Investigation of Lactobacillus Probiotics Derived from Traditional Dairy Products in Eliciting Anti-Tumor Responses in Mouse Colorectal Cancer Model

Background

Colorectal cancer (CRC) is a serious health problem, and finding new treatments is important. There is growing evidence for the antitumor activity of probiotics. This study investigated the anti-cancer potential of a probiotic mix containing Lactobacillus plantarum, L. brevis, L. helveticus, and L. delbrueckii, alone or in combination with the chemotherapy drug 5-fluorouracil, against CRC.

Methods

The research was carried out in Mashhad in 2021. The cytotoxic effect of Lactobacillus isolates on CRC cells was investigated in two-dimensional and three-dimensional cell culture models. Histological staining and molecular approaches were used to investigate the regulatory mechanism of Lactobacillus isolates on cell migration, inflammation, fibrosis, cell cycle progression, apoptosis, and tumor necrosis in the CRC mouse model. Statistical analysis was performed using SPSS software version 20 with a significance level of P<0.05. The tests employed included the Kolmogorov-Smirnov, ANOVA, Dunnett's post hoc, and Kruskal-Wallis.

Results

Lactobacillus strains effectively suppressed tumor growth in CRC by promoting cell death and inhibiting fibrosis and inflammation. These bacteria regulated apoptosis-related genes such as Bcl-2-associated protein x (P=0.0033), and BCL-2 (P=0.0029), leading to increased tumor necrosis. Treatment with bacterial supernatants reduced tumor size and fibrosis by downregulating collagen type I, alpha 1 (Col1a1) (P=0.024), Col1a2 (P=0.0231), and actin alpha 2 (P=0.0466), and transforming growth factor-beta expression. Additionally, they suppressed inflammation by decreasing tumor necrosis factor-alpha (P=0.0001), interleukin 6, and IL-1β (P=0.0198) levels in tumor tissues. Furthermore, the treatment inhibited CRC cell migration by modulating epithelial cadherin (P=0.0198) and matrix metallopeptidase 2 (P=0.033) expression.

Conclusion

Findings indicated that co-administration of Lactobacillus isolates with 5-FU could improve the anti-tumor properties of the standard drug, 5-FU, supporting the therapeutic potential of these safe isolated lactic acid bacteria for CRC patients in vivo.

A critical review of novel antibiotic resistance prevention approaches with a focus on postbiotics

Antibiotic resistance is a significant public health issue, causing illnesses that were once easily treatable with antibiotics to develop into dangerous infections, leading to substantial disability and even death. To help fight this growing threat, scientists are developing new methods and techniques that play a crucial role in treating infections and preventing the inappropriate use of antibiotics. These effective therapeutic methods include phage therapies, quorum-sensing inhibitors, immunotherapeutics, predatory bacteria, antimicrobial adjuvants, haemofiltration, nanoantibiotics, microbiota transplantation, plant-derived antimicrobials, RNA therapy, vaccine development, and probiotics. As a result of the activity of probiotics in the intestine, compounds derived from the structure and metabolism of these bacteria are obtained, called postbiotics, which include multiple agents with various therapeutic applications, especially antimicrobial effects, by using different mechanisms. These compounds have been chosen in particular because they don't promote the spread of antibiotic resistance and don't include substances that can increase antibiotic resistance. This manuscript provides an overview of the novel approaches to preventing antibiotic resistance with emphasis on the various postbiotic metabolites derived from the gut beneficial microbes, their activities, recent related progressions in the food and medical fields, as well as concisely giving an insight into the new concept of postbiotics as "hyperpostbiotic".

Evaluation of probiotic bifidobacteria strains from Iranian traditional dairy products for their anti-hyperlipidemic potential

This study investigated the therapeutic potential of probiotic bifidobacteria, isolated from Iranian fermented dairy products, in a hyperlipidemic animal model. Bifidobacterium strains were extracted from traditional dairy samples and screened using physiological and phenotypic examinations, 16S rRNA analysis, and probiotic properties such as tolerance to gastrointestinal juice, antimicrobial activity, and antibiotic susceptibility. The ability of the screened bifidobacteria to reduce serum and liver lipids in vivo was tested using male Wistar rats. Six strains of bifidobacteria were isolated from traditional Iranian fermented dairy. These strains showed promising in vitro activity in lowering triglyceride and cholesterol, tolerance to simulated gastrointestinal juice, the ability to adhere to Caco-2 cells, acceptable antibiotic susceptibility, and a broad spectrum of antibacterial activity. The diet supplemented with isolated bifidobacteria significantly reduced serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), liver tissue lipid levels, and hepatic enzymes in animals when compared to a high-fat diet without strains (p < 0.01). Additionally, the potential probiotic-supplemented diet significantly increased bile acid excretion in the feces and upregulated hepatic CYP7A1 expression levels (p < 0.05), while NPC1L1, ACAT2, and MTP gene expressions in small intestinal cells were downregulated (p < 0.05). Bifidobacteria isolated from Iranian traditional dairy showed potential for use in the production of fermented foods that have hypolipemic activity in the host.

