Lactobacillus fermentum species ameliorate dextran sulfate sodium-induced colitis by regulating the immune response and altering gut microbiota

Secoisolariciresinol diglucoside-derived metabolite, enterolactone, attenuates atopic dermatitis by suppressing Th2 immune response

Atopic dermatitis (AD) is a severe inflammatory skin disease caused by a combination of genetic, immune, and environmental factors. Intestinal microbiome disorders and changes in the immune microenvironment are associated with AD. We observed that gut bacterial metabolite enterolactone (ENL) was significantly reduced in AD model mice. Notably, patients with early childhood-onset AD exhibited decreased sera ENL level compared to the healthy controls, and the ENL level was negatively correlated with the SCORAD index. Secoisolariciresinol-diglycoside (SDG) is a natural dietary lignan of flaxseeds that can be converted by intestinal bacteria to ENL. Repeated applications of 2,4-dinitrochlorobenzene (DNCB) were performed on the ear and dorsal skin of mice to induce AD-like symptoms and skin lesions. Oral administration of SDG significantly decreased serum IgE levels and limited skin inflammation in the DNCB-induced AD mice. In addition, SDG treatment strongly limited the Th2 responses in AD mice. Moreover, we demonstrated that the IL-4 production was significantly suppressed by ENL under Th2 polarization conditions via the JAK-STAT6 signaling pathway in a concentration-dependent manner. We concluded that SDG and its derived metabolite ENL ameliorated AD development by reducing the Th2 immune response. These results suggested that SDG and ENL might be exploited as potential therapeutic candidates for AD treatment.

A Japanese Herbal Formula, Daikenchuto, Alleviates Experimental Colitis by Reshaping Microbial Profiles and Enhancing Group 3 Innate Lymphoid Cells

Daikenchuto (DKT) is one of the most widely used Japanese herbal formulae for various gastrointestinal disorders. It consists of Zanthoxylum Fructus (Japanese pepper), Zingiberis Siccatum Rhizoma (processed ginger), Ginseng radix, and maltose powder. However, the use of DKT in clinical settings is still controversial due to the limited molecular evidence and largely unknown therapeutic effects. Here, we investigated the anti-inflammatory actions of DKT in the dextran sodium sulfate (DSS)-induced colitis model in mice. We observed that DKT remarkably attenuated the severity of experimental colitis while maintaining the members of the symbiotic microbiota such as family Lactobacillaceae and increasing levels of propionate, an immunomodulatory microbial metabolite, in the colon. DKT also protected colonic epithelial integrity by upregulating the fucosyltransferase gene Fut2 and the antimicrobial peptide gene Reg3g. More remarkably, DKT restored the reduced colonic group 3 innate lymphoid cells (ILC3s), mainly RORγt^high-ILC3s, in DSS-induced colitis. We further demonstrated that ILC3-deficient mice showed increased mortality during experimental colitis, suggesting that ILC3s play a protective function on colonic inflammation. These findings demonstrate that DKT possesses anti-inflammatory activity, partly via ILC3 function, to maintain the colonic microenvironment. Our study also provides insights into the molecular basis of herbal medicine effects, promotes more profound mechanistic studies towards herbal formulae and contributes to future drug development.

Co-administration of Lactobacillus gasseri KBL697 and tumor necrosis factor-alpha inhibitor infliximab improves colitis in mice

Inflammatory bowel disease (IBD) refers to disorders involving chronic inflammation of the gastrointestinal tract. Well-established treatments for IBD have not yet to be suggested. To address this gap, we investigated the effects of co-administration of Lactobacillus gasseri (L. gasseri) KBL697 and infliximab (IFX), the first approved tumor necrosis factor (TNF)-alpha inhibitor, on the dextran sodium sulfate-induced colitis mouse model. 2 × 10⁹ colony-forming units/g of L. gasseri KBL697 were administered to seven-week-old female C57BL/6J mice daily by oral gavage. On day three, IFX (5 mg/kg) suspended in 1 × PBS (200 µL) was intravenously injected in the IFX-treated group and all mice were sacrificed on day nine. Co-administration of L. gasseri KBL697 and IFX improved colitis symptoms in mice, including body weight, disease activity index, colon length, and histology score. Additionally, pro-inflammatory cytokines, such as interferon-gamma, interleukin (IL)-2, IL-6, IL-17A, and TNF were significantly decreased, while IL-10, an anti-inflammatory cytokine, was increased. Expression levels of tight junction genes and CD4 + CD25 + Foxp3 + T regulatory cells in the mesenteric lymph nodes were synergistically upregulated with the combined treatment. Furthermore, co-administered mice displayed altered cecum microbial diversity and composition with increases in the genus Prevotella. Related changes in the predicted amino and nucleic acid metabolic pathways were also evident, along with increased acetate and butyrate level. Therefore, the synergistic effect of L. gasseri KBL697 and IFX co-administration is a possible method of prevention and treatment for IBD.

The Metabolites of Lactobacillus fermentum F-B9-1 Relieved Dextran Sulfate Sodium-Induced Experimental Ulcerative Colitis in Mice

Because of the increased incidence and prevalence, ulcerative colitis (UC) has become a global health issue in the world. Current therapies for UC are not totally effective which result in persistent and recurrent symptom of many patients. Lactobacillus with anti-inflammatory effects might be beneficial to the prevention or treatment for UC. Here, we examined the ameliorative effects of the metabolites of Lactobacillus fermentum F-B9-1 (MLF) in Caco-2 cells and dextran sodium sulfate (DSS)-induced UC model mice. MLF displayed intestinal barrier-protective activities in Caco-2 cells by increasing the expression of Occludin and ZO-1. They also showed anti-inflammatory potential in interleukin (IL)-1β and IL-6. In order to further examine the in vivo anti-inflammatory effect of MLF, the MLF was gavaged in the DSS-induced UC model mice. The intragastric administration of MLF effectively alleviated colitis symptoms of weight loss, diarrhea, colon shortening, and histopathological scores, protected intestinal barrier function by increasing Occludin and ZO-1, and attenuated colonic and systemic inflammation by suppressing production of IL-1β and IL-6. Finally, the use of MLF remodeled the diversity of the gut microbiota and increased the number of beneficial microorganisms. Overall, the results demonstrated that MLF relieved DSS-induced UC in mice. And MLF might be an effective therapy method to UC in the clinic in the future.

Bifidobacterium longum relieves constipation by regulating the intestinal barrier of mice

Constipation is a major health concern worldwide, requiring effective and safe treatment options. This study mainly focused on three species and nine strains of bifidobacteria from different sources to study their abilities to relieve constipation induced by loperamide in BALB/C mice. By monitoring constipation-related indicators, it was found that only Bifidobacterium longum (B. longum) relieved constipation, which indicated that bifidobacteria had inter-species differences in relieving constipation. Furthermore, through the detection of biological, chemical, mechanical, and immune barriers in mice, it was discovered that B. longum upregulates the relative abundance of 22 genera that were positively related to faecal water content, small intestinal propulsion rate, acetate, propionate, and intestinal mechanical barrier and negatively correlated with inflammatory factors, AQP8 and the time of first black stool and downregulates the relative abundance of Akkermansia. Furthermore, it increased the level of acetate in faeces and reduced the expression of AQP8 in the colon. This enhances intestinal motility and improves water and electrolyte metabolism. Meanwhile, it inhibited inflammation and prevented loperamide-induced intestinal barrier damage in constipated mice by upregulating occludin and downregulating IL-1β and TNF-α. In summary, B. longum relieved constipation by regulating the intestinal barrier in constipated mice.

Immunomodulatory effects of mixed Lactobacillus plantarum on lipopolysaccharide-induced intestinal injury in mice

The intestine is the largest digestive and immune organ in the human body, with an intact intestinal mucosal barrier. Lactobacillus plantarum is an important strain of probiotics in the intestine for boosting intestinal immunity to defend against intestinal injury. In the lipopolysaccharide-induced intestinal injury model, mixed L. plantarum (L. plantarum KLDS 1.0318, L. plantarum KLDS 1.0344, and L. plantarum KLDS 1.0386) was suggested to boost intestinal immunity. In detail, compared with LPS-induced mice, mice in the mixed L. plantarum group showed significantly reduced intestine (jejunum, ileum, and colon) tissue injury, pro-inflammatory cytokine (TNF-α, IL-6 and IL-12) levels, myeloperoxidase activities, and serum D-lactate (P < 0.05) content. Moreover, the mixed L. plantarum significantly increased the number of immunocytes (CD4+ T cells, IgA plasma cells) and the expression of tight junction proteins (Claudin1 and Occludin). The results also showed that the mixed L. plantarum significantly down-regulated (P < 0.05) the intestinal protein expression of TLR4, p-IκB, and NF-κB p65. The mixed L. plantarum group increased the relative abundance of the genera, including Lactobacillus, Lachnoclostridium, and Desulfovibrio, which are related to improving the levels of SCFAs (acetic acid, butyric acid) and total bile acid (P < 0.05). Overall, these results indicated that the mixed L. plantarum had great functionality in reducing LPS-induced intestinal injury.

