Effects of dietary lysolecithin on growth performance, serum biochemical indexes, antioxidant capacity, lipid metabolism and inflammation-related genes expression of juvenile large yellow croaker (Larimichthys crocea)

Effects of Lysophospholipids on the Antioxidant Capacity, Digestive Performance, and Intestinal Microbiota of Litopenaeus vannamei

This study seeks to assess the impact of varying concentrations of lysophospholipids on the antioxidant capacity, digestive performance, and intestinal microbiota of L. vannamei. A total of 840 shrimp, with an average initial weight of 2.22 ± 0.11 g, were randomly distributed across 28 aquaculture tanks (30 shrimp per tank), organized into 7 distinct treatment groups, each comprising 4 replicates. The control group (DL2) was administered a basal diet formula supplemented with 2% soy lecithin, whereas the experimental groups received lysophospholipids at varying concentrations of 0% (RL0), 0.1% (RL0.1), 0.5% (RL0.5), 1% (RL1), 1.5% (RL1.5), and 2% (RL2). The results revealed that the total antioxidant capacity (T-AOC) level in the RL0.1 group was significantly elevated compared to the DL2 and RL2 groups (p < 0.05). Furthermore, glutathione peroxidase (GSH-Px) and catalase (CAT) activities were markedly higher in the RL1 and RL1.5 groups relative to other groups (p < 0.05). Superoxide dismutase (SOD) activity exhibited a significant increase across all lysophospholipid-supplemented groups when compared to the DL2 group (p < 0.05). Malondialdehyde (MDA) levels were notably elevated in the RL0.5, RL1.5, and RL2 groups relative to the other groups (p < 0.05). Regarding antioxidant-related genes in the hemocytes, the relative expression levels of Nrf1, Nrf2, GPx, SOD, CAT, and Hippo were significantly higher in the RL0.5 and RL1 groups compared to the DL2 group (p < 0.05). Additionally, the relative expression levels of GPx and SOD were significantly elevated in the RL2 group compared to the DL2 group (p < 0.05). In the intestinal tract, the activities of trypsin and α-amylase (AMS) were significantly elevated in the RL0.1, RL0.5, and RL1 groups compared to the DL2 group (p < 0.05). Additionally, the RL0.1 group demonstrated significantly higher lipase (LPS) activity than the other groups supplemented with lysophospholipids (p < 0.05). Furthermore, the relative expression levels of the trypsin and α-amylase genes were significantly increased in the RL1 and RL1.5 groups in comparison to the DL2 group (p < 0.05). Sequencing analysis of the intestinal microbiota indicated that the incorporation of lysophospholipids resulted in an enhancement of the composition and structure of the intestinal microbiota. The functional abundance of the intestinal microbiome was primarily enriched in metabolic pathways. Overall, the incorporation of lysophospholipids into the diet exerted a beneficial effect on the antioxidant capacity, digestive performance, and intestinal microbiota of L. vannamei, especially with the supplementation of 0.1% lysophospholipids.

Phosphatidylethanolamine exerts anti-inflammatory action by regulating mitochondrial function in macrophages of large yellow croaker (Larimichthys crocea)

Phosphatidylethanolamine (PE) is a ubiquitous bioactive lipid in cells, which participates in regulating many metabolic processes. Exogenous PE has been reported to play a positive regulatory role in macrophage inflammatory responses. However, the molecular mechanisms of PE in regulating macrophage inflammation are not completely understood. In the present study, transcriptomic analysis of PE-stimulated macrophages of large yellow croaker revealed that differentially expressed genes were mainly active in cellular components of the mitochondrial respiratory chain, which corresponded to the significant enrichment of the oxidative phosphorylation pathway. Consistent with this result, PE significantly increased ATP content and protein expression of NDUFB3 (mitochondrial respiratory chain complex I subunit) in macrophages. Meanwhile, transcriptomic data showed that PE treatment downregulated the transcript levels of nlrp3 and upregulated the transcript levels of suppressor of cytokine signaling 3 (socs3), suggesting that PE may alleviate macrophage inflammation by interfering with the activation of NLRP3 inflammasome. Further analysis showed that PE significantly attenuated dietary PA-mediated macrophage inflammation via NLRP3-Caspase-1 in vitro and in vivo. Given that PE abundance is strongly correlated with mitochondrial function, the present study hypothesized that PE-mediated inflammatory modulation may be attributed to the positive effects on mitochondrial function. As expected, PE significantly ameliorated PA-induced mitochondrial dysfunction and reduced intracellular reactive oxygen species production and malondialdehyde content in macrophages, indicating that the improvement of mitochondrial function is an important mechanism involved in the positive effect of PE on PA-induced inflammation. In conclusion, this study elucidates the critical role of mitochondrial function in PE-mediated regulation of inflammation in macrophages, which expands the understanding of the regulatory mechanisms of phospholipid metabolism on dietary fatty acid-induced inflammation. This study may provide new intervention targets and nutritional regulation strategies for improving chronic inflammatory diseases.

