Lactobacillus paracasei strain 06TCa19 suppresses inflammatory chemokine induced by Helicobacter pylori in human gastric epithelial cells

Effects of Lactobacillus spp. on Helicobacter pylori: A Promising Frontier in the Era of Antibiotic Resistance

Helicobacter pylori, a pathogenic bacterium responsible for multiple gastrointestinal disorders, has emerged as a major global concern due to rise in antibiotic resistance. Unwanted side effects of antibiotics therapy are further complicating the treatment strategies. Consequently, an alternative approach, using probiotics has emerged as a promising solution for treating H. pylori infections. Probiotics have shown considerable potential in increasing the cure rate and reducing the side effects through diverse mechanisms. Among the widely employed probiotics, Lactobacillus spp. has garnered particular attention in this review. After reviewing the studies on effects of Lactobacillus spp. on H. pylori, it is evident that several Lactobacillus spp. have demonstrated their potential efficacy against H. pylori infection, when administered alone or in conjunction with antibiotics, in a strain-specific manner. Furthermore, the inclusion of Lactobacillus spp. in the treatment regimen has also been associated with a reduction in the side effects related to antibiotic-based therapies. Future research may focus on identifying optimal strains and treatment regimens, understanding the long-term impacts of use, and determining their role in preventing H. pylori infection in various populations.

Lactobacillus acidophilus NCFM and Lactiplantibacillus plantarum Lp-115 inhibit Helicobacter pylori colonization and gastric inflammation in a murine model

Purpose

To determine the role of Lactobacillus strains and their combinations in inhibiting the colonization of H. pylori and gastric mucosa inflammation.

Methods

Human gastric adenocarcinoma AGS cells were incubated with H. pylori and six probiotic strains (Lactobacillus acidophilus NCFM, L. acidophilus La-14, Lactiplantibacillus plantarum Lp-115, Lacticaseibacillus paracasei Lpc-37, Lacticaseibacillus rhamnosus Lr-32, and L. rhamnosus GG) and the adhesion ability of H. pylori in different combinations was evaluated by fluorescence microscopy and urease activity assay. Male C57BL/6 mice were randomly divided into five groups (uninfected, H. pylori, H. pylori+NCFM, H. pylori+Lp-115, and H. pylori+NCFM+Lp-115) and treated with two lactobacilli strains (NCFM and Lp-115) for six weeks. H. pylori colonization and tissue inflammation statuses were determined by rapid urease test, Hematoxylin-Eosin (HE) staining, immunohistochemistry, and qRT-PCR and ELISA.

Results

L. acidophilus NCFM, L. acidophilus La-14, L. plantarum Lp-115, L. paracasei Lpc-37, L. rhamnosus Lr-32, and L. rhamnosus GG reduced H. pylori adhesion and inflammation caused by H. pylori infection in AGS cells and mice. Among all probiotics L. acidophilus NCFM and L. plantarum, Lp-115 showed significant effects on the H. pylori eradication and reduction of inflammation in-vitro and in-vivo. Compared with the H. pylori infection group, the mRNA and protein expression levels of IL-8 and TNF-α in the six Lactobacillus intervention groups were significantly reduced. The changes in the urease activity (ureA and ureB) for 1-7h in each group showed that L. acidophilus NCFM, L. acidophilus La-14, L. plantarum Lp-115, and L. rhamnosus GG effectively reduced the colonization of H. pylori. We observed a higher ratio of lymphocyte and plasma cell infiltration into the lamina propria of the gastric mucosa and neutrophil infiltration in H. pylori+NCFM+Lp-115 mice. The infiltration of inflammatory cells in lamina propria of the gastric mucosa was reduced in the H. pylori+NCFM+Lp-115 group. Additionally, the expression of IFN-γ was decreased significantly in the NCFM and Lp-115 treated C57BL/6 mice.

