Optimization of growth of Levilactobacillus brevis SP 48 and in vitro evaluation of the effect of viable cells and high molecular weight potential postbiotics on Helicobacter pylori

Abstract

Several Levilactobacillus brevis strains have the potential to be used as probiotics since they provide health benefits due to the interaction of live cells, and of their secreted products, with the host (tissues). Therefore, the development of simple fermentation processes that improve cell viability to reduce industrial production costs, and at the same time the characterization and biological evaluation of cell-free postbiotics that can further promote application, are of great interest. In the present study, small scale batch fermentations on semi defined media, deprived of animal derived raw materials, were used to optimize growth of L. brevis SP48, reaching 1.2 ± 0.4 × 1010 CFU/ml of viable cells after 16 h of growth. Displacement, competition, and inhibition assays compared the effect, on Helicobacter pylori, of L. brevis cells to that of its partially purified potentially postbiotic fraction rich in exopolysaccharides and proteins. The expression of pro and anti-inflammatory biochemical markers indicated that both samples activated antimicrobial defenses and innate immunity in a gastric model. Moreover, these compounds also acted as modulators of the inflammatory response in a gut in vitro model. These data demonstrate that the high molecular weight compounds secreted by L. brevis SP48 can contrast H. pylori and reduce inflammation related to intestinal bowel disease, potentially overcoming issues related to the preservation of probiotic viability.

Bifidobacterium animalis subsp. lactis HN019 live probiotics and postbiotics: production strategies and bioactivity evaluation for potential therapeutic properties

“…This EPS, mainly composed of glucose, inhibited the production of the pro-inflammatory mediator NF-kß through the suppression of TLR-4 in mouse macrophages (RAW 264.7) cells ( Kwon et al, 2020 ). In our previous research, both live Levilactobacillus brevis SP-48 cells and bioactive compounds purified from the fermentation broth, exerted an immunomodulatory effect by downregulating the expression of TLR-4 and NF- kß in differentiated Caco-2 cells after exposure to LPS ( Cimini et al, 2022 ).…”

In Vitro Evaluation of the Most Active Probiotic Strains Able to Improve the Intestinal Barrier Functions and to Prevent Inflammatory Diseases of the Gastrointestinal System

“…The choice of the strains was due to them being commercialized and having already been the subject of various studies; in fact, L. brevis SP-48 is present in commercial products (e.g., Florap lady) that promote the balance of the intestinal flora and the functionality of the urinary tract. Moreover, our recent study indicated that it inhibited H. pylori and acted as modulator of the immune system, reducing the inflammation potentially related to the treatment of intestinal bowel disease [ 49 ].…”

Exploration of microbiome diversity of stacked fermented grains by flow cytometry and cell sorting

“…Microorganisms in the fermentation process exist in both dead and living forms, and only active microorganisms can metabolize substances that affect the surrounding environment ( Cimini et al, 2022 ). Many microorganisms that are no longer biologically active can still be detected via high-throughput sequencing; therefore, it is important to understand the fermentation process by rapid analysis and sorting of the flora using flow cytometry combined with the absolute characterization of the microorganisms using high-throughput sequencing.…”