Effects of abomasal infusion of soybean or sunflower lecithin on nutrient digestibility and milk production in lactating dairy cows

The fatty acid (FA) and phospholipid composition of dietary lecithin may influence FA digestibility and milk production in cattle. Eight multiparous Holstein cows (99.4 ± 9.2 DIM; 48.9 ± 3.8 kg of milk/d) were enrolled in a 3 × 3 incomplete Latin square design with 3 treatments provided as continuous abomasal infusates spanning 14-d experimental periods: water (CON), soybean lecithin (SBL; 74.5 g of deoiled soy lecithin), or sunflower lecithin (SFL; 133.5 g of hydrolyzed sunflower lecithin). Cows were fed the same diet, which contained (% DM) 27.0% NDF, 15.6% CP, 26.2% starch, and 5.87% FA. Treatments did not modify BW, milk fat, protein, or lactose contents, or the efficiency of producing ECM. Cows infused with SFL had greater milk yields than those receiving SBL or CON treatments. Cows infused with SFL had higher total solids, protein, and lactose yields than cows receiving the SBL or CON treatments. Sunflower lecithin enhanced feed efficiency (milk yield/DMI) relative to SBL or CON. Treatment did not affect intakes or apparent total-tract digestibilities for NDF, CP, starch, or 16-carbon (16C) FA. Cows receiving SFL had greater total FA and 18-carbon (18C) FA intakes than SBL or CON, but treatments did not affect their digestibility. Milk FA composition was modified by treatment. Cows receiving SFL had a greater concentration of PUFA and lower concentrations of SFA and MUFA in milk relative to SBL or CON. In conclusion, the abomasal infusion of SFL improved milk production and milk FA composition, indicating potential benefits for dairy cow nutrition and milk quality.

The effects of kelp powder and fucoidan on the intestinal digestive capacity, immune response, and bacterial community structure composition of large yellow croakers (Larimichthys crocea)

Feed terrestrial components can induce intestinal stress in fish, affecting their overall health and growth. Recent studies suggest that seaweed products may improve fish intestinal health. In this experiment, three types of feed were prepared: a basic diet (C group), a diet with 0.2 % fucoidan (F group), and a diet with 3 % kelp powder (K group). These diets were fed to large yellow croaker (Larimichthys crocea) over an 8-week period. Each feed was randomly assigned to three seawater cages (4.0 m × 4.0 m × 5.0 m) containing 700 fish per cage. The study assessed changes in growth and intestinal health, including intestinal tissue morphology, digestive enzyme activities, expression of immune-related genes, and bacterial community structure. Results showed that incorporating seaweed products into the diet improved the growth and quality traits of large yellow croakers and significantly enhanced their intestinal digestive capacity (P < 0.05). Specifically, the 0.2 % fucoidan diet significantly increased the intestinal villus length and the activities of digestive enzymes such as trypsin, lipase, and α-amylase (P < 0.05). The 3 % kelp powder diet significantly enhanced the intestinal crypt depth and the activities of trypsin and lipase (P < 0.05). Both seaweed additives significantly enhanced intestinal health by mitigating inflammatory factors. Notably, the control group's biomarkers indicated a high presence of potential pathogenic bacteria, such as Streptococcus, Pseudomonas, Enterococcus, Herbaspirillum, Neisseria, Haemophilus, and Stenotrophomonas. After the addition of seaweed additives, these bacteria were no longer the indicator bacteria, while the abundance of beneficial bacteria like Ligilactobacillus and Lactobacillus increased. Significant reductions in the expression of inflammatory factors (e.g., il-6, tnf-α, ifn-γ in the fucoidan group and il-8 in the kelp powder group) further supported these findings. Our findings suggested that both seaweed additives helped balance intestinal microbial communities and reduce bacterial antigen load. Considering the effects, costs, manufacturing, and nutrition, adding 3 % kelp powder to the feed of large yellow croaker might be preferable. This study substantiated the beneficial effects of seaweed on the aquaculture of large yellow croaker, particularly in improving intestinal health. These findings advocated for its wider and more scientifically validated use in fish farming practices.

