Beneficial Effects of Natural Mineral Waters on Intestinal Inflammation and the Mucosa-Associated Microbiota

Abstract

Natural mineral water (NMWs) intake has been traditionally used in the treatment of various gastrointestinal diseases. We investigated the effect of two French NMWs, one a calcium and magnesium sulphate, sodium chloride, carbonic, and ferruginous water (NMW1), the other a mainly bicarbonate water (NMW2) on the prevention of intestinal inflammation. Intestinal epithelial cells stimulated with heat inactivated Escherichia coli or H₂O₂ were treated with NMWs to evaluate the anti-inflammatory effects. Moderate colitis was induced by 1% dextran sulfate sodium (DSS) in Balbc/J mice drinking NMW1, NWW2, or control water. General signs and histological features of colitis, fecal lipocalin-2 and pro-inflammatory KC cytokine levels, global mucosa-associated microbiota, were analyzed. We demonstrated that both NMW1 and NMW2 exhibited anti-inflammatory effects using intestinal cells. In induced-colitis mice, NMW1 was effective in dampening intestinal inflammation, with significant reductions in disease activity scores, fecal lipocalin-2 levels, pro-inflammatory KC cytokine release, and intestinal epithelial lesion sizes. Moreover, NMW1 was sufficient to prevent alterations in the mucosa-associated microbiota. These observations, through mechanisms involving modulation of the mucosa-associated microbiota, emphasize the need of investigation of the potential clinical efficiency of such NMWs to contribute, in human beings, to a state of low inflammation in inflammatory bowel disease.

Keywords: intestinal inflammation; mucosa-associated microbiota; natural mineral water.

Figure 1

Secretion of the pro-inflammatory cytokine IL-8 by T84 cells after stimulation with an LF82 bacterial lysate (A) or exposure to H₂O₂ (B) in the presence of 50 µL of different waters (distilled water or NMW1 or NMW2). The results are presented as the mean ± SEM of at least five independent experiments. Statistical comparisons were carried out by one-way ANOVA with the Bonferroni post hoc test (** p < 0.01, *** p < 0.001, **** p < 0.0001, ns—not significant) after normality testing using the Kolmogorov–Smirnov test.

Figure 2

Effect of the administration of NMW1 or NMW2 on a DSS-induced inflammation model. (A) Experimental protocol. (B) Evaluation of the disease activity index (DAI) on days 4, 11, and 18. (C) Production of the proinflammatory cytokine KC by the colonic mucosa. (D) Determination of fecal lipocalin-2 levels. The results are presented as the median. Statistical comparisons were carried out after normality testing using Kolmogorov–Smirnov tests, and subsequent one-way ANOVA with the Bonferroni post hoc test was performed (* p < 0.05, ** p < 0.01).

Figure 3

Effect of the administration of NMW1 or NMW2 on histological lesions. (A) Global histological score. (B) Infiltration of immune cells into the colonic mucosa. (C) Evaluation of epithelial lesions in the colonic mucosa. (D) HES staining of the colonic mucosa showing epithelial lesions (bar represents 50 µm). The results are presented as the median. Statistical comparisons were carried out after normality testing using Kolmogorov–Smirnov tests, and subsequent one-way ANOVA with the Bonferroni post hoc test was performed (* p < 0.05).

Figure 4

Analysis of the composition of the microbiota associated with the colonic mucosa of mice treated with DSS that received or did not receive NMW1 or NMW2. (A) Analysis of beta diversity. (B) Comparison of the microbiota at the phylum level. (C) Differential analysis of the comparison of the microbiota (LEfSe) between the three conditions. (D) Variations in the abundances of different species between the three conditions.