Potential Role of Probiotic Strain Lactiplantibacillus plantarum in Control of Histamine Metabolism

Abstract

Histamine intolerance is a condition that occurs when there is an imbalance between the accumulation and degradation of histamine within the body. Excess histamine is metabolized and then degraded by two enzymes, of which the most abundant is the vesicular diamine oxidase (DAO). An imbalance or a state of dysbiosis of the intestinal microbiota has been observed in patients with histamine intolerance compared to healthy individuals. Studies indicate that the administration of bifidobacteria or lactobacilli alone or in mixtures can alter colonic microbiota populations and metabolic activities. The present study has evaluated the ability of a probiotic bacterial strain to stimulate the release of cellular DAO from an in vitro model of the human intestinal epithelial barrier. The results indicate that, under the experimental conditions used, probiotic strain Lactiplantibacillus plantarum LP115 has a significant stimulatory effect on DAO secretion in adenocarcinoma cell line HT-29.

Keywords: HT29 cells; Lactiplantibacillus plantarum LP115; diamine oxidase (DAO); histamine intolerance; probiotics.

Figure 1

Acidification kinetics of L. plantarum (Lp) in skim and whole milk.

Figure 2

MTT results expressed as the relative cell survival. HT-29 cells were challenged using L. plantarum probiotics in three different colony-forming unit (CFU)/cell ratios (i.e., 0.1:1, 1:1, and 10:1) for 24 h. Statistical analysis: one-way ANOVA followed by Bonferroni post hoc, (only statistically significant differences are labeled in the chart). Lp: L. plantarum.

Figure 3

DAO levels in supernatants of L. plantarum-treated HT-29 cells. HT-29 cells were treated using L. plantarum probiotic in three different colony-forming unit (CFU)/cell ratios (i.e., 0.1:1, 1:1, and 10:1) for 2 h (A) and 4 h (B) of treatment. Data are expressed as the mean ± SD of three independent experiments. Statistical analysis: one-way ANOVA followed by Bonferroni post hoc. * p-value < 0.05, ** p-value < 0.01, *** p-value < 0.001, **** p-value ≤ 0.0001 (n = 3). (only statistically significant differences are labeled in the charts), Lp, L. plantarum.

Figure 4

Histamine levels in supernatants of L. plantarum-treated HT-29 cells. HT-29 cells were treated using L. plantarum probiotics in three different colony-forming unit (CFU)/cell ratios (i.e., 0.1:1, 1:1, and 10:1) for 2 h (A) and 4 h (B) of treatment in the presence of histamine (115 ng/mL). Data are expressed as the mean ± SD of three independent experiments. Statistical analysis: one-way ANOVA followed by Bonferroni post hoc. * p-value < 0.05, ** p-value < 0.01, *** p-value < 0.001 (n = 3) (only statistically significant differences are labeled in the charts). Lp: L. plantarum.

Figure 5

Western blot analysis for DAO protein in L. plantarum-treated HT-29 cells challenged using three different colony-forming unit (CFU)/cell ratios (i.e., 0.1:1, 1:1, and 10:1) after 2 h of treatment. The Western blot signals were normalized using α-tubulin as the loading control. Results are expressed as mean ± SD of the relative normalized expression. Statistical analysis: one-way ANOVA followed by Bonferroni post hoc.

Figure 6

Western blot analysis for DAO protein in L. plantarum-treated HT-29 cells challenged using three different colony-forming unit (CFU)/cell ratios (i.e., 0.1:1, 1:1, and 10:1) after 4 h of treatment. The Western blot signals were normalized using α-tubulin as the loading control. Results are expressed as mean ± SD of the relative normalized expression. Statistical analysis: one-way ANOVA followed by Bonferroni post hoc. * p-value < 0.05. Lp: L. plantarum.