Production of Reactive Oxygen (ROS) and Nitrogen (RNS) Species in Macrophages J774A.1 Activated by the Interaction between Two Escherichia coli Pathotypes and Two Probiotic Commercial Strains.

Probiotics play an important role against infectious pathogens, such as Escherichia coli (E. coli), mainly through the production of antimicrobial compounds and their immunomodulatory effect. This protection can be detected both on the live probiotic microorganisms and in their inactive forms (paraprobiotics). Probiotics may affect different cells involved in immunity, such as macrophages. Macrophages are activated through contact with microorganisms or their products (lipopolysaccharides, endotoxins or cell walls). The aim of this work was the evaluation of the effect of two probiotic bacteria (Escherichia coli Nissle 1917 and Bifidobacterium animalis subsp. lactis HN019 on macrophage cell line J774A.1 when challenged with two pathogenic strains of E. coli. Macrophage activation was revealed through the detection of reactive oxygen (ROS) and nitrogen (RNS) species by flow cytometry. The effect varied depending on the kind of probiotic preparation (immunobiotic, paraprobiotic or postbiotic) and on the strain of E. coli (enterohemorrhagic or enteropathogenic). A clear immunomodulatory effect was observed in all cases. A higher production of ROS compared with RNS was also observed.

Paraprobiotics strains accelerate wound repair by stimulating re-epithelialization of NIH-3T3 cells, decreasing inflammatory response and oxidative stress.

The present study aimed to evaluate the potential and specificity of the inflammatory and antioxidant response of Microbe-Associated Molecular Patterns (MAMPs) in NIH-3T3 fibroblast cells, as well as in the healing process of skin wounds. Cells (NIH-3T3) were cultivated in supplemented specific medium. NIH-3T3 cells were treated with MAMPs (Bifidobacterium lactis or Lactobacillus casei or Lactobacillus gasseri or Lactobacillus paracasei or Streptococcus thermophilus), at two concentrations and insulted with LPS or H2O2. Cell viability, myeloperoxidase activity, nitrite/nitrate, oxidative damage and inflammatory parameters were measured. In addition, scratch assay was performed. Significant scratch closure was observed after 24 h and 48 h, and the effect of 0.1 g/mL MAMPs on wound healing was found to be highly statistically significant. In the viability cellular assay, Lactobacillus showed better response in 0.1 g/mL dose, whereas B. lactis and S. thermophilus showed better response in 0.01 g/mL dose. There was reduction in IL-6 and IL-1ß levels in all treatments insulted with LPS. MAMP's showed preventive efficacy in reducing the effects caused by LPS. The MAMP's action in decreasing the production of ROS, inflammatory activity and increasing cell viability, besides significant cell proliferation during wound healing processes suggests remodeling mechanisms and new possibilities for wound healing.

Could paraprobiotics be a safer alternative to probiotics for managing cancer chemotherapy-induced gastrointestinal toxicities?

Clinical oncology has shown outstanding progress improving patient survival due to the incorporation of new drugs. However, treatment success may be reduced by the emergency of dose-limiting side effects, such as intestinal mucositis and diarrhea. Mucositis and diarrhea management is symptomatic, and there is no preventive therapy. Bacterial and fungal-based compounds have been suggested as an alternative for preventing the development of diarrhea in cancer patients. Using probiotics is safe and effective in immunocompetent individuals, but concerns remain during immunosuppressive conditions. Paraprobiotics, formulations composed of non-viable microorganisms, have been proposed to overcome such limitation. The present literature review discusses current evidence regarding the possible use of paraprobiotics as an alternative to probiotics to prevent gastrointestinal toxicity of cancer chemotherapy.

Paraprobiotic obtained by ohmic heating added in whey-grape juice drink is effective to control postprandial glycemia in healthy adults.

The effect of paraprobiotic Lacticaseibacillus casei 01 inactivated by ohmic heating (8 V/cm, 95 °C/7 min, 60 Hz) whey-grape juice drink at the postprandial glycemia was evaluated. In vitro hypoglycemic activity was assessed by the α-glucosidase and α-amylase inhibition, while in vivo activity was determined using 15 healthy subjects, which consumed bread + probiotic whey drink, bread + paraprobiotic whey drink, and bread alone as a control. The probiotic and paraprobiotic grape-flavored whey drinks showed similar α-glucosidase and α-amylase inhibition (51.2 vs 51.8% and 43.2 vs 44.2%, respectively). The consumption of both paraprobiotic and probiotic whey drinks increased the incremental glucose rate when compared to the control due to the presence of sugar in its composition, without changes in the other parameters evaluated (maximum glucose value, glucose incremental percentage, and peak blood glucose time), showing a reduced glycemic response. In addition, the consumption of the paraprobiotic drink maintained the maximum glucose increase similar to the control, while an increase in this parameter was observed after the consumption of the probiotic drink. Therefore, the paraprobiotic grape-flavored whey drink may be an effective alternative to replace the probiotic product in reducing the postprandial glycemia in healthy individuals.

Heat-killed Lactobacillus reuteri and cell-free culture supernatant have similar effects to viable probiotics during interaction with Porphyromonas gingivalis.

BACKGROUND AND OBJECTIVE: In the last decade, numerous studies have been published to clarify the role of probiotics, especially Lactobacillus reuteri, as an adjunct to conventional periodontal treatment. Although the health benefits of probiotics are numerous, they are live bacteria, and the administration of live organisms is not risk-free. We evaluated the antimicrobial effect of L reuteri and its cell-free culture supernatant on Porphyromonas gingivalis, a keystone periodontal pathogen, in vitro. We also evaluated the influence of this probiotic in its live, heat-killed (HKL, paraprobiotic) form and its supernatant on the Galleria mellonella invertebrate model after infection by P gingivalis. METHODS: The interaction assay was conducted with P gingivalis and L reuteri preparations (live cells and supernatant preparation). For this, P gingivalis and L reuteri preparations were added to tubes containing Brain Heart Infusion broth and incubated for 3 days. The suspensions were then seeded onto appropriate culture media for the calculation of colony-forming units per mL (CFU/mL). An in vivo assay with the G mellonella model was also performed. Live L reuteri, HKL, or supernatant was inoculated 2 hours prior to infection with P gingivalis. Survival was evaluated over 7 days, and the number of hemocytes in the hemolymph was estimated 3 hours after P gingivalis infection. Data were then subjected to statistical testing (α = 5%). RESULTS: Both live L reuteri and its supernatant had antimicrobial activity against P gingivalis (CFU reduction up to 86%, P < .05). Moreover, treatment with live and HKL had similar effects on G mellonella survival (increased survival up to 46%, P < .05). However, only live L reuteri was able to significantly increase the hemocyte density in this invertebrate model. CONCLUSION: Lactobacillus reuteri antimicrobial activity against P gingivalis and its effects on G mellonella survival after infection with a periodontopathogen do not depend on cell viability. This allows the development of products without live bacterium while maintaining similar effects.