/kg diet (MSPIII) promoted the rabbits’ growth, upregulated the nutrient transporters and tight-junction-related genes, and modified cytokines expression. Supplementing MSPTT for L. monocytogenes experimentally-infected rabbits restored the impaired growth and intestinal barriers, reduced clinical signs of severity and mortalities, and attenuated the excessive inflammatory reactions. Notably, enrofloxacin decreased L. monocytogenes and beneficial microbial loads; unlike MSPTT, which decreased pathogenic bacterial loads and sustained the beneficial ones. Histopathological changes were greatly reduced in MSPTT, confirming its promising role in restricting L. monocytogenes translocation to different organs. Therefore, our results suggest the use of MSPTT as an alternative to antibiotics, thereby conferring protection for rabbits against L. monocytogenes infection.

Leuconostoc mesenteroides LVBH107 Antibacterial Activity against Porphyromonas gingivalis and Anti-Inflammatory Activity against P. gingivalis Lipopolysaccharide-Stimulated RAW 264.7 Cells

Probiotics, active microorganisms benefiting human health, currently serve as nutritional supplements and clinical treatments. Periodontitis, a chronic infectious oral disease caused by Porphyromonas gingivalis (P. gingivalis), activates the host immune response to release numerous proinflammatory cytokines. Here, we aimed to clarify Leuconostoc mesenterica (L. mesenteroides) LVBH107 probiotic effects based on the inhibition of P.gingivalis activities while also evaluating the effectiveness of an in vitro P.gingivalis lipopolysaccharide-stimulated RAW 264.7 cell-based inflammation mode. L. mesenteroides LVBH107 survived at acid, bile salts, lysozyme, and hydrogen peroxide conditions, auto-aggregated and co-aggregated with P. gingivalis, exhibited strong hydrophobicity and electrostatic action, and strongly adhered to gingival epithelial and HT-29 cells (thus exhibiting oral tissue adherence and colonization abilities). Moreover, L.mesenteroides LVBH107 exhibited sensitivity to antibiotics erythromycin, doxycycline, minocycline, ampicillin, and others (thus indicating it lacked antibiotic resistance plasmids), effectively inhibited P.gingivalis biofilm formation and inflammation (in vitro inflammation model), reduced the secretion of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1β) and inflammatory mediators (NO and PGE₂), and decreased the expression levels of inflammation related genes. Thus, L.mesenterica LVBH107 holds promise as a probiotic that can inhibit P.gingivalis biofilm formation and exert anti-inflammatory activity to maintain oral health.

Artificial Gastrointestinal Models for Nutraceuticals Research—Achievements and Challenges: A Practical Review

Imitating the human digestive system as closely as possible is the goal of modern science. The main reason is to find an alternative to expensive, risky and time-consuming clinical trials. Of particular interest are models that simulate the gut microbiome. This paper aims to characterize the human gut microbiome, highlight the importance of its contribution to disease, and present in vitro models that allow studying the microbiome outside the human body but under near-natural conditions. A review of studies using models SHIME, SIMGI, TIM-2, ECSIM, EnteroMix, and PolyfermS will provide an overview of the options available and the choice of a model that suits the researcher’s expectations with advantages and disadvantages.

A recombinant Bifidobacterium bifidum BGN4 strain expressing the streptococcal superoxide dismutase gene ameliorates inflammatory bowel disease

Background

Inflammatory bowel disease (IBD) is a gastrointestinal disease characterized by diarrhea, rectal bleeding, abdominal pain, and weight loss. Recombinant probiotics producing specific proteins with IBD therapeutic potential are currently considered novel drug substitutes. In this study, a Bifidobacterium bifidum BGN4-SK strain was designed to produce the antioxidant enzymes streptococcal superoxide dismutase (SOD) and lactobacillus catalase (CAT), and a B. bifidum BGN4-pBESIL10 strain was proposed to generate an anti-inflammatory cytokine, human interleukin (IL)-10. In vitro and in vivo efficacy of these genetically modified Bifidobacterium strains were evaluated for colitis amelioration.

Results

In a lipopolysaccharide (LPS)-stimulated HT-29 cell model, tumor necrosis factor (TNF)-α and IL-8 production was significantly suppressed in the B. bifidum BGN4-SK treatment, followed by B. bifidum BGN4-pBESIL10 treatment, when compared to the LPS-treated control. Synergistic effects on TNF-α suppression were also observed. In a dextran sodium sulphate (DSS)-induced colitis mouse model, B. bifidum BGN4-SK treatment significantly enhanced levels of antioxidant enzymes SOD, glutathione peroxidase (GSH-Px) and CAT, compared to the DSS-only group. B. bifidum BGN4-SK significantly ameliorated the symptoms of DSS-induced colitis, increased the expression of tight junction genes (claudin and ZO-1), and decreased pro-inflammatory cytokines IL-6, IL-1β and TNF-α.

Conclusions

These findings suggest that B. bifidum BGN4-SK ameliorated DSS-induced colitis by generating antioxidant enzymes, maintaining the epithelial barrier, and decreasing the production of pro-inflammatory cytokines. Although B. bifidum BGN4-pBESIL10 exerted anti-inflammatory effects in vitro, the enhancement of IL-10 production and alleviation of colitis were very limited.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12934-022-01840-2.

