Helicobacter pylori infection is associated with important gastric pathologies. An aggressive proinflammatory immune response is generated in the gastric tissue infected with H. pylori, resulting in gastritis and a series of morphological changes that increase the susceptibility to cancer development. Probiotics could present an alternative solution to prevent or decrease H. pylori infection. Among them, the use of immunomodulatory lactic acid bacteria represents a promising option to reduce the severity of chronic inflammatory-mediated tissue damage and to improve protective immunity against H. pylori. We previously isolated Lactobacillus fermentum UCO-979C from human gastric tissue and demonstrated its capacity to reduce adhesion of H. pylori to human gastric epithelial cells (AGS cells). In this work, the ability of L. fermentum UCO-979C to modulate immune response in AGS cells and PMA phorbol 12-myristate 13-acetate (PMA)-differentiated THP-1 (human monocytic leukaemia) macrophages in response to H. pylori infection was evaluated. We demonstrated that the UCO-979C strain is able to differentially modulate the cytokine response of gastric epithelial cells and macrophages after H. pylori infection. Of note, L. fermentum UCO-979C was able to significantly reduce the production of inflammatory cytokines and chemokines in AGS and THP-1 cells as well as increase the levels of immunoregulatory cytokines, indicating a remarkable anti-inflammatory effect. These findings strongly support the probiotic potential of L. fermentum UCO-979C and provide evidence of its beneficial effects against the inflammatory damage induced by H. pylori infection. Although our findings should be proven in appropriate experiments in vivo, in both H. pylori infection animal models and human trials, the results of the present work provide a scientific rationale for the use of L. fermentum UCO-979C to prevent or reduce H. pylori-induced gastric inflammation in humans.

Previously, we isolated lactic acid bacteria from the slime of the garden snail Helix aspersa Müller and selected Weissella viridescens UCO-SMC3 because of its ability to inhibit in vitro the growth of the skin-associated pathogen Cutibacterium acnes. The present study aimed to characterize the antimicrobial and immunomodulatory properties of W. viridescens UCO-SMC3 and to demonstrate its beneficial effect in the treatment of acne vulgaris. Our in vitro studies showed that the UCO-SMC3 strain resists adverse gastrointestinal conditions, inhibits the growth of clinical isolates of C. acnes, and reduces the adhesion of the pathogen to keratinocytes. Furthermore, in vivo studies in a mice model of C. acnes infection demonstrated that W. viridescens UCO-SMC3 beneficially modulates the immune response against the skin pathogen. Both the oral and topical administration of the UCO-SCM3 strain was capable of reducing the replication of C. acnes in skin lesions and beneficially modulating the inflammatory response. Of note, orally administered W. viridescens UCO-SMC3 induced more remarkable changes in the immune response to C. acnes than the topical treatment. However, the topical administration of W. viridescens UCO-SMC3 was more efficient than the oral treatment to reduce pathogen bacterial loads in the skin, and effects probably related to its ability to inhibit and antagonize the adhesion of C. acnes. Furthermore, a pilot study in acne volunteers demonstrated the capacity of a facial cream containing the UCO-SMC3 strain to reduce acne lesions. The results presented here encourage further mechanistic and clinical investigations to characterize W. viridescens UCO-SMC3 as a probiotic for acne vulgaris treatment.

This report describes the draft genome sequence of Weissella viridescens UCO-SMC3, isolated from Helix aspersa Müller slime. The reads were generated by a whole-genome sequencing (WGS) strategy on an Illumina MiSeq sequencer and were assembled into contigs with a total estimated size of 1,612,814 bp.

Limosilactobacillus fermentum UCO-979C is a probiotic strain possessing anti-Helicobacter pylori and immunomodulatory activity. The aim of this work was to examine if this strain maintains its probiotic properties and its viability when added to dairy-based ice creams (cookies and cream, Greek yogurt, and chocolate with brownie) or to fruit-based ice creams (pineapple and raspberry) stored at −18 °C for 90 days. The probiotic anti-H. pylori activity using the well diffusion test, its immunomodulatory activity was measured using transforming growth factor beta 1 (TGF-β1) cytokine production by human gastric adenocarcinoma (AGS) cells, and its viability was measured using the microdrop technique. Assays were performed in triplicate. The L. fermentum UCO-979C strain maintained strong anti-H. pylori activity in dairy-based ice creams and mild activity in fruit-based ice cream. The production of pro-inflammatory cytokine TGF-β1 on AGS cells was higher in the probiotic recovered from Greek yogurt ice cream, maintaining a viability exceeding 107 colony-forming units/mL. The addition of the probiotic to ice creams did not significantly influence the physicochemical properties of the product. These data show the great potential of the L. fermentum UCO-979C strain in producing probiotic dairy-based and fruit-based ice creams.

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