Lactobacillus sakei S1 Improves Colitis Induced by 2,4,6-Trinitrobenzene Sulfonic Acid by the Inhibition of NF-κB Signaling in Mice

Lactobacillus delbrueckii subsp. bulgaricus Alleviates Acute Injury in Hypoxic Mice

Acute mountain sickness (AMS) is a common ailment in high-altitude areas caused by the body's inadequate adaptation to low-pressure, low-oxygen environments, leading to organ edema, oxidative stress, and impaired intestinal barrier function. The gastrointestinal tract, being the first to be affected by ischemia and hypoxia, is highly susceptible to injury. This study investigates the role of Lactobacillus delbrueckii subsp. bulgaricus in alleviating acute hypoxic-induced intestinal and tissue damage from the perspective of daily consumed lactic acid bacteria. An acute hypoxia mouse model was established to evaluate tissue injury, oxidative stress, inflammatory responses, and intestinal barrier function in various groups of mice. The results indicate that strain 4L3 significantly mitigated brain and lung edema caused by hypoxia, improved colonic tissue damage, and effectively increased the content of tight junction proteins in the ileum, reducing ileal permeability and alleviating mechanical barrier damage in the intestines due to acute hypoxia. Additionally, 4L3 helped to rebalance the intestinal microbiota. In summary, this study found that Lactobacillus delbrueckii subsp. bulgaricus strain 4L3 could alleviate acute intestinal damage caused by hypoxia, thereby reducing hypoxic stress. This suggests that probiotic lactic acid bacteria that exert beneficial effects in the intestines may alleviate acute injury under hypoxic conditions in mice, offering new insights for the prevention and treatment of AMS.

Intraspecific difference of Latilactobacillus sakei in inflammatory bowel diseases: Insights into potential mechanisms through comparative genomics and metabolomics analyses

Inflammatory bowel diseases (IBDs) are chronic inflammatory diseases of the gastrointestinal tract that have become a global health burden. Studies have revealed that Latilactobacillus sakei can effectively alleviate various immune diseases, including colitis, rheumatoid arthritis, and metabolic disorders. Here, we obtained 72 strains of L. sakei from 120 fermentation and fecal samples across China. In total, 16 strains from different sources were initially screened in an in vitro Caco-2 model induced by dextran sulfate sodium. Subsequently, six strains (four exhibiting effectiveness and two exhibiting ineffectiveness) were selected for further validation in an in vivo colitis mouse model. The results demonstrated that L. sakei strains exhibited varying degrees of amelioration of the colitis disease process. Notably, L. sakei CCFM1267, the most effective strain, significantly restored colon length and tight-junction protein expression, and reduced the levels of cytokines and associated inflammatory enzymes. Moreover, L. sakei CCFM1267 upregulated the abundance of Enterorhabdus, Alloprevotella, and Roseburia, leading to increased levels of acetic acid and propionic acid. Conversely, the other four strains (L. sakei QJSSZ1L4, QJSSZ4L10, QGZZYRHMT1L6, and QGZZYRHMT2L6) only exhibited a partial remission effect, while L. sakei QJSNT1L10 displayed minimal impact. Therefore, L. sakei CCFM1267 and QJSNT1L10 were selected for further exploration of the mechanisms underlying their differential mitigating effects. Comparative genomics analysis revealed significant variations between the two strains, particularly in genes associated with carbohydrate-active enzymes, such as the glycoside hydrolase family, which potentially contribute to the diverse profiles of short-chain fatty acids in vivo. Additionally, metabolome analysis demonstrated that acetylcholine and indole-3-acetic acid were the main differentiating metabolites of the two strains. Therefore, the strains of L. sakei exhibited varying degrees of effectiveness in alleviating IBD-related symptoms, and the possible reasons for these variations were attributed to discrepancies in the carbohydrate-active enzymes and metabolites among the strains.

