Abstract
[Display omitted]
•A novel strain identified as L. helveticus WHH2580 with immunomodulatory effects and milk fermenting ability was selected.•Neither antibiotic resistance nor virulence gene was found in the genome of strain WHH2580.•This strain exhibited great resistance against gastrointestinal conditions, including strong adhesion capability to HT-29 cells.•Milk fermented with WHH2580 also exhibits great immune-enhancing activity.
Several bacterial strains from traditional fermented foods were screened on a large scale to identify novel candidate probiotics that can be used as starters. Two in vitro cellular models were used to identify strains with immunomodulatory activity. Three strains with pro-inflammatory activity were selected, and their recovery effect was tested in vivo in an immunosuppressed murine model. Only Lactobacillus helveticus WHH2580 enhanced natural killer cell activity and splenic lymphocyte proliferation. Furthermore, milk fermented using the strain WHH2580 exerted an immunomodulatory effect with enhanced resistance to gastrointestinal conditions, including strong adhesion to HT-29 cells. Whole genome sequencing revealed the presence of a circular chromosome and two circular plasmids; no antibiotic resistance or putative virulence genes were discovered. These findings indicate the safety and positive role of L. helveticus WHH2580 in maintaining host health in mice and suggest that milk fermented with this strain can deliver this strain and thus promote immunity.