Lysolecithins improved growth performance, nutrient digestibility, immunity, and antioxidant ability in broiler chickens

OBJECTIVE

This study investigated the effects of dietary supplementation with lysolecithins (LPC) on growth performance, nutrient digestibility, blood profiles, immunity, and liver health in broiler chickens.

METHODS

A cohort of 240 one-day-old male Arbor Acres broilers of comparable weight was divided into four treatment groups, each comprising six replicates of 10 birds. The groups were defined as follows: positive control with recommended metabolizable energy (PC+ME), negative control with 90 kcal/kg reduced ME (NC+ME), PC supplemented with 300 mg/kg LPC (PC+LPC), and NC supplemented with 300 mg/kg LPC (NC+LPC).

RESULTS

LPC supplementation led to a statistically significant reduction in the feed conversion ratio (p = 0.05) and a decrease in the proportion of abdominal fat and the liver (p<0.05). Digestibility of dry matter was also enhanced (p<0.05). Malondialdehyde concentrations in the liver were significantly reduced by LPC (p<0.01), with a noteworthy interaction between energy levels and LPC affecting this reduction (p<0.05). Serum levels of interleukin-6 were reduced on day 21, and both endotoxin and interleukin-6 levels were lower on day 42. Notably, a significant interaction was observed between the energy levels and LPC on relative liver weight and endotoxin concentrations in the serum (p<0.05).

CONCLUSION

The study concluded that LPC positively affects growth performance, nutrient digestibility, immune response, and antioxidative capacity in broiler chickens, affirming its value as a beneficial feed additive in poultry nutrition.

Structural and ultrastructural aspects of the skin of large yellow croaker Larimichthys crocea

The skin color of the large yellow croaker (Larimichthys crocea) is a crucial indicator to determine its economic value. However, the location of pigment cells in the skin structure is uncertain. To determine the pigment cell type in the skin, the vertical order and ultrastructure of pigment cells were examined using light microscopy and transmission electron microscopy. Both dorsal and ventral skins comprise the epidermis, dermis, and hypodermis. Xanthophores, melanophores, and iridophores were observed in the dermis of the dorsal skin, whereas the latter two were in the dermis of the ventral skin. Interestingly, the size of xanthophores in the dorsal skin was significantly smaller than that of xanthophores in the ventral skin; however, the density of dorsal xanthophores was significantly higher than that of ventral xanthophores. The type L-iridophores with large crystalline structures were observed in the uppermost area of the upper pigment layer, which contributed to the strikingly metallic luster shown by the ventral skin. The melanophores were exclusively found in the dorsal skin, offering the purpose of camouflage. Taken together, our results indicated that the pigment cells display different arrangement patterns between dorsal and ventral skin, and the golden color in the ventral skin results from the coexistence of light-reflecting iridophores and light-absorbing xanthophores.