Mitigation of DSS-Induced Colitis Potentially via Th1/Th2 Cytokine and Immunological Function Balance Induced by Phenolic-Enriched Buckwheat (Fagopyrum esculentum Moench) Bee Pollen Extract

Colitis is an inflammatory disease that results from the overactivation of effector immune cells, producing a high quantity of pro-inflammatory cytokines. Our study aimed to explore whether buckwheat (F. esculentum) bee pollen extract (FBPE) could inhibit the progression of dextran sulfate sodium (DSS)-induced colitis via regulating immune function. We isolated and identified six main phenolic compounds of FBPE such as luteolin (9.46 mg/g) by column chromatography, HPLC-DAD, ESI-MS and NMR spectroscopy, then assessed their effects on colonic mucosal injury by clinical symptoms, histomorphology and immunohistochemistry examinations. The results showed that FBPE at 25.2 g/kg body weight (g/kg BW) changed the clinical symptoms of colitis, the ICAM-1 expression in colon, the activity of related inflammatory mediators in colon tissue and helped restore the immune system. Compared with the model group (40.28%), the CD4 positivity was significantly reduced in the HD (High-dose group: 25.2 g FBPE/kg BW/day) group (20.45%). Administration of 25.2 g/kg BW of FBPE decreased the IFN-γ, TNF-α and IL-4 levels, while enhancing the IL-10 level, and significantly inhibited the abnormally decreased IgG (Model: 13.25 mg/mL, HD: 14.06 mg/mL), showing a reversal effect on the Th1/Th2 levels in colitis. These findings suggested that FBPE at 25.2 g/kg BW had the effects of alleviating colitis and immunomodulation, which can help in the development of safe and effective immune therapy.

Limosilactobacillus fermentum, Current Evidence on the Antioxidant Properties and Opportunities to be Exploited as a Probiotic Microorganism

The unbalance in the production and removal of oxygen-reactive species in the human organism leads to oxidative stress, a physiological condition commonly linked to the occurrence of cancer, neurodegenerative, inflammatory, and metabolic disorders. The implications of oxidative stress in the gut have been associated with gut microbiota impairments and gut dysbiosis. Some lactobacilli strains have shown an efficient antioxidant system capable of protecting against oxidative stress and related-chronic diseases. Recently, in vitro and experimental studies and some clinical trials have demonstrated the efficacy of the administration of various Limosilactobacillus fermentum strains to modulate beneficially the host antioxidant system resulting in the amelioration of a variety of systemic diseases phenotypes. This review presents and discusses the currently available studies on identifying L. fermentum strains with anti-oxidant properties, their sources, range of the administered doses, and duration of the intervention in experiments with animals and clinical trials. This review strives to serve as a relevant and well-cataloged reference of L. fermentum strains with capabilities of inducing anti-oxidant effects and health-promoting benefits to the host, envisaging their broad applicability to disease control.

Your Regulatory T Cells Are What You Eat: How Diet and Gut Microbiota Affect Regulatory T Cell Development

Modern industrial practices have transformed the human diet over the last century, increasing the consumption of processed foods. Dietary imbalance of macro- and micro-nutrients and excessive caloric intake represent significant risk factors for various inflammatory disorders. Increased ingestion of food additives, residual contaminants from agricultural practices, food processing, and packaging can also contribute deleteriously to disease development. One common hallmark of inflammatory disorders, such as autoimmunity and allergies, is the defect in anti-inflammatory regulatory T cell (Treg) development and/or function. Treg represent a highly heterogeneous population of immunosuppressive immune cells contributing to peripheral tolerance. Tregs either develop in the thymus from autoreactive thymocytes, or in the periphery, from naïve CD4⁺ T cells, in response to environmental antigens and cues. Accumulating evidence demonstrates that various dietary factors can directly regulate Treg development. These dietary factors can also indirectly modulate Treg differentiation by altering the gut microbiota composition and thus the production of bacterial metabolites. This review provides an overview of Treg ontogeny, both thymic and peripherally differentiated, and highlights how diet and gut microbiota can regulate Treg development and function.

Probiotics as Potential Biological Immunomodulators in the Management of Oral Lichen Planus: What's New?

Oral lichen planus (OLP) is a T cell-mediated chronic inflammatory disorder with multifactorial aetiology and malignant transformation potential. Despite the treatments so far identified, new tailored and safe specific measures are needed. Recently, human microbiota imbalance has been linked to several immune-mediated diseases, opening new therapeutic perspectives for probiotics; besides their ability to directly interact with the host microbiota, they also display a strain-specific immune-modulatory effect. Thus, this non-systematic review aims to elucidate the molecular pathways underlying probiotic activity, mainly those of Lactobacilli and Bifidobacteria and their metabolites in OLP pathogenesis and malignant transformation, focusing on the most recent in vitro and in vivo research evidence. Findings related to their activity in other immune-mediated diseases are here included, suggesting a probiotic translational use in OLP. Probiotics show immune-modulatory and microbiota-balancing activities; they protect the host from pathogens, hamper an excessive effector T cell response, reduce nuclear factor-kappa B (NF-kB) signalling and basal keratinocytes abnormal apoptosis, shifting the mucosal response towards the production of anti-inflammatory cytokines, thus preventing uncontrolled damage. Therefore, probiotics could be a highly encouraging prevention and immunotherapeutic approach for a safer and more sustainable OLP management.

The role of probiotics in children with autism spectrum disorders: A study protocol for a randomised controlled trial

Background

Autism spectrum disorder (ASD) is a neurological and developmental condition that begins in infancy or earlier and lasts through the individual’s lifetime. The aetiology and mechanisms of ASD are not yet fully understood, and current treatment comprises mainly education and rehabilitation, without significant improvement in the core symptoms. Recent studies suggest that microbiota change in children with ASD after the ingestion of probiotics may improve the balance of microbiota and thus ASD symptoms.

Objective

The objectives of this study are to evaluate the efficacy of probiotics on the symptoms of children with ASD and the possible mechanisms involved.

Methods

This is a prospective controlled trial. A total of 160 children with ASD will be stratified and allocated to placebo and probiotics groups randomised according to the severity of their ASD symptoms. The probiotics group will be given probiotics supplements orally twice a day for 3 months and the control group will be given a placebo at the same amount, in addition to the baseline therapy of education and rehabilitation. All the children will be evaluated systematically by using different scales, questionnaires before, during, and after 3 months’ treatment, as well as 3 months after discontinuation. The potential impact of probiotics on immunity and inflammation, metabolism, and metagenome will also be investigated.

Discussion

Our previous study showed that the abundance of intestinal flora was greatly different in children with ASD, and that Bifidobacterium was associated with the severity of ASD. In the present study, we will investigate the impact of probiotics supplementation on the symptoms of Children with ASD, with the purpose of evaluating the possible therapeutic effects of additives on ASD and of providing a reference for clinical treatment. The results will help to disclose as yet unknown relationship between probiotics and ASD.

Trial registration

This study has been registered with Chinese Clinical Trial Registry (ChiCTR-2000037941).

Fusobacterium nucleatum promotes liver metastasis in colorectal cancer by regulating the hepatic immune niche and altering gut microbiota

Liver metastasis is the major cause of death in colorectal cancer (CRC) patients. Nevertheless, the underlying mechanisms remain unknown. Gut microbiota intricately affect the initiation and progression of CRC by instigating immune response through the secretion of pro-inflammatory cytokines. In this study, we investigated the contribution of Fusobacterium nucleatum (F.nucleatum) to the microbiota-liver axis of CRC in mice, focusing on the correlation between liver immunity and gut microbiota alterations. When F. nucleatum was orally administered to mice, CRC liver metastasis was evidently exaggerated and accompanied by noticeable deleterious effects on body weight, cecum weight, and overall survival time. Further evaluation of the immune response and cytokine profiles revealed a substantial increase in the levels of pro-inflammatory cytokines such as IL6, IL12, IL9, IL17A, CXCL1, MCP-1, TNF-α, and IFN-γ in the plasma of mice treated with F. nucleatum as compared to that in the untreated control mice. Besides, hepatic immune response was also modulated by recruitment of myeloid-derived suppressor cells, reduction in the infiltration of natural killer (NK) and T helper-17 (Th17) cells, as well as increase in regulatory T cell accumulation in the liver. Additionally, sustained F. nucleatum exposure abridged the murine gut microbiota diversity, inducing an imbalanced and restructured intestinal microflora. In particular, the abundance of CRC-promoting bacteria such as Enterococcus and Escherichia/Shigella was evidently elevated post F. nucleatum treatment. Thus, our findings suggest that F. nucleatum might be an important factor involved in promoting CRC liver metastasis by triggering of liver immunity through the regulation of gut microbiota structure and composition.

