Lactobacillus rhamnosus CNCM I-3690 and the commensal bacterium Faecalibacterium prausnitzii A2-165 exhibit similar protective effects to induced barrier hyper-permeability in mice

Bile acids as signaling molecules in inflammatory bowel disease: Implications for treatment strategies

ETHNOPHARMACOLOGICAL RELEVANCE

Inflammatory bowel disease (IBD) is a globally increasing disease. Despite continuous efforts, the clinical application of treatment drugs has not achieved satisfactory success and faces limitations such as adverse drug reactions. Numerous investigations have found that the pathogenesis of IBD is connected with disturbances in bile acid circulation and metabolism. Traditional Chinese medicine targeting bile acids (BAs) has shown significant therapeutic effects and advantages in treating inflammatory bowel disease.

AIM OF THIS REVIEW

IThis article reviews the role of bile acids and their receptors in IBD, as well as research progress on IBD therapeutic drugs based on bile acids. It explores bile acid metabolism and its interaction with the intestinal microbiota, summarizes clinical drugs for treating IBD including single herbal medicine, traditional herbal prescriptions, and analyzes the mechanisms of action in treating IBD.

MATERIALS AND METHODS

IThe electronic databases such as PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI) have been utilized to retrieve relevant literature up to January 2024, using keywords "bile acid", "bile acid receptor", "inflammatory bowel disease", "intestinal microbiota" and "targeted drugs".

RESULTS

IImbalance in bile acid levels can lead to intestinal inflammation, while IBD can disrupt the balance of microbes, result in alterations in the bile acid pool's composition and amount. This change can damage of intestinal mucosa healing ability. Bile acids are vital for keeping the gut barrier function intact, regulating gene expression, managing metabolic equilibrium, and influencing the properties and roles of the gut's microbial community. Consequently, focusing on bile acids could offer a potential treatment strategy for IBD.

CONCLUSION

IIBD can induce intestinal homeostasis imbalance and changes in BA pool, leading to fluctuations in levels of relevant metabolic enzymes, transporters, and nuclear receptors. Therefore, by regulating the balance of BA and key signaling molecules of bile acids, we can treat IBD. Traditional Chinese medicine has great potential and promising prospects in treating IBD. We should focus on the characteristics and advantages of Chinese medicine, promote the development and clinical application of innovative Chinese medicine, and ultimately make Chinese medicine targeting bile acids the mainstream treatment for IBD.

Lactobacillus rhamnosus: An emerging probiotic with therapeutic potential for depression

Depression, a complex psychological disorder, involves multiple biological pathways in its pathogenesis. In recent years, the gut-brain axis theory has provided novel insights into the pathogenesis of depression, particularly the crucial role of the gut microbiota in mood regulation. While there remains no universal consensus on the most efficacious strains for depression treatment, Lactobacillus rhamnosus has risen to prominence within the realm of probiotics for its potential to positively modulate depressive symptoms. This review preliminarily explores the clinical significance of Lactobacillus rhamnosus in the treatment of depression and summarizes the potential mechanisms by which Lactobacillus rhamnosus treats depression, including its regulation of gut microbiota, alterations in gene expression, improvement of intestinal barrier function, maintenance of neurotransmitter balance, suppression of inflammatory responses, modulation of the immune system, coping with oxidative stress, and optimization of metabolic processes. Future research needs to further explore these mechanisms and combine them with clinical research results to optimize treatment plans and provide more effective treatment options for patients with depression.

The Role of Gut Microbiota in Blood-Brain Barrier Disruption after Stroke

Growing evidence has proved that alterations in the gut microbiota have been linked to neurological disorders including stroke. Structural and functional disruption of the blood-brain barrier (BBB) is observed after stroke. In this context, there is pioneering evidence supporting that gut microbiota may be involved in the pathogenesis of stroke by regulating the BBB function. However, only a few experimental studies have been performed on stroke models to observe the BBB by altering the structure of gut microbiota, which warrant further exploration. Therefore, in order to provide a novel mechanism for stroke and highlight new insights into BBB modification as a stroke intervention, this review summarizes existing evidence of the relationship between gut microbiota and BBB integrity and discusses the mechanisms of gut microbiota on BBB dysfunction and its role in stroke.

Changes in amino acid concentrations and the gut microbiota composition are implicated in the mucosal healing of ulcerative colitis and can be used as noninvasive diagnostic biomarkers

BACKGROUND

Mucosal healing is the therapeutic target for ulcerative colitis (UC). While amino acids (AAs) and the gut microbiota are known to be involved in the pathogenesis of UC, their specific roles in mucosal healing have not been fully defined.

OBJECTIVES

To longitudinally assess the changes in AA concentrations and the gut microbiota composition in the context of mucosal healing in UC patients, with the aim of identifying new biomarkers with predictive value for mucosal healing in UC patients and providing a new theoretical basis for dietary therapy.

METHODS

A total of 15 UC patients with infliximab-induced mucosal healing were enrolled. Serum and fecal AA concentrations before and after mucosal healing were determined via targeted metabolomics. A receiver operating characteristic (ROC) curve was plotted to evaluate the value of different AAs in predicting mucosal healing in UC patients. The changes in the composition of the fecal gut microbiota were analyzed via metagenomics, and bioinformatics was used to analyze the functional genes and metabolic pathways associated with different bacterial species. Spearman correlation analyses of fecal AAs with significantly different concentrations and the differentially abundant bacterial species before and after mucosal healing were performed.

RESULTS

1. The fecal concentrations of alanine, aspartic acid, glutamic acid, glutamine, glycine, isoleucine, leucine, lysine, methionine, phenylalanine, proline, serine, threonine, tryptophan, tyrosine and valine were significantly decreased after mucosal healing. The serum concentrations of alanine, cysteine and valine significantly increased, whereas that of aspartic acid significantly decreased. Glutamic acid, leucine, lysine, methionine and threonine could accurately predict mucosal healing in UC patients, and the area under the curve (AUC) was > 0.9. After combining the 5 amino acids, the AUC reached 0.96. 2. There were significant differences in the gut microbiota composition before and after mucosal healing in UC, characterized by an increase in the abundance of beneficial microbiota (Faecalibacterium prausnitzii and Bacteroides fragilis) and a decrease in the abundance of harmful microbiota (Enterococcus faecalis). LEfSe analysis identified 57 species that could predict mucosal healing, and the AUC was 0.7846. 3. Amino acid metabolic pathways were enriched in samples after mucosal healing, was associated with the abundance of multiple species, such as Faecalibacterium prausnitzi, Bacteroides fragilis, Bacteroides vulgatus and Alistipes putredinis. 4. The fecal concentrations of several AAs were negatively correlated with the abundance of a variety of beneficial strains, such as Bacteroides fragilis, uncultured Clostridium sp., Firmicutes bacterium CAG:103, Adlercreutzia equolifaciens, Coprococcus comes and positively correlated with the abundance of several harmful strains, such as Citrobacter freundii, Enterococcus faecalis, Klebsiella aerogenes, Salmonella enterica.

CONCLUSION

Altered concentrations of amino acids and their associations with the gut microbiota are implicated in the mucosal healing of UC patients and can serve as noninvasive diagnostic biomarkers.

Acute Sarcopenia: Mechanisms and Management

BACKGROUND

Acute sarcopenia refers to the swift decline in muscle function and mass following acute events such as illness, surgery, trauma, or burns that presents significant challenges in hospitalized older adults.

METHODS

narrative review to describe the mechanisms and management of acute sarcopenia.

RESULTS

The prevalence of acute sarcopenia ranges from 28% to 69%, likely underdiagnosed due to the absence of muscle mass and function assessments in most clinical settings. Systemic inflammation, immune-endocrine dysregulation, and anabolic resistance are identified as key pathophysiological factors. Interventions include early mobilization, resistance exercise, neuromuscular electrical stimulation, and nutritional strategies such as protein supplementation, leucine, β-hydroxy-β-methyl-butyrate, omega-3 fatty acids, and creatine monohydrate. Pharmaceuticals show variable efficacy.

CONCLUSIONS

Future research should prioritize serial monitoring of muscle parameters, identification of predictive biomarkers, and the involvement of multidisciplinary teams from hospital admission to address sarcopenia. Early and targeted interventions are crucial to improve outcomes and prevent long-term disability associated with acute sarcopenia.