Conclusions

L. acidophilus NCFM and L. plantarum Lp-115 can reduce the adhesion of H. pylori and inhibit the gastric inflammatory response caused by H. pylori infection.

Preventive and therapeutic effect of Lactobacillus paracasei ZFM54 on Helicobacter pylori-induced gastritis by ameliorating inflammation and restoring gastric microbiota in mice model

Helicobacter pylori is the most prevalent pathogen causing chronic gastritis, gastroduodenal ulcers, and gastric tumors and is asymptomatically present in 50% of the world's population. This research is focused on investigating the effect of Lactobacillus paracasei ZFM 54 (CCTCC NO:2016667) on attenuating H. pylori-induced gastritis. H. pylori ZJC03 isolated from a patient with gastritis harbored the virulence genes of vacA and cagA and was highly resistant to metronidazole (MIC > 256 μg/mL). In vitro analysis revealed that the potential anti-H. pylori characteristics of L. paracasei ZFM54 in terms of 65.57 ± 1.87% survival rate in simulated gastric juices at a pH of 2.0, 69.00 ± 2.73% auto-aggregation, 30.28 ± 2.24% co-aggregation, 70.27 ± 2.23% urease inhibition, and 57.89 ± 1.27% radical scavenging. In H. pylori infectious mice, L. paracasei ZFM54 pre- and post-treatment reduced the levels of malondialdehyde in liver tissues to 0.71 ± 0.04 nmol/mgprot (p < 0.05) and 0.70 ± 0.06 nmol/mgprot (p < 0.05), respectively. Glutathione levels were increased to 1.78 ± 0.02 μmol/gprot (p < 0.05) and 1.76 ± 0.52 μmol/gprot (p < 0.05), respectively. L. paracasei ZFM54 significantly inhibited H. pylori-mediated inflammation observed in gastric mucosal repair and downregulated the mRNA expression of pro-inflammatory cytokines IFN-γ, IL-1β, and IL-6 (p < 0.01). Importantly, L. paracasei ZFM54 increased Firmicutes and Actinobacteriota and decreased the relative abundance of bacterial taxa belonging to Campilobacterota and Proteobacteria. With the preventive and therapeutic administration of L. paracasei ZFM54, significant reductions in the average relative abundance of genera Helicobacter, Muribaculum, Staphylococcus, Lachnospiraceae_NK4A136_group, Prevotellaceae_UCG-001, Alloprevotella, and Oscillibacter were observed compared to infected mice. These findings suggest that L. paracasei ZFM 54 has the potential to protect against H. pylori infection by ameliorating inflammation and restoring the gastric microbiota.

Relationship between Helicobacter pylori infection and gastrointestinal microecology

The prevalence of Helicobacter pylori (H. pylori) infection has exceeded 50% worldwide, and it is considered a high-risk factor for chronic gastritis, peptic ulcer, gastric adenocarcinoma, gastroesophageal reflux disease and functional dyspepsia. H. pylori drug resistance is a common problem worldwide. In recent years, the relationship between H. pylori infection and gastrointestinal microecology has received much attention. H. pylori infection changes the structure and composition of gastrointestinal microflora by regulating the gastrointestinal microecological environment, local pH value, cytokines and antimicrobial peptides, and immune response and then plays a crucial role in the occurrence and development of digestive system tumors, liver metabolism and extragastrointestinal diseases. The quadruple strategy of H. pylori eradication can also aggravate gastrointestinal microflora disorder. However, probiotics can reduce intestinal flora changes and imbalances through different mechanisms, thus enhancing the efficacy of H. pylori eradication therapy and reducing adverse reactions caused by eradication therapy. Therefore, this paper reviews the relationship between H. pylori infection and gastrointestinal microecology and its clinical application, providing a basis for clinical treatment.

