Effects of dietary organic acids and nature identical compounds on growth, immune parameters and gut microbiota of European sea bass

Abstract

A 71-day study was conducted to explore the effect of increasing dietary levels (0, 250, 500, 1000 mg kg feed−1; D0, D250, D500 and D1000, respectively) of a blend of microencapsulated organic acids (OA, specifically citric and sorbic acid) and nature identical compounds (NIC, specifically thymol and vanillin), on growth, intestinal immune parameters and gut microbiota (GM) of European sea bass juveniles reared under normal and subsequently suboptimal environmental conditions (high temperature, 30.0 ± 0.4 °C and low oxygen, 4.6 ± 0.6 mg L−1). OA and NIC did not promote growth, feed utilisation and feed intake at the inclusion tested but induced a significantly upregulation of IL-8, IL-10 and TGFβ. GM analyzed by next-generation sequencing showed that OA and NIC were able to exert prebiotic properties stimulating the development of beneficial bacteria taxa such as Lactobacillus, Leuconostoc, and Bacillus sp. Picrust analyses displayed a significant potential functional reconfiguration of GM promoting a decrease in inflammation-promoting and homeostatic functions at increasing OA and NIC administration. For the first time on this species the exposure to suboptimal rearing conditions was able to modify GM structure reducing LAB and increasing Proteobacteria, findings which were consistent with the inflammatory process observed at mRNA level.

Interaction Between Dietary Lipid Level and Seasonal Temperature Changes in Gilthead Sea Bream Sparus aurata: Effects on Growth, Fat Deposition, Plasma Biochemistry, Digestive Enzyme Activity, and Gut Bacterial Community

“…In this last-mentioned study, the authors revealed an increase in the abundance of Proteobateria, which has been proposed as a possible sign of gut microbiome imbalance in fish species. This is also in agreement with the observed increased taxa (Enterobacteriaceae) belonging to this phylum in sea bass gut microbiome, which experienced inflammatory gut mucosa after exposure to high temperature and low-oxygen condition (Busti et al, 2020b). In the present study, we did not observe a gut microbiome imbalance related to the lipid level tested, which remains within a general optimal requirement for this species.…”

“…In particular, while fish fed with L16 diet showed significant gut microbiome changes only at the autumn shift, parallel with a reduction in ecosystem diversity, for the L21 diet, both summer and autumn temperature shifts resulted in significant variations in the ecosystem. Temperature is known to modulate microbial diversity in animals especially in poikilothermic fish species (Sepulveda and Moeller, 2020); however, data explaining the interaction between diet and temperature changes in fish are scarce (Soriano et al, 2018;Busti et al, 2020b;Pelusio et al, 2020). Interestingly, among the few studies, which underlined the combined effect of temperature and dietary lipid level, Soriano et al (2018), in yellowtail kingfish, detected a reduced bacterial abundance and richness associated to a suboptimal low temperature and low dietary lipid level, suggesting that gut microbiome composition could maintain high relative abundance after the decrease in temperature only in the presence of appropriate nutritional conditions, pointing out the importance of optimal lipid level at low temperatures.…”

Oregano Essential Oils Promote Rumen Digestive Ability by Modulating Epithelial Development and Microbiota Composition in Beef Cattle

“…It was reported that farnesene play a significant role during oxidative injury of eukaryotic cells ( 63 ). Sorbic acid, a food preservative and feed additive ( 64 ), could inhibit the dehydrogenase system of bacteria preventing their reproduction ( 65 ). Evidence shows that diets with sorbic acid exert prebiotic properties, stimulating the development of beneficial bacteria taxa ( 64 ).…”

“…Sorbic acid, a food preservative and feed additive ( 64 ), could inhibit the dehydrogenase system of bacteria preventing their reproduction ( 65 ). Evidence shows that diets with sorbic acid exert prebiotic properties, stimulating the development of beneficial bacteria taxa ( 64 ). Aspirin, which has antibacterial and anti-inflammation activities, could prevent colorectal cancer by inhibiting cyclooxygenase enzymes and maintain intestinal barrier integrity ( 66 , 67 ).…”

Potassium diformate in the diet of sterlet sturgeon ( Acipenser ruthenus ): Zootechnical performance, humoral and skin mucosal immune responses, growth‐related gene expression and intestine morphology

“…(6-9 g kg −1 ), clearly enhanced the immune parameters of serum and mucus in sterlet sturgeon. According to previous reports, low doses of organic salts are involved in stimulating the growth of nonpathogenic bacteria and lactic acids, whereas the higher doses also have bacteriostatic effects, which can reduce the population of opportunistic bacteria(Busti et al, 2020). The exact mechanism of F I G U R E 4 Hind-gut morphological characteristics of sterlet sturgeon (Acipenser ruthenus).…”