Regulation of Peripheral Inflammation by a Non-Viable, Non-Colonizing Strain of Commensal Bacteria

Betaine alleviates deficits in motor behavior, neurotoxic effects, and neuroinflammatory responses in a rat model of demyelination

Multiple sclerosis (MS) is characterized as a chronic inflammatory demyelinating neurodegenerative disorder that leads to the deterioration of the myelin sheath and the loss of axons. Betaine, a trimethylglycine compound, is recognized for its ability to penetrate the blood-brain barrier (BBB) and exhibits properties that are antioxidant, anti-inflammatory, and neuroprotective. The cuprizone (CPZ) model serves as an effective tool for investigating the processes of demyelination and remyelination associated with MS. In our research, we examined the protective and therapeutic effects of betaine in a rat model of MS induced by CPZ. The experimental protocol involved administering 600 mg/kg of CPZ orally for 7 days, followed by 2 weeks with 200 mg/kg of CPZ. The protective group received a combination of betaine (1 g/kg/day, orally) and CPZ (200 mg/kg/day), while the therapeutic group was treated with CPZ (600 mg/kg) alongside betaine for three weeks. Behavioral assessments were conducted using inverted screen and rotarod tests to measure balance, motor coordination, and grasping ability. Following these evaluations, the rats were euthanized for analysis of oxidative stress and inflammatory biomarkers, toluidine blue staining, transmission electron microscopy (TEM) imaging, and myelin basic protein (MBP) immunostaining of the corpus callosum (CC). The results indicated that betaine significantly enhanced balance, motor coordination, and grasping ability, while decreasing oxidative stress, inhibiting interleukin (IL)-4 and IL-17 levels, and reversing the demyelination caused by CPZ. Notably, betaine also mitigated the increase in homocysteine (Hcy) levels and facilitated remyelination, evidenced by the presence of normal compacted myelin and increased expression of MBP in the CC. This study substantiates the remyelinating effects of betaine in the context of CPZ-induced demyelination. It suggests that it may contribute to the repair of myelin through the modulation of behavioral deficits, oxidative stress, neuroinflammation, ultrastructural changes, and MBP expression levels, indicating its potential as a complementary therapeutic agent in the management of MS.

Research progress on the interaction between intestinal flora and microRNA in pelvic inflammatory diseases

Pelvic inflammatory disease (PID) is a common infectious disease of the female upper reproductive tract, and its pathological basis is immune inflammatory response. The imbalance of gut microflora (GM) may lead to the development of inflammatory process. A large number of studies have shown that fecal microbiota transplantation, probiotics, bacteria, prebiotics, and dietary intervention may play a potential role in remodeling GM and treating diseases. MicroRNAs (miRNAs) are involved in cell development, proliferation, apoptosis and other physiological processes. In addition, they play an important role in the inflammatory process, participating in the regulation of proinflammatory and anti-inflammatory pathways. Differences in miRNA profiles may be PID diagnostic tools and serve as prognostic markers of the disease. The relationship between miRNA and GM has not been fully elucidated. Recent studies have shown the role of miRNA in the regulation and induction of GM dysbiosis. In turn, microbiota can regulate the expression of miRNA and improve the immune status of the body. Therefore, this review aims to describe the interaction between GM and miRNA in PID, and to find potential precise targeted therapy for PID.

Melanoidins from Shanxi aged vinegar: Characterization and behavior after in vitro simulated digestion and colonic fermentation

This study aims to elucidate the structure, physicochemical properties, and potential behavior of vinegar melanoidins (VM) during digestion and intestinal microbial fermentation in vitro. Our findings revealed that VM mainly consisted of carbohydrates. The particle size (166.46 ± 10.06 nm) of VM was significantly larger than that of model melanoidins (MM, 20.69 ± 0.05 nm). VM exhibited stability in vitro digestion process. However, the carbohydrate contents and Mw were reduced. Total phenol content (TPC), total flavonoid content (TFC), antioxidant capacity and SCFAs were significantly increased after colonic fermentation. TPC and TFC were 79.48 ± 9.52 mg GAE/g DW and 0.422 ± 0.024 mg RE/g DW at 48 h. In addition, VM exhibited intestinal modulatory effects on the microbiota by promoting an increase in beneficial bacteria including Firmicutes and Bifidobacterium. Collectively, these results suggest that VM as a potential prebiotic can be applied in the field of functional food.

