Bifidobacterium bifidum BGN4 Paraprobiotic Supplementation Alleviates Experimental Colitis by Maintaining Gut Barrier and Suppressing Nuclear Factor Kappa B Activation Signaling Molecules

Limosilactobacillus fermentum HF06-derived paraprobiotic and postbiotic alleviate intestinal barrier damage and gut microbiota disruption in mice with ulcerative colitis

BACKGROUND

Paraprobiotics and postbiotics have shown potential in the treatment of ulcerative colitis (UC). However, their in vivo application is still in its infancy and their mechanisms of action are not well understood.

RESULTS

Here, we investigated the mitigation effects of Limosilactobacillus fermentum HF06-derived paraprobiotic (6-PA) and postbiotic (6-PS) on dextran sulfate sodium induced UC and the potential mechanisms. Results indicated that the administration of 6-PA and 6-PS resulted in the inhibition of weight loss and colon shortening in mice with UC. Furthermore, they led to a significant reduction in both fecal moisture content and the levels of proinflammatory cytokines and oxidative stress in the intestine of the mice. 6-PA and 6-PS treatment strengthened the intestinal mucosal barrier by dramatically upregulating the levels of zonula occludens-1 and occludin proteins. In addition, 6-PA and 6-PS restored intestinal dysbiosis by regulating abundances of certain bacteria, such as Bifidobacterium, Faecalibaculum, Muribaculaceae, Corynebacterium, Escherichia-Shigella and Clostridium_sensu_stricto_1, and regulated the level of short-chain fatty acids.

CONCLUSION

These findings illustrated for the first time that L. fermentum HF06-derived paraprobiotic and postbiotic enhanced the intestinal barrier function, and restored gut microbiota alterations. © 2023 Society of Chemical Industry.

Probiotics intervention in colorectal cancer: From traditional approaches to novel strategies

ABSTRACT

The intestine harbors a large population of microorganisms that interact with epithelial cells to maintain host healthy physiological status. These intestinal microbiota engage in the fermentation of non-digestible nutrients and produce beneficial metabolites to regulate host homeostasis, metabolism, and immune response. The disruption of microbiota, known as dysbiosis, has been implicated in many intestinal diseases, including colorectal cancer (CRC). As the third most common cancer and the second leading cause of cancer-related death worldwide, CRC poses a significant health burden. There is an urgent need for novel interventions to reduce CRC incidence and improve clinical outcomes. Modulating the intestinal microbiota has emerged as a promising approach for CRC prevention and treatment. Current research efforts in CRC probiotics primarily focus on reducing the incidence of CRC, alleviating treatment-related side effects, and potentiating the efficacy of anticancer therapy, which is the key to successful translation to clinical practice. This paper aims to review the traditional probiotics and new interventions, such as next-generation probiotics and postbiotics, in the context of CRC. The underlying mechanisms of probiotic anti-cancer effects are also discussed, including the restoration of microbial composition, reinforcement of gut barrier integrity, induction of cancer cell apoptosis, inactivation of carcinogens, and modulation of host immune response. This paper further evaluates the novel strategy of probiotics as an adjuvant therapy in boosting the efficacy of chemotherapy and immunotherapy. Despite all the promising findings presented in studies, the evaluation of potential risks, optimization of delivery methods, and consideration of intra-patient variability of gut microbial baseline must be thoroughly interpreted before bench-to-bedside translation.