Multi-Strain-Probiotic-Loaded Nanoparticles Reduced Colon Inflammation and Orchestrated the Expressions of Tight Junction, NLRP3 Inflammasome and Caspase-1 Genes in DSS-Induced Colitis Model

Gut modulation by multi-strain probiotics (MSPs) is considered an effective strategy for treating inflammatory bowel disease (IBD). The combination of nanomaterial-based MSPs can improve their viability and resistance and can allow their targeted release in the gastrointestinal tract to be achieved. Thus, our aim is to investigate the prospective role of MSP integration into nanomaterials (MSPNPs) and the underlying molecular mechanisms supporting their application as an alternative therapy for IBD using a colitis rat model. To induce the colitis model, rats received 5% DSS, and the efficacy of disease progression after oral administration of MSPNPs was assessed by evaluating the severity of clinical signs, inflammatory response, expressions of tight-junction-related genes and NLRP3 inflammasome and caspase-1 genes, microbial composition and histopathological examination of colonic tissues. The oral administration of MSPNPs successfully alleviated the colonic damage induced by DSS as proved by the reduced severity of clinical signs and fecal calprotectin levels. Compared with the untreated DSS-induced control group, the high activities of colonic NO and MPO and serum CRP levels were prominently reduced in rats treated with MSPNPs. Of note, colonic inflammation in the group treated with MSPNPs was ameliorated by downstreaming NLRP3 inflammasome, caspase-1, IL-18 and IL-1β expressions. After colitis onset, treatment with MSPNPs was more effective than that with free MSPs in restoring the expressions of tight-junction-related genes (upregulation of occludin, ZO-1, JAM, MUC and FABP-2) and beneficial gut microbiota. Interestingly, treatment with MSPNPs accelerated the healing of intestinal epithelium as detected in histopathological findings. In conclusion, the incorporation of MPSs into nanomaterials is recommended as a perspective strategy to overcome the challenges they face and augment their therapeutic role for treating of colitis.

Probiotics Function in Preventing Atopic Dermatitis in Children

Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by relapsing eczematous injuries and severe pruritus. In the last few years, the AD prevalence has been increasing, reaching 20% in children and 10% in adults in high-income countries. Recently, the potential role of probiotics in AD prevention has generated considerable interest. As many clinical studies show, the gut microbiota is able to modulate systemic inflammatory and immune responses influencing the development of sensitization and allergy. Probiotics are used increasingly against AD. However, the molecular mechanisms underlying the probiotics mediated anti-allergic effect remain unclear and there is controversy about their efficacy. In this narrative review, we examine the actual evidence on the effect of probiotic supplementation for AD prevention in the pediatric population, discussing also the potential biological mechanisms of action in this regard.

Lactobacillus spp. for Gastrointestinal Health: Current and Future Perspectives

In recent decades, probiotic bacteria have become increasingly popular as a result of mounting scientific evidence to indicate their beneficial role in modulating human health. Although there is strong evidence associating various Lactobacillus probiotics to various health benefits, further research is needed, in particular to determine the various mechanisms by which probiotics may exert these effects and indeed to gauge inter-individual value one can expect from consuming these products. One must take into consideration the differences in individual and combination strains, and conditions which create difficulty in making direct comparisons. The aim of this paper is to review the current understanding of the means by which Lactobacillus species stand to benefit our gastrointestinal health.

Probiotics Exhibit Strain-Specific Protective Effects in T84 Cells Challenged With Clostridioides difficile-Infected Fecal Water

Clostridioides difficile infection (CDI) is frequently associated with intestinal injury and mucosal barrier dysfunction, leading to an inflammatory response involving neutrophil localization and upregulation of pro-inflammatory cytokines. The severity of clinical manifestations is associated with the extent of the immune response, which requires mitigation for better clinical management. Probiotics could play a protective role in this disorder due to their immunomodulatory ability in gastrointestinal disorders. We assessed five single-strain and three multi-strain probiotics for their ability to modulate CDI fecal water (FW)-induced effects on T84 cells. The CDI-FW significantly (p < 0.05) decreased T84 cell viability. The CDI-FW-exposed cells also exhibited increased pro-inflammatory cytokine production as characterized by interleukin (IL)-8, C-X-C motif chemokine 5, macrophage inhibitory factor (MIF), IL-32, and tumor necrosis factor (TNF) ligand superfamily member 8. Probiotics were associated with strain-specific attenuation of the CDI-FW mediated effects, whereby Saccharomyces boulardii CNCM I-1079 and Lacticaseibacillus rhamnosus R0011 were most effective in reducing pro-inflammatory cytokine production and in increasing T84 cell viability. ProtecFlor™, Lactobacillus helveticus R0052, and Bifidobacterium longum R0175 showed moderate effectiveness, and L. rhamnosus GG R0343 along with the two other multi-strain combinations were the least effective. Overall, the findings showed that probiotic strains possess the capability to modulate the CDI-mediated inflammatory response in the gut lumen.

The Emerging Role of the Gut Microbiome in the Cancer Response to Immune Checkpoint Inhibitors: A Narrative Review

The discovery of immune checkpoint inhibitors (ICIs) has revolutionized the care of cancer patients. However, the response to ICI therapy exhibits substantial interindividual variability. Efforts have been directed to identify biomarkers that predict the clinical response to ICIs. In recent years, the gut microbiome has emerged as a critical player that influences the efficacy of immunotherapy. An increasing number of studies have suggested that the baseline composition of a patient's gut microbiota and its dysbiosis are correlated with the outcome of cancer immunotherapy. This review tackles the rapidly growing body of evidence evaluating the relationship between the gut microbiome and the response to ICI therapy. Additionally, this review highlights the impact of antibiotic-induced dysbiosis on ICI efficacy and discusses the possible therapeutic interventions to optimize the gut microbiota composition to augment immunotherapy efficacy.