Multifunctional effects of Lactobacillus sakei HEM 224 on the gastrointestinal tract and airway inflammation

Mucosal tissues serve as the first defense line and their commensal microbiota play a role in sustaining of host health. This study aimed to isolate and evaluate a putative probiotic strain on various mucosal regions. Lactobacillus sakei HEM 224 was isolated from traditional Korean kimchi and identified. In the safety assessment L. sakei HEM 224 showed negative results for hemolysis, biogenic amine production and transferable antibiotic resistance. The probiotic potential of strain HEM 224 in diverse mucosal areas was shown in two different models, viz. a murine model with colitis induced by dextran sulfate sodium (DSS) and an allergic airway inflammation model induced by ovalbumin (OVA). In the colitis model, oral administration of L. sakei HEM 224 improved colitis physiology with immunomodulation, enhancing barrier components and gut microbiota alteration. In the allergic airway inflammation model, the intranasal administration of the strain decreased type 2 inflammation and enhanced epithelial barrier integrity from the airways. These results demonstrate that L. sakei HEM 224 can ameliorate inflammatory conditions in both the gastrointestinal and respiratory tracts through the reinforcement of the epithelial barrier and immunomodulation.

Lactic Acid Bacteria Isolated from Human Breast Milk Improve Colitis Induced by 2,4,6-Trinitrobenzene Sulfonic Acid by Inhibiting NF-κB Signaling in Mice

Inflammatory bowel disease (IBD), a chronic inflammatory disease, results from dysregulation of the immune responses. Some lactic acid bacteria (LAB), including Lactobacillus, alleviate IBD through immunomodulation. In this study, the anti-colitis effect of LAB isolated from human breast milk was investigated in a mouse model induced acute colitis with 2,4,6-trinitrobenzene sulfonic acid (TNBS). TNBS remarkably increased weight loss, colon shortening, and colonic mucosal proliferation, as well as the expression levels of inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α) and interleukin (IL)-1β. Oral administration of LAB isolated from human breast milk resulted in a reduction in TNBS-induced colon shortening, as well as induced cyclooxygenase (COX)-2, nitric oxide synthase (iNOS), nuclear factor-kappa B (NF-κB). In addition, LAB suppressed inflammatory cytokines such as TNF-α, IL-6, and IL-1β, and thus showed an effect of suppressing the level of inflammation induced by TNBS. Furthermore, LAB alleviated gut microbiota dysbiosis, and inhibited intestinal permeability by increasing the expression of intestinal tight junction protein including ZO-1. Collectively, these results suggest that LAB isolated from human breast milk can be used as a functional food for colitis treatment by regulating NF-κB signaling, gut microbiota and increasing expression of intestinal tight junction protein.

Oral Administration of Lactobacillus sakei CVL-001 Improves Recovery from Dextran Sulfate Sodium-Induced Colitis in Mice by Microbiota Modulation

Inflammatory bowel disease (IBD) is an intestinal chronic inflammatory disease, and its incidence is steadily increasing. IBD is closely related to the intestinal microbiota, and probiotics are known to be a potential therapeutic agent for IBD. In our study, we evaluated the protective effect of Lactobacillus sakei CVL-001, isolated from Baechu kimchi, on dextran sulfated sodium (DSS)-induced colitis in mice. The oral administration of L. sakei CVL-001 according to the experimental schedule alleviated weight loss and disease activity in the mice with colitis. Furthermore, the length and histopathology of the colon improved. The expression of tumor necrosis factor (TNF)-α and interleukin (IL)-1β genes decreased in the colons of mice that were administered L. sakei CVL-001, whereas that of IL-10 increased. The expressions of genes coding for E-cadherin, claudin3, occludin, and mucin were also restored. In co-housed conditions, L. sakei CVL-001 administration did not improve disease activity, colon length, and histopathology. Microbiota analysis revealed that L. sakei CVL-001 administration increased the abundance of microbiota and altered Firmicutes/Bacteroidetes ratio, and decreased Proteobacteria. In conclusion, L. sakei CVL-001 administration protects mice from DSS-induced colitis by regulating immune response and intestinal integrity via gut microbiota modulation.

