Effect of Bifidobacterium bifidum BF-1 on gastric protection and mucin production in an acute gastric injury rat model

Homeostasis in the stomach environment is maintained by the balance of protective factors such as gastric mucus and aggressive factors such as gastric acid, stress, alcohol, and drugs. An overload of aggressive factors that upsets this balance can induce gastric injury. Fermented milk that contains Bifidobacterium bifidum BF-1 (BF-1), a probiotic strain, and Streptococcus thermophilus YIT 2021 (ST) is known to improve Helicobacter pylori-associated gastritis in humans. Here, we investigated the gastroprotective potential of BF-1 in a rat model of acid-ethanol-induced acute gastric injury to fully elucidate its potential compared with ST. Living BF-1, ST, or vehicle was orally administrated to rats, and acid-ethanol gastric injury was induced 2 h later. The gastric injury rate was determined and shown to be significantly lower in the BF-1 group than in the vehicle group, which showed a similar level to the ST group. The production of gastric mucin and the expression of several target genes associated with protection and inflammation were examined before and after induction of gastric injury. Interestingly, mucin 5ac (muc5ac) gene expression in gastric corpus samples and gastric mucin production in stomach samples from the BF-1 group, but not the ST group, were significantly higher than those in the respective samples from the vehicle group. These findings indicate that BF-1 has the potential to provide gastroprotection, alleviating acute gastric injury by enhancing the production of gastric mucin in a rat model.