Bifidobacterium bifidum BGN4 fractions ameliorate palmitic acid-induced hepatocyte ferroptosis by inhibiting SREBP1-CYP2E1 pathway

Metabolic dysfunction-associated fatty liver disease (MAFLD) is strongly associated with disturbances in the intestinal microbiota. Herein, the biological effects and mechanism of Bifidobacterium bifidum BGN4 fractions in regulating hepatocyte ferroptosis during MAFLD progression were investigated. To establish an in vitro model of MAFLD, LO2 cells were subjected to palmitic acid (PA). The mRNA and protein expressions were assessed using quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot, respectively. LO2 cell proliferation was examined using 5-diphenyltetrazolium bromide (MTT) and ethynyl-2'-deoxyuridine (EdU) assays, whereas its apoptosis was evaluated by flow cytometry. Furthermore, level of reactive oxygen species (ROS) was measured using 2', 7,-Dichlorodihydrofluorescein diacetate (DCFH-DA) staining. Additionally, the levels of Fe2+, malondialdehyde (MDA), and glutathione (GSH), as well as the activities of superoxide dismutase (SOD) and glutathione peroxidase (GPX) were detected using corresponding kits. Chromatin immunoprecipitation and dual-luciferase reporter gene assays were performed to analyze the interaction between sterol-regulatory element binding protein 1 (SREBP1) and cytochrome P450-2E1 (CYP2E1) promoter. Our results revealed that Bifidobacterium bifidum BGN4 fractions effectively ameliorated PA-induced hepatocyte injury, oxidative stress, and ferroptosis. However, these beneficial effects of BGN4 fractions on PA-induced hepatocyte were dramatically reversed by SREBP1 overexpression, suggesting that BGN4 attenuated MAFLD by acting on SREBP1. Moreover, we observed that BGN4 fractions inhibited CYP2E1 transcription by suppressing SREBP1 nuclear translocation. In addition, CYP2E1 overexpression eliminated the inhibitory effect of BGN4 fractions on PA-induced hepatocyte oxidative stress and ferroptosis. These findings collectively indicated that BGN4 fractions reduced CYP2E1 expression by inhibiting SREBP1 nuclear translocation, thereby suppressing hepatocyte oxidative stress and ferroptosis during the development of MAFLD.

Bifidobacterium and the intestinal mucus layer

Bifidobacterium species are integral members of the human gut microbiota and these microbes have significant interactions with the intestinal mucus layer. This review delves into Bifidobacterium-mucus dynamics, shedding light on the multifaceted nature of this relationship. We cover conserved features of Bifidobacterium-mucus interactions, such as mucus adhesion and positive regulation of goblet cell and mucus production, as well as species and strain-specific attributes of mucus degradation. For each interface, we explore the molecular mechanisms underlying these interactions and their potential implications for human health. Notably, we emphasize the ability of Bifidobacterium species to positively influence the mucus layer, shedding light on its potential as a mucin-builder and a therapeutic agent for diseases associated with disrupted mucus barriers. By elucidating the complex interplay between Bifidobacterium and intestinal mucus, we aim to contribute to a deeper understanding of the gut microbiota-host interface and pave the way for novel therapeutic strategies.

Mesalazine hollow suppositories based on 3D printing for treatment of ulcerative colitis

Mesalazine (MSZ) suppositories are a first-line medication for the localized treatment of ulcerative colitis (UC). However, the frequent defecation of patients with UC influences the retention of the suppository in the rectum and multiple doses have to be applied. Here, a mesalazine hollow suppository (MHS) is developed using three-dimensional (3D) printing. The MHS is composed of an inner supporting spring and an outer MSZ-loaded curved hollow shell. Springs were prepared using fused deposition modeling (FDM) 3D printing with thermoplastic urethane filaments, followed by splitting. The optimal parameters, including elasticity, filament diameter, spring inner diameter, and filament distance, were screened. The shell was prepared by FDM 3D printing utilizing MSZ, polyvinyl alcohol, and polyethylene glycol, which were assembled with springs to obtain FDM 3D-printed MHS (F-MHS); if 3D-printed metal molding was used in preparing shell, mold-formed MHS (M-MHS) was obtained. The F-MHS exhibited faster MSZ release than the M-MHS; therefore, the molding method is preferable. The inserted M-MHS was retained in the rat rectum for 5 h without affecting defecation. M-MHS alleviated tissue damage of UC rats and reduced inflammation with low levels of myeloperoxidase and proinflammatory cytokines. Personalized MHS is a promising medication for the localized treatment of UC.