Molecular cloning, tissue expression pattern, responses to different fatty acids and potential functions of lysophosphatidylcholine acyltransferase 1 (LPCAT1) in large yellow croaker (Larimichthys crocea)

In farmed fish, diets rich in palm oil have been observed to promote abnormal lipid build-up in the liver, subsequently leading to physiological harm and disease onset. Emerging research suggests that integrating phospholipids into the feed could serve as a potent countermeasure against hepatic impairments induced by vegetable oil consumption. Phosphatidylcholine is the most abundant type among phospholipids. In the metabolic processes of mammal, lysophosphatidylcholine acyltransferase 1 (LPCAT1), crucial for phosphatidylcholine remodeling, demonstrates a marked affinity towards palmitic acid (PA). Nonetheless, aspects concerning the cloning, tissue-specific distribution, and affinity of the LPCAT1 gene to diverse oil sources have yet to be elucidated in the large yellow croaker (Larimichthys crocea). Within the scope of this study, we successfully isolated and cloned the cDNA of the LPCAT1 gene from the large yellow croaker. Subsequent analysis revealed distinct gene expression patterns of LPCAT1 across ten different tissues of the species. The fully sequenced coding DNA sequence (CDS) of LPCAT1 spans 1503 bp and encodes a sequence of 500 amino acids. Comparative sequence alignment indicates that LPCAT1 shares a 69.75 % amino acid similarity with its counterparts in other species. Although LPCAT1 manifests across various tissues of the large yellow croaker, its predominance is markedly evident in the liver and gills. Furthermore, post exposure of the large yellow croaker's hepatocytes to varied fatty acids, PA has a strong response to LPCAT1. Upon the addition of appropriate lysolecithin to palm oil feed, the mRNA expression of LPCAT1 in the liver cells of the large yellow croaker showed significant variations compared to other subtypes. Concurrently, the mRNA expression of pro-inflammatory genes il-1β, il-6, il-8, tnf-α and ifn-γ in the liver tissue of the large yellow croaker decreased. Interestingly, they exhibit the same trend of change. In conclusion, we have cloned the LPCAT1 gene on fish successfully and find the augmented gene response of LPCAT1 in hepatocytes under PA treatment first. The results of this study suggest that LPCAT1 may be associated with liver inflammation in fish and offer new insights into mitigating liver diseases in fish caused by palm oil feed.

Comparison of Lysophospholipids and Bile Acids on the Growth Performance, Lipid Deposition, and Intestinal Health of Largemouth Bass (Micropterus salmoides)

Lysophospholipids (LPLs) and bile acids (BA) are commonly used as emulsifiers in aquaculture. This study investigated the effects of dietary supplementation of LPLs or BA on the growth performance, lipid deposition, and intestinal health of largemouth juveniles. Fish were randomly allotted into three groups in quadruplicate and fed with a basal diet (CON) or diets containing 300 mg/kg LPLs (LPLs), or 300 mg/kg commercially available BA product (BA) for 8 weeks. The results showed that compared with the control group, LPLs and BA supplemented groups showed a higher weight gain trend, and LPLs supplementation promoted the protein deposition in fish body. Both BA and LPLs supplementations helped to maintain liver health by decreasing the activities of aspartate aminotransferase and alanine aminotransferase in serum. Besides, LPLs supplementation decreased overall lipid deposition in terms of mesenteric fat index and liver lipid content. Furthermore, LPLs supplementation showed unique advantage in improving intestinal barrier, as characterized by the increased villus length and higher expression of the tight junction protein zo-1 expression. LPLs supplementation also increased the alpha diversity index and the abundances of Proteobacteria in the intestinal microbiota which is positively correlated with the abundance of SCFA in the gut. These findings will promote the application of novel feed additives and especially provide a basis for the rational selection of emulsifiers in the aquaculture industry.

Effect of lysophospholipids on the growth performance, nutrient digestibility, lipid metabolism and meat quality of fattening rabbits

The present study aimed to investigate the effect of emulsifier lysophospholipids (LP), enzymatically modified from soy phospholipids, on the growth performance, nutrient digestibility, lipid metabolism and meat quality of fattening rabbits. The LP was added in control (CON), LP1, LP2 and LP3 at 0, 200, 400 and 600 mg/kg, respectively. A total of 240 rabbits at approximately 52 d of age were divided into 4 groups with 6 replicates of 10 rabbits each. The feeding trial lasted for 42 d. Results showed that compared to CON, LP1, LP2 and LP3 increased (p < 0.05) body weight gain, feed efficiency, the apparent faecal digestibility of gross energy, crude protein and ether extract, the percentages of dissectible fat and ether extract in the longissimus and legs, the serum contents of apolipoprotein B, free fatty acid and total phospholipids in the longissimus, but decreased (p < 0.05) serum total triglyceride and total cholesterol. Meanwhile, LP1, LP2 and LP3 had higher (p < 0.05) carcass weight, longissimus weight and percentages of foreleg and hindleg than the CON; and the three LP diets also increased (p < 0.05) the tenderness, lightness and redness of longissimus. It is concluded that soy LP as an emulsifier can improve the growth, digestibility and meat quality of fattening rabbits.

