Influence of dietary supplementation with flaxseed and lactobacilli on the mucosal morphology and proliferative cell rate in the jejunal mucosa of piglets after weaning.

The aim of the study was to investigate the influence of flaxseed and lactobacilli supplementation to the diet of piglets during the time period between 10 days before and 21 days after weaning. The morphometry of the jejunal mucosa and proliferative ratio of both epithelial and lamina propria cells were compared with those found in a group of piglets fed with the usual diet added with sunflower oil during the same time period. The addition of flaxseed oil to the diet significantly increased the crypt depth in comparison with both groups supplemented with sunflower (P < 0.05 and 0.001 respectively) on the weaning day. Moreover, the flaxseed addition caused a significant decrease in villus height (P < 0.01) and crypt depth (P < 0.01) 21 days postweaning in comparison with the sunflower group. The proliferative ratio of the epithelial cells in the sunflower group on the weaning day was significantly higher than in both flaxseed groups (P < 0.01). Paradoxically, significantly higher proliferative activity in the mucosal connective tissue in the group with flaxseed supplementation in comparison with the sunflower group was observed on the day of weaning, as well as 3 days later (P < 0.05 both). A combination of flaxseed with lactobacilli showed significantly lower proliferative activity in the connective tissue cells from weaning up to 7 days after weaning (P < 0.05 all) in comparison with the flaxseed group.

Influence of dietary supplementation with flaxseed and lactobacilli on the cells of local innate immunity response in the jejunal mucosa in piglets after weaning.

A histological study was designed to determine the influence of flaxseed and/or lactobacilli inclusion in the diet of piglets from 10 days before to 21 days after weaning. The selected inflammatory cell population incidence in the piglet jejunal mucosa was investigated. Significantly higher numbers of myeloperoxidase-positive (P<0.01) and CD163-positive (P<0.001) cells in the jejunal mucosa were recorded on the weaning day and for 7 days after (P<0.001 and P<0.01, respectively) in the flaxseed group compared with the basal diet. The number of intraepithelial lymphocytes was also significantly increased until 3 days after weaning (P<0.001). A prolonged significant increase in the myeloperoxidase-positive cells and intraepithelial lymphocyte numbers in the flaxseed+lactobacilli group was detected. In contrast, the number of CD163-positive cells in the flaxseed+lactobacilli group was significantly lower on the day of weaning (P<0.05) and 3 days after (P<0.01). The same effect was observed in the group with lactobacilli alone during the first 3 days after weaning (P<0.05 and P<0.01, respectively) and these findings indicate down-regulation of CD163 expression in the jejunal mucosa by lactobacilli. The presence of lactobacilli in the diet had a stimulatory effect on goblet cell quantity in the epithelium (P<0.001) and a distinct 50% reduction in the flaxseed group (P<0.01) compared with the basal diet was observed on the weaning day. A significant increase in myeloperoxidase-positive cell number in the jejunal mucosa in the flaxseed+lactobacilli group was the only significant difference (P<0.05 and P<0.01, respectively) found 21 days after weaning in comparison with all the other groups, indicating the pro-inflammatory effect of this feed additive combination. We conclude that dietary supplementation with flaxseed and lactobacilli on the cells of local innate immunity response in the jejunal mucosa in piglets after weaning might be linked with significant anti-inflammatory effects in the jejunal mucosa.

The influence of omega-3 polyunsaturated fatty acids (omega-3 pufa) on lactobacilli adhesion to the intestinal mucosa and on immunity in gnotobiotic piglets.

The effect of application of omega-3 polyunsaturated fatty acids (omega-3 PUFA) on intestinal colonization by Lactobacillus paracasei and on cellular immunity has been investigated in gnotobiotic pigs. The administration of polyunsaturated fatty acids positively affected the adhesion of Lactobacillus paracasei to the jejunal mucosa of gnotobiotic piglets. When compared to the control group, the number of Lactobacillus paracasei adhering to the jejunal mucosa was by 12% higher in piglets of the experimental group (5.10 log 10/cm2 vs. 4.55 log 10/cm2). The respective counts of Lactobacillus paracasei adhering to the ileal and colonic mucosa of 28 day old gnotobiotic piglets reached 4.45 and 5.05 log 10/cm2 in group C and 4.44 and 4.95 log 10/cm2 in group E. Omega-3 PUFA supplementation increased the phagocytic activity of neutrophils by almost 100% on day 28 of life as well as the subpopulations of lymphocytes (CD8) in the peripheral blood of germ-free piglets on day 21 of life. Our results indicate that the action of probiotics in the gut may be modulated by dietary PUFA. The stimulatory effect of PUFA upon adhesion of lactobacilli could be used for enhancing the effectiveness of probiotics in inhibiting digestive tract pathogens.