Effects of Exopolysaccharides from Lactiplantibacillus plantarum JLAU103 on Intestinal Immune Response, Oxidative Stress, and Microbial Communities in Cyclophosphamide-Induced Immunosuppressed Mice

This study investigated the effects of the exopolysaccharide from Lactiplantibacillus plantarum JLAU103 (EPS103) on the intestinal immune response, oxidative stress, intestinal mucosal barrier, and microbial community in cyclophosphamide-induced immune-suppressed mice. The results showed that EPS103 promoted the secretion of cytokines and the generation of secretory immunoglobulin A and mucin-2 in the small intestine of mice, which might be related to the activation of the MAPK pathway. Additionally, EPS103 protected against oxidative stress by activating antioxidation enzymes and Nrf2/Keap1 pathways. It also improved the intestinal physical barrier functions via regulating the ratio of villous height to crypt depth and upregulating the expression of tight-junction proteins. Meanwhile, EPS103 promoted the generation of short-chain fatty acids (SCFAs) and modulated the constituents of gut microbiota. These results suggested that EPS103 may modulate the intestinal immunoresponse relying on the regulation of SCFA production and gut microbiota in immunosuppressed mice, resulting in the activation of systemic immunity.

Bacillus toyonensis SAU-19 and SAU-20 Isolated From Ageratina adenophora Alleviates the Intestinal Structure and Integrity Damage Associated With Gut Dysbiosis in Mice Fed High Fat Diet

This study was performed to identify potential probiotic endophytes from Ageratina adenophora and evaluate their ameliorating effects on gut injury and integrity damage associated with microbiota dysbiosis in mice fed high fat diet. Using morphological and biochemical tests, and 16S rRNA gene sequencing technique, two bacteria endophytes were identified as strains of Bacillus toyonensis and were named Bacillus toyonensis SAU-19 (GenBank No. MW287198) and Bacillus toyonensis SAU-20 (GenBank No. MW287199). Sixty (60) mice were divided into five groups, group 1 was the negative control fed normal diet (NS), group 2 was fed High fat diet (HF), Group 3 was fed High fat diet + 106 Lactobacillus rhamnosus (LGG), group 4 was fed High fat + 106 Bacillus toyonensis SAU-19 and group 5 fed High fat diet + 106 Bacillus toyonensis SAU-20. After 35 days, histological and immunohistochemistry examination were performed in the ileum tissues. Furthermore, DAO and antioxidants activities were measured in serum, mRNA expressions of tight junction proteins (occludin and ZO-1) and inflammation related cytokines (IL-1β, TFN-α, IL-2, IL-4, and IL-10) in the ileum tissues as well as sIgA levels and total bacteria (Escherichia coli, Salmonella, Staphylococcus, and Lactobacillus) in the small intestine and cecum content. The results showed an increase in the DAO activity, oxidative stress parameter (MDA), pro-inflammation cytokines (IL-1β, TFN-α, IL-2), reduce immunity (sIgA), and destroyed intestinal structure and integrity (reduce tight junction proteins) in the high fat diet group and this was associated with destruction of the gut microbiota composition (increasing pathogenic bacteria; E. coli, Salmonella, Staphylococcus and reducing beneficial bacteria, Lactobacillus spp.) in mice (P < 0.05). However, the administration of Bacillus toyonensis SAU-19 and SAU-20 reverted these effects. Our findings indicated that, Bacillus toyonensis SAU-19 and SAU-20 isolated from A. adenophora could prevent the excess weight gain from high fat diet feeding, improved antioxidant status and alleviated the intestine integrity damage as well as reduce the population of enteric bacteria such as E. coli, Salmonella, and S. aureus and increasing the population of beneficial bacteria such as Lactobacillus in the gut of mice fed high fat diet, therefore, can serve as a potential probiotics in humans and animals.

B. adolescentis ameliorates chronic colitis by regulating Treg/Th2 response and gut microbiota remodeling

Inflammatory bowel disease (IBD) is defined as an immune dysregulation disease with poor prognosis. Various therapies based on gut microbe modulation have been proposed. In this study, we aim to explore the therapeutic effect of B. adolescentis on IBD, as well as the immune and microecology mechanism of B. adolescentis in IBD. The fecal level of B. adolescentis was decreased in the IBD patients compared with the normal people in our cohort and the GMrepo database. To further clarify the role of B. adolescentis in IBD, we induced chronic colitis with three cycles of dextran sulfate sodium (DSS). We found B. adolescentis gavage exhibited protective effects as evidenced by the significantly decreased diarrhea score, spleen weight, and increased colon length. Accordingly, the cumulative histological grading was decreased in the B. adolescentis administration group. In addition, tight junction protein and mucin family were enhanced after B. adolescentis treatment. Furthermore, distinct effects were found with decreased pro-inflammatory cytokines such as TNF-α, IL-6, IL-1β, IL-18, IL-22, IL-9 and increased anti-inflammatory cytokines IL-10, IL-4, IL-5. Importantly, the colon lamina propria in the B. adolescentis group consisted of more Treg and Th2 cells, which inhibited extreme gut inflammation. Additionally, 16srRNA sequencing showed an evident increase in the B:F ratio in the B. adolescentis group. In particular, B. adolescentis application inhibited the excessive growth of Akkermansia and Escherichia-Shigella in genus level. In conclusion, B. adolescentis refined the DSS-induced chronic colitis by stimulating protective Treg/Th2 response and gut microbiota remodeling. B. adolescentis regularly treatment might improve the therapeutic effects for inflammatory bowel disease.

Gut microbiota: impacts on gastrointestinal cancer immunotherapy

The association of gut microbiota with gastrointestinal carcinogenesis has been heavily investigated since the recent advance in sequencing technology. Accumulating evidence has revealed the critical roles of commensal microbes in cancer progression. Given by its importance, emerging studies have focussed on targeting microbiota to ameliorate therapeutic effectiveness. It is now clear that the microbial community is closely related to the efficacy of chemotherapy, while the correlation of microbiota with immunotherapy is much less studied. Herein, we review the up-to-date findings on the influence of gut microbiota on three common immunotherapies including adoptive cell transfer, immune checkpoint blockade, and CpG-oligodeoxynucleotide therapy. We then explore three microbiota-targeted strategies that may improve treatment efficacy, involving dietary intervention, probiotics supplementation, and fecal microbiota transplantation.

Strains producing different short-chain fatty acids alleviate DSS-induced ulcerative colitis by regulating intestinal microecology

B. bifidum H3-R2, P. freudenreichii B1 and C. butyricum C1-6 exert protective effects against DSS-induced UC in mice by modulating inflammatory factors, intestinal barrier, related signalling pathways, gut microbiome and SCFAs levels.

Probiotics and gut microbiota: mechanistic insights into gut immune homeostasis through TLR pathway regulation

Consumption of probiotics as a useful functional food improves the host's wellbeing, and, when paired with prebiotics (indigestible dietary fibre/carbohydrate), often benefits the host through anaerobic fermentation.

The potential role of adherence factors in probiotic function in the gastrointestinal tract of adults and pediatrics: a narrative review of experimental and human studies

Numerous studies point to the important role of probiotic bacteria in gastrointestinal health. Probiotics act through mechanisms affecting enteric pathogens, epithelial barrier function, immune signaling, and conditioning of indigenous microbiota. Once administered, probiotics reach the gastrointestinal tract and interact with the host through bacterial surface molecules, here called adhesion factors, which are either strain- or specie-specific. Probiotic adhesion, through structural adhesion factors, is a mechanism that facilitates persistence within the gastrointestinal tract and triggers the initial host responses. Thus, an understanding of specific probiotic adhesion mechanisms could predict how specific probiotic strains elicit benefits and the potential of adherence factors as a proxy to predict probiotic function. This review summarizes the present understanding of probiotic adherence in the gastrointestinal tract. It highlights the bacterial adhesion structure types, their molecular communication with the host and the consequent impact on intestinal diseases in both adult and pediatric populations. Finally, we discuss knockout/isolation studies as direct evidence for adhesion factors conferring anti-inflammatory and pathogen inhibition properties to a probiotic.What is known: Probiotics can be used to treat clinical conditions.Probiotics improve dysbiosis and symptoms.Clinical trials may not confirm in vitro and animal studies.What is new: Adhesion structures may be important for probiotic function.Need to systematically determine physical characteristics of probiotics before selecting for clinical trials.Probiotics may be genetically engineered to add to clinical efficacy.