Characterization of potential probiotics Lactobacillus species isolated from the gastrointestinal tract of Rhode Island Red (RIR) chicken in Ethiopia

Background and aims

Nowadays, probiotic microorganisms are given high attention due to their potential for the improvement of animal production and productivity. The natural gut microflora of poultry can serve as an excellent source of optimum probiotic strains. Therefore, this study isolated, identified and characterized potential probiotic Lactobacillus strains from the digestive tract content of RIR chicken in Ethiopia.

Methods

A total of five RIR chickens were randomly taken and a sample was taken from each gastrointestinal content for further analysis. For further characterization, among 190 isolates only 10 representative isolates were randomly taken for further in vitro probiotic potential characterization. The selected isolates were screened and identified based on the biochemical, morphological, and 16S rRNA gene sequences.

Results

Survival isolates of IS3, IS4, IS6, and IS7 were significantly different (P < 0.05) at pH 2. IS3, IS4, IS6, and IS7 showed tolerance for 0.3% bile salt. Isolates of IS1, IS2, IS5, IS7, and IS8 were ampicillin-resistant, and chloramphenicol, ciprofloxacin, and erythromycin were used as antibiotics. All ten isolates showed antagonistic activity against Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Staphylococcus intermedius, and Salmonella enteritidis. The optimum temperature for all isolates was 45 °C, and all the isolates could grow at 0.69 mol/L of NaCl. Using phylogenetic analysis of the 16SrRNA gene sequence; IS3 was identified as Lactobacillus salivarius, while IS4, IS6, and IS7 were identified as Lactobacillus reuteri.

Conclusions

The results indicated that the selected Lactobacillus isolates can survive the stress conditions of the gastrointestinal tract and can thus be considered potential probiotic candidates for chickens.

The effect of probiotic supplementation on episiotomy wound healing among primiparous women: a triple-blind randomized clinical trial

BACKGROUND

Probiotics increase the defense power of immune system and accelerate the wound healing process by anti-inflammatory mechanisms at the wound site. The present study aimed at evaluating the effect of Lactobacillus casei oral supplementation on episiotomy wound healing among primiparous women.

METHODS

This triple-blind randomized clinical trial was performed on 74 primiparous women delivered in Alzahra Hospital, Tabriz, Iran. Participants with mediolateral episiotomy (incision length equal to and less than 5 cm) were randomly assigned to the probiotic and placebo groups. The probiotic group received Lactobacillus casei 431 with 1.5 * 109 colony-forming unit /capsule once a day from the day after birth to 14 days. Wound healing as a primary outcome was measured by Redness, Edema, Ecchymosis, Discharge, Approximation and pain as a secondary outcome by the Visual Analogue Scale before discharge, 5 ± 1 and 15 ± 1 days after birth. The data were analyzed using independent t-test and repeated measures one way analysis of variance.

RESULTS

The mean (standard deviation: SD) score of wound healing in the probiotic group altered from 4.91(1.86) before discharge to 1.55 (0.99) during 5 ± 1 days after birth and reached to 0.95 (0.27) during 15 ± 1 days after birth. Further, the mean (SD) score of wound healing in the placebo group altered from 4.62 (1.99) before discharge to 2.80 (1.20) during 5 ± 1 days after birth and reached to 1.45(0.71) during 15 ± 1 days after birth (adjusted mean difference: -0.50, confidence interval 95%: -0.96 to -0.05, P = 0.03).

CONCLUSION

Lactobacillus casei oral supplementation is effective in healing episiotomy wounds. It is suggested to evaluate the effect of topical use of Lactobacillus casei on episiotomy repair and pain in further studies.

TRIAL REGISTRATION

Iranian Registry of Clinical Trials (IRCT): IRCT20170506033834N7. Date of registration: 11/08/2021.

Probiotics, their action modality and the use of multi-omics in metamorphosis of commensal microbiota into target-based probiotics

This review article addresses the strategic formulation of human probiotics and allows the reader to walk along the journey that metamorphoses commensal microbiota into target-based probiotics. It recapitulates what are probiotics, their history, and the main mechanisms through which probiotics exert beneficial effects on the host. It articulates how a given probiotic preparation could not be all-encompassing and how each probiotic strain has its unique repertoire of functional genes. It answers what criteria should be met to formulate probiotics intended for human use, and why certain probiotics meet ill-fate in pre-clinical and clinical trials? It communicates the reasons that taint the reputation of probiotics and cause discord between the industry, medical and scientific communities. It revisits the notion of host-adapted strains carrying niche-specific genetic modifications. Lastly, this paper emphasizes the strategic development of target-based probiotics using host-adapted microbial isolates with known molecular effectors that would serve as better candidates for bioprophylactic and biotherapeutic interventions in disease-susceptible individuals.