Effects of Probiotic Supplementation on Exercise with Predominance of Aerobic Metabolism in Trained Population: A Systematic Review, Meta-Analysis and Meta-Regression

The scientific literature about probiotic intake and its effect on sports performance is growing. Therefore, the main aim of this systematic review, meta-analysis and meta-regression was to review all information about the effects of probiotic supplementation on performance tests with predominance of aerobic metabolism in trained populations (athletes and/or Division I players and/or trained population: ≥8 h/week and/or ≥5 workouts/week). A structured search was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA®) statement and PICOS guidelines in PubMed/MEDLINE, Web of Science (WOS), and Scopus international databases from inception to 1 November 2021. Studies involving probiotic supplementation in trained population and execution of performance test with aerobic metabolism predominance (test lasted more than 5 min) were considered for inclusion. Fifteen articles were included in the final systematic review (in total, 388 participants were included). After 3 studies were removed due to a lack of data for the meta-analysis and meta-regression, 12 studies with 232 participants were involved. With the objective of assessing the risk of bias of included studies, Cochrane Collaboration Guidelines and the Physiotherapy Evidence Database (PEDro) scale were performed. For all included studies the following data was extracted: authors, year of publication, study design, the size of the sample, probiotic administration (dose and time), and characteristics of participants. The random effects model and pooled standardized mean differences (SMDs) were used according to Hedges’ g for the meta-analysis. In order to determine if dose and duration covariates could predict probiotic effects, a meta-regression was also conducted. Results showed a small positive and significant effect on the performance test with aerobic metabolic predominance (SMD = 0.29; CI = 0.08−0.50; p < 0.05). Moreover, the subgroup analysis displayed significant greater benefits when the dose was ≥30 × 109 colony forming units (CFU) (SMD, 0.47; CI, 0.05 to 0.89; p < 0.05), when supplementation duration was ≤4 weeks (SMD, 0.44; CI, 0.05 to 0.84; p < 0.05), when single strain probiotics were used (SMD, 0.33; CI, 0.06 to 0.60; p < 0.05), when participants were males (SMD, 0.30; CI, 0.04 to 0.56; p < 0.05), and when the test was performed to exhaustion (SMD, 0.45; CI, 0.05 to 0.48; p < 0.05). However, with references to the findings of the meta-regression, selected covariates did not predict probiotic effects in highly trained population. In summary, the current systematic review and meta-analysis supported the potential effects of probiotics supplementation to improve performance in a test in which aerobic metabolism is predominant in trained population. However, more research is needed to fully understand the mechanisms of action of this supplement.

Mechanism of Lactobacillus reuteri Probiotic in Increasing Intestinal Mucosal Immune System

Probiotics are defined as live microorganisms which, when consumed in adequate quantities as food ingredients, provide health benefits to the host. Lactobacillus, Bifidobacterium, and Saccharomyces, are three probiotics that are intensively used as probiotics in humans and animals. Probiotics have beneficial effects on health when given adequate amounts. The concept of probiotics on human health, namely modulating the gut microbiota and its effect on the host. Probiotics play an important role in maintaining intestinal integrity through a number of different interactions, including changes in cytokine expression in the mucosa. Probiotics compete with intestinal pathogens for mucosal receptors, thereby increasing interepithelial resistance. Probiotics such as Lactobacillus casei sp GG strain was used as a prophylaxis that could increase the expression of epithelial mucin, thereby reducing the translocation of pathogenic bacteria. Abnormal local immune response is characterized by decreased secretion of IgA, thus allowing enterocyte attachment and local translocation of bacterial antigens, which are the main stimulation of pathological events. Colonic stasis can promote the growth of pathogenic bacteria which allows malignant porin bacterial strains to thrive. The gut microbiota has a major influence on human health. The microbial population has an important role in the host, such as the metabolic activity of probiotics producing energy and nutrient absorption, developing the host immune system, and preventing colonization and infection of pathogens. Lactobacillus reuteri is a hetero-fermentative bacterium that lives in the digestive tract of humans. L. reuteri has been used to treat infant necrotizing pseudomembrane. In this paper, the mechanism of L reuteri to increase host immunological response will be reviewed.

Probiotic Properties of Lactic Acid Bacteria with High Conjugated Linoleic Acid Converting Activity Isolated from Jeot-Gal, High-Salt Fermented Seafood

Conjugated linoleic acid (CLA) isomers are potent health-promoting fatty acids. This study evaluated the probiotic properties of 10 strains of high CLA-producing lactic acid bacteria (LAB) isolated from Jeot-gal, a high-salt, fermented seafood. Two isolates, Lactiplantibacillus plantarum JBCC105683 and Lactiplantibacillus pentosus JBCC105676, produced the largest amounts of CLA (748.8 and 726.9 μg/mL, respectively). Five isolates, L. plantarum JBCC105675, L. pentosus JBCC105676, L. pentosus JBCC105674, L. plantarum JBCC105683, and Lactiplantibacillus paraplantarum JBCC105655 synthesized more cis-9, trans-11-CLA than trans-10, cis-12-CLA (approximately 80:20 ratio). All the strains survived severe artificial acidic environments and showed antimicrobial activity and strong adhesion capability to Caco-2 cells as compared to the commercial strain Lactocaseibacillus rhamnosus GG. Among them, Pediococcus acidilactici JBCC105117, L. paraplantarum JBCC105655, and L. plantarum JBCC105683 strongly stimulated the immunological regulatory gene PMK-1 and the host defense antimicrobial peptide gene clec-60 in Caenorhabditis elegans. Moreover, three strains showed a significant induction of tumor necrosis factor-α, interleukin (IL)-1β, IL-6, IL-12, and IL-10 production in RAW 264.7 macrophages, indicating that they were promising candidates for probiotics with high CLA-converting activity. Our results indicate that the newly isolated CLA-producing LAB might be useful as a functional probiotic with beneficial health effects that modulate the immune system.

The immunomodulatory effects of long-term supplementation with Lactobacillus casei Shirota depend on ovalbumin presentation in BALB/c mice

Immunomodulation is an ability of several particular probiotics. However, it still remains unclear whether the immunomodulatory effects of specific probiotics vary for different antigen presentation models with the same antigen. To investigate this matter, six groups of BALB/c mice (n = 10) were exposed to one of two antigen presentation models: ovalbumin (OVA) by injection alone, or injection plus intranasal administration. Moreover, the mice were fed distilled water or Lactobacillus casei Shirota fermented beverage (LcSFB) at low (2.5 × 109 CFU/kg body weight) or high doses (5 × 109 CFU/kg body weight) by gavage for 8 weeks. LcSFB enhanced the proliferation of splenocytes, production of OVA-specific immunoglobulin (Ig)-G and IgA, and the ratio of T-helper (Th)-2/Th1 cytokines in mice injected with OVA. Conversely, in the mice treated with OVA by injection plus intranasal administration, LcSFB attenuated the immune responses against OVA by reducing the proliferation of splenocytes, levels of OVA-specific IgE, IgG, and IgM, and ratio of Th2/Th1 cytokines. Moreover, LcSFB increased the percentage of regulatory T cells in the injection plus intranasal administration group. Taken together, this work indicates the immunoregulatory effects of LcSFB depend on how the antigen is presented. Therefore, the use of probiotics to boost the immune system must be carefully considered.