Isosteviol Sodium Exerts Anti-Colitic Effects on BALB/c Mice with Dextran Sodium Sulfate-Induced Colitis Through Metabolic Reprogramming and Immune Response Modulation

PURPOSE

Inflammatory bowel diseases (IBDs) are global health problems that are associated with immune regulation, but clinical IBDs treatment is currently inadequate. Effective preventive or therapeutic methods for immune disorders rely on controlling the function of immune cells. Isosteviol sodium (STV-Na) has antioxidant activity, but the therapeutic effect of STV-Na against IBD remain undocumented. Herein, we investigated the therapeutic effect of STV-Na in mice models with IBDs.

METHODS

Mice received 3.5% DSS for 7 days to establish IBD models. Intraperitoneal STV-Na was given 2 days before DSS and lasted for 9 days. Commercially available drugs used in treating IBDs (5-aminosalicylic acid, dexamethasone, and infliximab) were used as positive controls. Samples were collected 7 days after colitis induction. Histopathological score, biochemical parameters, molecular biology methods, and metabolomics were used for evaluating the therapeutic effect of STV-Na.

RESULTS

Our data revealed that STV-Na could significantly alleviate colon inflammation in mice with colitis. Specifically, STV-Na treatment improved body weight loss, increased colon length, decreased histology scores, and restored the hematological parameters of mice with colitis. The untargeted metabolomics analysis revealed that metabolic profiles were restored by STV-Na treatment. Furthermore, STV-Na therapy suppressed the number of CD68 macrophages and F4/80 cell infiltration. And STV-Na suppressed M1 and M2 macrophage numbers along with the mRNA expressions of proinflammatory cytokines. Moreover, STV-Na administration increased the number of regulatory T (Treg) cells while decreasing Th1/Th2/Th17 cell counts in the spleen. Additionally, STV-Na treatment restored intestinal barrier disruption in DSS-triggered colitis tissues by ameliorating the TJ proteins, increasing goblet cell proportions, and mucin protein production, and decreasing the permeability to FITC-dextran, which was accompanied by decreased plasma LPS and DAO contents.

CONCLUSION

These results indicate that STV-Na can ameliorate colitis by modulating immune responses along with metabolic reprogramming, and could therefore be a promising therapeutic strategy for IBDs.

Development of Anti-inflammatory Probiotic Limosilactobacillus reuteri EFEL6901 as Kimchi Starter: in vitro and In vivo Evidence

The use of probiotic starters can improve the sensory and health-promoting properties of fermented foods. In this study, we developed an anti-inflammatory probiotic starter, Limosilactobacillus reuteri EFEL6901, for use in kimchi fermentation. The EFEL6901 strain was safe for use in foods and was stable under human gastrointestinal conditions. In in vitro experiments, EFEL6901 cells adhered well to colonic epithelial cells and decreased nitric oxide production in lipopolysaccharide-induced macrophages. In in vivo experiments, oral administration of EFEL6901 to DSS-induced colitis mice models significantly alleviated the observed colitis symptoms, prevented body weight loss, lowered the disease activity index score, and prevented colon length shortening. Analysis of these results indicated that EFEL6901 played a probiotic role by preventing the overproduction of pro-inflammatory cytokines, improving gut barrier function, and up-regulating the concentrations of short-chain fatty acids. In addition, EFEL6901 made a fast growth in a simulated kimchi juice and it synthesized similar amounts of metabolites in nabak-kimchi comparable to a commercial kimchi. This study demonstrates that EFEL6901 can be used as a suitable kimchi starter to promote gut health and product quality.

Microbiota Targeted Interventions of Probiotic Lactobacillus as an Anti-Ageing Approach: A Review

With the implementation of modern scientific protocols, the average human lifespan has significantly improved, but age-related problems remain a challenge. With the advent of ageing, there are alterations in gut microbiota and gut barrier functions, weak immune responses, increased oxidative stress, and other age-related disorders. This review has highlighted and discussed the current understanding on the significance of gut microbiota dysbiosis and ageing and its inherent effects against age-related oxidative stress as well as on the gut health and gut-brain axis. Further, we have discussed the key mechanism of action of Lactobacillus strains in the longevity of life, alleviating gut dysbiosis, and improving oxidative stress and inflammation to provide an outline of the role of Lactobacillus strains in restoration of gut microbiota dysbiosis and alleviating certain conditions during ageing. Microbiota-targeted interventions of some characterized strains of probiotic Lactobacillus for the restoration of gut microbial community are considered as a potential approach to improve several neurological conditions. However, very limited human studies are available on this alarmed issue and recommend further studies to identify the unique Lactobacillus strains with potential anti-ageing properties and to discover its novel core microbiome-association, which will help to increase the therapeutic potential of probiotic Lactobacillus strains to ageing.

Sulfated polysaccharides from pacific abalone attenuated DSS-induced acute and chronic ulcerative colitis in mice via regulating intestinal micro-ecology and the NF-κB pathway

Due to potential side effects of current drugs in colitis treatment, polysaccharides with anti-inflammatory activities can be considered as alternative molecules for colitis treatment. Sulfated polysaccharide from pacific abalone (AGSP) reduced the level of lipopolysaccharides (LPS) and increased the production of short chain fatty acids in the colon of mice, and it reduced the levels of interleukin (IL)-6, IL-1β and tumor necrosis factor (TNF)-α and increased the IL-10 level in in vitro cell models, suggesting that it can be used as a probiotic agent to inhibit intestinal inflammation. Furthermore, AGSP reduced the disease activity index and intestinal damage, improved the mucosal immune response, and inhibited oxidative damage in mice with DSS-induced acute and chronic colitis, which can be associated with modulation of the NF-κB signaling pathway and gut microbiota. AGSP regulated the structure of the gut microbiota and reduced the level of Bacteroides that had positive correlation with the colitis symptoms. The in vitro result showed that AGSP may inhibit mucin degradation by Bacteroides via the change of the polysaccharide utilization strategy, which can protect intestinal barrier integrity. This study is useful to understand the mechanism by which AGSP ameliorates colitis and related diseases and promotes further development of AGSP.

Armillaria luteo-virens Sacc Ameliorates Dextran Sulfate Sodium Induced Colitis through Modulation of Gut Microbiota and Microbiota-Related Bile Acids

Armillaria luteo-virens Sacc (ALS) is a rare wild Chinese medicinal and edible basidiomycete. However, its protective effect on intestinal functions and the underlying mechanism is still unknown. This work explored the improvement of dextran sulfate sodium (DSS)-induced colitis by ALS. ALS supplementation markedly improved colitis symptoms, gut barrier integrity, and goblet loss in DSS-treated mice. In addition, ALS inhibited colonic inflammation through the inhibition/activation of the mitogen-activated protein kinases/NF-κB signaling pathway. The 16S rRNA gene-based microbiota analysis revealed that ALS altered the gut microbiota composition, decreasing the richness of Enterobacteriaceae and increasing the abundance of Lactobacillaceae. The bile-acid-targeted metabolomic analysis showed that ALS recovered the microbial bile acid metabolism in the gut, enabling the activation of the farnesoid X receptor signaling by these acids, thus maintaining the intestinal homeostasis. Importantly, broad-spectrum antibiotic treatment reduced the efficacy of ALS-induced protection from colitis. Overall, our findings suggest that ALS may represent a novel approach in the nutritional intervention to prevent colitis.

The Association of Irritable Bowel Complaints and Perceived Immune Fitness among Individuals That Report Impaired Wound Healing: Supportive Evidence for the Gut–Brain–Skin Axis

The gut–brain–skin axis is important in wound healing. The aim of this study was to investigate the association between experiencing irritable bowel syndrome (IBS) symptoms, perceived immune fitness, and impaired wound healing. N = 1942 Dutch students (mean (SD) age 21.3 (2.1), 83.6% women) completed an online survey. They were allocated to one of four groups: (1) control group (N = 1544), (2) wound infection (WI) group (N = 65), (3) slow healing wounds (SHW) group (N = 236), or (4) a combination group (COMBI), which experienced both WI and SHW (N = 87). Participants rated their perceived immune fitness on a scale ranging from very poor (0) to excellent (10), and the severity of IBS symptoms (constipation, diarrhea, and pain) was assessed with the Birmingham IBS Symptom Questionnaire. Compared to the control group, perceived immune fitness was significantly poorer for the SHW group (p < 0.001) and COMBI group (p < 0.001), but not for the WI group. Compared to the control group, constipation was reported significantly more frequently by the SHW group (p < 0.001) and the WI group (p = 0.012), diarrhea was reported significantly more frequent by the SHW group (p = 0.038) and the COMBI group (p = 0.004), and pain was reported significantly more frequent by the SHW group (p = 0.020) and COMBI group (p = 0.001). Correlations between IBS complaints and perceived immune fitness were statistically significant (p < 0.001), and also a highly significant and negative association was found between the percentage of participants that reported impaired wound healing and perceived immune fitness (r = −0.97, p < 0.001). In conclusion, among participants with self-reported impaired wound healing, IBS complaints were significantly more severe, and accompanied by a significantly reduced perceived immune fitness.