Latilactobacillus sakei Furu2019 and stachyose as probiotics, prebiotics, and synbiotics alleviate constipation in mice

Introduction

Slow transit constipation (STC) is a common disorder in the digestive system. This study aimed to evaluate the effects of stachyose (ST) and Latilactobacillus sakei Furu 2019 (L. sakei) alone or combined on diphenoxylate-induced constipation and explore the underlying mechanisms using a mouse model.

Methods

ICR mice were randomly divided into five groups. The normal and constipation model groups were intragastrically administrated with PBS. The ST, L. sakei, and synbiotic groups were intragastrically administrated with ST (1.5 g/kg body weight), alive L. sakei (3 × 10⁹ CFU/mouse), or ST + L. sakei (1.5 g/kg plus 3 × 10⁹ CFU/mouse), respectively. After 21 days of intervention, all mice except the normal mice were intragastrically administrated with diphenoxylate (10 mg/kg body weight). Defecation indexes, constipation-related intestinal factors, serum neurotransmitters, hormone levels, short-chain fatty acids (SCFAs), and intestinal microbiota were measured.

Results

Our results showed that three interventions with ST, L. sakei, and synbiotic combination (ST + L. sakei) all alleviated constipation, and synbiotic intervention was superior to ST or L. sakei alone in some defecation indicators. The RT-PCR and immunohistochemical experiment showed that all three interventions relieved constipation by affecting aquaporins (AQP4 and AQP8), interstitial cells of Cajal (SCF and c-Kit), glial cell-derived neurotrophic factor (GDNF), and Nitric Oxide Synthase (NOS). The three interventions exhibited a different ability to increase the serum excitatory neurotransmitters and hormones (5-hydroxytryptamine, substance P, motilin), and reduce the serum inhibitory neurotransmitters (vasoactive intestinal peptide, endothelin). The result of 16S rDNA sequencing of feces showed that synbiotic intervention significantly increased the relative abundance of beneficial bacteria such as Akkermansia, and regulated the gut microbes of STC mice. In conclusion, oral administration of ST or L. sakei alone or combined are all effective to relieve constipation and the symbiotic use may have a promising preventive effect on STC.

Latilactobacillus sakei: a candidate probiotic with a key role in food fermentations and health promotion

Latilactobacillus sakei is used extensively in industrial production and food fermentations. The species is primarily derived from fermented meat and vegetable products and is also found in human feces. Genomics and metabolomics have revealed unique metabolic pathways in L. sakei and molecular mechanisms underlying its competitive advantages in different habitats, which are mostly attributed to its flexible carbohydrate metabolism, cold tolerance, acid and salt tolerance, ability to cope with oxygen changes, and heme uptake. In recent years, probiotic effects of L. sakei and its metabolites have been identified, including the ability to effectively alleviate metabolic syndrome, inflammatory bowel disease, and atopic dermatitis. This review summarizes the genomic and metabolic characteristics of L. sakei and its metabolites and describes their applications, laying a foundation for their expanded use across the food and healthcare industries.

Clostridium butyricum CB1 up-regulates FcRn expression via activation of TLR2/4-NF-κB signaling pathway in porcine small intestinal cells