Interactions between soluble dietary fibers from three edible fungi and gut microbiota

Edible fungi are emerging as a valuable dietary fiber source with health benefits, where their bioactivity hinges on their structure. This study targets the structure-activity relationship of soluble dietary fibers from Lentinus edodes (LESDF), Agaricus bisporus (ABSDF), and Hericium erinaceus (HESDF), focusing on their impact on gut microbiota and health. We explored the properties and structures of edible fungi, finding their soluble fibers affect metabolites and gut microbiota by increasing gas and lowering pH. Among these, HESDF demonstrated superior effects (pH: △1.4 ± 0.07; Gas production: △24.5 ± 0.4 mL). Furthermore, different types of edible fungi dietary fiber exhibited distinct capabilities in promoting the production of short-chain fatty acids by gut microorganisms. For instance, ABSDF exceled in acetic acid production (26.12 ± 0.35 mM) and propionic acid production (9.50 ± 0.13 mM), while HESDF stood out in butyric acid production (17.86 ± 0.09 mM). LESDF showed higher levels of Phascolarctobacterium, ABSDF had elevated levels of Ruminococcus, and HESDF displayed increased levels of Faecalibacterium. These results contribute to our understanding of how soluble dietary fiber from different edible fungi impacts gut microbiota and offers insights for the development and utilization of these fibers as functional food.

Yoyo Dieting, Post-Obesity Weight Loss, and Their Relationship with Gut Health

Excessive body weight is associated with many chronic metabolic diseases and weight loss, so far, remains the gold standard treatment. However, despite tremendous efforts exploring optimal treatments for obesity, many individuals find losing weight and maintaining a healthy body weight difficult. Weight loss is often not sustainable resulting in weight regain and subsequent efforts to lose weight. This cyclic pattern of weight loss and regain is termed "yoyo dieting" and predisposes individuals to obesity and metabolic comorbidities. How yoyo dieting might worsen obesity complications during the weight recurrence phase remains unclear. In particular, there is limited data on the role of the gut microbiome in yoyo dieting. Gut health distress, especially gut inflammation and microbiome perturbation, is strongly associated with metabolic dysfunction and disturbance of energy homeostasis in obesity. In this review, we summarise current evidence of the crosstalk between the gastrointestinal system and energy balance, and the effects of yoyo dieting on gut inflammation and gut microbiota reshaping. Finally, we focus on the potential effects of post-dieting weight loss in improving gut health and identify current knowledge gaps within the field, including gut-derived peptide hormones and their potential suitability as targets to combat weight regain, and how yoyo dieting and associated changes in the microbiome affect the gut barrier and the enteric nervous system, which largely remain to be determined.

The PI3K/Akt-Nrf2 Signaling Pathway and Mitophagy Synergistically Mediate Hydroxytyrosol to Alleviate Intestinal Oxidative Damage

Oxidative stress is a major pathogenic factor in many intestinal diseases, such as inflammatory bowel disease (IBD) and colorectal cancer (CRC). The Nrf2 signaling pathway and mitophagy can reduce reactive oxygen species (ROS) and alleviate oxidative stress, but their relationship is unclear. Hydroxytyrosol (HT), a polyphenolic compound abundant in olive oil, has strong antioxidant activity and may help treat these diseases. We used pigs as a model to investigate HT's effect on intestinal oxidative damage and its mechanisms. Diquat (DQ) induced oxidative stress and impaired intestinal barrier function, which HT mitigated. Mechanistic studies in IPEC-J2 cells showed that HT protected against oxidative damage by activating the PI3K/Akt-Nrf2 signaling pathway and promoting mitophagy. Our study highlighted the synergistic relationship between Nrf2 and mitophagy in mediating HT's antioxidant effects. Inhibition studies confirmed that disrupting either pathway compromised HT's protective effects. Maintaining redox balance through Nrf2 and mitophagy is important for eliminating excess ROS. Nrf2 increases antioxidant enzymes to clear existing ROS, while mitophagy removes damaged mitochondria and reduces ROS generation. This study demonstrates that these pathways collaboratively modulate the antioxidant effects of HT, with neither being dispensable. Targeting Nrf2 and mitophagy could be a promising strategy for treating oxidative stress-related intestinal diseases, with HT as a potential treatment.

Lactobacillus rhamnosus GG and Tannic Acid Synergistically Promote the Gut Barrier Integrity in a Rat Model of Experimental Diarrhea via Selective Immunomodulatory Cytokine Targeting

SCOPE

Diarrhea is a common health issue that contributes to a significant annual death rate among children and the elderly worldwide. The anti-diarrheal activity of Lactobacillus rhamnosus GG (LGG) and tannic acid (TA), alone or combined, is examined, in addition to their effect on intestinal barrier integrity.

METHODS AND RESULTS

Fifty-six adult male Wistar rats are randomly assigned into seven groups: control, LGG alone, TA alone, diarrhea model, diarrhea+LGG, diarrhea+TA, and diarrhea+LGG+TA-treated groups. Diarrhea is induced by high-lactose diet (HLD) consumption. LGG (1x109 CFU/rat) and TA (100 mg Kg-1 d-1) were given orally 4 days after HLD feeding and continued for 10 days. Ileum specimens are processed for biochemical analysis of the local intestinal cytokines, polymerase chain reaction (PCR), and histological study. Also, immunohistochemistry-based identification of Proliferating Cell Nuclear Antigen (PCNA) and zonula occludens 1 (ZO-1) is performed. Compared to the diarrhea model group, both treatments maintain the intestinal mucosal structure and proliferative activity and preserve ZO-1 expression, with the combination group showing the maximal effect. However, LGG-treated diarrheic rats show a remarkable decrease in the intestinal tissue concentrations of tumor necrosis factor-alpha (TNF-α) and nuclear factor Kappa beta (NF-κB); meanwhile, TA treatment leads to a selective decrease of interferon-gamma (INF-γ) and transforming growth factor-beta (TGF-β1).

CONCLUSION

Individual LGG and TA treatments significantly alleviate diarrhea, probably through a selective immunomodulatory cytokine-dependent mechanism, while the combination of both synergistically maintains the intestinal mucosa by keeping the intestinal epithelial barrier function and regenerative capability.

Idiopathic Rapid Eye Movement Sleep Behavior Disorder (iRBD) Shares Similar Fecal Short-Chain Fatty Acid Alterations with Multiple System Atrophy (MSA) and Parkinson's Disease (PD)

BACKGROUND

Idiopathic rapid eye movement sleep behavior disorder (iRBD) is considered as a prodromal stage of synucleinopathies. Fecal short-chain fatty acid (SCFA) changes in iRBD and the relationships with synucleinopathies have never been investigated.

OBJECTIVES

To investigate fecal SCFA changes among iRBD, multiple system atrophy (MSA), and Parkinson's disease (PD), and evaluate their relationships.

METHODS

Fecal SCFAs and gut microbiota were measured in 29 iRBD, 42 MSA, 40 PD, and 35 normal controls (NC) using gas chromatography-mass spectrometry and 16S rRNA gene sequencing.

RESULTS

Compared with NC, fecal SCFA levels (propionic, acetic, and butyric acid) were lower in iRBD, MSA, and PD. Combinations of these SCFAs could differentiate NC from iRBD (AUC 0.809), MSA (AUC 0.794), and PD (AUC 0.701). Decreased fecal SCFAs were associated with the common reducing SCFA-producing gut microbiota in iRBD, MSA, and PD.

CONCLUSIONS

iRBD shares similar fecal SCFA alterations with MSA and PD, and the combination of these SCFAs might be a potential synucleinopathies-related biomarker. © 2024 International Parkinson and Movement Disorder Society.

Computational prediction of new therapeutic effects of probiotics

Probiotics are living microorganisms that provide health benefits to their hosts, potentially aiding in the treatment or prevention of various diseases, including diarrhea, irritable bowel syndrome, ulcerative colitis, and Crohn's disease. Motivated by successful applications of link prediction in medical and biological networks, we applied link prediction to the probiotic-disease network to identify unreported relations. Using data from the Probio database and International Classification of Diseases-10th Revision (ICD-10) resources, we constructed a bipartite graph focused on the relationship between probiotics and diseases. We applied customized link prediction algorithms for this bipartite network, including common neighbors, Jaccard coefficient, and Adamic/Adar ranking formulas. We evaluated the results using Area under the Curve (AUC) and precision metrics. Our analysis revealed that common neighbors outperformed the other methods, with an AUC of 0.96 and precision of 0.6, indicating that basic formulas can predict at least six out of ten probable relations correctly. To support our findings, we conducted an exact search of the top 20 predictions and found six confirming papers on Google Scholar and Science Direct. Evidence suggests that Lactobacillus jensenii may provide prophylactic and therapeutic benefits for gastrointestinal diseases and that Lactobacillus acidophilus may have potential activity against urologic and female genital illnesses. Further investigation of other predictions through additional preclinical and clinical studies is recommended. Future research may focus on deploying more powerful link prediction algorithms to achieve better and more accurate results.