Effect of Probiotic Supplementation on Glycemic Outcomes in Patients with Abnormal Glucose Metabolism: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

INTRODUCTION

The effectiveness of probiotics in patients with abnormal glucose metabolism has not been clearly demonstrated. It is also unclear if outcomes are consistent across different probiotic formulations.

METHODS

A literature search was conducted using PubMed, EMBASE, and Cochrane CENTRAL database from inception through May 2020. Randomized controlled trials that evaluated the effect of probiotics on fasting blood glucose (FBG) or hemoglobin A1c (HbA1c) in patients with prediabetes, type 2 diabetes mellitus, or gestational diabetes were included. Outcomes of interest included FBG, HbA1c, fasting insulin, homeostatic model assessment of insulin resistance (HOMA-IR), homeostatic model assessment of β-cell function (HOMA-B), and quantitative insulin sensitivity check index (QUICKI). Weighted mean difference (WMD) and 95% confidence intervals (CIs) were calculated using the DerSimonian and Laird random-effects model.

RESULTS

31 studies involving 1,948 participants were included in this analysis. Compared to control, probiotics had a significant favorable effect on FBG (WMD -5.77 mg/dL, 95% CI -8.48 to -3.06), HbA1c (WMD -0.32%, 95% CI -0.47 to -0.18), fasting insulin (WMD -2.95 µIU/mL, 95% CI -3.76 to -2.14), HOMA-IR (WMD -0.82, 95% CI -1.05 to -0.59), HOMA-B (WMD -14.86, 95% CI -24.57 to -5.16), and QUICKI (WMD 0.015, 95% CI 0.011-0.019). Further, probiotics were associated with favorable outcomes on all parameters at doses between 1 and 10 × 109 colony-forming unit per day (p < 0.004 for all) and formulations containing 2-4 strains (p < 0.05 for all).

DISCUSSION/CONCLUSION

Probiotics appear to have a modest effect on glycemic parameters in patients with abnormal glucose metabolism. Due to the limited number of trials conducted in patients with prediabetes, more studies are warranted in this population.

Probiotics improve re-epithelialization of scratches infected by Porphyromonas gingivalis through up-regulating CXCL8-CXCR1/CXCR2 axis

Porphyromonas gingivalis inhibits the release of CXCL8 by gingival epithelial cells and reduces their proliferation. We previously reported that Bifidocaterium sp. and Lactobacillus sp. immunomodulate gingival epithelial cells response to this periodontal pathogen, but their effects on re-epithelialization properties are still unknown. Herein we explored these activities of potential probiotics on gingival epithelial cells and clarified their mechanisms. The immortalized OBA-9 lineage was used to perform in vitro scratches. Twelve clinical isolates and commercially available strains of Bifidobacterium sp. and Lactobacillus sp. were screened. L. casei 324 m and B. pseudolongum 119^1A were selected to perform mechanistic assays with P. gingivalis W83 infection and the following parameters were measured: percentage of re-epithelialization by DAPI immunofluorescence area measurement; cell number by Trypan Blue exclusion assay; CXCL8 regulation by ELISA and RT-qPCR; and expression of CXCL8 cognate receptors-CXCR1 and CXCR2 by Flow Cytometry. Complementary mechanistic assays were performed with CXCL8, in the presence or absence of the CXCR1/CXCR2 inhibitor-reparixin. L. casei 324 m and B. pseudolongum 119^1A enhanced re-epithelialization/cell proliferation as well as inhibited the harmful effects of P. gingivalis W83 on these activities through an increase in the expression and release of CXCL8 and in the number of cells positive for CXCR1/CXCR2. Further, we revealed that the beneficial effects of these potential probiotics were dependent on activation of the CXCL8-CXCR1/CXCR2 axis. The current findings indicate that these potential probiotics strains may improve wound healing in the context of the periodontal tissues by a CXCL8 dependent mechanism.

The Impact of Weaning Stress on Gut Health and the Mechanistic Aspects of Several Feed Additives Contributing to Improved Gut Health Function in Weanling Piglets-A Review

Simple Summary

The current review aimed to provide an overview on the problems associated with weaning with a special focus on gut health, and also highlighted the nutritional approach using different kinds of feed additives and their mechanistic aspects in mitigating production inefficiencies and gut health dysfunction in weanling pigs.

Abstract

Newly weaned pig encounters psychosocial, physical, and nutritional stressors simultaneously when their immune system is not fully developed. These stressors have a cumulative effect on the immune response that contributes to the post-weaning growth lag which is characterized by depression in feed intake, reduced or negative growth rates, and increased susceptibility to pathogens in the first 24 to 48 h post-weaning. Consequently, the intestinal integrity, and digestive and absorptive capacity are impaired, and there is an increase in intestinal oxidative stress. It also causes the shifts in the taxonomic and functional properties of intestinal microbiome abruptly, thereby adversely affecting the health and performance of animals. It has been suggested that the effects of weaning stress on immune functions, intestinal barrier functions, and nervous system function in early weaned pigs extends into adulthood. The inclusion of different types of feed additives into the diet have been reported to alleviate the negative effects of weaning stress. The objective of this paper was to provide an overview on how the weaning stress affects gut health and the impact it has on production efficiencies, as well as the mechanistic aspects of several feed additives applied in reducing the weaning associated gut health problems and performance inefficiencies.

