Fermented soybean liquid alleviated peptic ulcer through the destruction of acidic proton pump rather than suppression of urease of helicobacter pylori: A kinetic analysis

Fermented soybean liquid (FSL) has been well cited for its broad spectrum of biological effects, yet its documented gastropeptic ulcer (GPU) ameliorating effect is still lacking. It was hypothesized that to avoid the injury exerted by gastric fluid, HP has to be sheltered in chyme emulsions immediately on infection. The HP urease (HPU) and the acidic proton pump (PP) may act as the two-point pH modulator to maintain an optimum pH between 6 and 7, and FSL is able to destroy such a modulating mechanism. FSL exhibited higher contents of isoflavonoids (2.5-17.3-fold) and essential amino acids (1.5-4.0-fold) than the nonfermented. FSL administered at 1 g/20 mL tid for 3 months eradicated Helicobacter pylori (HP) by 82% in 37 volunteers having GPU (p <0.20); simultaneously, the plasma conjugated diene and TBARs levels were significantly resumed (p <0.05). Kinetic analysis based on the conventional urease theory revealed that a cluster of 2.0 × 10⁹ of HP cells is required for a single attack in the gastric lumen at pH 1.0-2.5. To verify the hypothesis, chyme-shelter testing was conducted in artificial gastric fluid (pH 2.4 ± 0.20). Results showed the HP cell viability was time- and size-dependent. At 20 min of contact time, the viability was 100, 4.2, 31.4, 43.3, 57.2, and 82.6%, respectively, in intact, dispersed, and particulate chymes (mesh sizes 80, 60, 40, and 20). The corresponding data became 96.2, 0.0, 14.5, 18.5, 21.3, and 28.6%, respectively, at a contact time of 40 min. Conclusively, the kinetic analysis and the chyme-shelter testing revealed that direct infection by bare HP cells is unlikely in real status. FSL is beneficial to GPU most probably due to its ability to raise blood alkalinity levels, destroying the PP and its ROS suppressing effect.