Probiotics combined with prebiotics alleviated seasonal allergic rhinitis by altering the composition and metabolic function of intestinal microbiota: a prospective, randomized, double-blind, placebo-controlled clinical trial

Background

Numerous studies have established that probiotics or prebiotics can relieve the symptoms of allergic rhinitis (AR), but their mechanism of action remain underexplored. This study aimed to observe the clinical efficacy of probiotics combined with prebiotics in seasonal AR patients and explore their underlying mechanisms.

Methods

We conducted a prospective, randomized, double-blind, placebo-controlled clinical trial. The test group was given probiotics combined with prebiotics, whereas the placebo group was administered simulated preparation for 90 days. Outcome measures included total nasal symptom score (TNSS), visual analog scale, rhinitis quality of life questionnaire, fractional exhaled nitric oxide, and the rate and intensity of Loratadine use. Serum TNF-α, INF-γ, IL-4, IL-17, and IgE levels were measured by enzyme-linked immunosorbent assay. Intestinal microbiota was detected by 16S rRNA gene sequencing and quantitative PCR. Short-chain fatty acids were analyzed by gas chromatography-mass spectrometry.

Results

106 participants (N = 53 for both test group and placebo group) completed the study. From baseline to day 91, mean difference between groups (MDBG) in the reduction of TNSS was -1.1 (-2.2, -0.1) (P = 0.04); MDBG in the increment of TNF-α was 7.1 pg/ml (95% CI: 0.8, 13.4, P = 0.03); the INF-γ level was significantly increased (P = 0.01), whereas that of IL-17 (P = 0.005) was significantly decreased in the test group, whilst mean difference within groups was not statistically significant in the placebo group; MDBG in the increment of acetate was 12.4% (95% CI: 7.1%, 17.6%, P <0.001). After the administration of probiotics and prebiotics, the composition and metabolic function of the intestinal microbiota were significantly altered and positively related to the beneficial effect on seasonal AR patients.

Conclusion

Probiotics combined with prebiotics administered for 90 days significantly attenuated the symptoms of seasonal AR patients, which may related to fluctuations in the composition and metabolic function of the intestinal microbiota and further ameliorating host immunity.

A dynamic atlas of immunocyte migration from the gut

Dysbiosis in the gut microbiota affects several systemic diseases, possibly by driving the migration of perturbed intestinal immunocytes to extraintestinal tissues. Combining Kaede photoconvertible mice and single-cell genomics, we generated a detailed map of migratory trajectories from the colon, at baseline, and in several models of intestinal and extraintestinal inflammation. All lineages emigrated from the colon in an S1P-dependent manner. B lymphocytes represented the largest contingent, with the unexpected circulation of nonexperienced follicular B cells, which carried a gut-imprinted transcriptomic signature. T cell emigration included distinct groups of RORγ+ and IEL-like CD160+ subsets. Gut inflammation curtailed emigration, except for dendritic cells disseminating to lymph nodes. Colon-emigrating cells distributed differentially to distinct sites of extraintestinal models of inflammation (psoriasis-like skin, arthritic synovium, and tumors). Thus, specific cellular trails originating in the gut and influenced by microbiota may shape peripheral immunity in varied ways.

Immune Portrayal of a New Therapy Targeting Microbiota in an Animal Model of Psoriasis

BACKGROUND

Despite all the available treatments, psoriasis remains incurable; therefore, finding personalized therapies is a continuous challenge. Psoriasis is linked to a gut microbiota imbalance, highlighting the importance of the gut-skin axis and its inflammatory mediators. Restoring this imbalance can open new perspectives in psoriasis therapy. We investigated the effect of purified IgY raised against pathological human bacteria antibiotic-resistant in induced murine psoriatic dermatitis (PSO).

METHODS

To evaluate the immune portrayal in an imiquimod experimental model, before and after IgY treatment, xMAP array and flow cytometry were used.

RESULTS

There were significant changes in IL-1α,β, IL-5, IL-6, IL-9, IL-10, IL-12 (p70), IL-13, IL-15, IL-17a, IFN-γ, TNF-α, IP-10/CXCL10, MCP-1/CCL2, MIP-1α/CCL3, MIP-1β/CCL4, MIG/CXCL9, and KC/CXCL1 serum levels. T (CD3ε+), B (CD19+) and NK (NK1.1+) cells were also quantified. In our model, TNF-α, IL-6, and IL-1β cytokines and CXCL1 chemokine have extremely high circulatory levels in the PSO group. Upon experimental therapy, the cytokine serum values were not different between IgY-treated groups and spontaneously remitted PSO.