Utilizing Probiotics for the Prevention and Treatment of Gastrointestinal Diseases

Probiotics are heavily advertised to promote a healthy gastrointestinal tract and boost the immune system. This review article summarizes the history and diversity of probiotics, outlines conventional in vitro assays and in vivo models, assesses the pharmacologic effects of probiotic and pharmaceutical co-administration, and the broad impact of clinical probiotic utilization for gastrointestinal disease indications.

Lactiplantibacillus plantarum 22A-3-induced TGF-β1 secretion from intestinal epithelial cells stimulated CD103+ DC and Foxp3+ Treg differentiation and amelioration of colitis in mice

In the present study, we evaluated the anti-inflammatory properties of Lactiplantibacillus plantarum 22A-3 (LP22A3) and attempted to elucidate the underlying molecular mechanism. The oral administration of LP22A3 significantly inhibited body weight reduction and decreased colon shortening and colitis score in mice with dextran sulfate sodium (DSS)-induced colitis. It was demonstrated that the production of the active-form of TGF-β tended to increase in both the intestinal epithelial cells (IECs) of the ileum and serum but not in the colon of non-DSS-treated mice by LP22A3. IL-10 level in serum was also elevated by LP22A3-treatment. The mRNA expression of TGF-β, IL-10 and Foxp3 increased only in the small intestines of LP22A3-treated mice. Both the aldehyde dehydrogenase 1 family member A2 (Aldh1a2) mRNA expression and population of CD103⁺ dendritic cells (DCs) in the small intestine significantly increased in the LP22A3-treated group. LP22A3 induced TGF-β secretion from the IECs of the small intestine with retinoic acid production probably through TLR2, resulting in an increase in CD103⁺ DCs and the Foxp3⁺ Treg population. Both cells secrete a high level of anti-inflammatory cytokines, TGF-β and IL-10 contributing to the protective condition in the intestine and thus making it less susceptible to inflammation. This suggested that oral administration of LP22A-3 may be an alternative therapeutic strategy for IBD.

Dietary Supplementation With Xylo-oligosaccharides Modifies the Intestinal Epithelial Morphology, Barrier Function and the Fecal Microbiota Composition and Activity in Weaned Piglets

The present study determined the effects of dietary xylo-oligosaccharides (XOS) supplementation on the morphology of jejunum and ileum epithelium, fecal microbiota composition, metabolic activity, and expression of genes related to colon barrier function. A total of 150 piglets were randomly assigned to one of five groups: a blank control group (receiving a basal diet), three XOS groups (receiving the basal diet supplemented with 100, 250, and 500 g/t XOS, respectively), as well as a positive control group, used as a matter of comparison, that received the basal diet supplemented with 0.04 kg/t virginiamycin, 0.2 kg/t colistin, and 3,000 mg/kg ZnO. The trial was carried out for 56 days. The results showed that the lowest dose tested (100 g/t XOS) increased (P < 0.05) the ileal villus height, the relative amount of Lactobacillus and Bifidobacterium spp., and the concentration of acetic acid and short-chain fatty acid in feces when compared with the blank control group. In conclusion, dietary 100 g/t XOS supplementation modifies the intestinal ecosystem in weaned piglets in an apparently overall beneficial way.

Potential probiotic yeast isolated from an Indonesian indigenous fermented fish (Ikan Budu)

Budu is a fermented food resulting from the activities of microorganisms like lactic acid bacteria and yeast. Budu, therefore, serves as a source of probiotics that can have beneficial effects on livestock and humans. Nonetheless, their selection has to be done with caution. The current study purposed to find out whether budu has desirable probiotic properties. This was done by determining its pH, bile acid tolerance, hydrophobicity, and inhibition of pathogens such as Staphylococcus aureus, Salmonella enteritidis, and Escherichia coli. An in vitro experiment was conducted using three Saccharomyces cerevisiae (coded as SC 11, SC 12, and SC 21) in the preparation of budu. The whole experiment was repeated four times. The budus were tested for their probiotic properties (low pH, bile salts, hydrophobicity, and inhibition of pathogenic bacteria). The results showed that the three Saccharomyces cerevisiae survived in gastric juice and bile acid, exhibited good hydrophobicity, and could inhibit pathogenic bacteria, both gram-positive and negative pathogens. They were able to survive at pH 2 for 3 h (40.70 to 55.1%), at pH 2 for 5 h (35.25 to 46.88%), in 0.3% bile acid incubated for 3 h (69.69 to 86.56%), in 0.3% bile acid incubated for 5 h (82.22 to 88.18%) and hydrophobicity ability of 97.0 to 98.1%. The inhibition activity against pathogenic bacteria, that is, Escherichia coli was 2.50 to 3.81 mm, Staphylococcus aureus was 1.66 to 3.71 mm, and Salmonella enteritidis was 1.20 to 2.64 mm.

Gut probiotic bacteria of Barbonymus gonionotus improve growth, hematological parameters and reproductive performances of the host

This study aimed to isolate and identify probiotic bacteria from the gut of Barbonymus gonionotus and evaluate their effects on growth, hematological parameters, and breeding performances of the host. Five probiotic bacteria viz. Enterococcus xiangfangensis (GFB-1), Pseudomonas stutzeri (GFB-2), Bacillus subtilis (GFB-3), Citrobacter freundii (GFB-4), and P. aeruginosa (GFB-5) were isolated and identified using 16S rRNA gene sequencing. Application of a consortium of probiotic strains (1-3 × 1.35 × 109 CFU kg-1) or individual strain such as GFB-1 (1.62 × 109 CFU kg-1), GFB-2 (1.43 × 109 CFU kg-1), GFB-3 (1.06 × 109 CFU kg-1), GFB-4 (1.5 × 109 CFU kg-1) or GFB-5 (1.43 × 109 CFU kg-1feed) through feed significantly improved growth, histological and hematological parameters and reproductive performances of B. gonionotus compared to untreated control. Moreover, the application of these probiotics significantly increased gut lactic acid bacteria and activities of digestive enzymes but did not show any antibiotic resistance nor any cytotoxicity in vitro. The highest beneficial effects on treated fishes were recorded by the application of GFB-1, GFB-2, GFB-3, and a consortium of these bacteria (T2). This is the first report of the improvement of growth and health of B. gonionotus fishes by its gut bacteria.