Timosaponin BⅡ reduces colonic inflammation and alleviates DSS-induced ulcerative colitis by inhibiting NLRP3

ETHNOPHARMACOLOGICAL RELEVANCE

The Timosaponin BⅡ (TBⅡ) is one of the main active components of the traditional Chinese medicine Anemarrhena asphodeloides, and it is a steroidal saponin with various pharmacological activities such as anti-oxidation, anti-inflammatory and anti-apoptosis. However, its role in acute ulcerative colitis remains unexplored thus far.

AIM OF THE STUDY

This study aims to investigate the protective effect of TBⅡ against dextran sulfate sodium (DSS)-induced ulcerative colitis in mice and elucidate its underlying mechanisms.

METHODS

Wild-type (WT) and NLRP3 knockout (NLRP3-/-) mice were applied to evaluate the protective effect of TBⅡ in DSS-induced mice colitis. Pharmacological inhibition of NLRP3 or adenovirus-mediated NLRP3 overexpression in bone marrow-derived macrophages (BMDM) from WT mice and colonic epithelial HCoEpiC cells was used to assess the role of TBⅡ in LPS + ATP-induced cell model. RNA-seq, ELISA, western blots, immunofluorescence staining, and expression analysis by qPCR were performed to examine the alterations of colonic NLRP3 expression in DSS-induced colon tissues and LPS + ATP-induced cells, respectively.

RESULTS

In mice with DSS-induced ulcerative colitis, TBⅡ treatment attenuated clinical symptoms, repaired the intestinal mucosal barrier, reduced inflammatory infiltration, and alleviated colonic inflammation. RNA-seq analysis and protein expression levels demonstrated that TBⅡ could prominently inhibit NLRP3 signaling. TBⅡ-mediated NLRP3 inhibition was associated with alleviating intestinal permeability and inflammatory response via the blockage of communication between epithelial cells and macrophages, probably in an NLRP3 inhibition mechanism. However, pharmacological inhibition of NLRP3 by MCC950 or Ad-NLRP3 mediated NLRP3 overexpression significantly impaired the TBⅡ-mediated anti-inflammatory effect. Mechanistically, TBⅡ-mediated NLRP3 inhibition may be partly associated with the suppression of NF-κB, a master pro-inflammatory factor for transcriptional regulation of NLRP3 expression in the priming step. Moreover, co-treatment TBⅡ with NF-κB inhibitor BAY11-7082 partly impaired TBⅡ-mediated NLRP3 inhibition, and consequently affected the IL-1β mature and secretion. Importantly, TBⅡ-mediated amelioration was not further enhanced in NLPR3-/- mice.

CONCLUSION

TBⅡ exerted a prominent protective effect against DSS-induced colitis via regulation of alleviation of intestinal permeability and inflammatory response via the blockage of crosstalk between epithelial cells and macrophages in an NLRP3-mediated inhibitory mechanism. These beneficial effects could make TBⅡ a promising drug for relieving colitis.

Effects of Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets on the Structure and Function of the Intestinal Flora in Rabbits Undergoing Hepatic Artery Infusion Chemotherapy

Few studies have explored the biological mechanism by which probiotics alleviate adverse reactions to chemotherapy drugs after local hepatic chemotherapy perfusion by regulating the intestinal flora. This study investigates the effects of Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets on the intestinal microbial structure and intestinal barrier function, as well as the potential mechanism in rabbits after local hepatic chemotherapy infusion. Eighteen New Zealand White rabbits were randomly divided into a control group, a hepatic local chemotherapy perfusion group, and a hepatic local chemotherapy perfusion + Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets group to assess the effects of Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets on the adverse reactions. The administration of Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets alleviated the intestinal flora disorder caused by local hepatic perfusion chemotherapy, promoted the growth of beneficial bacteria, and inhibited the growth of harmful bacteria. The Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets also reduced the levels of serum pro-inflammatory cytokines and liver injury factors induced by local hepatic perfusion chemotherapy. Our findings indicate that Combined Live Bifidobacterium, Lactobacillus, Enterococcus, and Bacillus Cereus Tablets can ameliorate the toxicity and side effects of chemotherapy by regulating intestinal flora, blocking pro-inflammatory cytokines, reducing liver injury factors, and repairing the intestinal barrier. Probiotics may be used as a potential alternative therapeutic strategy to prevent the adverse reactions caused by chemotherapy with local hepatic perfusion.

Associations between gut microbiota and gynecological cancers: A bi-directional two-sample Mendelian randomization study

Growing evidence has suggested that gut microbiota is associated with gynecologic cancers. However, whether there is a causal relationship between these associations remains to be determined. A two-sample Mendelian randomization (MR) evaluation was carried out to investigate the mechanism associating gut microbiota and 3 prevalent gynecological cancers, ovarian cancer (OC), endometrial cancer, and cervical cancer as well as their subtypes in individuals of European ancestry. The Genome-wide association studies statistics, which are publically accessible, were used. Eligible instrumental single nucleotide polymorphisms that were significantly related to the gut microbiota were selected. Multiple MR analysis approaches were carried out, including inverse variance weighted, MR-Egger, Weighted Median methods, and a range of sensitivity analyses. Lastly, we undertook a reverse MR analysis to evaluate the potential of reverse causality. We sifted through 196 bacterial taxa and identified 33 suggestive causal relationships between genetic liability in the gut microbiota and gynecological cancers. We found that 11 of these genera could be pathogenic risk factors for gynecological cancers, while 19 could lessen the risk of cancer. In the other direction, gynecological cancers altered gut microbiota composition. Our MR analysis revealed that the gut microbiota was causally associated with OC, endometrial cancer, and cervical cancer. This may assist in providing new insights for further mechanistic and clinical studies of microbiota-mediated gynecological cancer.

Border Control: The Role of the Microbiome in Regulating Epithelial Barrier Function

The gut mucosal epithelium is one of the largest organs in the body and plays a critical role in regulating the crosstalk between the resident microbiome and the host. To this effect, the tight control of what is permitted through this barrier is of high importance. There should be restricted passage of harmful microorganisms and antigens while at the same time allowing the absorption of nutrients and water. An increased gut permeability, or "leaky gut", has been associated with a variety of diseases ranging from infections, metabolic diseases, and inflammatory and autoimmune diseases to neurological conditions. Several factors can affect gut permeability, including cytokines, dietary components, and the gut microbiome. Here, we discuss how the gut microbiome impacts the permeability of the gut epithelial barrier and how this can be harnessed for therapeutic purposes.

Gut microbiota, intestinal permeability, and systemic inflammation: a narrative review

The intestine is the largest interface between the internal body and the external environment. The intestinal barrier is a dynamic system influenced by the composition of the intestinal microbiome and the activity of intercellular connections, regulated by hormones, dietary components, inflammatory mediators, and the enteric nervous system (ENS). Over the years, it has become increasingly evident that maintaining a stable intestinal barrier is crucial to prevent various potentially harmful substances and pathogens from entering the internal environment. Disruption of the barrier is referred to as 'leaky gut' or leaky gut wall syndrome and seems to be characterized by the release of bacterial metabolites and endotoxins, such as lipopolysaccharide (LPS), into the circulation. This condition, mainly caused by bacterial infections, oxidative stress, high-fat diet, exposure to alcohol or chronic allergens, and dysbiosis, appear to be highly connected with the development and/or progression of several metabolic and autoimmune systemic diseases, including obesity, non-alcoholic fatty liver disease (NAFLD), neurodegeneration, cardiovascular disease, inflammatory bowel disease, and type 1 diabetes mellitus (T1D). In this review, starting from a description of the mechanisms that enable barrier homeostasis and analyzing the relationship between this complex ecosystem and various pathological conditions, we explore the role of the gut barrier in driving systemic inflammation, also shedding light on current and future therapeutic interventions.

