Efficacy of Saccharomyces yeast postbiotics on cell turnover, immune responses, and oxidative stress in the jejunal mucosa of young pigs

Abstract

This study aimed to determine the effects of Saccharomyces yeast postbiotics on cell turnover, immune responses, and oxidative stress in the jejunal mucosa of pigs. Thirty-two newly weaned pigs at 6.05 ± 0.24 kg were assigned to two dietary treatments based on a randomized complete block design. The treatments were control group receiving a basal diet and a group supplemented with Saccharomyces yeast postbiotics (175 g/ton diet) in the basal diet. After 35 d of the study, pigs were euthanized and jejunal mucosa were collected to assess immune status, oxidative stress, barrier markers, cell proliferation, and apoptosis. Saccharomyces yeast postbiotics reduced (P < 0.05) the fecal score from d 3 to d 7 and tended to increase the gene expression of interferon-γ (IFN-γ) (P = 0.071) and mammalian/mechanistic target of rapamycin (mTOR) (P = 0.080), decrease the gene expression of B-cell lymphoma 2-associated X protein 1 (BAX1) (P < 0.05), tended to decrease the gene expression of serum and glucocorticoid-induced protein kinase 1 (SGK1) (P = 0.066), increased (P < 0.05) cell proliferation in the crypts, and tended to increase the villus height (P = 0.078) and crypt depth (P = 0.052) in the jejunum. In conclusion, the supplementation of Saccharomyces yeast postbiotics in nursery diets reduced diarrhea within the first week after weaning and provided protection to the villi in the jejunum by enhancing the immune responses of nursery pigs, promoting crypt cell proliferation, and reducing the expression of genes associated with apoptosis without affecting inflammatory and oxidative stress status in the jejunum of the nursery pigs.

Keywords: Saccharomyces yeast postbiotics; Apoptosis; Cell proliferation; Immunocompetence; Jejunal mucosa; Nursery pigs.

Figure 1

Representative images of immunohistochemistry (Ki67) staining for jejunal morphology and crypt cell proliferation were obtained. Ten images at 40 × magnification of well-oriented villi and their associated crypts ((A): Control; (B): Postbiotic) were acquired for measuring villus height (from the top to the base of the villus, as indicated with a double arrow line in blue) and crypt depth (from the base of the villus to the bottom of the crypt, as indicated with a double arrow line in red). Ten images at 100 × magnification of the crypts ((C): control; (D): Postbiotic) were captured for counting the Ki67 + staining cells as an indicator of crypt cell proliferation.