Antioxidant and Anti-Inflammatory Properties of Probiotic Candidate Strains Isolated during Fermentation of Agave (Agave angustifolia Haw)

Abstract

Agave species are a source of diverse products for human use, such as food, fiber, and beverages, which include mezcal, a distilled beverage produced by spontaneous fermentation. Agave is an excellent source of high amounts of sugars, minerals, and phenolic compounds, which favor the growth of lactic acid bacteria (LAB) and yeast communities. In this work, 20 promising LAB strains with probiotic characteristics were isolated from the agave fermentation stage in mezcal production. The strains belonged to Lactobacillus plantarum (15), Lactobacillus rhamnosus (2), Enterococcus faecium (2), and Lactococcus lactis (1). These isolates were characterized for their resistance under gastrointestinal conditions, such as lysozyme, acid pH, and bile salts. In addition, the adherence of these LABs to human intestinal epithelial cells (Caco-2 and HT-29 cells) was tested in vitro and their antioxidant and immunomodulatory profile was determined using cellular models. Lactobacillus rhamnosus LM07 and Lactobacillus plantarum LM17 and LM19 strains were selected for their antioxidant properties, and their capacities in an oxidative stress model in intestinal epithelial cells IECs (Caco-2 and HT-29 cells) in the presence of hydrogen peroxide were evaluated. Interestingly, Lactobacillus rhamnosus LM07 and Lactobacillus plantarum LM17 and LM19 strains showed anti-inflammatory properties in TNF-α-stimulated HT-29 cells. Subsequently, bacterial strains exhibiting antioxidant and anti-inflammatory properties were tested in vivo in a mouse model with dinitrobenzene sulfonic acid (DNBS)-induced chronic colitis. Weight loss, intestinal permeability, and cytokine profiles were measured in mice as indicators of inflammation. One of the selected strains, Lactobacillus plantarum LM17, improved the health of the mice, as observed by reduced weight loss, and significantly decreased intestinal permeability. Altogether, our results demonstrate the potential of LAB (and lactobacilli in particular) isolated from the agave fermentation stage in mezcal production. Lactobacillus rhamnosus LM07 and Lactobacillus plantarum LM17 strains represent potential candidates for developing new probiotic supplements to treat inflammatory bowel disease (IBD).

Keywords: IBD; Lactobacillus; agave; antioxidant; immunomodulation; probiotics.

Figure 1

Cell surface properties of lactic acid bacteria (LAB) isolated during fermentation of agave by affinity to solvents. Results are presented by the mean ± SEM; * indicates significant (p < 0.05) superiority to L. plantarum Lp115 values.

Figure 2

In vitro adhesion of lactic acid bacteria (LAB) isolated from agave to HT-29 (A) and Caco-2 cells (B). Results are the mean ± SEM from three independent experiments. * Indicates a significant difference as compared to L. plantarum Lp115 (p < 0.05).

Figure 3

DPPH radical-scavenging (A) and hydroxyl radical-scavenging (B) activities of lactic acid bacteria (LAB). Results are the mean from three independent experiments; error bars indicate the mean ± SEM. * indicates a significant difference as compared to L. plantarum Lp115 (p < 0.05).

Figure 4

Effect of LAB isolated from agave samples on IL-8 production on HT-29 cells. Results are presented as means ± SEM. * indicates a significant difference as compared to the PBS group (p < 0.05).

Figure 5

Effect of Lactobacillus strains isolated from agave samples in a DNBS chronic colitis model. (A) Body weight variation of mice, (B) macroscopic score, (C) gut permeability, and (D) MPO/mg of tissue. Results are presented as the means ± SEM. ns: not significant, * Indicates a significant difference as compared to the DNBS group (p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001).