Characterization and Antibacterial Activity Against Helicobacter pylori of Lactic Acid Bacteria Isolated from Thai Fermented Rice Noodle

A Bifidobacterium animalis subsp. lactis strain that can suppress Helicobacter pylori: isolation, in vitro and in vivo validation

The administration of probiotics is an effective approach for treatment of Helicobacter pylori, which is associated with human gastrointestinal diseases and cancers. To explore more effective probiotics for H. pylori infection elimination, bacteria from infant feces were screened in this study. We successfully isolated the Bifidobacterium animalis subsp. lactis strains and evaluated its efficacy to inhibit H. pylori growth in vitro and in vivo. The results showed that a B. animalis strain (named BB18) sustained a high survival rate after incubation in gastric juice. The rapid urease test suggested that B. animalis BB18 reduced pathogen loads in H. pylori-infected Mongolian gerbils. Alleviation of H. pylori infection-induced gastric mucosa damage and decreased levels inflammatory cytokines were observed after the B. animalis BB18 administration. These findings demonstrated that B. animalis BB18 can inhibit H. pylori infection both in vitro and in vivo, suggesting its potential application for the prevention and eradication therapy of H. pylori infection.

Functional genome analysis and anti-Helicobacter pylori activity of a novel bacteriocinogenic Lactococcus sp. NH2-7C from Thai fermented pork (Nham)

Helicobacter pylori, linked to gastric diseases, is targeted for probiotic treatment through bacteriocin production. Bacteriocins have gained recognition for their non-toxic effects on host cells and their ability to combat a wide range of pathogens. This study aimed to taxonomically characterize and evaluate the safety and probiotic properties of the novel species of Lactococcus sp. NH2-7C isolated from fermented pork, as well as its bacteriocin NH2-7C, both in vitro and in silico. Comparative genotypic analysis revealed an average nucleotide identity of 94.96%, an average amino acid identity of 94.29%, and a digital DNA-DNA hybridization value of 63.80% when compared to Lactococcus lactis subsp. lactis JCM 5805T. These findings suggest that strain NH2-7C represents a novel species within the genus Lactococcus. In silico assessments confirmed the non-pathogenic nature of strain NH2-7C and the absence of genes associated with virulence and biogenic amine formation. Whole-genome analysis revealed the presence of the nisA gene responsible for nisin A production, indicating its potential as a beneficial compound with anti-Helicobacter pylori activity and non-toxic characteristics. Probiotic assessments indicated bile salt hydrolase and cholesterol assimilation activities, along with the modulation of interleukin-6 and tumour necrosis factor-α secretion. Strain NH2-7C demonstrated gastrointestinal tolerance and the ability to adhere to Caco-2 cells, affirming its safety and probiotic potential. Additionally, its ability to produce bacteriocins supports its suitability as a functional probiotic strain with therapeutic potential. However, further in vitro and in vivo investigations are crucial to ensure its safety and explore potential applications for Lactococcus sp. NH2-7C as a probiotic agent.

The Weissella Genus: Clinically Treatable Bacteria with Antimicrobial/Probiotic Effects on Inflammation and Cancer

Weissella is a genus earlier considered a member of the family Leuconostocaceae, which was reclassified into the family Lactobacillaceae in 1993. Recently, there have been studies emphasizing the probiotic and anti-inflammatory potential of various species of Weissella, of which W. confusa and W. cibaria are the most representative. Other species within this genus include: W. paramesenteroides, W. viridescens, W. halotolerans, W. minor, W. kandleri, W. soli, W. ghanensis, W. hellenica, W. thailandensis, W. fabalis, W. cryptocerci, W. koreensis, W. beninensis, W. fabaria, W. oryzae, W. ceti, W. uvarum, W. bombi, W. sagaensis, W. kimchi, W. muntiaci, W. jogaejeotgali, W. coleopterorum, W. hanii, W. salipiscis, and W. diestrammenae. Weissella confusa, W. paramesenteroides, W. koreensis, and W. cibaria are among the few species that have been isolated from human samples, although the identification of these and other species is possible using metagenomics, as we have shown for inflammatory bowel disease (IBD) and healthy controls. We were able to isolate Weissella in gut-associated bacteria (post 24 h food deprivation and laxatives). Other sources of isolation include fermented food, soil, and skin/gut/saliva of insects/animals. With the potential for hospital and industrial applications, there is a concern about possible infections. Herein, we present the current applications of Weissella on its antimicrobial and anti-inflammatory mechanistic effects, the predisposing factors (e.g., vancomycin) for pathogenicity in humans, and the antimicrobials used in patients. To address the medical concerns, we examined 28 case reports focused on W. confusa and found that 78.5% of infections were bacteremia (of which 7 were fatal; 1 for lack of treatment), 8 were associated with underlying malignancies, and 8 with gastrointestinal procedures/diseases of which 2 were Crohn’s disease patients. In cases of a successful resolution, commonly administered antibiotics included: cephalosporin, ampicillin, piperacillin-tazobactam, and daptomycin. Despite reports of Weissella-related infections, the evolving mechanistic findings suggest that Weissella are clinically treatable bacteria with emerging antimicrobial and probiotic benefits ranging from oral health, skin care, obesity, and inflammatory diseases to cancer.