Akkermansia muciniphila Alleviates Dextran Sulfate Sodium (DSS)-Induced Acute Colitis by NLRP3 Activation

Akkermansia muciniphila has been proved to play a crucial role in the progression of colitis, but its underlying mechanism remains inconclusive. In this study, we aim to investigate the effect of A. muciniphila on the development of acute colitis and explore the underlying mechanism. We found that the fecal level of A. muciniphila was decreased in ulcerative colitis (UC) patients compared to the healthy people in the GMrepo database. Oral administration of A. muciniphila strain BAA-835 significantly ameliorated the symptoms in dextran sulfate sodium (DSS)-induced acute colitis, evidenced by decreased body weight loss, colon length shortening, and colon histological inflammatory score. In addition, the number of goblet cells and the mucin family were enhanced after A. muciniphila treatment. Furthermore, proinflammatory cytokines such as tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and monocyte chemoattractant protein 1 (MCP-1) had a downward trend. Mechanistically, the expression of NLRP3, caspase-1 p20, and IL-1β p17 were upregulated in A. muciniphila-treated mice. Additionally, the colon tissues from high-A. muciniphila UC patients had a higher NLRP3 expression than that from low-A. muciniphila UC patients. Moreover, the upregulation of NLRP3 was observed in mouse macrophage Raw264.7 cells and bone marrow-derived macrophage (BMDM) cells after incubation with A. muciniphila. To clarify whether the protective effect of A. muciniphila in colitis depends on NLRP3, we performed the NLRP3-deficient assay in NLRP3-/- mice in vivo. The evidence showed that NLRP3 deficiency eliminated the protective effects of A. muciniphila in acute colitis. In conclusion, A. muciniphila alleviates DSS-induced acute colitis by NLRP3 activation, which enriches the mechanism and provides a new prospect for the probiotic-based treatment of colitis. IMPORTANCE The gut microbiota and host immune response interaction influences the progression of intestinal inflammatory disease. As a well-recognized next-generation probiotic, Akkermansia muciniphila has been proved to play a crucial role in the progression of colitis, but its underlying mechanism remains inconclusive. We found that oral administration of A. muciniphila strain BAA-835 significantly ameliorated the symptoms of acute colitis. Mechanistically, the expression of NLRP3 was upregulated in the A. muciniphila group, and the protective effect of A. muciniphila in colitis depends on NLRP3 activation. This enriches the mechanism and provides a new prospect for the probiotic-based treatment of colitis, which would promote a deeper understanding of the complex characteristics of A. muciniphila and provide guidance for the treatment of human colitis in the future.

Effects of a Mixed Limosilactobacillus fermentum Formulation with Claimed Probiotic Properties on Cardiometabolic Variables, Biomarkers of Inflammation and Oxidative Stress in Male Rats Fed a High-Fat Diet

High-fat diet (HFD) consumption has been linked to dyslipidemia, low-grade inflammation and oxidative stress. This study investigated the effects of a mixed formulation with Limosilactobacillusfermentum 139, L. fermentum 263 and L. fermentum 296 on cardiometabolic parameters, fecal short-chain fatty acid (SCFA) contents and biomarkers of inflammation and oxidative stress in colon and heart tissues of male rats fed an HFD. Male Wistar rats were grouped into control diet (CTL, n = 6), HFD (n = 6) and HFD with L. fermentum formulation (HFD-Lf, n = 6) groups. The L.fermentum formulation (1 × 10⁹ CFU/mL of each strain) was administered twice a day for 4 weeks. After a 4-week follow-up, biochemical parameters, fecal SCFA, cytokines and oxidative stress variables were evaluated. HFD consumption caused hyperlipidemia, hyperglycemia, low-grade inflammation, reduced fecal acetate and propionate contents and increased biomarkers of oxidative stress in colon and heart tissues when compared to the CTL group. Rats receiving the L. fermentum formulation had reduced hyperlipidemia and hyperglycemia, but similar SCFA contents in comparison with the HFD group (p < 0.05). Rats receiving the L. fermentum formulation had increased antioxidant capacity throughout the colon and heart tissues when compared with the control group. Administration of a mixed L. fermentum formulation prevented hyperlipidemia, inflammation and oxidative stress in colon and heart tissues induced by HFD consumption.

Retardant effect of dihydroartemisinin on ulcerative colitis in a JAK2/STAT3-dependent manner

Dihydroartemisinin (DHA) is a semi-synthetic derivative and the main active metabolite of artemisinin. The purpose of this study was to investigate the effect of DHA on the ulcerative colitis (UC) in both in vivo and in vitro models. Weight, survival rate, colon length, and Disease Activity Index score were used to evaluate the severity of colitis. Reverse transcription quantitative polymerase chain reaction and enzyme-linked immunosorbent assay were used to detect the expressions of cytokines interleukin (IL)-1, IL-1β, IL-4, IL-6, IL-10, IL-12, and tumor necrosis factor-α (TNF-α). The expressions of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3), and the phosphorylation of JAK2 (p-JAK2) and STAT3 (p-STAT3), were measured by western blot analysis. Western blot analysis and immunohistochemistry were used to detect the expressions of tight junction proteins. We found that the weights and colon lengths of mice in dextran sodium sulfate (DSS)+DHA group were significantly lower and longer than those in the DSS group, respectively. Compared with those in the DSS group, the expressions of IL-1β, IL-6, IL-17, and TNF-α in the DSS+DHA and DSS+5-aminosalicylic acid (5-ASA) groups were decreased, while the expressions of IL-4 and IL-10 were significantly upregulated. DHA largely increased the expressions of zonula occludens-1 and occludin. Western blot analysis and/or immunohistochemical staining analysis showed that the expressions of JAK2, STAT3, p-JAK2, and p-STAT3 in DSS+DHA and DSS+5-ASA groups were significantly lower than those in DSS group. DHA has a specific therapeutic effect on UC. The anti-inflammatory mechanism of DHA is related to the blockage of the JAK2/STAT3 signaling pathway. These findings provide evidence that DHA may be a useful drug and is expected to become a promising new treatment for human UC.

Microbiota and Probiotics: The Role of Limosilactobacillus Reuteri in Diverticulitis

The microbiota is the set of commensal microorganisms, residing in the organism, helping proper functioning of organs and systems. The role that the microbiota plays in maintaining the health of vertebrates is widely accepted, particularly in the gastrointestinal system, where it is fundamental for immunity, development, and conversion of nutrients. Dysbiosis is an alteration of the microbiota which refers to a disturbed balance, which can cause a number of pathologies. Probiotics have proven to be effective in modulating the microbiota of the gastrointestinal system and, therefore, in promoting the health of the individual. In particular, Lactobacilli are a group of Gram-positive bacteria, which are able to produce lactic acid through glucose metabolism. They are present in different microenvironments, ranging from the vagina, to the mouth, to different tracts of the small intestine. In the present review, we will discuss the use of Limosilactobacillus in human health in general and more specifically in diverticulitis. In particular we analyze the role of Limosilactobacillus reuteri and its anti-inflammatory action. For this review, articles were identified using the electronic PubMed database through a comprehensive search, conducted by combining key terms such as "diverticulitis", "Limosilactobacillus reuteri", "human health and disease", "probiotics". We selected all the articles published in the last 10 years and screened 1017 papers. Articles referenced in the screened papers were evaluated if considered interesting for our topic. Probiotics have proven to be effective in modulating the microbiota of the gastrointestinal system and, therefore, in promoting the health of the individual. The importance of probiotics in treating diverticular disease and acute diverticulitis can be further understood if taking into consideration some pathophysiological aspects, associated to the microbiota. L. reuteri plays an important role in human health and disease. The effectiveness of L. reuteri in stimulating a correct bowl motility partly explains its effectiveness in treating diverticulitis. The most important action of L. reuteri is probably its immunomodulating activity. Levels of IL-6, IL-8, and Tumor necrosis factor (TNF-alpha) are reduced after supplementation with different strands of Lactobacilli, while T-regulatory cells increase in number and activity. Anyway, new mechanisms of action of probiotics come to light from the many investigations currently taking place in numerous centres around the world and to improve how exactly probiotic administration could make the difference in the management of diverticular disease and acute diverticulitis.