Probiotics for the treatment of ulcerative colitis: a review of experimental research from 2018 to 2022

Ulcerative colitis (UC) has become a worldwide public health problem, and the prevalence of the disease among children has been increasing. The pathogenesis of UC has not been elucidated, but dysbiosis of the gut microbiota is considered the main cause of chronic intestinal inflammation. This review focuses on the therapeutic effects of probiotics on UC and the potential mechanisms involved. In animal studies, probiotics have been shown to alleviate symptoms of UC, including weight loss, diarrhea, blood in the stool, and a shortened colon length, while also restoring intestinal microecological homeostasis, improving gut barrier function, modulating the intestinal immune response, and attenuating intestinal inflammation, thereby providing theoretical support for the development of probiotic-based microbial products as an adjunctive therapy for UC. However, the efficacy of probiotics is influenced by factors such as the bacterial strain, dose, and form. Hence, the mechanisms of action need to be investigated further. Relevant clinical trials are currently lacking, so the extension of animal experimental findings to clinical application requires a longer period of consideration for validation.

Manipulating Microbiota in Inflammatory Bowel Disease Treatment: Clinical and Natural Product Interventions Explored

Inflammatory bowel disease (IBD) is a complex multifactorial chronic inflammatory disease, that includes Crohn's disease (CD) and ulcerative colitis (UC), having progressively increasing global incidence. Disturbed intestinal flora has been highlighted as an important feature of IBD and offers promising strategies for IBD remedies. A brief overview of the variations occurring in intestinal flora during IBD is presented, and the role of the gut microbiota in intestinal barrier maintenance, immune and metabolic regulation, and the absorption and supply of nutrients is reviewed. More importantly, we review drug research on gut microbiota in the past ten years, including research on clinical and natural drugs, as well as adjuvant therapies, such as Fecal Microbiota Transplantation and probiotic supplements. We also summarize the interventions and mechanisms of these drugs on gut microbiota.

Preclinical evidence of probiotics in ulcerative colitis: a systematic review and network meta-analysis

The imbalance of gastrointestinal microbial composition has been identified as the main factor of chronic inflammatory diseases. At present, probiotics have a beneficial effect on the microbial composition of the human gastrointestinal tract, but it is still controversial and the specific mechanism is unknown. The purpose of this network meta-analysis is to compare the mechanism of different probiotics on ulcerative colitis. PubMed, Embase, and Web of Science were searched till 16 November 2022. The SYRCLE risk bias assessment tool was used to assess the quality of the research studies. A total of 42 studies, 839 ulcerative colitis models, and 24 kinds of probiotics were finally included. The results showed that L. rhamnosus has the best effect in relieving weight loss and improving the Shannon index in the ulcerative colitis model. E. faecium has the best effect in reducing colon injury; L. reuteri has the best effect in reducing the DAI; L. acidophilus has the best effect in reducing the HIS index and increasing the expression of tight junction protein ZO-1; and L. coryniformis has the best effect in reducing the content of serum pro-inflammatory factor TNF-α. It indicated that probiotics can improve ulcerative colitis by improving histopathological manifestations, reducing inflammatory reaction, and repairing the mucosal barrier, and different probiotics showed different effects. However, considering the limitations of this study, preclinical studies that require more large samples and high-quality and more reliable and rigorous experimental designs and reports need to be conducted in the future. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/#record details, identifier CRD42022383383.