Traditional fermented foods as vehicle of non-dairy probiotics: Perspectives in South East Asia countries

Food fermentation is a food processing technology that utilizes the growth and metabolic activity of microorganisms for the stabilization and transformation of food materials. Notwithstanding, the technology has evolved beyond food preservation into a tool for creating desirable organoleptic, nutritional, and functional attributes in food products. This narrative review outlines a compilation of traditional fermented foods which available in the South East Asia (SEA) regions as a source vehicle for non-dairy probiotics. The nutritional values of traditional fermented foods are well-appreciated, especially in the resource-poor regions. The sensory and organoleptic preferences of traditional fermented foods as means of dietary routine variations were demonstrated. Furthermore, the evidence underlying its potent impacts on public health promotion and disease prevention is outlined. Lastly, the challenges and future prospects for the integration of traditional fermented foods practice are elucidated.

Lactobacillus plantarum ZJ316 Attenuates Helicobacter pylori-Induced Gastritis in C57BL/6 Mice

Helicobacter pylori is a highly prevalent human-specific pathogen that causes various gastric diseases. In the present study, Lactobacillus plantarum ZJ316, which could survive well in simulated gastrointestinal conditions, was found to have significant anti-H. pylori ability. Animal assays revealed that L. plantarum ZJ316 had preventive and therapeutic effects on H. pylori-induced gastritis. L. plantarum ZJ316 significantly decreased interferon γ (IFN-γ) and interleukin 6 (IL-6) levels, increased the IL-10 level, and repaired mucosal damage. Moreover, 16S rRNA gene sequencing revealed that the relative abundance of H. pylori could be significantly reduced by L. plantarum ZJ316 administration. Members of the families Dehalobacteriaceae and Geodermatophilaceae were more prevalent in the prevention group, while Lactobacillaceae and Actinomycetaceae were more prevalent in the treatment group. These results indicate that L. plantarum ZJ316 serves as a potential candidate for the prevention and treatment of H. pylori-induced gastritis by regulating the gastric microbiota and reducing mucosal inflammation.

Role of Probiotics in Eradication Therapy for Helicobacter pylori Infection

Probiotics are defined as, "Live microorganisms that, when administered in adequate amounts, confer a health benefit on the host", and have various effects including inhibitory capabilities on pathogens, stimulation of organ functions and activation of immune responses in the human. Probiotics were reported to inhibit Helicobacter pylori not only in vitro, but also in vivo studies. The mechanisms by which probiotics inhibit H. pylori infection include competition for nutrients, production of bactericidal substances, competitive inhibition of adherence and stimulation of host functions and immunity. In addition, probiotics are clinically used for eradication therapy of H. pylori infection, and the effects of probiotics as single treatment and combination use with other drugs including proton pump inhibitors and antibiotics against H. pylori are reported. It has been testified that probiotics increase the eradication rate and prevent adverse events including diarrhea, nausea, vomiting and taste disorder. In the Maastrich V/Florence Consensus Report 2017, it was stated that some probiotics may have a beneficial effect on H. pylori eradication and are effective in reducing side effects of eradication therapy, but more research is needed to answer several questions concerning the mechanisms of probiotics action. In addition, strain specificity, dosages and duration times of probiotics used for H. pylori eradication therapy need to be clarified in future studies.

Comparative Analysis of Inhibition-Based and Indicator-Independent Colorimetric Assay for Screening of Bacteriocin-Producing Lactic Acid Bacteria

Screening of bacteriocin-producing lactic acid bacteria (LAB) is an important aspect for the search of new/novel probiotic strains. Here, a vesicle-based colorimetric assay was compared with conventional inhibition-based antimicrobial assays using 54 isolates of LAB. All isolates demonstrated zone of growth inhibition ranging from 2.5 to 7.5 mm against indicator strain, Micrococcus luteus MTCC106 using point inoculation method. Cell-free supernatant of the isolates showed zone of growth inhibition varying from 14.5 to 25 mm using agar well diffusion assay. These isolates inhibited the growth of indicator strain by 89.56-98.65%. The antimicrobial activity present in cell-free supernatant of different isolates was found to be in the range of 10-160 AU ml^- 1. The treatment of polydiacetylene (PDA) vesicles with cell-free supernatant of selected isolates led to blue-red color transition, and presence of protein band on tricine SDS-PAGE confirmed the presence of membrane-acting peptides, bacteriocins. The colorimetric responses (CR%) varied between 0 and 59%, and the assay was found to be more sensitive, faster, and reliable as compared to the other conventional indicator-based methods used. Therefore, the colorimetric assay may be specifically applied for screening of bacteriocin-producing LAB.