Flaxseed oligosaccharides alleviate DSS-induced colitis through modulation of gut microbiota and repair of the intestinal barrier in mice

Intestinal epithelial barrier dysfunction with dysbiosis of gut microbiota contributes to the occurrence and acceleration of colitis. This study aimed to evaluate the effect of flaxseed oligosaccharides (FOSs) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) mice and to elucidate the underlying mechanisms. UC was induced in mice by administering 2% DSS in drinking water for 8 days. Then, FOS (50 mg kg-1 d-1, 100 mg kg-1 d-1 and 200 mg kg-1 d-1) was administered by gavage for 14 days. The results showed that FOS treatment (200 mg kg-1 d-1) significantly ameliorated colitis by decreasing disease activity index (DAI), increasing colon length and improving colonic histology. FOS treatment (200 mg kg-1 d-1) down-regulated the critical markers of oxidative stresses, including malondialdehyde (MDA) and myeloperoxidase (MPO). Furthermore, FOS (200 mg kg-1 d-1) significantly suppressed the levels of pro-inflammatory cytokines including tumor necrosis factor (TNF)-α, interleukin (IL)-6 and interleukin (IL)-1β but increased that of anti-inflammatory cytokine interleukin (IL)-10. The 16S rDNA gene high-throughput sequencing results indicated that FOS treatment increased the gut microbial diversity and inhibited the proliferation of inflammation-related bacteria such as unidentified_Clostridiales. An increase in total short-chain fatty acids (SCFAs), propionic acid and butyric acid, was also observed by FOS supplementation. FOS (200 mg kg-1d-1) also protected the intestinal barrier by increasing the protein levels of Claudin1 and Occludin. In conclusion, FOS attenuated DSS-induced colitis by modulating the gut microbiota and repairing the intestinal barrier.

Nutraceuticals in Viral Infections: An Overview of the Immunomodulating Properties

Nutraceuticals, including vitamin D, vitamin A, zinc, lactoferrin, polyphenols coenzyme Q, magnesium, and selenium, are implicated in the modulation of the complex molecular pathways involved in the immune response against viral pathogens. A common element of the activity of nutraceuticals is their ability to enhance the innate immune response against pathogens by acting on the major cellular subsets and inducing the release of pro-inflammatory cytokines and antimicrobial peptides. In some cases, this action is accompanied by a direct antimicrobial effect, as evidenced in the specific case of lactoferrin. Furthermore, nutraceuticals act through complex molecular mechanisms to minimize the damage caused by the activation of the immune system against pathogens, reducing the oxidative damage, influencing the antigen presentation, enhancing the differentiation and proliferation of regulatory T cells, driving the differentiation of lymphocyte subsets, and modulating the production of pro-inflammatory cytokines. In this paper, we review the main molecular mechanisms responsible for the immunomodulatory function of nutraceuticals, focusing on the most relevant aspects for the prevention and treatment of viral infections.

Dietary interventions for better management of osteoporosis: An overview

Osteoporosis is a public health concern and a cause of bone loss, increased risk of skeletal fracture, and a heavy economic burden. It is common in postmenopausal women and the elderly and is impacted by dietary factors, lifestyle and some secondary factors. Although many drugs are available for the treatment of osteoporosis, these therapies are accompanied by subsequent side effects. Hence, dietary interventions are highly important to prevent osteoporosis. This review was aimed to provide a comprehensive understanding of the roles of dietary nutrients derived from natural foods and of common dietary patterns in the regulation of osteoporosis. Nutrients from daily diets, such as unsaturated fatty acids, proteins, minerals, peptides, phytoestrogens, and prebiotics, can regulate bone metabolism and reverse bone loss. Meanwhile, these nutrients generally existed in food groups and certain dietary patterns also play critical roles in skeletal health. Appropriate dietary interventions (nutrients and dietary patterns) could be primary and effective strategies to prevent and treat osteoporosis across the lifespan for the consumers and food enterprises.

Mitochondrial transcription factor A plays opposite roles in the initiation and progression of colitis-associated cancer

Background

Mitochondria are key regulators in cell proliferation and apoptosis. Alterations in mitochondrial function are closely associated with inflammation and tumorigenesis. This study aimed to investigate whether mitochondrial transcription factor A (TFAM), a key regulator of mitochondrial DNA transcription and replication, is involved in the initiation and progression of colitis‐associated cancer (CAC).

Methods

TFAM expression was examined in tissue samples of inflammatory bowel diseases (IBD) and CAC by immunohistochemistry. Intestinal epithelial cell (IEC)‐specific TFAM‐knockout mice (TFAM^△IEC) and colorectal cancer (CRC) cells with TFAM knockdown or overexpression were used to evaluate the role of TFAM in colitis and the initiation and progression of CAC. The underlying mechanisms of TFAM were also explored by analyzing mitochondrial respiration function and biogenesis.

Results

The expression of TFAM was downregulated in active IBD and negatively associated with the disease activity. The downregulation of TFAM in IECs was induced by interleukin‐6 in a signal transducer and activator of transcription 3 (STAT3)/miR‐23b‐dependent manner. In addition, TFAM knockout impaired IEC turnover to promote dextran sulfate sodium (DSS)‐induced colitis in mice. Of note, TFAM knockout increased the susceptibility of mice to azoxymethane/DSS‐induced CAC and TFAM overexpression protected mice from intestinal inflammation and colitis‐associated tumorigenesis. By contrast, TFAM expression was upregulated in CAC tissues and contributed to cell growth. Furthermore, it was demonstrated that β‐catenin induced the upregulation of TFAM through c‐Myc in CRC cells. Mechanistically, TFAM promoted the proliferation of both IECs and CRC cells by increasing mitochondrial biogenesis and activity.

Conclusions

TFAM plays a dual role in the initiation and progression of CAC, providing a novel understanding of CAC pathogenesis.

Suitability Analysis of 17 Probiotic Type Strains of Lactic Acid Bacteria as Starter for Kimchi Fermentation

The use of probiotic starters can improve the sensory and health-promoting properties of fermented foods. This study aimed to evaluate the suitability of probiotic lactic acid bacteria (LAB) as a starter for kimchi fermentation. Seventeen probiotic type strains were tested for their growth rates, volatile aroma compounds, metabolites, and sensory characteristics of kimchi, and their characteristics were compared to those of Leuconostoc (Le.) mesenteroides DRC 1506, a commercial kimchi starter. Among the tested strains, Limosilactobacillus fermentum, Limosilactobacillus reuteri, Lacticaseibacillus rhamnosus, Lacticaseibacillus paracasei, and Ligilactobacillus salivarius exhibited high or moderate growth rates in simulated kimchi juice (SKJ) at 37 °C and 15 °C. When these five strains were inoculated in kimchi and metabolite profiles were analyzed during fermentation using GC/MS and ¹H-NMR, data from the principal component analysis (PCA) showed that L. fermentum and L. reuteri were highly correlated with Le. mesenteroides in concentrations of sugar, mannitol, lactate, acetate, and total volatile compounds. Sensory test results also indicated that these three strains showed similar sensory preferences. In conclusion, L. fermentum and L. reuteri can be considered potential candidates as probiotic starters or cocultures to develop health-promoting kimchi products.

Lactobacillus ruminis Alleviates DSS-Induced Colitis by Inflammatory Cytokines and Gut Microbiota Modulation

Lactobacillus ruminis can stimulate the immune response in vitro, but previous studies were only carried out in vitro and the anti-inflammatory effects of L. ruminis needs more in vivo evidences. In this study, the immune regulation and potential mechanisms of L. ruminis was investigated in DSS-induced colitis mice. L. ruminis FXJWS27L3 and L. ruminis FXJSW17L1 relieved the symptoms of colitis, including inhibition of colon shortening and colon tissue damage. L. ruminis FXJWS27L3 significantly reduced the pro-inflammatory cytokines IL-1β, TNF-α, and IL-17, while L. ruminis FXJSW17L1 significantly increased short chain fatty acids in mice feces. Moreover, L. ruminis FXJWS27L3 and L. ruminis FXJSW17L1 treatments significantly increased the gut microbiota diversity and balance the intestine microbiota profiles, which improved the imbalance of intestine microbiota composition to a certain extent. The results showed that L. ruminis can alleviate DSS-induced colitis, which possibly was related to promoting the expression of pro-inflammatory cytokines, up-regulating SCFAs and restoring the imbalance of gut microbiota.

Fecal microbiota transplantation ameliorates experimental colitis via gut microbiota and T-cell modulation

BACKGROUND

Emerging evidence has demonstrated that fecal microbiota transplantation (FMT) has a promising therapeutic effect on mice with experimental colitis and patients with ulcerative colitis (UC), although the mechanism of FMT is unclear.

AIM

To evaluate the protective effect of FMT on UC and clarify its potential dependence on the gut microbiota, through association analysis of gut microbiota with colon transcriptome in mice.