Bacteria-based drug delivery for treating non-oncological diseases

Bacteria inhabit all over the human body, especially the skin, gastrointestinal tract, respiratory tract, urogenital tract, as well as specific lesion sites, such as wound and tumor. By leveraging their distinctive attributes including rapid proliferation, inherent abilities to colonize various biointerfaces in vivo and produce diverse biomolecules, and the flexibility to be functionalized via genetic engineering or surface modification, bacteria have been widely developed as living therapeutic agents, showing promising potential to make a great impact on the exploration of advanced drug delivery systems. In this review, we present an overview of bacteria-based drug delivery and its applications in treating non-oncological diseases. We systematically summarize the physiological positions where living bacterial therapeutic agents can be delivered to, including the skin, gastrointestinal tract, respiratory tract, and female genital tract. We discuss the success of using bacteria-based drug delivery systems in the treatment of diseases that occur in specific locations, such as skin wound healing/infection, inflammatory bowel disease, respiratory diseases, and vaginitis. We also discuss the advantages as well as the limitations of these living therapeutics and bacteria-based drug delivery, highlighting the key points that need to be considered for further translation. This review article may provide unique insights for designing next-generation bacteria-based therapeutics and developing advanced drug delivery systems.

Gut microbiota influence frailty syndrome in older adults: mechanisms and therapeutic strategies

Frailty syndrome denotes a decreased capacity of the body to maintain the homeostasis and stress of the internal environment, which simultaneously increases the risk of adverse health outcomes in older adults, including disability, hospitalization, falls, and death. To promote healthy aging, we should find strategies to cope with frailty. However, the pathogenesis of frailty syndrome is not yet clear. Recent studies have shown that the diversity, composition, and metabolites of gut microbiota significantly changed in older adults with frailty. In addition, several frailty symptoms were alleviated by adjusting gut microbiota with prebiotics, probiotics, and symbiosis. Therefore, we attempt to explore the pathogenesis of frailty syndrome in older people from gut microbiota and summarize the existing interventions for frailty syndrome targeting gut microbiota, with the aim of providing timely and necessary interventions and assistance for older adults with frailty.

All-trans retinoic acid alleviates collagen-induced arthritis and promotes intestinal homeostasis

All-trans retinoic acid (ATRA) has emerged as a promising adjunctive treatment for rheumatoid arthritis. However, the mechanism by which ATRA mitigates arthritis remains unclear. In this study, we aimed to explore ATRA alleviation of arthritis and the role of ATRA in regulating intestinal homeostasis. Thus, we established a collagen-induced arthritis (CIA) model in Wistar rats. After 6 weeks of ATRA treatment, the arthritis index of CIA rats decreased, synovial inflammation was alleviated, and the disruption of Th17/Treg differentiation in peripheral blood was reversed. Additionally, the Th17/Treg ratio in the mesenteric lymph nodes decreased and the expression of Foxp3 mRNA increased and that of IL-17 mRNA decreased in the colon and ileum. Microscopically, we observed reduced intestinal inflammation. Transmission electron microscopy revealed that ATRA could repair tight junctions, which was accompanied by an increase in the expression of Claudin-1, Occludin and ZO-1. Moreover, ATRA regulated the composition of the gut microbiota, as was characterized based on the reduced abundance of Desulfobacterota and the increased abundance of Lactobacillus. In conclusion, ATRA demonstrates the potential to alleviate arthritis in CIA rats, which might be correlated with modulating the gut microbiota and regulating the intestinal immune response. Our findings provide novel insights into ATRA-mediated alleviation of arthritis.

Current insights on gut microbiome and chronic urticaria: progress in the pathogenesis and opportunities for novel therapeutic approaches

Chronic urticaria (CU) is a prevalent skin disorder greatly impacting the patients' life quality, in which immune dysregulation mediated by gut microbiome plays a significant role. Several studies have found the gut dysbiosis exists in patients with CU. In addition, infection may also be one of the causes of CU. The primary treatment currently used for CU is the second-generation non-sedating H1-antihistamines (nsAH). However, there are some limitations in current therapies. Based on the latest evidence, this review provides an updated overview of how the gut dysbiosis influences CU development, explores potential therapeutic approaches based on the gut microbiota and summarizes the interaction between gut microbiota and current treatment.

Faecalibacterium prausnitzii promotes intestinal epithelial IL-18 production through activation of the HIF1α pathway

Introduction

Intestinal epithelial cells produce interleukin-18 (IL-18), a key factor in promoting epithelial barrier integrity. Here, we analyzed the potential role of gut bacteria and the hypoxia-inducible factor 1α (HIF1α) pathway in regulating mucosal IL18 expression in inflammatory bowel disease (IBD).

Methods

Mucosal samples from patients with IBD (n = 760) were analyzed for bacterial composition, IL18 levels and HIF1α pathway activation. Wild-type Caco-2 and CRISPR/Cas9-engineered Caco-2-HIF1A-null cells were cocultured with Faecalibacterium prausnitzii in a "Human oxygen-Bacteria anaerobic" in vitro system and analyzed by RNA sequencing.

Results

Mucosal IL18 mRNA levels correlated positively with the abundance of mucosal-associated butyrate-producing bacteria, in particular F. prausnitzii, and with HIF1α pathway activation in patients with IBD. HIF1α-mediated expression of IL18, either by a pharmacological agonist (dimethyloxallyl glycine) or F. prausnitzii, was abrogated in Caco-2-HIF1A-null cells.

Conclusion

Butyrate-producing gut bacteria like F. prausnitzii regulate mucosal IL18 expression in a HIF1α-dependent manner that may aid in mucosal healing in IBD.

Probiotics in Postoperative Pain Management

Postoperative pain is the unpleasant sensory and emotional experience after surgery, its origin being both the inflammatory reaction induced by the surgical trauma on the abdominal wall and the splanchnic pain induced by the activation of nociceptors of the viscera, which are highly sensitive to distension, ischemia, and inflammation. Nowadays, it is well recognized that there is a close relationship between the gut microbiome and pain perception, and that microbiome is highly affected by both anesthesia and surgical manipulation. Thus, efforts to restore the disturbed microbiome via supplementation with beneficial bacteria, namely probiotics, seem to be effective. In this article, the knowledge gained mainly from experimental research on this topic is analyzed, the concluding message being that each probiotic strain works in its own way towards pain relief.

F. prausnitzii-derived extracellular vesicles attenuate experimental colitis by regulating intestinal homeostasis in mice

BACKGROUND

Emerging evidence has shown that extracellular vesicles (EVs) derived from gut bacteria play a crucial role in microbiota-host interactions. Here, we aimed to evaluate the attenuating effect of EVs derived from a reduced commensal bacterium, F. prausnitzii (Fp-EVs), in inflammatory bowel disease (IBD) on dextran sulfate sodium (DSS)-induced colitis in mice.

RESULTS

Fp-EVs isolated by ultracentrifugation and typically exhibited a double concave disc shape with an average diameter of 172 nm. Fp-EVs treatment reduced DSS-induced weight loss, disease activity index (DAI) score, colon length shortening, histological damage, neutrophil infiltration and increased intestinal epithelial apoptotic cells in DSS-induced colitis mice. Fp-EVs upregulated the protein expression of zona occludens (ZO)-1 and Occludin and increased the ratio of Tregs in the colon tissue of colitis mice. Furthermore, Fp-EVs downregulated the expression of the proinflammatory cytokines interleukin-1β (IL-1β), IL-2, IL-6, IL-12a, IL-17a, Interferon-γ (IFN-γ), tumor necrosis factor - α (TNF-α), granulocyte-macrophage colony stimulating factor (GM-CSF) and upregulated the anti-inflammatory cytokines IL-4, IL-10, and transforming growth factor β (TGF-β) in DSS-treated mice. Moreover, Fp-EV treatment markedly reduced the phosphorylation of these proteins Nuclear factor-κB (NF-κB) and Mitogen activated protein kinase (MAPK), and regulated the expression of nuclear factor erythroid 2-related factor (Nrf2) and heme oxygenase-1 (HO-1).