Helicobacter pylori promotes gastric cancer progression through the tumor microenvironment

Gastric cancer (GC) is a leading type of cancer. Although immunotherapy has yielded important recent progress in the treatment of GC, the prognosis remains poor due to drug resistance and frequent recurrence and metastasis. There are multiple known risk factors for GC, and infection with Helicobacter pylori is one of the most significant. The mechanisms underlying the associations of H. pylori and GC remain unclear, but it is well known that infection can alter the tumor microenvironment (TME). The TME and the tumor itself constitute a complete ecosystem, and the TME plays critical roles in tumor progression, metastasis, and drug resistance. H. pylori infection can act synergistically with the TME to cause DNA damage and abnormal expression of multiple genes and activation of signaling pathways. It also modulates the host immune system in ways that enhance the proliferation and metastasis of tumor cells, promote epithelial-mesenchymal transition, inhibit apoptosis, and provide energy support for tumor growth. This review elaborates myriad ways that H. pylori infections promote the occurrence and progression of GC by influencing the TME, providing new directions for immunotherapy treatments for this important disease. KEY POINTS: • H. pylori infections cause DNA damage and affect the repair of the TME to DNA damage. • H. pylori infections regulate oncogenes or activate the oncogenic signaling pathways. • H. pylori infections modulate the immune system within the TME.

Lactobacillus plantarum 23-1 improves intestinal inflammation and barrier function through the TLR4/NF-κB signaling pathway in obese mice

As a natural active ingredient, lactic acid bacteria have potential anti-inflammatory effects. In this study, male C57BL/6J mice were given a high-fat diet (HFD) to establish an obese mouse model. Lactobacillus plantarum 23-1 (LP23-1) with prebiotic characteristics was intervened for 8 weeks to evaluate its remission effect on obese animals and related mechanisms. The effects of LP23-1 on lipid accumulation and intestinal inflammation in HFD-fed mice were systematically evaluated by detecting lipid accumulation, blood lipid level, pathological changes in the liver and small intestine, oxidative stress and inflammatory cell level, lipid transport-related gene expression, the inflammatory signaling pathway, and intestinal tight junction (TJ) mRNA and protein expression. The results showed that LP23-1 could significantly reduce the body weight and fat index of HFD-fed mice, improve the lipid levels of serum and liver, reduce the histopathological damage to the liver and small intestine, and alleviate oxidative stress and inflammatory response caused by obesity. In addition, reverse transcription-polymerase chain reaction and western blot analysis showed that LP23-1 could regulate the mRNA expression of lipid transport-related genes; activate the TLR4/NF-κB signaling pathway; reduce intestinal inflammation; improve the mRNA and protein expression of intestinal TJ proteins zona occludens-1 (ZO-1), occludin, claudin-1, and Muc2; repair intestinal mucosal injury; and enhance intestinal barrier function. The aforementioned results showed that LP23-1 through the TLR4/NF-κB signaling pathway and intestinal barrier function reduced obesity symptoms. This study provided new insights into the mechanism of LP23-1 in reducing obesity and provided a theoretical basis for developing new functional foods.

Probiotics for the Treatment of Gastric Diseases

Common gastric diseases include chronic gastritis, gastric ulcers and gastric cancer. The etiology of gastric diseases is complicated, including genetics, diet, excessive smoking and drinking, environmental factors, and bacterial infections. As live microorganisms, probiotics can confer health benefits to the host. At present, probiotics have been widely used in the preparation of foods, health products, and medicines. Due to their positive effects in improving diarrhea, constipation, alleviating allergies, enhancing immunity, and maintaining intestinal homeostasis, studies worldwide have focused on whether probiotics also provide therapeutic effects on gastric diseases. Thus, this review summarizes the possible mechanism of probiotics in the treatment of gastric diseases and provides a reference for expanding not only their application but also that of other microecological agents.