METHODS

Dextran sodium sulfate (DSS)-induced experimental colitis was established and fecal microbiota was transplanted by gavage. Severity of colon inflammation was measured by body weight, disease activity index, colon length and histological score. Gut microbiota alteration was analyzed through 16S ribosomal ribonucleic acid sequencing. The differentially expressed genes (DEGs) in the colon were obtained by transcriptome sequencing. The activation status of colonic T lymphocytes in the lamina propria was evaluated by flow cytometry.

RESULTS

Compared with the DSS group, the weight loss, colon length shortening and inflammation were significantly alleviated in the FMT group. The scores of disease activity index and colon histology decreased obviously after FMT. FMT restored the balance of gut microbiota, especially by upregulating the relative abundance of Lactobacillus and downregulating the relative abundance of Clostridium_sensu_stricto_1 and Turicibacter. In the transcriptomic analysis, 128 DEGs intersected after DSS treatment and FMT. Functional annotation analysis suggested that these DEGs were mainly involved in T-lymphocyte activation. In the DSS group, there was an increase in colonic T helper CD4⁺ and T cytotoxic CD8⁺ cells by flow cytometry. FMT selectively downregulated the ratio of colonic CD4⁺ and CD8⁺ T cells to maintain intestinal homeostasis. Furthermore, Clostri dium_sensu_stricto_1 was significantly related to inflammation-related genes including REG3G, CCL8 and IDO1.

CONCLUSION

FMT ameliorated DSS-induced colitis in mice via regulating the gut microbiota and T-cell modulation.

Dietary conjugated linoleic acid links reduced intestinal inflammation to amelioration of CNS autoimmunity

A close interaction between gut immune responses and distant organ-specific autoimmunity including the CNS in multiple sclerosis has been established in recent years. This so-called gut–CNS axis can be shaped by dietary factors, either directly or via indirect modulation of the gut microbiome and its metabolites. Here, we report that dietary supplementation with conjugated linoleic acid, a mixture of linoleic acid isomers, ameliorates CNS autoimmunity in a spontaneous mouse model of multiple sclerosis, accompanied by an attenuation of intestinal barrier dysfunction and inflammation as well as an increase in intestinal myeloid-derived suppressor-like cells. Protective effects of dietary supplementation with conjugated linoleic acid were not abrogated upon microbiota eradication, indicating that the microbiome is dispensable for these conjugated linoleic acid-mediated effects. Instead, we observed a range of direct anti-inflammatory effects of conjugated linoleic acid on murine myeloid cells including an enhanced IL10 production and the capacity to suppress T-cell proliferation. Finally, in a human pilot study in patients with multiple sclerosis (n = 15, under first-line disease-modifying treatment), dietary conjugated linoleic acid-supplementation for 6 months significantly enhanced the anti-inflammatory profiles as well as functional signatures of circulating myeloid cells. Together, our results identify conjugated linoleic acid as a potent modulator of the gut–CNS axis by targeting myeloid cells in the intestine, which in turn control encephalitogenic T-cell responses.

Limosilactobacillus fermentum CECT5716: Mechanisms and Therapeutic Insights

Probiotics microorganisms exert their health-associated activities through some of the following general actions: competitive exclusion, enhancement of intestinal barrier function, production of bacteriocins, improvement of altered microbiota, and modulation of the immune response. Among them, Limosilactobacillus fermentum CECT5716 has become one of the most promising probiotics and it has been described to possess potential beneficial effects on inflammatory processes and immunological alterations. Different studies, preclinical and clinical trials, have evidenced its anti-inflammatory and immunomodulatory properties and elucidated the precise mechanisms of action involved in its beneficial effects. Therefore, the aim of this review is to provide an updated overview of the effect on host health, mechanisms, and future therapeutic approaches.

RSPO4-CRISPR alleviates liver injury and restores gut microbiota in a rat model of liver fibrosis

Wnt signaling dysfunction and gut dysbiosis may lead to liver fibrosis, yet the underlying mechanisms are not well elucidated. This study demonstrated the role of RSPO4, a Wnt signaling agonist, in liver fibrogenesis and its impact on the gut microbiome. RSPO4 gene in CCl4-induced fibrotic-liver rats was knockout by Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) system, with healthy rats served as the control. Tissue samples and hepatic stellate cells (HSCs) isolated from rats were examined for curative effect of RSPO4-CRISPR treatment. Fecal sample were collected and analyzed with 16 S rRNA sequencing. We found RSPO4-CRISPR relieved liver fibrosis in rats and reversed HSC activation. Further, results showed RSPO4-CRISPR tended to restore the microflora composition. Significance species between groups were identified. Bacteroides and Escherichia-Shigella were the key microbes in the model and negative group, whereas Lactobacillus, Romboutsia, and Lachnospiraceae NK4A136 group were abundant in the control. Notably, Bacteroidales S24-7 group and Ruminococcaceae UCG-005 were the significantly enriched in CRISPR group. We show that the microbiome of rats treated with RSPO4-CRISPR presents a trend towards the restoration of the original condition. Our findings pave a new way to evaluate the curative effect of liver fibrosis treatment.

Harnessing the potential of Lactobacillus species for therapeutic delivery at the lumenal-mucosal interface

Lactobacillus species have been studied for over 30 years in their role as commensal organisms in the human gut. Recently there has been a surge of interest in their abilities to natively and recombinantly stimulate immune activities, and studies have identified strains and novel molecules that convey particular advantages for applications as both immune adjuvants and immunomodulators. In this review, we discuss the recent advances in Lactobacillus-related activity at the gut/microbiota interface, the efforts to probe the boundaries of the direct and indirect therapeutic potential of these bacteria, and highlight the continued interest in harnessing the native capacity for the production of biogenic compounds shown to influence nervous system activity. Taken together, these aspects underscore Lactobacillus species as versatile therapeutic delivery vehicles capable of effector production at the lumenal-mucosal interface, and further establish a foundation of efficacy upon which future engineered strains can expand.

Baicalin attenuated Mycoplasma gallisepticum-induced immune impairment in chicken bursa of fabricius through modulation of autophagy and inhibited inflammation and apoptosis

BACKGROUND

Mycoplasma gallisepticum (MG) is the primary etiologic agent of chronic respiratory disease in poultry. However, the mechanism underlying MG-induced immune dysregulation in chicken is still elusive. Baicalin shows excellent anti-bacterial, anti-inflammatory, anti-carcinogenic and anti-viral properties. In the present study, the preventive effects of baicalin against immune impairment in chicken bursa of fabricius (BF) were studied in an MG infection model.

RESULTS

Histopathological examination showed increased inflammatory cell infiltrations and fragmented nuclei in the model group. Ultrastructural analysis revealed the phenomenon of apoptosis in bursal cells, along with the deformation of mitochondrial membrane and swollen mitochondria in the model group. However, these abnormal morphological changes were partially alleviated by baicalin. Meanwhile, baicalin treatment attenuated the level of proinflammatory cytokines, and suppressed nuclear factor-kappa B expression at both protein and mRNA level. Terminal deoxynucleotidyl transferase-mediated dUTP nick endlabeling assay showed extensive apoptosis in BF in the model group. The mRNA and protein expression levels of apoptosis-related genes were upregulated in BF, while baicalin treatment significantly alleviated apoptosis in BF. In addition, alterations in mRNA and protein expression levels of autophagy-related genes and mitochondrial dynamics proteins were significantly alleviated by baicalin. Moreover, baicalin treatment significantly attenuated MG-induced decrease in CD8⁺ cells and reduced bacterial load in chicken BF compared to the model group.

CONCLUSIONS

These results suggested that baicalin could effectively inhibit MG-induced immune impairment and alleviate inflammatory responses and apoptosis in chicken BF. © 2020 Society of Chemical Industry.

Helminth Interactions with Bacteria in the Host Gut Are Essential for Its Immunomodulatory Effect

Colonization by the benign tapeworm, Hymenolepis diminuta, has been associated with a reduction in intestinal inflammation and changes in bacterial microbiota. However, the role of microbiota in the tapeworm anti-inflammatory effect is not yet clear, and the aim of this study was to determine whether disruption of the microflora during worm colonization can affect the course of intestinal inflammation. We added a phase for disrupting the intestinal microbiota using antibiotics to the experimental design for which we previously demonstrated the protective effect of H. diminuta. We monitored the immunological markers, clinical parameters, bacterial microbiota, and histological changes in the colon of rats. After a combination of colonization, antibiotics, and colitis induction, we had four differently affected experimental groups. We observed a different course of the immune response in each group, but no protective effect was found. Rats treated with colonization and antibiotics showed a strong induction of the Th2 response as well as a significant change in microbial diversity. The microbial results also revealed differences in the richness and abundance of some bacterial taxa, influenced by various factors. Our data suggest that interactions between the tapeworm and bacteria may have a major impact on its protective effect.