Role of probiotics in prevention and treatment of enteric infections: a comprehensive review

Microorganisms that inhabits human digestive tract affect global health and enteric disorders. Previous studies have documented the effectiveness and mode of action of probiotics and classified as human-friendly biota and a competitor to enteric pathogens. Statistical studies reported more than 1.5 billion cases of gastrointestinal infections caused by enteric pathogens and their long-term exposure can lead to mental retardation, temporary or permanent physical weakness, and leaving the patient susceptible for opportunistic pathogens, which can cause fatality. We reviewed previous literature providing evidence about therapeutic approaches regarding probiotics to cure enteric infections efficiently by producing inhibitory substances, immune system modulation, improved barrier function. The therapeutic effects of probiotics have shown success against many foodborne pathogens and their therapeutic effectiveness has been exponentially increased using genetically engineered probiotics. The bioengineered probiotic strains are expected to provide a better and alternative approach than traditional antibiotic therapy against enteric pathogens, but the novelty of these strains also raise doubts about the possible untapped side effects, for which there is a need for further studies to eliminate the concerns relating to the use and safety of probiotics. Many such developments and optimization of the classical techniques will revolutionize the treatments for enteric infections.

Periplaneta americana Oligosaccharides Exert Anti-Inflammatory Activity through Immunoregulation and Modulation of Gut Microbiota in Acute Colitis Mice Model

The incidence and prevalence of inflammatory bowel disorders (IBD) are increasing around the world due to bacterial infection, abnormal immune response, etc. The conventional medicines for IBD treatment possess serious side effects. Periplaneta americana (P. americana), a traditional Chinese medicine, has been used to treat arthritis, fever, aches, inflammation, and other diseases. This study aimed to evaluate the anti-inflammatory effects of oligosaccharides from P. Americana (OPA) and its possible mechanisms in vivo. OPA were purified and biochemical characterization was analyzed by HPGPC, HPLC, FT-IR, and GC–MS. Acute colitis mice model was established, the acute toxicity and anti-inflammatory activity were tested in vivo. The results showed OPA with molecular mass of 1.0 kDa were composed of 83% glucose, 6% galactose, 11% xylose, and the backbone was (1→4)-Glcp. OPA had potent antioxidant activities in vitro and significantly alleviated the clinical symptoms of colitis, relieved colon damage without toxic side effects in vivo. OPA exhibited anti-inflammatory activity by regulating Th1/Th2, reducing oxidative stress, preserving intestinal barrier integrity, and inhibiting TLR4/MAPK/NF-κB pathway. Moreover, OPA protected gut by increasing microbial diversity and beneficial bacteria, and reducing pathogenic bacteria in feces. OPA might be the candidate of complementary and alternative medicines of IBD with low-cost and high safety.

Treatment of Spleen-Deficiency Syndrome With Atractyloside A From Bran-Processed Atractylodes lancea by Protection of the Intestinal Mucosal Barrier

Atractylodes lancea (Thunb.) DC. (AL) is used in traditional Chinese medicine for the treatment of spleen-deficiency syndrome (SDS). Bran-processed Atractylodes lancea (BAL) has been found to be more effective than unprocessed AL. However, the compound in BAL active against SDS remains unclear. The pharmacological efficacy of BAL and its mechanism of action against SDS were investigated by HPLC-ELSD. Candidate compound AA (atractyloside A) in AL and BAL extracts was identified by HPLC-MS analysis. AA was tested in a rat model of SDS in which body weight, gastric residual rate, and intestinal propulsion were measured, and motilin (MTL), gastrin (GAS), and c-Kit were quantified by enzyme-linked immunosorbent assay. Potential targets and associated pathways were identified based on network pharmacology analysis. mRNA expression levels were measured by qRT-PCR and protein expression levels were measured by Western blot analysis and immunohistochemistry. AA increased body weight, intestinal propulsion, MTL, GAS, and c-Kit levels, while decreasing gastric residual volume and intestinal tissue damage, as same as Epidermal Growth Factor Receptor and Proliferating Cell Nuclear Antigen levels. Seventy-one potential pharmacologic targets were identified. Analysis of protein interaction, Gene Ontology (GO) functional analysis, pathway enrichment analysis, and docking and molecular interactions highlighted MAPK signaling as the potential signal transduction pathway. Validation experiments indicated that treatment with AA increased MTL, GAS, ZO-1, and OCLN levels, while reducing AQP1, AQP3, and FGF2 levels. In addition, phosphorylation of p38 and myosin light-chain kinase (MLCK) expression were inhibited. AA improved gastrointestinal function by protecting the intestinal mucosal barrier via inhibition of the p38 MAPK pathway. The results have clinical implications for the therapy of SDS.

Gnotobiotic rainbow trout (Oncorhynchus mykiss) model reveals endogenous bacteria that protect against Flavobacterium columnare infection

The health and environmental risks associated with antibiotic use in aquaculture have promoted bacterial probiotics as an alternative approach to control fish infections in vulnerable larval and juvenile stages. However, evidence-based identification of probiotics is often hindered by the complexity of bacteria-host interactions and host variability in microbiologically uncontrolled conditions. While these difficulties can be partially resolved using gnotobiotic models harboring no or reduced microbiota, most host-microbe interaction studies are carried out in animal models with little relevance for fish farming. Here we studied host-microbiota-pathogen interactions in a germ-free and gnotobiotic model of rainbow trout (Oncorhynchus mykiss), one of the most widely cultured salmonids. We demonstrated that germ-free larvae raised in sterile conditions displayed no significant difference in growth after 35 days compared to conventionally-raised larvae, but were extremely sensitive to infection by Flavobacterium columnare, a common freshwater fish pathogen causing major economic losses worldwide. Furthermore, re-conventionalization with 11 culturable species from the conventional trout microbiota conferred resistance to F. columnare infection. Using mono-re-conventionalized germ-free trout, we identified that this protection is determined by a commensal Flavobacterium strain displaying antibacterial activity against F. columnare. Finally, we demonstrated that use of gnotobiotic trout is a suitable approach for the identification of both endogenous and exogenous probiotic bacterial strains protecting teleostean hosts against F. columnare. This study therefore establishes an ecologically-relevant gnotobiotic model for the study of host-pathogen interactions and colonization resistance in farmed fish.