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

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

The impacts of probiotics in eradication therapy of Helicobacter pylori

Helicobacter pylori (H. pylori) is a well-known pathogen that infects approximately half of the world's population. It is a pathogenic agent with potential health hazards related to diverse diseases, especially digestive diseases, such as chronic gastritis, peptic ulcer, and gastric carcinoma. In clinical, antibiotics are commonly applied in eradication therapy of H. pylori. However, the increase in antibiotic resistance and side effects has induced the failure of eradication therapy. Recent studies have shown that probiotic supplementation has promising application prospects. It can restore the gastrointestinal microbiota balance and prevent dysbacteriosis caused by antibiotics. Furthermore, it has been reported to have direct or indirect inhibitory effects on H. pylori. Probiotics may have a beneficial effect on H. pylori eradication. However, the strain, dosages, duration times, and safety of probiotic supplementation need further study before clinical applications.

In Vitro Framework to Assess the Anti-Helicobacter pylori Potential of Lactic Acid Bacteria Secretions as Alternatives to Antibiotics

Helicobacter pylori is a prevalent bacterium that can cause gastric ulcers and cancers. Lactic acid bacteria (LAB) ameliorate treatment outcomes against H. pylori, suggesting that they could be a source of bioactive molecules usable as alternatives to current antibiotics for which resistance is mounting. We developed an in vitro framework to compare the anti-H. pylori properties of 25 LAB and their secretions against H. pylori. All studies were done at acidic and neutralized pH, with or without urea to mimic various gastric compartments. Eighteen LAB strains secreted molecules that curtailed the growth of H. pylori and the activity was urea-resistant in five LAB. Several LAB supernatants also reduced the urease activity of H. pylori. Pre-treatment of H. pylori with acidic LAB supernatants abrogated its flagella-mediated motility and decreased its ability to elicit pro-inflammatory IL-8 cytokine from human gastric cells, without reverting the H. pylori-induced repression of other pro-inflammatory cytokines. This study identified the LAB that have the most anti-H. pylori effects, decreasing its viability, its production of virulence factors, its motility and/or its ability to elicit pro-inflammatory IL-8 from gastric cells. Once identified, these molecules can be used as alternatives or complements to current antibiotics to fight H. pylori infections.

Modulatory Effects of Probiotics During Pathogenic Infections With Emphasis on Immune Regulation

In order to inhibit pathogenic complications and to enhance animal and poultry growth, antibiotics have been extensively used for many years. Antibiotics applications not only affect target pathogens but also intestinal beneficially microbes, inducing long-lasting changes in intestinal microbiota associated with diseases. The application of antibiotics also has many other side effects like, intestinal barrier dysfunction, antibiotics residues in foodstuffs, nephropathy, allergy, bone marrow toxicity, mutagenicity, reproductive disorders, hepatotoxicity carcinogenicity, and antibiotic-resistant bacteria, which greatly compromise the efficacy of antibiotics. Thus, the development of new antibiotics is necessary, while the search for antibiotic alternatives continues. Probiotics are considered the ideal antibiotic substitute; in recent years, probiotic research concerning their application during pathogenic infections in humans, aquaculture, poultry, and livestock industry, with emphasis on modulating the immune system of the host, has been attracting considerable interest. Hence, the adverse effects of antibiotics and remedial effects of probiotics during infectious diseases have become central points of focus among researchers. Probiotics are live microorganisms, and when given in adequate quantities, confer good health effects to the host through different mechanisms. Among them, the regulation of host immune response during pathogenic infections is one of the most important mechanisms. A number of studies have investigated different aspects of probiotics. In this review, we mainly summarize recent discoveries and discuss two important aspects: (1) the application of probiotics during pathogenic infections; and (2) their modulatory effects on the immune response of the host during infectious and non-infectious diseases.

