Dietary supplementation of encapsulated organic acids enhances performance and modulates immune regulation and morphology of jejunal mucosa in piglets.

The aim of the study was to test two encapsulated regimens containing organic acids and/or zinc oxide (ZnO) on weaned piglet performance and jejunal mucosa morphology and immunity. For that, weaned piglets were allocated to treatments including control, supplemented with encapsulated organic acids (ACID group), and supplemented with organic acids and ZnO, both encapsulated (ACIDplus group). Antibiotics were used at similar concentrations in all groups during the first two weeks, but withdrawn from the ACIDplus group during the last three weeks of the experiment. ZnO was given with feed in the Control and ACID groups only during the first two weeks. The experimental period lasted 5 weeks. Piglets from the ACID group exhibited higher average daily gain compared to other groups during the last 3 weeks of the experiment (P<0.05). The ACIDplus group performed similarly with controls. The mucosal height of jejunum was higher in both ACID (P<0.01) and ACIDplus groups compared to controls (P<0.05). Immunohistochemical analysis of jejunal mucosa, showed higher numbers of neutrophils in ACID and ACIDplus groups compared to controls (P<0.01 and P<0.001, respectively). Treatments had the opposite effect on mucosal regulatory T-cells (Foxp3-positive cells) in jejunum, being higher (P<0.001) in control group compared to ACID and ACIDplus groups. The number of CD3-positive cells was higher (P<0.05) in the ACIDplus and control groups compared to the ACID group. In conclusion, the encapsulated products used had beneficial effects on growth performance coexisting with improvements on jejunal histomorphology and modulation of mucosal immunity.

Microbial lysate upregulates host oxytocin.

Neuropeptide hormone oxytocin has roles in social bonding, energy metabolism, and wound healing contributing to good physical, mental and social health. It was previously shown that feeding of a human commensal microbe Lactobacillus reuteri (L. reuteri) is sufficient to up-regulate endogenous oxytocin levels and improve wound healing capacity in mice. Here we show that oral L. reuteri-induced skin wound repair benefits extend to human subjects. Further, dietary supplementation with a sterile lysate of this microbe alone is sufficient to boost systemic oxytocin levels and improve wound repair capacity. Oxytocin-producing cells were found to be increased in the caudal paraventricular nucleus [PVN] of the hypothalamus after feeding of a sterile lysed preparation of L. reuteri, coincident with lowered blood levels of stress hormone corticosterone and more rapid epidermal closure, in mouse models. We conclude that microbe viability is not essential for regulating host oxytocin levels. The results suggest that a peptide or metabolite produced by bacteria may modulate host oxytocin secretion for potential public or personalized health goals.