Beneficial Health Effects of Malic Acid Water Treatment on Cultured Intestinal Epithelial Cells and Functional Neutrophils

Abstract

The Swiss company Evodrop has developed a malic acid granulate cartridge technology to reduce calcium carbonate deposition in water pipes and improves the quality of drinking water. Cell biological methods were used to investigate whether tap water, after passing through the filter system with the malic acid granulate cartridge, has additional beneficial effects in comparison to the original tap water. By using cultured intestinal epithelial cells, we examined the regeneration and the intestinal epithelial barrier integrity as well as the anti-inflammatory potential of this water treatment. The regeneration of the intestinal epithelial cells was significantly stimulated by the malic acid filter cartridge treatment when compared to the initial tap water. The residual cell-free area was 17.3 ± 1.7% (mean ± standard deviation) for the untreated tap water and only 10.5 ± 3.0% (mean ± standard deviation) for the tap water after malic acid filter cartridge treatment. This difference in colonized area was statistically significant (p ≤ 0.05). In addition, the cell layers incubated with the untreated tap water had a transepithelial electrical resistance (TEER) of 1,522 ± 111 Ω/cm2 (mean ± standard deviation) and the cells incubated with the tap water after malic acid filter cartridge treatment had a TEER of 4,183 ± 495 Ω/cm2 (mean ± standard deviation). This represents an increase in intestinal epithelial barrier integrity by more than 2.5-fold and was statistically highly significant (p ≤ 0.01). Both water samples caused a concentration-dependent reduction in endogenous radical formation during an oxidative burst of functional neutrophils as inflammatory-mediating cells. However, the reduction of radical formation, and thus also the anti-inflammatory effect, was 22 ± 4.7% (mean ± standard deviation; p ≤ 0.01) better with the tap water after malic acid filter cartridge treatment than with the untreated tap water at a concentration of 40 vol%. Even at 10 vol%, the tap water after malic acid filter cartridge treatment reduced radical formation by 15.2 ± 6.6% (mean ± standard deviation; p ≤ 0.05) when compared with the untreated tap water. The cell culture tests performed in this study proved that tap water, after passing through the filter system with the malic acid granulate cartridge from Evodrop AG, achieved a considerable improvement in quality. This was demonstrated in intestinal epithelial cells by the significant increase in cellular regeneration and integrity of the intestinal epithelial barrier and by the reduction in radical formation of inflammation-mediating cells. Therefore, the malic acid water treatment can contribute to maintain and improve intestinal health and human well-being.