Gut microbiota mediates the protective role of Lactobacillus plantarum in ameliorating deoxynivalenol-induced apoptosis and intestinal inflammation of broiler chickens

Abstract

The protection of Lactobacillus plantarum JM113 against deoxynivalenol (DON)-induced apoptosis and intestinal inflammation on the jejunum of broiler chickens and the potential roles of gut microbiota were determined. A total of 144 one-day-old male broilers (Arbor Acres) were randomly divided into 3 treatment groups consisting of 6 replicates with 8 birds per replicate, including the CON (basal diet), the DON (basal diet + 10 mg/kg DON), and the DL (basal diet + 10 mg/kg DON + 1 × 10⁹ CFU/kg L. plantarum JM113). The DON-diet decreased (P < 0.05) the mRNA expression of mucosal defense proteins and mechanistic target of rapamycin pathway genes. Meanwhile, DON challenge significantly increased Bcl-2-associated X gene/B-cell lymphoma 2 gene (Bcl-2) in the jejunum (P < 0.05) and demonstrated proapoptosis status. In contrast, the DL group showed normal immunity-related gene expression of jejunal mucosa and manifested a superior antiapoptosis status. Adding L. plantarum JM113 significantly raised (P < 0.05) propionic acid, n-butyric acid, and total short-chain fatty acids concentrations in cecal contents of birds fed with DON diet. In addition, DON exposure altered bacterial community structure and disturbed the abundance of several bacterial phyla, families, and genera, leading to dysbiosis. Supplementation with JM113 shifted the gut microbiota composition to that of the CON group. Finally, Spearman correlation analysis suggested that most positive correlations with the mRNA expression of immunity-related and apoptosis-regulatory gene were observed within the phylum Bacteroidetes, and most negative correlations with the indicators were observed within the phylum Firmicutes. The mRNA expression of Bcl-2, TLR2, mTOR, Raptor, and RPS6KB1 (P < 0.05), which are regarded as important cell proliferation and antiapoptosis parameters, were significantly negatively associated with the relative abundances of norank_f__Erysipelotrichaceae, Subdoligranulum, and Anaeroplasma, whereas they had a strong positive correlation with Ruminococcaceae_UCG-004, Alistipes, and Ruminococcaceae_NK4A214_group. These results implied that L. plantarum JM113 supplementation could ameliorate DON-induced apoptosis and intestinal inflammation via manipulating the bacterial community composition and could be used as a potential candidate to attenuate intestinal impairments.

Keywords: Lactobacillus; broiler chicken; deoxynivalenol; gut microbiota; intestinal inflammation.

Figure 1

IL-10 and IL-12 production by spleen cells after stimulation with L. plantarum JM113. The RPMI-1640 medium alone was used as a negative control (CON), while lipopolysaccharide (10 μg/mL) was used as a positive control (LPS). L. plantarum JM113 (10⁸ to 10⁹ cfu/mL) were cultured with spleen cells. After 48 h of culture, IL-10 and IL-12 produced in the culture supernatants were analyzed. Each value represents the mean value ± SEM. ^a–c Numbers with different superscripts differ statistically at P ≤ 0.05. Abbreviation: IL, interleukin.

Figure 2

Effects of L. plantarum JM113 and deoxynivalenol on the relative mRNA expression of immunity-related and apoptosis-regulatory gene in jejunal mucosa of 42-day-old broilers. (A) β-Defensin-8 and polymeric Ig receptor (PIgR); (B) Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4); (C) B-cell lymphoma 2 gene (Bcl-2) and Bcl-2-associated X gene (Bax); (D) mechanistic target of rapamycin (mTOR), regulatory-associated protein of mTOR complex 1 (Raptor), and ribosomal protein S6 kinase polypeptide 1 (RPS6KB1).Values are means ± SEM (n = 6), and different letters denote significant difference (P < 0.05). Dietary treatments were as follows: CON = basal diet; DON = basal diet +10 mg deoxynivalenol per kg diet; DL = basal diet +10 mg deoxynivalenol per kg diet +1 × 10⁹ cfu L plantarum JM113 per kg diet.

Figure 3

Effects of L. plantarum JM113 and deoxynivalenol on total short-chain fatty acids (SCFA), acetic acid, propionic acid, isobutyric acid, n-butyric acid, isopentanoic acid, and n-pentanoic acid concentrations in cecal digesta of 42-day-old broilers. Values are means (n = 6), and different letters denote significant difference (P < 0.05). Dietary treatments were as follows: CON = basal diet; DON = basal diet +10 mg deoxynivalenol per kg diet; DL = basal diet +10 mg deoxynivalenol per kg diet +1 × 10⁹ cfu L plantarum JM113 per kg diet.

Figure 4

Effects of L. plantarum JM113 on cecal microbiota of broiler chickens challenged with deoxynivalenol. (A) Percent of community abundance on phylum level; (B) percent of community abundance on family level; (C) Chao1 richness; (D) Shannon index; (E) Simpson index; (F) Cladogram showing the phylogenetic distribution of the bacterial lineages; (G) Indicator bacteria with linear discriminant analysis (LDA) scores of 2 or greater in bacterial communities, different-colored regions represent different treatments, circles indicate phylogenetic levels from phylum to genus, and the diameter of each circle is proportional to the abundance of the group. Values are means ± SEM (n = 6), and different letters denote significant difference (P < 0.05), *P < 0.05, † 0.10 < P < 0.05. Dietary treatments were as follows: CON = basal diet; DON = basal diet +10 mg deoxynivalenol per kg diet; DL = basal diet +10 mg deoxynivalenol per kg diet +1 × 10⁹ cfu L plantarum JM113 per kg diet.

Figure 5

Correlation analysis between short-chain fatty acid (SCFA) concentrations and relative abundance of the top 50 genera in cecal digesta of 42-day-old broilers fed diets with deoxynivalenol and with or without L. plantarum JM113. Colors refer to the degree of correlation. *0.01 < P ≤ 0.05,**0.001 < P ≤ 0.01,***P ≤ 0.001.

Figure 6

Correlation matrix between mRNA expression of immunity-related and apoptosis-regulatory gene with relative abundance of the top 50 genera in cecal digesta of 42-day-old broilers fed diets with deoxynivalenol and with or without L. plantarum JM113. Colors refer to the degree of correlation. * 0.01 < P ≤ 0.05,** 0.001 < P ≤ 0.01,***P ≤ 0.001. Abbreviations: Bcl-2, B-cell lymphoma 2 gene; Bax, Bcl-2-associated X gene; mTOR, mechanistic target of rapamycin, PIgR, β-Defensin-8 and polymeric Ig receptor; Raptor, regulatory-associated protein of mTOR complex 1; RPS6KB1, ribosomal protein S6 kinase polypeptide 1; TLR2, Toll-like receptor 2; TLR4, Toll-like receptor 4.