The Role of Mucosal Immunity and Recombinant Probiotics in SARS-CoV2 Vaccine Development

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2), causing the 2019 novel coronavirus disease (COVID-19), was introduced by WHO (World Health Organization) as "pandemic" in March 2020. According to WHO, thus far (23 November 2020) 58,425,681 infected cases including 1,385,218 deaths have been reported worldwide. In order to reduce transmission and spread of this lethal virus, attempts are globally being made to develop an appropriate vaccine. Intending to neutralize pathogens at their initial entrance site, protective mucosal immunity is inevitably required. In SARS-CoV2 infection and transmission, respiratory mucosa plays a key role; hence, apparently mucosal vaccination could be a superior approach to elicit mucosal and systemic immune responses simultaneously. In this review, the advantages of mucosal vaccination to control COVID-19 infection, limitations, and outcomes of mucosal vaccines have been highlighted. Considering the gut microbiota dysregulation in COVID-19, we further provide evidences on utilization of recombinant probiotics, particularly lactic acid bacteria (LAB) as vaccine carrier. Their intrinsic immunomodulatory features, natural adjuvanticity, and feasible expression of relevant antigen in the mucosal surface make them more appealing as live cell factory. Among all available platforms, bioengineered probiotics are considered as the most affordable, most practical, and safest vaccination approach to halt this emerging virus.

Changes in the Crohn's Disease Activity Index and Safety of Administering Saccharomyces Boulardii in Patients with Crohn's Disease in Clinical Remission: A Single Hospital-based Retrospective Cohort Study

Background/Aims

Crohn's disease (CD) is characterized by uncontrolled inflammation of the intestine. Saccharomyces boulardii (S. boulardii), a probiotic, stabilizes the intestinal wall. This study examined the changes in the CD activity index (CDAI) after taking S. boulardii in patients with CD in clinical remission.

Methods

In this single hospital-based retrospective cohort study, the medical records of CD patients in clinical remission, who had received S. boulardii for more than 6 months, were reviewed. The CDAI, BMI, and serum levels of hemoglobin (Hb), ferritin, iron, vitamin B12, folate, total protein, albumin, total cholesterol, CRP, and fecal calprotectin (FC) between the initiation and the 6th month were compared. The timing and reasons for the discontinuation were also investigated.

Results

One hundred and fifty-four patients were included, and 92 patients, who received for more than 6 months, were analyzed. The changes in CDAI, BMI, Hb, and total cholesterol were significant as follows: CDAI from 38.52 to 30.53 (p<0.01), BMI (kg/m² ) from 23.38 to 23.97 (p<0.01), Hb (g/dL) from 13.73 to 14.03 (p<0.01), and total cholesterol (mg/dL) from 154.9 to 161.5 (p<0.01). On the other hand, the changes in FC, CRP, ferritin, vitamin B12, folate, total protein, and albumin were not statistically significant. Only one patient stopped due to a flare-up, but this was not believed to be related to the drug.

Conclusions

In patients with CD in remission, S. boulardii appears to improve the CDAI, BMI, serum Hb, and total cholesterol level without safety issues. Further randomized controlled studies will be needed.

In vitro Inhibition of Clinical Isolates of Otitis Media Pathogens by the Probiotic Streptococcus salivarius BLIS K12

Otitis media is a common childhood infection, frequently requiring antibiotics. With high rates of antibiotic prescribing and increasing antibiotic resistance, new strategies in otitis media prevention and treatment are needed. The aim of this study was to assess the in vitro inhibitory activity Streptococcus salivarius BLIS K12 against otitis media pathogens. Efficacy of the bacteriocin activity of S. salivarius BLIS K12 against the otitis media isolates was assessed using the deferred antagonism test. Overall, 48% of pathogenic isolates exhibited some growth inhibition by S. salivarius BLIS K12. S. salivarius BLIS K12 can inhibit the in vitro growth of the most common pathogens.

Mining zebrafish microbiota reveals key community-level resistance against fish pathogen infection

The long-known resistance to pathogens provided by host-associated microbiota fostered the notion that adding protective bacteria could prevent or attenuate infection. However, the identification of endogenous or exogenous bacteria conferring such protection is often hindered by the complexity of host microbial communities. Here, we used zebrafish and the fish pathogen Flavobacterium columnare as a model system to study the determinants of microbiota-associated colonization resistance. We compared infection susceptibility in germ-free, conventional and reconventionalized larvae and showed that a consortium of 10 culturable bacterial species are sufficient to protect zebrafish. Whereas survival to F. columnare infection does not rely on host innate immunity, we used antibiotic dysbiosis to alter zebrafish microbiota composition, leading to the identification of two different protection strategies. We first identified that the bacterium Chryseobacterium massiliae individually protects both larvae and adult zebrafish. We also showed that an assembly of 9 endogenous zebrafish species that do not otherwise protect individually confer a community-level resistance to infection. Our study therefore provides a rational approach to identify key endogenous protecting bacteria and promising candidates to engineer resilient microbial communities. It also shows how direct experimental analysis of colonization resistance in low-complexity in vivo models can reveal unsuspected ecological strategies at play in microbiota-based protection against pathogens.