Effects of a Potential Probiotic Strain Lactobacillus gasseri ATCC 33323 on Helicobacter pylori-Induced Inflammatory Response and Gene Expression in Coinfected Gastric Epithelial Cells

In the present study, we aimed to investigate the modulatory effects of a potential probiotic bacterium Lactobacillus gasseri ATCC 33323 on Helicobacter pylori-induced inflammatory response and gene expression in human gastric adenocarcinoma (AGS) cell line. The gastric epithelial cells were coinfected with a collection of H. pylori clinical strains alone or in combination with L. gasseri at a multiplicity of infection (MOI) of 1:100 for each bacterium, and incubated for different time points of 3, 6, and 12 h. IL-8 secretion from coinfected AGS cells after incubation at each time point was measured by an enzyme-linked immunosorbent assay (ELISA). The mRNA expression of IL-8, Bcl-2, β-catenin, integrin α₅, and integrin β₁ genes was determined by quantitative RT-PCR amplification of total RNA extracted from coinfected epithelial cells. L. gasseri significantly (P < 0.05 and P < 0.01) decreased the production of IL-8 in AGS cells coinfected with H. pylori strains at 6 h post-infection. We also detected that L. gasseri significantly (P < 0.05) down-regulated the gene expression level of IL-8 in H. pylori-stimulated AGS cells after 6 and 12 h of coinfection. Similarly, L. gasseri caused a significant decrease (P < 0.05) in mRNA expression of Bcl-2, β-catenin, integrin α₅, and integrin β₁ genes in AGS cells at 3 and 6 h after infection with H. pylori strains as compared with non-infected control cells. In conclusion, our results demonstrated that L. gasseri ameliorates H. pylori-induced inflammation and could be developed as a supplementation to the current treatment regimens administrated against H. pylori infection.

Fermented milk containing Lactobacillus paracasei and Glycyrrhiza glabra has a beneficial effect in patients with Helicobacter pylori infection: A randomized, double-blind, placebo-controlled study

BACKGROUND

Lactobacillus paracasei and Glycyrrhiza glabra have been reported as having beneficial effects on Helicobacter pylori infection. We aimed to assess the efficacy and safety of fermented milk containing L paracasei HP7 and G glabra in patients with H pylori infection.

METHODS

This multicenter, prospective, randomized, double-blind, placebo-controlled clinical trial was conducted in 2 hospitals from April to December 2017. Patients with H pylori infection were randomized into either the treatment group (fermented milk with L paracasei HP7 and G glabra) or placebo group (fermented milk only) once daily for 8 weeks. The primary endpoint was the gastric load of H pylori measured by C-urea breath test (UBT). Secondary endpoints were histologic and clinical improvement.

RESULTS

A total of 142 patients were randomly allocated to the treatment (n = 71) or placebo groups (n = 71). Compared to baseline data, the quantitative value of C-UBT at 8 weeks was significantly reduced in the treatment group (from 20.8 ± 13.2% to 16.9 ± 10.8%, P = .035), but not in the placebo group (P = .130). Chronic inflammation improved significantly only in the treatment group (P = .013), whereas the neutrophil activity deteriorated significantly only in the placebo group (P = .003). Moreover, the treatment group had significant improvement in gastrointestinal symptoms (P = .049) and quality of life (P = .029). No serious adverse events were observed.

CONCLUSION

The combination of fermented milk containing L paracasei and G glabra reduced H pylori density and improved histologic inflammation. However, their mechanisms of action should be elucidated in further studies.

Probiotics in digestive, emotional, and pain-related disorders

In recent years, interest in the relationship between gut microbiota and disease states has grown considerably. Indeed, several strategies have been employed to modify the microbiome through the administration of different diets, by the administration of antibiotics or probiotics, or even by transplantation of feces. In the present manuscript, we focus specifically on the potential application of probiotics, which seem to be a safe strategy, in the management of digestive, pain, and emotional disorders. We present evidence from animal models and human studies, notwithstanding that translation to clinic still deserves further investigation. The microbiome influences gut functions as well as neurological activity by a variety of mechanisms, which are also discussed. The design and performance of larger trials is urgently needed to verify whether these new strategies might be useful not only for the treatment of disorders affecting the gastrointestinal tract but also in the management of emotional and pain disorders not directly related to the gut.