CONCLUSIONS

Using the murine model of psoriatic dermatitis, we show that the orally purified IgY treatment can lead to an improvement in skin lesion healing along with the normalization of cellular and humoral immune parameters.

Study of the Relationship between Mucosal Immunity and Commensal Microbiota: A Bibliometric Analysis

This study presents the first bibliometric evaluation and systematic analysis of publications related to mucosal immunity and commensal microbiota over the last two decades and summarizes the contribution of countries, institutions, and scholars in the study of this field. A total of 1423 articles related to mucosal immunity and commensal microbiota in vivo published in 532 journals by 7774 authors from 1771 institutions in 74 countries/regions were analyzed. The interaction between commensal microbiota in vivo and mucosal immunity is essential in regulating the immune response of the body, maintaining communication between different kinds of commensal microbiota and the host, and so on. Several hot spots in this field have been found to have received extensive attention in recent years, especially the effects of metabolites of key strains on mucosal immunity, the physiopathological phenomena of commensal microbiota in various sites including the intestine, and the relationship between COVID-19, mucosal immunity and microbiota. We hope that the full picture of the last 20 years in this research area provided in this study will serve to deliver necessary cutting-edge information to relevant researchers.

Clinical translation of anti-inflammatory effects of Prevotella histicola in Th1, Th2, and Th17 inflammation

Introduction

EDP1815 is a non-colonizing pharmaceutical preparation of a single stain of Prevotella histicola isolated from the duodenum of a human donor. We report here preclinical and clinical studies showing that the action of EDP1815, an orally delivered and gut restricted single strain of commensal bacteria can regulate inflammatory responses throughout the body.

Methods

Supported by evidence for anti-inflammatory activity in three preclinical mouse models of Th1-, TH2-, and Th17-mediated inflammation, EDP1815 was tested clinically in three Phase 1b studies in patients with psoriasis, patients with atopic dermatitis, and healthy volunteers in a KLH skin challenge model.

Results

Preclinically, EDP1815 was efficacious in all three mouse models of inflammation, showing reduction in skin inflammation as well as related tissue cytokines. In the Phase 1b studies, EDP1815 was found to be well tolerated by participants, with a safety profile comparable to placebo, including no severe or consistent side-effects reported, and no evidence of immunosuppression with no opportunistic infection occurring in these studies. In psoriasis patients, signs of clinical efficacy were seen after 4 weeks of treatment, which continued beyond the treatment period in the higher-dose cohort. In atopic dermatitis patients, improvements were seen throughout the key physician-and patient-reported outcomes. In a healthy-volunteer study of a KLH-induced skin inflammatory response, consistent anti-inflammatory effects were seen in two cohorts through imaging-based measures of skin inflammation.

Discussion

This is the first report demonstrating clinical effects from targeting peripheral inflammation with a non-colonizing gut-restricted single strain of commensal bacteria, providing proof of concept for a new class of medicines. These clinical effects occur without systemic exposure of EDP1815 or modification of the resident gut microbiota, and with placebo-like safety and tolerability. The breadth of these clinical effects of EDP1815, combined with its excellent safety and tolerability profile and oral administration, suggests the potential for a new type of effective, safe, oral, and accessible anti-inflammatory medicine to treat the wide range of diseases driven by inflammation.Clinical Trial Registration: EudraCT # 2018-002807-32; EudraCT # 2018-002807-32; NL8676; https://clinicaltrials.gov/ct2/show/NCT03733353; http://www.trialregister.nl.

Harnessing the small intestinal axis to resolve systemic inflammation

This Perspective presents the potential of the Small Intestinal Axis, a sub-division of the Gut-immune Axis, to modulate systemic inflammation based on sensing contents of the gut lumen. Gut mucosal immunity regulates tolerance to food and gut contents and is a significant factor in maintaining systemic homeostasis without compromising immunity to pathogens. This is achieved through anatomical structures and signaling pathways that link the tolerogenic potential of the proximal small intestine to systemic immunity. Non-live preparations of microbes isolated from human small intestinal mucosa, and the extracellular vesicles (EVs) which they shed, can resolve systemic inflammation without systemic exposure after oral delivery. The mechanism involves primary interactions with pattern recognition receptors followed by trafficking of immune cells through mesenteric lymph nodes. This generates in the periphery a population of circulating CD4+ T cells which have regulatory function but an atypical FoxP3- phenotype. There is no modification of the resident gut microbiome. Discoveries using this novel approach of targeting mucosal microbial elements to the tolerogenic proximal regions of the small intestine are revealing some of the mysteries of the relationship between the gut and immune system.