Probiotic Lactobacillus fermentum UCO-979C biofilm formation on AGS and Caco-2 cells and Helicobacter pylori inhibition

Abstract

The ability of the human isolate Lactobacillus fermentum UCO-979C to form biofilm and synthesize exopolysaccharide on abiotic and biotic models is described. These properties were compared with the well-known Lactobacillus casei Shirota to better understand their anti-Helicobacter pylori probiotic activities. The two strains of lactobacilli synthesized exopolysaccharide as detected by the Dubois method and formed biofilm on abiotic and biotic surfaces visualized by crystal violet staining and scanning electron microscopy. Concomitantly, these strains inhibited H. pylori urease activity by up to 80.4% (strain UCO-979C) and 66.8% (strain Shirota) in gastric adenocarcinoma (AGS) cells, but the two species showed equal levels of inhibition (~84%) in colorectal adenocarcinoma (Caco-2) cells. The results suggest that L. fermentum UCO-979C has probiotic potential against H. pylori infections. However, further analyses are needed to explain the increased activity observed against the pathogen in AGS cells as compared to L. casei Shirota.

The Exopolysaccharide of Lactobacillus fermentum UCO-979C Is Partially Involved in Its Immunomodulatory Effect and Its Ability to Improve the Resistance against Helicobacter pylori Infection

“…Our previous in vitro studies have clearly demonstrated the ability of L. fermentum UCO-979C to inhibit H. pylori growth and adhesion to human gastric epithelial cells [15] and to beneficially regulate the inflammatory response triggered by the pathogen in both epithelial cells and macrophages [17]. In this work, in a first set of experiments, we aimed to confirm the immunomodulatory and anti-H. pylori effects of L. fermentum UCO-979C in an in vivo animal model.…”

“…We have reported that L. fermentum UCO-979C produces large amount of EPS and is able to form biofilms on AGS and Caco-2 cell lines, inhibiting the colonization by H. pylori by up to 80% [15]. Thus, it was concluded that the EPS was a key molecule in the ability of L. fermentum UCO-979C to inhibit H. pylori colonization.…”

“…L. fermentum CRL973 was obtained from the CERELA-CONICET culture collection (Tucumán, Argentina). Lactobacilli strains were grown in Mann-Rogosa-Sharpe Agar (MRS) (Difco, Lawrence, KS, USA) at 37 • C. After an overnight growth, bacteria were transferred to MRS broth and cultured at 37 • C until stationary phase [15][16][17]. Afterwards, the bacteria were pelleted (3000× g for 10 min), washed twice with phosphate-buffered saline (PBS) and suspended in specific media for in vivo or in vitro assays.…”

“…Thus, probiotics have appeared as an alternative to modulate stomach microbiota and/or gastric inflammation and to reduce the severity and complications of H. pylori infection [13,14]. In this regard, our previous studies demonstrated the benefits of Lactobacillus fermentum UCO-979C against the pathogenic bacteria H. pylori, which were related to its capability of forming biofilms [15]. L. fermentum UCO-979C inhibited bacterial growth, reduced H. pylori urease activity, decreased pathogen adhesion to human gastric epithelial cells and beneficially regulated the inflammatory response in in vitro model by reducing the inflammatory chemokine IL-8 [16].…”

What Roles Do Probiotics Play in the Eradication of Helicobacter pylori? Current Knowledge and Ongoing Research

“…DOB value is affected by many factors, such as the density of HP colonization, urease activity, and gastric emptying. Different probiotics can reduce the DOB value by inhibiting urease activity [ 35 ] or decreasing the attachment of HP to the gastric mucosa, suppressing the HP density [ 36 ].…”