CONCLUSION

Our findings revealed that Fp-EVs attenuated DSS-induced colitis by modulating the intestinal mucosal barrier function and immunological profile. Our findings reveal that Fp-EVs attenuate DSS-induced colitis by modulating intestinal mucosal barrier function and the immunological profile.

Impact of Oral Administration of Lactiplantibacillus plantarum Strain CNCM I-4459 on Obesity Induced by High-Fat Diet in Mice

Recent evidence suggests that some lactobacilli strains, particularly Lactiplantibacillus plantarum, have a beneficial effect on obesity-associated syndromes. Several studies have investigated probiotic challenges in models of high-fat diet (HFD)-induced obesity, specifically with respect to its impact on hepatic and/or adipocyte metabolism, gut inflammation and epithelial barrier integrity, and microbiota composition. However, only a few studies have combined these aspects to generate a global understanding of how probiotics exert their protective effects. Here, we used the probiotic strain L. plantarum CNCM I-4459 and explored its impact on a mouse model of HFD-induced obesity. Briefly, mice were administered 1 × 109 CFUs/day and fed HFD for 12 weeks. Treatment with this strain improved insulin sensitivity by lowering serum levels of fasting glucose and fructosamine. Administration of the probiotic also affected the transport and metabolism of glucose, resulting in the downregulation of the hepatic Glut-4 and G6pase genes. Additionally, L. plantarum CNCM I-4459 promoted a decreased concentration of LDL-c and modulated hepatic lipid metabolism (downregulation of Fasn, Plin, and Cpt1α genes). Probiotic treatment also restored HFD-disrupted intestinal microbial composition by increasing microbial diversity and lowering the ratio of Firmicutes to Bacteroidetes. In conclusion, this probiotic strain represents a potential approach for at least partial restoration of the glucose sensitivity and lipid disruption that is associated with obesity.

Intervention study of tai chi training on the intestinal flora of college student basketball players

BACKGROUND

In recent years, the interactions between host and host-associated gut flora have received increasingly widespread attention. Tai chi is a traditional Chinese exercise, which can significantly benefit adults with health condition. But the studies on the function of intestinal flora and its correlation with tai chi exercise, are limited. In addition, the influence of tai chi on intestinal flora has largely been understudied. In this study, we investigated the changes in intestinal microflora by 16S rRNA sequencing to clarify the specific mechanism of tai chi on the regulation of intestinal flora and seek to formulate a reasonable "exercise prescription."

METHODS

Design: randomized controlled trial. Participants: thirty college basketball players randomly divided into control (n = 15) and test (n = 15) groups. Intervention: experimental group practiced 24-style simplified tai chi ≥ 6 times/week for 20 weeks. Outcomes: serum biochemical markers, blood pressure, and intestinal microbial composition measured post-intervention. Analysis: intent-to-treat analysis.

RESULTS

Primary outcomes: after tai chi intervention, the level of high-density lipoprotein cholesterol (1.22 mmol/L) and triglycerides (0.64 mmol/L) were significantly decreased. Secondary outcomes: aspartate transaminase, alanine aminotransferase, total cholesterol, and low-density lipoprotein remained unchanged. Microbiota: α-diversity index significantly increased, particularly with increased Blautia. Blood pressure: test group showed significantly lower diastolic blood pressure (83-95 mm Hg) compared to control.

DISCUSSION

Considering other markers, increased gut flora diversity during exercise may imply a healthier gut environment. Physical exercise promotes a decrease in the inflammatory process by reducing the levels of bacteria associated with pro-inflammation, such as Proteobacteria. Further research is required to understand the nuanced link between gut flora diversity and exercise intensity.

CONCLUSION

24-style simplified tai chi enhances human intestinal flora diversity. Improvements observed in blood lipid profiles and blood pressure levels.

The gut microbes in inflammatory bowel disease: Future novel target option for pharmacotherapy

Gut microbes constitute the main microbiota in the human body, which can regulate biological processes such as immunity, cell proliferation, and differentiation, hence playing a specific function in intestinal diseases. In recent years, gut microbes have become a research hotspot in the pharmaceutical field. Because of their enormous number, diversity, and functional complexity, gut microbes have essential functions in the development of many digestive diseases. Inflammatory bowel disease (IBD) is a chronic non-specific inflammatory disease with a complex etiology, the exact cause and pathogenesis are unclear. There are no medicines that can cure IBD, and more research on therapeutic drugs is urgently needed. It has been reported that gut microbes play a critical role in pathogenesis, and there is a tight and complex association between gut microbes and IBD. The dysregulation of gut microbes may be a predisposing factor for IBD, and at the same time, IBD may exacerbate gut microbes' disorders, but the mechanism of interaction between the two is still not well defined. The study of the relationship between gut microbes and IBD is not only important to elucidate the pathogenesis but also has a positive effect on the treatment based on the regimen of regulating gut microbes. This review describes the latest research progress on the functions of gut microbes and their relationship with IBD, which can provide reference and assistance for further research. It may provide a theoretical basis for the application of probiotics, fecal microbiota transplantation, and other therapeutic methods to regulate gut microbes in IBD.

Faecalibacterium: a bacterial genus with promising human health applications

In humans, many diseases are associated with alterations in gut microbiota, namely increases or decreases in the abundance of specific bacterial groups. One example is the genus Faecalibacterium. Numerous studies have underscored that low levels of Faecalibacterium are correlated with inflammatory conditions, with inflammatory bowel disease (IBD) in the forefront. Its representation is also diminished in the case of several diseases, including colorectal cancer (CRC), dermatitis, and depression. Additionally, the relative presence of this genus is considered to reflect, at least in part, intestinal health status because Faecalibacterium is frequently present at reduced levels in individuals with gastrointestinal diseases or disorders. In this review, we first thoroughly describe updates to the taxonomy of Faecalibacterium, which has transformed a single-species taxon to a multispecies taxon over the last decade. We then explore the links discovered between Faecalibacterium abundance and various diseases since the first IBD-focused studies were published. Next, we examine current available strategies for modulating Faecalibacterium levels in the gut. Finally, we summarize the mechanisms underlying the beneficial effects that have been attributed to this genus. Together, epidemiological and experimental data strongly support the use of Faecalibacterium as a next-generation probiotic (NGP) or live biotherapeutic product (LBP).

Over-production of exopolysaccharide by Lacticaseibacillus rhamnosus CNCM I-3690 strain cutbacks its beneficial effect on the host

Most lactobacilli produce extracellular polysaccharides that are considered to contribute to the probiotic effect of many strains. Lacticaseibacillus rhamnosus CNCM I-3690 is an anti-inflammatory strain able to counterbalance gut barrier dysfunction. In this study ten spontaneous variants of CNCM I-3690 with different EPS-production were generated and characterized by their ropy phenotype, the quantification of the secreted EPS and genetic analysis. Amongst them, two were further analysed in vitro and in vivo: an EPS over-producer (7292) and a low-producer derivative of 7292 (7358, with similar EPS levels than the wild type (WT) strain). Our results showed that 7292 does not have anti-inflammatory profile in vitro, and lost the capacity to adhere to the colonic epithelial cells as well as the protective effect on the permeability. Finally, 7292 lost the protective effects of the WT strain in a murine model of gut dysfunction. Notably, strain 7292 was unable to stimulate goblet cell mucus production and colonic IL-10 production, all key features for the beneficial effect of the WT strain. Furthermore, transcriptome analysis of colonic samples from 7292-treated mice showed a down-regulation of anti-inflammatory genes. Altogether, our results point out that the increase of EPS production in CNCM I-3690 impairs its protective effects and highlight the importance of the correct EPS synthesis for the beneficial effects of this strain.

ApoE Mimetic Peptides to Improve the Vicious Cycle of Malnutrition and Enteric Infections by Targeting the Intestinal and Blood-Brain Barriers

Apolipoprotein E (apoE) mimetic peptides are engineered fragments of the native apoE protein’s LDL-receptor binding site that improve the outcomes following a brain injury and intestinal inflammation in a variety of models. The vicious cycle of enteric infections and malnutrition is closely related to environmental-driven enteric dysfunction early in life, and such chronic inflammatory conditions may blunt the developmental trajectories of children with worrisome and often irreversible physical and cognitive faltering. This window of time for microbiota maturation and brain plasticity is key to protecting cognitive domains, brain health, and achieving optimal/full developmental potential. This review summarizes the potential role of promising apoE mimetic peptides to improve the function of the gut-brain axis, including targeting the blood-brain barrier in children afflicted with malnutrition and enteric infections.