The neonatal Fc receptor (FcRn) mediates the bidirectional transport of immunoglobulin G (IgG) across hyperpolarized epithelial cells. Overexpression of FcRn increases serum IgG and humoral immune response. Probiotics can improve the host's serum and intestinal mucosal IgG. However, whether probiotics regulate FcRn and its specific mechanism are still unclear. Our research showed that heat inactivated Clostridium butyricum CB1 (heat-inactivated CB1) up-regulated FcRn expression in porcine small intestinal epithelial (IPI-2I) cells. Furthermore, heat-inactivated CB1 stimulation activated the nuclear factor kappa B (NF-κB) signaling pathway. Moreover, FcRn expression decreased after blocking the NF-κB signaling pathway by NF-κB inhibitor BAY11-7028, suggesting that heat-inactivated CB1 induced FcRn expression via the NF-κB signaling pathway. Using small interfering RNAs (siRNAs), we found that knockdown of TLR2/4, MyD88 and TRIF reduced NF-κB activity induced by heat-inactivated CB1, as well as up-regulation of FcRn expression after heat-inactivated CB1 stimulation. Taken together, our data indicated that heat-inactivated CB1 up-regulated FcRn expression via TLR2/4-MyD88/TRIF-NF-κB signaling pathway. These results provided a new perspective for us to understand the enhancement of C. butyricum on intestinal mucosal immunity.

Regulation of Intestinal Inflammation by Dietary Fats

With the epidemic of human obesity, dietary fats have increasingly become a focal point of biomedical research. Epidemiological studies indicate that high-fat diets (HFDs), especially those rich in long-chain saturated fatty acids (e.g., Western Diet, National Health Examination survey; NHANES 'What We Eat in America' report) have multi-organ pro-inflammatory effects. Experimental studies have confirmed some of these disease associations, and have begun to elaborate mechanisms of disease induction. However, many of the observed effects from epidemiological studies appear to be an over-simplification of the mechanistic complexity that depends on dynamic interactions between the host, the particular fatty acid, and the rather personalized genetics and variability of the gut microbiota. Of interest, experimental studies have shown that certain saturated fats (e.g., lauric and myristic fatty acid-rich coconut oil) could exert the opposite effect; that is, desirable anti-inflammatory and protective mechanisms promoting gut health by unanticipated pathways. Owing to the experimental advantages of laboratory animals for the study of mechanisms under well-controlled dietary settings, we focus this review on the current understanding of how dietary fatty acids impact intestinal biology. We center this discussion on studies from mice and rats, with validation in cell culture systems or human studies. We provide a scoping overview of the most studied diseases mechanisms associated with the induction or prevention of Inflammatory Bowel Disease in rodent models relevant to Crohn's Disease and Ulcerative Colitis after feeding either high-fat diet (HFD) or feed containing specific fatty acid or other target dietary molecule. Finally, we provide a general outlook on areas that have been largely or scarcely studied, and assess the effects of HFDs on acute and chronic forms of intestinal inflammation.

Lactobacillus sakei suppresses collagen-induced arthritis and modulates the differentiation of T helper 17 cells and regulatory B cells

BACKGROUND

To evaluate the immunomodulatory effect of Lactobacillus sakei in a mouse model of rheumatoid arthritis (RA) and in human immune cells.

METHODS

We evaluated whether L. sakei reduced the severity of collagen-induced arthritis (CIA) and modulated interleukin (IL)-17 and IL-10 levels, as well as whether it affected the differentiation of CD4⁺ T cells and regulatory B cells. We evaluated osteoclastogenesis after culturing bone marrow-derived mononuclear cells with L. sakei.

RESULTS

The differentiation of T helper 17 cells and the serum level of IL-17 were suppressed by L. sakei in both human peripheral blood mononuclear cells and mouse splenocytes. The serum level of IL-10 was significantly increased in the L. sakei-treated group, whereas the regulatory T cell population was unchanged. The population of regulatory B cells significantly increased the in L. sakei-treated group. Oral administration of L. sakei reduced the arthritis incidence and score in mice with CIA. Finally, osteoclastogenesis and the mRNA levels of osteoclast-related genes were suppressed in the L. sakei-treated group.

CONCLUSION

L. sakei exerted an anti-inflammatory effect in an animal model of RA, regulated Th17 and regulatory B cell differentiation, and suppressed osteoclastogenesis. Our findings suggest that L. sakei has therapeutic potential for RA.