Prevention and Alleviation of Dextran Sulfate Sodium Salt-Induced Inflammatory Bowel Disease in Mice With Bacillus subtilis-Fermented Milk via Inhibition of the Inflammatory Responses and Regulation of the Intestinal Flora

The pathogenesis of inflammatory bowel disease (IBD) might be related to the local inflammatory damage and the dysbacteriosis of intestinal flora. Probiotics can regulate the intestinal flora and ameliorate IBD. The probiotic Bacillus subtilis strain B. subtilis JNFE0126 was used as the starter of fermented milk. However, the therapeutic effects of B. subtilis-fermented milk on IBD remain to be explored. In this research, the therapeutic effect of B. subtilis-fermented milk on dextran sulfate sodium salt (DSS)-induced IBD mouse model was evaluated. Besides, the expression of pro-inflammatory/anti-inflammatory cytokines, the proliferation of the intestinal stem cells, and the reconstruction of the mucosa barrier were investigated. Finally, alteration of the gut microbiota was investigated by taxonomic analysis. As shown by the results, the disease activity index (DAI) of IBD was significantly decreased through oral administration of B. subtilis (JNFE0126)-fermented milk, and intestinal mucosa injury was attenuated. Moreover, B. subtilis could reduce the inflammatory response of the intestinal mucosa, induce proliferation of the intestinal stem cell, and promote reconstruction of the mucosal barrier. Furthermore, B. subtilis could rebalance the intestinal flora, increasing the abundance of Bacillus, Alistipes, and Lactobacillus while decreasing the abundance of Escherichia and Bacteroides. In conclusion, oral administration of the B. subtilis-fermented milk could alleviate DSS-induced IBD via inhibition of inflammatory response, promotion of the mucosal barrier reconstruction, and regulation of the intestinal flora.

Intestinal Regulatory T Cells

Mucosal surfaces are distinctive sites exposed to environmental, dietary, and microbial antigens. Particularly in the gut, the host continuously actively adapts via complex interactions between the microbiota and dietary compounds and immune and other tissue cells. Regulatory T cells (Tregs) are critical for tuning the intestinal immune response to self- and non-self-antigens in the intestine. Its importance in intestinal homeostasis is illustrated by the onset of overt inflammation caused by deficiency in Treg generation, function, or stability in the gut. A substantial imbalance in Tregs has been observed in intestinal tissue during pathogenic conditions, when a tightly regulated and equilibrated system becomes dysregulated and leads to unimpeded and chronic immune responses. In this chapter, we compile and critically discuss the current knowledge on the key factors that promote Treg-mediated tolerance in the gut, such as those involved in intestinal Treg differentiation, specificity and suppressive function, and their immunophenotype during health and disease. We also discuss the current state of knowledge on Treg dysregulation in human intestine during pathological states such as inflammatory bowel disease (IBD), necrotizing enterocolitis (NEC), graft-versus-host disease (GVHD), and colorectal cancer (CRC), and how that knowledge is guiding development of Treg-targeted therapies to treat or prevent intestinal disorders.

Lactobacillus fermentum CQPC08 protects rats from lead-induced oxidative damage by regulating the Keap1/Nrf2/ARE pathway

In this experiment, Lactobacillus fermentum CQPC08 (LF-CQPC08) isolated from traditionally fermented pickles was used to study its mitigation effect on lead acetate-induced oxidative stress and lead ion adsorption capacity in rats. In vitro experiments showed that the survival rate in artificial gastric juice and the growth efficiency in artificial bile salt of LF-CQPC08 was 93.6% ± 2.2% and 77.2% ± 0.8%, and the surface hydrophobicity rate was 45.5% ± 0.3%. The scavenging rates of hydroxyl radical, superoxide anion, and 1,1-diphenyl-2-picrylhydrazyl (DPPH) were 47.8% ± 0.9%, 63.9% ± 1.2%, and 83.6% ± 1.5%, respectively, and the reduction power was 107.3 ± 2.8 μmol L-1. LF-CQPC08 could not only adsorb 76.9% ± 1.0% lead ions in aqueous solution but also reduce the lead content in serum, liver, kidneys, and brain tissue of Sprague-Dawley (SD) rats, as well as maintain the cell structure and tissue state of the liver and kidneys. In addition, by examining the indicators of inflammation and oxidation in the serum, liver, and kidneys of SD rats, we found that LF-CQPC08 can reduce the proinflammatory factors interleukin (IL)-1 beta (1β), IL-6, tumor necrosis factor alpha, and interferon gamma in the body, increase the level of anti-inflammatory factor IL-10, enhance the activity of antioxidant enzymes such as superoxide dismutase and catalase and glutathione levels in serum and organ tissues, and reduce the production of reactive oxygen species and accumulation of lipid peroxide malondialdehyde. LF-CQPC08 can also activate the Keap1/Nrf2/ARE signaling pathway to promote high-level expression of the downstream antioxidants heme oxygenase 1 (HO-1), NAD(P)H : quinone oxidoreductase 1 (NQO1), and γ-glutamylcysteine synthetase (γ-GCS). As food-grade lactic acid bacteria, LF-CQPC08 has great potential and research value in removing heavy metals from food and alleviating the toxicity of heavy metals in the future.

Asymptomatic Hyperamylasemia in Stevens-Johnson Syndrome Is Associated with Intestinal Barrier Dysfunction

Methods

A retrospective study on SJS patients was conducted at a tertiary medical center. All patients diagnosed as SJS, with available serum amylase index, were included. Clinical data of all subjects were retrospectively collected and analyzed. Colonic mucosal biopsies were obtained to measure tight junction protein expression.

Results

A total of nine patients were included in the present study for study analysis. The average serum amylase of the study cohort was 228.78 ± 204.18 U/L. Among which, five patients had a positive fecal occult blood test (FOBT). Colonic mucosal biopsies were obtained and stained with occludin and zonula occludens-1 (ZO-1). The expression of occludin and ZO-1 was significantly downregulated in SJS patients (p < 0.01), which was indicative of intestinal barrier dysfunction.

Conclusion

Hyperamylasemia often extends beyond pancreatic diseases. Clinical awareness of asymptomatic hyperamylasemia secondary to other systemic diseases can help avoid unnecessary overexamination and overtreatment.

Alleviation of DSS-induced colitis via Lactobacillus acidophilus treatment in mice

Gut microbiota play a major role in host physiology and immunity. Inflammatory bowel diseases (IBDs), the important immune-related diseases, can occur through immune system malfunction originating due to dysregulation of the gut microbiota. The aim of this study was to investigate the capabilities and mechanisms of Lactobacillus acidophilus (L. acidophilus) KBL402 and KBL409 treatment in the alleviation of colitis using the in vivo dextran sodium sulfate (DSS)-induced colitis mice model. Various colitis symptoms of mice, including disease activity index score [4.55 ± 0.99 (P < 0.001) and 5.12 ± 0.94 (P < 0.001), respectively], colon length [6.18 ± 0.43 mm (P < 0.001) and 6.62 ± 0.47 mm (P < 0.001), respectively], and colon histological score [(5.33 ± 1.03 (P < 0.001) and 4.00 ± 0.89 (P < 0.01), respectively)], were significantly restored with L. acidophilus KBL402 or KBL409 administration (1 × 10⁹ colony-forming units) for 8 days. Moreover, inflammatory cytokines, chemokines, and myeloperoxidase were downregulated in mice with L. acidophilus treatment. Upregulation of anti-inflammatory cytokine IL-10 or regulatory T cells were discovered with L. acidophilus KBL402 (12.90 ± 7.87 pg mL^-1) (P < 0.05) or L. acidophilus KBL409 treatment (10.63 ± 2.70%) (P < 0.05), respectively. Expressions of inflammation-related micro-RNAs (miRs) were also significantly altered in mice with L. acidophilus. Finally, L. acidophilus treatment could restore the diversity of the gut microbiota. Mice with L. acidophilus KBL402 treatment showed a high relative abundance of the genus Akkermansia (0.022 ± 0.017) and Prevotella (0.010 ± 0.006) (P < 0.01). Butyrate and propionate, the major short-chain fatty acids, in the ceca of DSS + KBL402-treated mice were significantly higher than in that of the mice with DSS-induced colitis (0.03 ± 0.02 ng mg^-1 and 0.03 ± 0.01 ng mg^-1, respectively) (P < 0.05). Our study suggests that L. acidophilus KBL402 and KBL409 could be useful for the prevention or treatment of IBDs in various ways including the modulation of immune responses and miR expression, restoration of the gut microbiota, and production of metabolites.