The modulatory effects of gut microbes and metabolites on blood–brain barrier integrity and brain function in sepsis-associated encephalopathy

Background

Intestinal microbiota homeostasis and the gut-brain axis are key players associated with host health and alterations in metabolic, inflammatory, and neurodegenerative disorders. Sepsis-associated encephalopathy (SAE), which is closely associated with bacterial translocation, is a common secondary organ dysfunction and an urgent, unsolved problem affecting patient quality of life. Our study examined the neuroprotective effects of the gut microbiome and short-chain fatty acid (SCFA) metabolites on SAE.

Methods

Male C57BL/6 mice were administered SCFAs in drinking water, then subjected to cecal ligation and puncture (CLP) surgery to induce SAE. 16S rRNA sequencing was used to investigate gut microbiome changes. The open field test (OFT) and Y-maze were performed to evaluate brain function. The permeability of the blood–brain barrier (BBB) was assessed by Evans blue (EB) staining. Hematoxylin and eosin (HE) staining was used to examine intestinal tissue morphology. The expression levels of tight junction (TJ) proteins and inflammatory cytokines was assessed by western blots and immunohistochemistry. In vitro, bEND.3 cells were incubated with SCFAs and then with lipopolysaccharide (LPS). Immunofluorescence was used to examine the expression of TJ proteins.

Results

The composition of the gut microbiota was altered in SAE mice; this change may be related to SCFA metabolism. SCFA treatment significantly alleviated behavioral dysfunction and neuroinflammation in SAE mice. SCFAs upregulated occludin and ZO-1 expression in the intestine and brain in SAE mice and LPS-treated cerebromicrovascular cells.

Conclusions

These findings suggested that disturbances in the gut microbiota and SCFA metabolites play key roles in SAE. SCFA supplementation could exert neuroprotective effects against SAE by preserving BBB integrity.

Endogenous small intestinal microbiome determinants of transient colonisation efficiency by bacteria from fermented dairy products: a randomised controlled trial

BACKGROUND

The effects of fermented food consumption on the small intestine microbiome and its role on host homeostasis are largely uncharacterised as our knowledge on intestinal microbiota relies mainly on faecal samples analysis. We investigated changes in small intestinal microbial composition and functionality, short chain fatty acid (SCFA) profiles, and on gastro-intestinal (GI) permeability in ileostomy subjects upon the consumption of fermented milk products.

RESULTS

We report the results from a randomised, cross-over, explorative study where 16 ileostomy subjects underwent 3, 2-week intervention periods. In each period, they consumed either milk fermented by Lacticaseibacillus rhamnosus CNCM I-3690, or milk fermented by Streptococcus thermophilus CNCM I-1630 and Lactobacillus delbrueckii subsp. bulgaricus CNCM I-1519, or a chemically acidified milk (placebo) daily. We performed metataxonomic, metatranscriptomic analysis, and SCFA profiling of ileostomy effluents as well as a sugar permeability test to investigate the microbiome impact of these interventions and their potential effect on mucosal barrier function. Consumption of the intervention products impacted the overall small intestinal microbiome composition and functionality, mainly due to the introduction of the product-derived bacteria that reach in several samples 50% of the total microbial community. The interventions did not affect the SCFA levels in ileostoma effluent, or gastro-intestinal permeability and the effects on the endogenous microbial community were negligible. The impact on microbiome composition was highly personalised, and we identified the poorly characterised bacterial family, Peptostreptococcaceae, to be positively associated with a low abundance of the ingested bacteria. Activity profiling of the microbiota revealed that carbon- versus amino acid-derived energy metabolism of the endogenous microbiome could be responsible for the individual-specific intervention effects on the small intestine microbiome composition and function, reflected also on urine microbial metabolites generated through proteolytic fermentation.

CONCLUSIONS

The ingested bacteria are the main drivers of the intervention effect on the small intestinal microbiota composition. Their transient abundance level is highly personalised and influenced by the energy metabolism of the ecosystem that is reflected by its microbial composition ( http://www.

CLINICALTRIALS

gov , ID NCT NCT02920294). Video Abstract.

The Potential Therapeutic Role of Lactobacillaceae rhamnosus for Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a heterogeneous group of diseases associated with chronic inflammation of the intestinal tract, and is highly prevalent worldwide. Although its origin is not yet fully understood, new evidence emphasizes that environmental factors, especially dietary factors and intestinal microbiota disorders are key triggers of IBD. Probiotics, such as Lactobacillaceae spp., play an essential role in human health as they exert beneficial effects on the composition of the human gastrointestinal microbial community and immune system. Probiotic-based therapies have been shown to be effective in alleviating IBD. Among these, Lactobacillaceae rhamnosus is one of the most widely used strains. L. rhamnosus is widely present in the intestines of healthy individuals; it regulates the intestinal immune system and reduces inflammation through a variety of mechanisms. The purpose of this study was to identify scientific evidence related to L. rhamnosus and IBD, review and summarize the results, and discuss the possible mechanisms of action as a starting point for future research on IBD treatment.

Complete Genome Sequences of Eight Faecalibacterium sp. Strains Isolated from Healthy Human Stool

Eight Faecalibacterium sp. strains were isolated from feces of healthy human volunteers. Here, we describe their genome sequences. The genome sizes ranged from 2.78 Mbp to 3.23 Mbp, with an average GC content of 56.6% and encoding 2,795 protein-coding genes on average.

Inflammatory Bowel Disease: A focus on the Role of Probiotics in Ulcerative Colitis

Inflammatory bowel disease (IBD) is a cluster of disorders of the gastrointestinal tract characterized by chronic inflammation and imbalance of the gut microbiota in a genetically vulnerable host. Crohn’s disease and ulcerative colitis (UC) are well-known types of IBD, and due to its high prevalence, IBD has attracted the attention of researchers globally. The exact etiology of IBD is still unknown; however, various theories have been proposed to provide some explanatory clues that include gene-environment interactions and dysregulated immune response to the intestinal microbiota. These diseases are manifested by several clinical symptoms that depend on the affected segment of the intestine such as diarrhea, abdominal pain, and rectal bleeding. In this era of personalized medicine, various options are developing starting from improved intestinal microecology, small molecules, exosome therapy, to lastly stem cell transplantation. From another aspect, and in parallel to pharmacological intervention, nutrition, and dietary support have shown effectiveness in IBD management. There is an increasing evidence supporting the benefit of probiotics in the prophylaxis and treatment of IBD. There are several studies that have demonstrated that different probiotics alleviate UC. The present review summarizes the progress in the IBD studies focusing and exploring more on the role of probiotics as a potential adjunct approach in UC management.

L. rhamnosus CNCM I-3690 survival, adaptation, and small bowel microbiome impact in human

Fermented foods and beverages are a significant source of dietary bacteria that enter the gastrointestinal (GI) tract. However, little is known about how these microbes survive and adapt to the small intestinal environment. Colony-forming units (CFU) enumeration and viability qPCR of Lacticaseibacillus rhamnosus CNCM I-3690 in the ileal effluent of 10 ileostomy subjects during 12-h post consumption of a dairy product fermented with this strain demonstrated the high level of survival of this strain during human small intestine passage. Metatranscriptome analyses revealed the in situ transcriptome of L. rhamnosus in the small intestine, which was contrasted with transcriptome data obtained from in vitro cultivation. These comparative analyses revealed substantial metabolic adaptations of L. rhamnosus during small intestine transit, including adjustments of carbohydrate metabolism, surface-protein expression, and translation machinery. The prominent presence of L. rhamnosus in the effluent samples did not elicit an appreciable effect on the composition of the endogenous small intestine microbiome, but significantly altered the ecosystem's overall activity profile, particularly of pathways associated with carbohydrate metabolism. Strikingly, two of the previously recognized gut-brain metabolic modules expressed in situ by L. rhamnosus (inositol degradation and glutamate synthesis II) are among the most dominantly enriched activities in the ecosystem's activity profile. This study establishes the survival capacity of L. rhamnosus in the human small intestine and highlights its functional adjustment in situ, which we postulate to play a role in the probiotic effects associated with this strain.

The efficacy of probiotics on the prevention of pouchitis for patients after ileal pouch-anal anastomosis: A meta-analysis

BACKGROUND

To date, a few studies indicated that probiotics are beneficial to pouchitis, but no meta-analyses summarized the outcomes of probiotics in pouchitis in detail.