The Potential Effects of Probiotics and ω-3 Fatty Acids on Chronic Low-Grade Inflammation

Chronic low-grade inflammation negatively impacts health and is associated with aging and obesity, among other health outcomes. A large number of immune mediators are present in the digestive tract and interact with gut bacteria to impact immune function. The gut microbiota itself is also an important initiator of inflammation, for example by releasing compounds such as lipopolysaccharides (LPS) that may influence cytokine production and immune cell function. Certain nutrients (e.g., probiotics, ω-3 fatty acids [FA]) may increase gut microbiota diversity and reduce inflammation. Lactobacilli and Bifidobacteria, among others, prevent gut hyperpermeability and lower LPS-dependent chronic low-grade inflammation. Furthermore, ω-3 FA generate positive effects on inflammation-related conditions (e.g., hypertriglyceridemia, diabetes) by interacting with immune, metabolic, and inflammatory pathways. Ω-3 FA also increase LPS-suppressing bacteria (i.e., Bifidobacteria) and decrease LPS-producing bacteria (i.e., Enterobacteria). Additionally, ω-3 FA appear to promote short-chain FA production. Therefore, combining probiotics with ω-3 FA presents a promising strategy to promote beneficial immune regulation via the gut microbiota, with potential beneficial effects on conditions of inflammatory origin, as commonly experienced by aged and obese individuals, as well as improvements in gut-brain-axis communication.

Bi-Directional interactions between microbiota and ionizing radiation in head and neck and pelvic radiotherapy - clinical relevance

Purpose: Rapid developments in high throughput screening technology for the detection and identification of the human microbiota have helped in understanding its influence on human health and disease. In the recent past, several seminal studies have demonstrated the influence of microbiota on outcomes of therapy-associated radiation exposure. In this review, we highlight the concepts related to the mechanisms by which radiation alters the microbiota composition linked with radiation-associated toxicity in head and neck and pelvic regions. We further discuss specific microbial changes that can be employed as a biomarker for radiation and tumor response.Conclusion: Knowledge of the influence of microbiota in radiation response and advances in microbiota manipulation techniques would help to design personalized treatment augmenting the efficacy of radiotherapy.

Probiotics as a prophylaxis to prevent oral candidiasis in patients with Sjogren's syndrome: a double-blinded, placebo-controlled, randomized trial

Patients with Sjögren's syndrome are at a higher risk to develop oral candidiasis than the general population. As antifungals have many side-effects, new approaches are needed to address this problem. This randomized controlled study aimed to evaluate the short-term efficacy of probiotics in the reduction of oral candidal growth in patients with SS. Thirty-two Sjogren's syndrome patients were randomly allocated in two groups receiving either Probiotics or placebo capsules twice a day for 5 weeks. The strains included in the probiotic capsule were Lactobacillus acidophilus, Lactobacillus bulgaricus, Streptococcus thermophilus and Bifidobacteriumbifidum. Oral rinse solution samples were collected and candidal levels were determined (CFU/mL) at baseline and after the 5-week experimental period. Pain, erythema and angular cheilitis were also assessed at baseline and after 2, 4 and 5-week. In the probiotic group, there was a statistically significant reduction of the candidal load from baseline to the 5th week respectively. However, the change in candidal load at the same time in the placebo group was not statistically significant. The tested probiotic product may represent an unconventional method to reduce candidal colonization, to prevent oral candidosis in patients with Sjogren's syndrome.Clinical trials registration ID NCT03840538 (https://clinicaltrials.gov/show/NCT03840538).

The anti-inflammatory, anti-oxidant and protective effects of a probiotic mixture on organ toxicity in a rat model

Aim: The objective of this study was to evaluate the possible protective effects of probiotic bacteria, especially Bifidobacterium and Lactobacillus strains, on 4,4'-dichlorodiphenyltrichloroethane (DDT)-induced toxicity. For this reason, we evaluated the relationship between probiotics and toxicity by checking immunological and immunohistochemical parameters. Materials & methods: Probiotic pretreatment was applied to 36 Wistar albino rats for 12 consecutive days. Serum aspartate aminotransferase and alanine aminotransferase levels were detected. CD3 and NF-κB staining methods were then performed by immunohistochemistry. Finally, pro- and anti-inflammatory cytokines were measured by ELISA. Results: DDT caused a serious increase/decrease in some cytokine parameters. The effective dose was 1 × 10¹¹ colony-forming unit probiotic treatment. CD3 and NF-κB positivity were intense in DDT group whereas the intensity was reduced in probiotic treatment groups. Discussion: The probiotic mixture has a potential to prevent inflammatory and oxidative stress related organ injuries. Further studies should be performed to explain the possible mechanisms.

Unique genetic basis of the distinct antibiotic potency of high acetic acid production in the probiotic yeast Saccharomyces cerevisiae var. boulardii

The yeast Saccharomyces boulardii has been used worldwide as a popular, commercial probiotic, but the basis of its probiotic action remains obscure. It is considered conspecific with budding yeast Saccharomyces cerevisiae, which is generally used in classical food applications. They have an almost identical genome sequence, making the genetic basis of probiotic potency in S. boulardii puzzling. We now show that S. boulardii produces at 37°C unusually high levels of acetic acid, which is strongly inhibitory to bacterial growth in agar-well diffusion assays and could be vital for its unique application as a probiotic among yeasts. Using pooled-segregant whole-genome sequence analysis with S. boulardii and S. cerevisiae parent strains, we succeeded in mapping the underlying QTLs and identified mutant alleles of SDH1 and WHI2 as the causative alleles. Both genes contain a SNP unique to S. boulardii (sdh1^F317Y and whi2^S287*) and are fully responsible for its high acetic acid production. S. boulardii strains show different levels of acetic acid production, depending on the copy number of the whi2^S287* allele. Our results offer the first molecular explanation as to why S. boulardii could exert probiotic action as opposed to S. cerevisiae. They reveal for the first time the molecular-genetic basis of a probiotic action-related trait in S. boulardii and show that antibacterial potency of a probiotic microorganism can be due to strain-specific mutations within the same species. We suggest that acquisition of antibacterial activity through medium acidification offered a selective advantage to S. boulardii in its ecological niche and for its application as a probiotic.