Effects of Dietary Maltol on Innate Immunity, Gut Health, and Growth Performance of Broiler Chickens Challenged With Eimeria maxima

Abstract

Two studies were conducted to evaluate the effects of maltol as a postbiotic on innate immunity, gut health, and enteric infection. In the first study, an in vitro culture system was used to evaluate the effects of maltol on the innate immune response of chicken macrophage cells (CMC), gut integrity of chicken intestinal epithelial cells (IEC), anti-parasitic activity against Eimeria maxima, and differentiation of quail muscle cells (QMC) and primary chicken embryonic muscle cells (PMC). All cells seeded in the 24-well plates were treated with maltol at concentrations of 0.1, 1.0, and 10.0 μg. CMC and IEC were stimulated by lipopolysaccharide to induce an innate immune response, and QMC and PMC were treated with 0.5 and 2% fetal bovine serum, respectively. After 18 h of incubation, pro-inflammatory cytokines, tight junction proteins (TJPs), and muscle cell growth markers were measured. In the second study, the dietary effect of maltol was evaluated on disease parameters in broiler chickens infected with E. maxima. Eighty male 1-day-old broiler chickens were allocated into the following four treatment groups: (1) Control group without infection, (2) Basal diet with E. maxima, (3) High maltol (HI; 10.0 mg /kg feed) with E. maxima, and (4) Low maltol (LO; 1.0 mg/kg feed) with E. maxima. Body weights (BW) were measured on days 0, 7, 14, 20, and 22. All chickens except the CON group were orally infected with 104E. maxima per chicken on day 14. Jejunum samples were collected for gut lesion scoring, and the gene expression of cytokines and TJPs. Data was analyzed using PROC MIXED in SAS. In vitro, maltol not only increased TJPs in IEC and cytokines in the LPS-stimulated CMC but also showed direct cytotoxicity against sporozoites of E. maxima. In vivo, the HI group improved the BW, reduced the gut lesion scores and fecal oocyst shedding, and decreased jejunal TNFSF15 and IL-1β expression in E. maxima-infected chickens. In conclusion, these results demonstrate the beneficial effects of dietary maltol in the enhancement of growth performance, gut health, and coccidiosis resistance and the applicability of maltol as a postbiotic for the replacement of antibiotic growth promoters in commercial poultry production.

Coccidiosis: Recent Progress in Host Immunity and Alternatives to Antibiotic Strategies

“…With the development of "omics" technologies related to the investigation of gut health, the term "postbiotics" was coined and defined as a novel class of feed additives that are generally produced by beneficial gut microbes and which exert a positive influence on host health. In a recent in vivo feeding trial, the dietary feeding of Bacillus subtilis 1781 strain induced an alteration of chicken gut metabolites which was associated with the growth-and immune-promoting effects of B. subtilis probiotics [169]. Interestingly, among the highly altered gut metabolites, maltol was one of the significantly increased metabolites that mediated various physiological functions associated with antioxidant and anti-inflammatory activities.…”

“…Probiotics are live microbial feed supplements which beneficially affect the host animal by improving its intestinal microbial balance. Prebiotics, by contrast, are non-digestible feed ingredients that beneficially affect the host by selectively stimulating the growth and/or activity of one or a limited number of bacteria in the gut [169][170][171]. Synergetic combinations of probiotics and prebiotics are known as synbiotics.…”

Gut Microbiota-Derived Indole-3-Carboxylate Influences Mucosal Integrity and Immunity Through the Activation of the Aryl Hydrocarbon Receptors and Nutrient Transporters in Broiler Chickens Challenged With Eimeria maxima

“…We therefore evaluated the effects of ICOOH on muscle cell growth by using QMCs and PMCs in vitro . In the present study, we used different FBS concentrations (0.5% FBS in QMCs and 2% FBS in PMCs) to induce myogenic differentiation as in previous studies ( 50 ). In the current study, the MyoG level, when using the lowered FBS concentration, was elevated, thus supporting MyoG as a differentiation marker.…”

Anti-Inflammatory Activities of the Ethanol Extract of Prasiola japonica, an Edible Freshwater Green Algae, and Its Various Solvent Fractions in LPS-Induced Macrophages and Carrageenan-Induced Paw Edema via the AP-1 Pathway

“…The major flavonols, such as quercetin, kaempferol, isorhamnetin, and galangin, were found to exhibit anti-inflammatory activity [ 29 , 31 ]. Maltol exerts a significant liver protection effect, and possesses anti-inflammatory and antiapoptotic actions [ 32 ]. Some studies demonstrated that bavachinin, nobiletin, and 3′-deoxysappanone B regulate the production of several cytokines as well as inflammatory mediators in activated macrophages and various other cell types [ 32 , 33 , 34 , 35 , 36 , 37 , 38 ].…”

“…Maltol exerts a significant liver protection effect, and possesses anti-inflammatory and antiapoptotic actions [ 32 ]. Some studies demonstrated that bavachinin, nobiletin, and 3′-deoxysappanone B regulate the production of several cytokines as well as inflammatory mediators in activated macrophages and various other cell types [ 32 , 33 , 34 , 35 , 36 , 37 , 38 ]. Consequently, we evaluated whether these components of Pj-EE-CF could be responsible for its anti-inflammatory effect.…”