OBJECTIVE

This meta-analysis discusses probiotics in the prevention of pouchitis for patients after ileal pouch-anal anastomosis (IPAA) and the relationship between probiotics preventive effect and the duration of therapy and history.

METHODS

PubMed, EMBASE and Cochrane Library databases were searched from inception until February 2022. Risk ratio (RR), mean difference (MD) and their 95% confidence interval (CI) were analyzed by Review Manager 5.3. The subgroup analysis was also performed to explore the agent for influencing outcomes.

RESULTS

A total of 8 studies were included in this meta-analysis. The incidence of pouchitis in probiotics was significantly lower than that in the control (RR = 0.19, 95%CI [0.12, 0.32], P⁢ï⁢¼⁢ 0.00001), and the PDAI (pouchitis disease activity index) in probiotics was also significantly lower (MD =-5.65, 95%CI [-9.48, -1.83]). After the subgroup analysis, we found that probiotics work better in the short-term (RR = 0.12, 95%CI [0.04, 0.40], P= 0.0004), but may not achieve the desired effect in the long-term (RR = 1.20, 95%CI [0.40, 3.60], P= 0.75).

CONCLUSIONS

Probiotics are beneficial in the prevention of pouchitis after IPAA, especially in the short-term.

Inflammatory bowel disease therapeutic strategies by modulation of the microbiota: how and when to introduce pre-, pro-, syn-, or postbiotics?

Inflammatory bowel diseases (IBD), a heterogeneous group of inflammatory conditions that encompass both ulcerative colitis and Crohn's disease, represent a major public health concern. The etiology of IBD is not yet fully understood and no cure is available, with current treatments only showing long-term effectiveness in a minority of patients. A need to increase our knowledge on IBD pathophysiology is growing, to define preventive measures, to improve disease outcome, and to develop new effective and lasting treatments. IBD pathogenesis is sustained by aberrant immune responses, associated with alterations of the intestinal epithelial barrier (IEB), modifications of the enteric nervous system, and changes in microbiota composition. Currently, most of the treatments target the inflammation and the immune system, but holistic approaches targeting lifestyle and diet improvements are emerging. As dysbiosis is involved in IBD pathogenesis, pre-, pro-, syn-, and postbiotics are used/tested to reduce the inflammation or strengthen the IEB. The present review will resume these works, pointing out the stage of life, the duration, and the environmental conditions that should go along with microbiota or microbiota-derived treatments.

Modulation of intestinal epithelial cell proliferation and apoptosis by Lactobacillus gasseri SF1183

The gut microbiota exerts a variety of positive effects on the intestinal homeostasis, including the production of beneficial molecules, control of the epithelial barrier integrity and the regulation of the balance between host's cell death and proliferation. The interactions between commensal bacteria and intestinal cells are still under-investigated and is then of paramount importance to address such interactions at the molecular and cellular levels. We report an in vitro analysis of the effects of molecules secreted by Lactobacillus gasseri SF1183 on HCT116 cells, selected as a model of intestinal epithelial cells. SF1183 is a L. gasseri strain isolated from an ileal biopsy of a human healthy volunteer, able to prevent colitis symptoms in vivo. Expanding previous findings, we show that bioactive molecules secreted by SF1183 reduce the proliferation of HCT116 cells in a reversible manner determining a variation in cell cycle markers (p21WAF, p53, cyclin D1) and resulting in the protection of HCT116 cells from TNF-alfa induced apoptosis, an effect potentially relevant for the protection of the epithelial barrier integrity and reconstitution of tissue homeostasis. Consistently, SF1183 secreted molecules increase the recruitment of occludin, a major component of TJ, at the cell-cell contacts, suggesting a reinforcement of the barrier function.

Serpin-positive Bifidobacterium breve CNCM I-5644 improves intestinal permeability in two models of irritable bowel syndrome

Probiotic supplementation can help to mitigate the pathogenesis of irritable bowel syndrome (IBS) by reinforcing the intestinal barrier, and reducing both inflammation and proteolytic activity. Here, a combination of in vitro tests was performed on 33 Bifidobacterium strains as probiotic candidates for IBS. In addition to the classical tests performed, the detection of the serine protease inhibitor (serpin) enzyme capable of decreasing the high proteolytic activity found in IBS patients was included. Three serpin-positive strains were selected: Bifidobacterium breve CNCM I-5644, Bifidobacterium longum subsp. infantis CNCM I-5645 and B. longum CNCM I-5646 for their immunomodulation properties and protection of intestinal epithelial integrity in vitro. Furthermore, we found that B. breve CNCM I-5644 strain prevented intestinal hyperpermeability by upregulating Cingulin and Tight Junction Protein 1 mRNA levels and reducing pro-inflammatory markers. The ability of CNCM I-5644 strain to restore intestinal hyperpermeability (FITC-dextran) was shown in the murine model of low-grade inflammation induced by dinitrobenzene sulfonic acid (DNBS). This effect of this strain was corroborated in a second model of IBS, the neonatal maternal separation model in mice. Altogether, these data suggest that serpin-positive B. breve CNCM I-5644 may partially prevent disorders associated with increased barrier permeability such as IBS.

Gut-liver axis: Pathophysiological concepts and clinical implications

Bidirectional crosstalk along the gut-liver axis controls gastrointestinal health and disease and exploits environmental and host mediators. Nutrients, microbial antigens, metabolites, and bile acids regulate metabolism and immune responses in the gut and liver, which reciprocally shape microbial community structure and function. Perturbation of such host-microbe interactions is observed in a variety of experimental liver diseases and is facilitated by an impaired intestinal barrier, which is fueling hepatic inflammation and disease progression. Clinical evidence describes perturbation of the gut-liver crosstalk in non-alcoholic fatty liver disease, alcoholic liver disease, and primary sclerosing cholangitis. In liver cirrhosis, a common sequela of these diseases, the intestinal microbiota and microbial pathogen-associated molecular patterns constitute liver inflammation and clinical complications, such as hepatic encephalopathy. Understanding the intricate metabolic interplay between the gut and liver in health and disease opens an avenue for targeted therapies in the future, which is probed in controlled clinical trials.

Gut microbiome and human health: Exploring how the probiotic genus Lactobacillus modulate immune responses

The highest density of microbes resides in human gastrointestinal tract, known as “Gut microbiome”. Of note, the members of the genus Lactobacillus that belong to phyla Firmicutes are the most important probiotic bacteria of the gut microbiome. These gut-residing Lactobacillus species not only communicate with each other but also with the gut epithelial lining to balance the gut barrier integrity, mucosal barrier defence and ameliorate the host immune responses. The human body suffers from several inflammatory diseases affecting the gut, lungs, heart, bone or neural tissues. Mounting evidence supports the significant role of Lactobacillus spp. and their components (such as metabolites, peptidoglycans, and/or surface proteins) in modulatingimmune responses, primarily through exchange of immunological signals between gastrointestinal tract and distant organs. This bidirectional crosstalk which is mediated by Lactobacillus spp. promotes anti-inflammatory response, thereby supporting the improvement of symptoms pertaining to asthma, chronic obstructive pulmonary disease (COPD), neuroinflammatory diseases (such as multiple sclerosis, alzheimer’s disease, parkinson’s disease), cardiovascular diseases, inflammatory bowel disease (IBD) and chronic infections in patients. The metabolic disorders, obesity and diabetes are characterized by a low-grade inflammation. Genus Lactobacillus alleviates metabolic disorders by regulating the oxidative stress response and inflammatory pathways. Osteoporosis is also associated with bone inflammation and resorption. The Lactobacillus spp. and their metabolites act as powerful immune cell controllers and exhibit a regulatory role in bone resorption and formation, supporting bone health. Thus, this review demonstrated the mechanisms and summarized the evidence of the benefit of Lactobacillus spp. in alleviating inflammatory diseases pertaining to different organs from animal and clinical trials. The present narrative review explores in detail the complex interactions between the gut-dwelling Lactobacillus spp. and the immune components in distant organs to promote host’s health.

