In vitro inhibition ofHelicobacter pyloribyEnterococcus faeciumGM-1

Abstract

A strain of Enterococcus faecium that exhibits antibacterial activity against Helicobacter pylori was isolated from the feces of newborn babies. This strain was selected for its ability to inhibit the growth of H. pylori and to withstand harsh environmental conditions, such as acidic pH and high bile concentration. Biochemical tests and 16S rRNA sequencing specific for Enterococcus faecium GM-1 were used to identify the isolated bacterial strain. In vitro studies were used to investigate the inhibitory effects of E. faecium GM-1 on H. pylori. These results showed that the culture supernatant of E. faecium GM-1 significantly decreased the viability and urease activity of H. pylori. This inhibitory activity remained after adjustment of pH of culture supernatant to neutral. However, treatment with proteolytic enzymes reduced the anti-H. pylori activity of GM-1. Therefore, some substance(s) of E. faecium GM-1 other than pH and lactic acid might be associated with this inhibitory activity. Analysis by electron microscopy also demonstrated that the addition of GM-1 destroyed the cell structure of H. pylori. Additional studies suggested that the binding of H. pylori to human colonial cells decreased in the presence of GM-1.

Anti-Helicobacter pylori activity of fermented milk with lactic acid bacteria

“…Recently, several studies have found that SCS from LAB exhibit antibacterial activity against H. pylori both in vitro and in vivo 15–18, 41. It has been reported that lactic acid and other potentially inhibitory metabolites such as acetic acid, formic acid and proteins in fermented milk or culture supernatant fractions have a direct effect on pathogens 18, 20, 22, 28, 42–44.…”

Antagonistic Activity of Spent Culture Supernatants of Lactic Acid Bacteria against Helicobacter Pylori Growth and Infection in Human Gastric Epithelial AGS Cells

“…Researchers have found that a 1% solution of lactic acid (about 100 mmol/L) was sufficient to inhibit the growth and urease activity of H. pylori (Bhatia and others 1989; Aiba and others 1998). Recently, several studies have reported that SCS from lactic acid bacteria exhibits antibacterial activity against H. pylori (Michetti and others 1999; Kang and Lee 2005). It has been demonstrated that the coccoid form of H. pylori results in a loss of infectivity (Kusters and others 1997; Enroth and others 1999).…”

Probiotics in Gastrointestinal Diseases: All that Glitters Is Not Gold

“…The mechanisms through which probiotics can antagonise H. pylori include inhibition of H. pylori growth by secreting antibacterial substances or by hindering the activity of urease enzyme and reduction of H. pylori infectivity by reducing its ability to adhere to gastric epithelial cells, by strengthening mucosal barrier, and by regulating immune and inflammatory responses of the host (Fig. 1) [22][23][24][25].…”