Lysozyme Transgenic Goats’ Milk Influences Gastrointestinal Morphology in Young Pigs ,

Abstract

Transgenesis provides a method of expressing novel proteins in milk to increase the functional benefits of milk consumption. Transgenic goats expressing human lysozyme (hLZ) at 67% of the concentration in human breast milk were produced, thereby enhancing the antimicrobial properties of goats' milk. The objective of this study was to investigate the impact of pasteurized milk containing hLZ on growth, the intestinal epithelium, and an enteropathogenic Escherichia coli (EPEC) infection in young weaned pigs. Pigs were placed into 4 groups and fed a diet of solid food and either control (nontransgenic) goats' milk or milk from hLZ-transgenic goats. Growth was assessed by weight gain. Nonchallenged pigs were necropsied after 6 wk, whereas the remaining pigs were necropsied at 7 wk following bacterial challenge. We determined the numbers of total coliforms and E. coli and examined small intestinal histology for all pigs. Complete blood counts were also determined pre- and postchallenge. Challenged pigs receiving hLZ milk had fewer total coliforms (P = 0.029) and E. coli (P = 0.030) in the ileum than controls. hLZ-fed pigs also had a greater duodenal villi width (P = 0.029) than controls. Additionally, nonchallenged hLZ-fed pigs had fewer intraepithelial lymphocytes per micron of villi height (P = 0.020) than nonchallenged controls. These results indicate that the consumption of pasteurized hLZ goats' milk has the potential to improve gastrointestinal health and is protective against an EPEC in young weaned pigs. These same benefits may occur in young children if they were to consume milk from hLZ-transgenic goats.

Effects of immune supplementation and immune challenge on oxidative status and physiology in a model bird: implications for ecologists

“…Because orally administered lysozyme must interact with the gastrointestinal tract and be absorbed to fully exert an effect, we used a dose based more on pharmacological effects than on naturally occurring physiological concentrations. Specifically, the dose we used was equal to the higher of two concentrations determined to be non-toxic in rats (Cerven et al, 2008), in line with the highest level provided to growing chicks (Humphrey et al, 2002), and approximately an order of magnitude higher than the dose provided to growing pigs (Brundige et al, 2008). …”

“…Rather, lysozyme-supplemented pigeons exhibited stronger inflammatory responses to LPS with greater increases in oxidative damage and oxygen consumption. Previous studies suggest that preventative and therapeutic administration of lysozyme has net positive effects in terms of growth and health (Sava, 1996;Humphrey et al, 2002;Brundige et al, 2008). In young pigs, consumption of lysozyme-supplemented milk improves gastrointestinal health and protects against bacterial infections without limiting growth (Brundige et al, 2008).…”

“…Previous studies suggest that preventative and therapeutic administration of lysozyme has net positive effects in terms of growth and health (Sava, 1996;Humphrey et al, 2002;Brundige et al, 2008). In young pigs, consumption of lysozyme-supplemented milk improves gastrointestinal health and protects against bacterial infections without limiting growth (Brundige et al, 2008). In chicks, lysozyme supplementation exerts similar effects to the preventative administration of antibiotics (Humphrey et al, 2002), perhaps by limiting the energy diverted towards background inflammation (sensu Roura et al, 1992).…”

“…Lysozyme is characterized by its ability to lyse susceptible bacteria, but the molecule also possesses numerous other anti-inflammatory, antibacterial and antiviral functions (reviewed in Sava, 1996). Lysozyme concentrations can vary naturally (among eggs/chicks within clutches and through time in adult birds) (Saino et al, 2002), and can positively affect immune function, health status and growth when orally administered (Sava, 1996;Siwicki et al, 1998;Humphrey et al, 2002;Brundige et al, 2008).…”

Consumption of Lysozyme-Rich Milk Can Alter Microbial Fecal Populations

“…We have developed transgenic dairy goats that express human lysozyme (HLZ) in their milk at 68% the level normally found in human milk (29) with the goal of incorporating the beneficial protective properties of human milk into readily available livestock milk in order to promote the intestinal and overall health of people of all ages. We previously demonstrated that consumption of milk from HLZ-transgenic goats by animal models results in the modulation of Escherichia coli and total coliform levels in the small intestine as determined using standard culture techniques (30), resistance to intestinal colonization by pathogenic E. coli (5), and histological and cytokine changes coupled with increases in serum metabolite makers indicative of improved gastrointestinal (GI) health (6,10).…”