The Protective Effects of Nutraceutical Components in Methotrexate-Induced Toxicity Models—An Overview

There are multiple concerns associated with methotrexate (MTX), widely recognized for anti-neoplastic and anti-inflammatory effects in life-threatening disease conditions, i.e., acute lymphoblastic leukemia, non-Hodgkin’s lymphoma, psoriasis, and rheumatoid arthritis, due to long-term side effects and associated toxicity, which limits its valuable potential. MTX acts as an inhibitor of dihydrofolate reductase, leading to suppression of purine and pyrimidine synthesis in high metabolic and turnover cells, targeting cancer and dysregulated immune cells. Due to low discrimination between neoplastic cells and naturally high turnover cells, MTX is prone to inhibiting the division of all fast-dividing cells, causing toxicity in multiple organs. Nutraceutical compounds are plant-based or food-derived compounds, used for their preventive and therapeutic role, ascertained in multiple organ dysfunctions, including cardiovascular disease, ischemic stroke, cancer, and neurodegenerative diseases. Gut microbiota and microbiota-derived metabolites take part in multiple physiological processes, their dysregulation being involved in disease pathogenesis. Modulation of gut microbiota by using nutraceutical compounds represents a promising therapeutic direction to restore intestinal dysfunction associated with MTX treatment. In this review, we address the main organ dysfunctions induced by MTX treatment, and modulations of them by using nutraceutical compounds. Moreover, we revealed the protective mechanisms of nutraceuticals in MTX-induced intestinal dysfunctions by modulation of gut microbiota.

A Multi-Strain Probiotic Formulation Improves Intestinal Barrier Function by the Modulation of Tight and Adherent Junction Proteins

In healthy individuals, tight junction proteins (TJPs) maintain the integrity of the intestinal barrier. Dysbiosis and increased intestinal permeability are observed in several diseases, such as inflammatory bowel disease. Many studies highlight the role of probiotics in preventing intestinal barrier dysfunction. The present study aims to investigate the effects of a commercially available probiotic formulation of L. rhamnosus LR 32, B. lactis BL 04, and B. longum BB 536 (Serobioma, Bromatech s.r.l., Milan, Italy) on TJPs and the integrity of the intestinal epithelial barrier, and the ability of this formulation to prevent lipopolysaccharide-induced, inflammation-associated damage. An in vitro model of the intestinal barrier was developed using a Caco-2 cell monolayer. The mRNA expression levels of the TJ genes were analyzed using real-time PCR. Changes in the amounts of proteins were assessed with Western blotting. The effect of Serobioma on the intestinal epithelial barrier function was assessed using transepithelial electrical resistance (TEER) measurements. The probiotic formulation tested in this study modulates the expression of TJPs and prevents inflammatory damage. Our findings provide new insights into the mechanisms by which probiotics are able to prevent damage to the gut epithelial barrier.

Evaluating Opicapone as Add-on Treatment to Levodopa/DDCI in Patients with Parkinson's Disease

COMT (catechol-O-methyltransferase) inhibitors are key therapeutic agents in the management of motor fluctuations (MF) in patients with Parkinson's disease (PD). As levodopa/DDCI add-on therapy, their main benefit lies in increasing ON-time and reducing OFF-time for PD patients in the middle stages of the disease. Two of the three available COMT inhibitors, tolcapone and entacapone, have been approved for over two decades. Opicapone, a third-generation COMT inhibitor approved in 2016, was designed with the aim of overcoming specific challenges of the earlier generation compounds, specifically hepatotoxicity and short effect duration. This review aims at highlighting the specific properties and characteristics of opicapone, namely combining efficacy with good tolerability as demonstrated in the registration studies and since then confirmed under real-world conditions. Opicapone has been shown to be effective in patients with early, as well as late motor fluctuations. Whilst patients in the earlier Hoehn and Yahr stages benefit more than patients in later stages, the incidence of dyskinesia in patients with recent onset MF is around half that of patients with more established fluctuations. With the added advantage of a once-daily administration, this particular COMT inhibitor provides a simple, yet effective therapy for patients with Parkinson's disease and MF.

Improved gut microbiome recovery following drug therapy is linked to abundance and replication of probiotic strains

Probiotics have been used for decades to alleviate the negative side-effects of oral antibiotics, but our mechanistic understanding on how they work is so far incomplete. Here, we performed a metagenomic analysis of the fecal microbiota in participants who underwent a 14-d Helicobacter pylori eradication therapy with or without consumption of a multi-strain probiotic intervention (L. paracasei CNCM I-1518, L. paracasei CNCM I-3689, L. rhamnosus CNCM I-3690, and four yogurt strains) in a randomized, double-blinded, controlled clinical trial. Using a strain-level analysis for detection and metagenomic determination of replication rate, ingested strains were detected and replicated transiently in fecal samples and in the gut during and following antibiotic administration. Consumption of the fermented milk product led to a significant, although modest, improvement in the recovery of microbiota composition. Stratification of participants into two groups based on the degree to which their microbiome recovered showed i) a higher fecal abundance of the probiotic L. paracasei and L. rhamnosus strains and ii) an elevated replication rate of one strain (L. paracasei CNCMI-1518) in the recovery group. Collectively, our findings show a small but measurable benefit of a fermented milk product on microbiome recovery after antibiotics, which was linked to the detection and replication of specific probiotic strains. Such functional insight can form the basis for the development of probiotic-based intervention aimed to protect gut microbiome from drug treatments.

Bile Salt Hydrolase-Competent Probiotics in the Management of IBD: Unlocking the "Bile Acid Code"

Bile acid (BA) species and the gut microbiota (GM) contribute to intestinal mucosa homeostasis. BAs shape the GM and, conversely, intestinal bacteria with bile salt hydrolase (BSH) activity modulate the BA pool composition. The mutual interaction between BAs and intestinal microorganisms also influences mucosal barrier integrity, which is important for inflammatory bowel disease (IBD) pathogenesis, prevention and therapy. High levels of secondary BAs are detrimental for the intestinal barrier and increase the intestinal inflammatory response and dysbiosis. Additionally, a lack of BSH-active bacteria plays a role in intestinal inflammation and BA dysmetabolism. Thus, BSH-competent bacteria in probiotic formulations are being actively studied in IBD. At the same time, studies exploring the modulation of the master regulator of BA homeostasis, the Farnesoid X Receptor (FXR), in intestinal inflammation and how this impacts the GM are gaining significant momentum. Overall, the choice of probiotic supplementation should be a peculiar issue of personalized medicine, considering not only the disease but also the specific BA and metabolic signatures of a given patient.

Leaky Gut in IBD: Intestinal Barrier-Gut Microbiota Interaction

Inflammatory bowel disease (IBD) is a global disease that is in increasing incidence. The gut, which contains the largest amount of lymphoid tissue in the human body, as well as a wide range of nervous system components, is integral in ensuring intestinal homeostasis and function. By interacting with gut microbiota, immune cells, and the enteric nervous system, the intestinal barrier, which is a solid barrier, protects the intestinal tract from the external environment, thereby maintaining homeostasis throughout the body. Destruction of the intestinal barrier is referred to as developing a "leaky gut," which causes a series of changes relating to the occurrence of IBD. Changes in the interactions between the intestinal barrier and gut microbiota are particularly crucial in the development of IBD. Exploring the leaky gut and its interaction with the gut microbiota, immune cells, and the neuroimmune system may help further explain the pathogenesis of IBD and provide potential therapeutic methods for future use.

Gut Microbes in Gynecologic Cancers: Causes or Biomarkers and Therapeutic Potential

The human intestine is home to a variety of microorganisms. In healthy populations, the intestinal flora shares a degree of similarity and stability, and they have a role in the metabolism, immunological response, and physiological function of key organs. With the rapid advent of high-throughput sequencing in recent years, several researchers have found that dysbiosis of the human gut microflora potentially cause physical problems and gynecological malignancies among postmenopausal women. Besides, dysbiosis hinders tumor treatment. Nonetheless, the importance of maintaining homeostatic gut microbiota and the effective use of probiotics in the treatment of gynecological malignancies should not be disregarded. Moreover, intestinal flora regulation and the involvement of probiotics as well as associated biologically active substances in gynecological malignancies could be an adjuvant treatment modality related to surgery and chemoradiotherapy in the future. Herein, this article aims to review the potential relationship between gut microorganisms and postmenopausal status as well as gynecologic malignancies; then the relationship between gut microbes and early screening as well as therapeutic aspects. Also, we describe the role of probiotics in the prevention, treatment, and prognosis of gynecologic malignancies.