Integrative analysis revealed the role of glucagon-like peptide-2 in improving experimental colitis in mice by inhibiting inflammatory pathways, regulating glucose metabolism, and modulating gut microbiota

Introduction

Ulcerative colitis (UC) is an inflammatory bowel disease characterized by recurrent and remitting inflammation of the mucosa of the colon and rectum, the incidence of which is on the rise. Glucagon-like peptide-2 (GLP-2) is a newly discovered neurotrophic factor, but its efficacy and mechanism of action in UC remain unclear. In this study, we investigated the protective effects and potential targets of GLP-2 on dextran sodium sulfate (DSS)-induced UC in mice through integrative analysis.

Methods

The effects of GLP-2 on UC were assessed by calculating the disease activity index, colonic mucosal damage index, and pathological histological scores. Enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry were used to detect the expression of GLP-2, nuclear factor kappa-B (NF-κB), interleukin-6 (IL-6), and signal transducer and activator of transcription-3 (STAT3). The 16SrRNA gene was used to detect changes in gut microbiota in mouse colonic tissues, and oral glucose tolerance test (OGTT) blood glucose levels were used to analyze the differences in flora.

Results

The results showed that GLP-2 could reduce the inflammation of UC mice, which may be achieved by inhibiting the potential targets of NF-κB, and Janus kinase (JAK)/STAT3 inflammatory pathways, regulating sugar metabolism, increasing dominant species, and improving microbial diversity.

Discussion

This study provides new insight into the potential of GLP-2 for achieving more ideal UC treatment goals in future.

Stronger gut microbiome modulatory effects by postbiotics than probiotics in a mouse colitis model

Probiotics are increasingly used as adjunctive therapy to manage gastrointestinal diseases, such as ulcerative colitis. However, probiotic use has posed some safety concerns. Thus, postbiotics are proposed as alternatives to probiotics in clinical applications. However, no study has directly compared the clinical benefits of probiotics and postbiotics. This study compared the beneficial effect of postbiotics and probiotics derived from the strain, Bifidobacterium adolescentis B8598, in a dextran sulfate sodium (DSS)-induced experimental colitis mouse model. Four groups of mice (n = 7 per group) were included in this work: Control (received water plus saline), DSS (received DSS without postbiotic/probiotic), Postbiotic (received DSS plus postbiotic), and Probiotic (received DSS plus probiotic). Our results showed that intragastric administration of both probiotic and postbiotic ameliorated colitis, reflected by decreased histology scores in Postbiotic and Probiotic groups compared with DSS group (P < 0.05). The fecal microbiota alpha diversity was not significantly affected by DSS-, postbiotic, or probiotic treatment. However, the postbiotic treatment showed stronger effects on modulating the fecal microbiota beta diversity, composition, and metagenomic potential than the probiotic treatment. Overall, our findings suggested that probiotics and postbiotics had similar ability to improve disease phenotype but had distinct ability to regulate the gut microbiota and metabolic pathways in the context of ulcerative colitis. In view of the smaller safety concern of postbiotics compared with probiotics and its stronger modulatory effect on the host gut microbiota, we propose that postbiotics are to be considered for use as next-generation biotherapeutics in managing ulcerative colitis or even other diseases.

Probiotics, their action modality and the use of multi-omics in metamorphosis of commensal microbiota into target-based probiotics

This review article addresses the strategic formulation of human probiotics and allows the reader to walk along the journey that metamorphoses commensal microbiota into target-based probiotics. It recapitulates what are probiotics, their history, and the main mechanisms through which probiotics exert beneficial effects on the host. It articulates how a given probiotic preparation could not be all-encompassing and how each probiotic strain has its unique repertoire of functional genes. It answers what criteria should be met to formulate probiotics intended for human use, and why certain probiotics meet ill-fate in pre-clinical and clinical trials? It communicates the reasons that taint the reputation of probiotics and cause discord between the industry, medical and scientific communities. It revisits the notion of host-adapted strains carrying niche-specific genetic modifications. Lastly, this paper emphasizes the strategic development of target-based probiotics using host-adapted microbial isolates with known molecular effectors that would serve as better candidates for bioprophylactic and biotherapeutic interventions in disease-susceptible individuals.