Complex probiotics can reduce diarrhea by boosting immunity and balancing gut microbiota in weaned piglets

Abstract

Purpose: SOLVENS (SLV) is a zootechnical feed additive based on viable spores of Bacillus licheniformis and Bacillus subtilis. This study aimed to evaluate the effects of SLV on the intestinal health of weaned piglets.

Methods: A total of 360 healthy 24-day-old weaned Duroc × Landrace × Yorkshire piglets were allocated to three treatment groups based on body weight and sex: T1 (Control, CON), T2 (SLV 200, 6.5×10⁸ CFU per kg feed), and T3 (SLV 400, 1.3×10⁹ CFU per kg feed). Each treatment consisted of 30 replicates with four pigs per replicate, and the experiment lasted 42 days. Piglets were fed mash pre-starter feed (days 1-14) and mash starter feed (days 15-42). Growth performance, fecal microorganisms, serum immunity, and intestinal barrier function were assessed. Experimental data were analyzed using SPSS 27.0 for one-way ANOVA, and multiple comparisons were made using the DUNCAN method.

Results: Compared with the control, SLV 200 and SLV 400 significantly reduced diarrhea rate (P < 0.05). SLV 200 increased fecal Lactobacilli and decreased Escherichia coli on day 14 (P < 0.05), while SLV 400 elevated Lactobacilli on days 14 and 42 and reduced E. coli on day 14 (P < 0.05). SLV 200 increased fecal sIgA and serum IgG on day 42 (P < 0.05), whereas SLV 400 elevated serum IgG and IgM on day 14 (P < 0.05) and serum IgA on day 42 (P < 0.05). Additionally, SLV 200 downregulated ileal interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) gene expression (P < 0.05), and SLV 400 reduced TNF-α expression (P < 0.05).

Conclusion: Dietary supplementation with SLV improved intestinal health by modulating gut microbiota and enhancing immunity in weaned piglets.

Keywords: compound probiotics; growth performance; immune modulation; intestinal health; weaned piglets.

Figure 1

Effects of SLV supplementation on fecal microflora of weaned piglets: (A) Lactobacillus; (B) Escherichia coli; (C) Clostridium perfringens. ¹Letters above the bars (a, b) indicate significant differences (P < 0.05) and x and y indicate a trend (0.05 ≤ P < 0.10) between the 3 treatments. (n=15). CON, control group; SLV 200, SOLVENS 200 (6.5×10⁸ CFU per kg feed); SLV 400, SOLVENS 400 (1.3×10⁹ CFU per kg feed). The same figure below. ²LAB, Lactobacillus; E. coli, Escherichia coli; C. perfringens, Clostridium perfringens.

Figure 2

Effects of SLV supplementation on secretory immunoglobulin A in feces of piglets. sIgA, secretory Immunoglobulin A Letters above the bars (a, b) indicate significant differences (P < 0.05) and x and y indicate a trend (0.05 ≤ P < 0.10) between the 3 treatments. (n=15).

Figure 3

Effects of SLV supplementation on serum immunoglobulin of piglets: (A) immunoglobulin A; (B) immunoglobulin G; (C) immunoglobulin M. ¹IgA, immunoglobulin A; IgG, immunoglobulin G; IgM, immunoglobulin M. Letters above the bars (a, b) indicate significant differences (P < 0.05). (n=15).

Figure 4

Spearman correlation among immunoglobulins, fecal microbiota, and diarrhea rate. Brown indicates a positive correlation, and green indicates a negative correlation. (A) Spearman correlation analysis for day 14 (or days 0–14); (B) Spearman correlation analysis for day 42 (or days 15–42). *, **, and *** indicate statistically significant correlations at P < 0.05, P < 0.01, and P < 0.001.

Figure 5

Effects of SLV supplementation on the ileal morphology of weaned piglets. Representative cross-sectional staining of the ileum with periodic acid-Schiff (PAS).

Figure 6

Effect of SLV on gene expression in the ileal mucosa of weaned piglets: (A) Relative expression of pro-inflammatory factors IL-1β, TNF-α and IL-6 in the ileum of weaned piglets; (B) Relative expression of anti-inflammatory factors IL-4, IL-10 in the ileum of weaned piglets; (C) Relative expression of tight junction proteins OCLD, CLDN-1 and ZO-1 in the ileum of weaned piglets; (D) Relative expression of mucins MUC2, MUC3 in the ileum of weaned piglets. ¹ IL-1β, interleukin-1β; TNF-α, tumor necrosis factor-a; IL-6, inter-leukin-6; IL-4, inter-leukin-4; IL-10, interleukin-10; ZO-1, zonula occludens-1; CLDN-1, claudin-1; OCLD, occluding; MUC2, mucin 2; MUC3, mucin 3. Letters above the bars (a, b) indicate significant differences (P < 0.05) and x and y indicate a trend (0.05 ≤ P < 0.10) between the 3 treatments. (n=15).