Regulation of low-density lipoprotein on lipid metabolism in macrophages of large yellow croaker (Larimichthys crocea)

Low-density lipoprotein (LDL) is the main carrier of cholesterol transport in plasma, which participates in regulating lipid homeostasis. Studies in mammals have shown that high levels of LDL in plasma absorbed by macrophages trigger the formation of lipid-rich foam cells, leading to the development of atherosclerotic plaques. Although lipid-rich atherosclerosis-like lesions have been discovered in the aorta of several fish species, the physiological function of LDL in fish macrophages remains poorly understood. In the present study, LDL was isolated from the plasma of large yellow croaker (Larimichthys crocea), and mass spectrometry analysis identified two truncated forms of apolipoprotein B100 in the LDL protein profile. Transcriptomic analysis of LDL-stimulated macrophages revealed that differentially expressed genes (DEGs) were enriched in various pathways related to lipid metabolism, as confirmed by the fact that LDL increased total cholesterol and cholesteryl esters content. Meanwhile, the gene and protein expression levels of perilipin2 (PLIN2), a DEG enriched in the PPAR signaling pathway, were upregulated in response to LDL stimulation. Importantly, knocking down plin2 significantly attenuates LDL-induced cholesterol accumulation and promotes cholesterol efflux. Furthermore, the transcription factor PPARγ, which is upregulated in response to LDL stimulation, can enhance the promoter activity of plin2. In conclusion, this study suggests that LDL may upregulate plin2 expression through PPARγ, resulting in cholesterol accumulation in fish macrophages. This study will facilitate the investigation of the function of LDL in regulating lipid homeostasis in macrophages and shed light on the evolutionary origin of LDL metabolism in vertebrates.

Phosphatidylethanolamine alleviates OX-LDL-induced macrophage inflammation by upregulating autophagy and inhibiting NLRP1 inflammasome activation

Oxidized low-density lipoprotein (OX-LDL)-induced inflammation and autophagy dysregulation are important events in the progression of atherosclerosis. Phosphatidylethanolamine (PE), a multifunctional phospholipid that is enriched in cells, has been proven to be directly involved in autophagy which is closely associated with inflammation. However, whether PE can influence OX-LDL-induced autophagy dysregulation and inflammation has not been reported. In the present study, we revealed that OX-LDL significantly induced macrophage inflammation through the CD36-NLRP1-caspase-1 signaling pathway in fish. Meanwhile, cellular PE levels were significantly decreased in response to OX-LDL induction. Based on the relationship between PE and autophagy, we then examined the effect of PE supplementation on OX-LDL-mediated autophagy impairment and inflammation induction in macrophages. As expected, exogenous PE restored impaired autophagy and alleviated inflammation in OX-LDL-stimulated cells. Notably, autophagy inhibitors reversed the inhibitory effect of PE on OX-LDL-induced maturation of IL-1β, indicating that the regulation of PE on OX-LDL-induced inflammation is dependent on autophagy. Furthermore, the positive effect of PE on OX-LDL-induced inflammation was relatively conserved in mouse and fish macrophages. In conclusion, we elucidated the role of the CD36-NLRP1-caspase-1 signaling pathway in OX-LDL-induced inflammation in fish and revealed for the first time that altering PE abundance in OX-LDL-treated cells could alleviate inflammasome-mediated inflammation by inducing autophagy. Given the relationship between OX-LDL-induced inflammation and atherosclerosis, this study prompts that the use of PE-rich foods promises to be a new strategy for atherosclerosis treatment in vertebrates.

Effects of Tributyrin Supplementation on Growth Performance, Intestinal Digestive Enzyme Activity, Antioxidant Capacity, and Inflammation-Related Gene Expression of Large Yellow Croaker (Larimichthys crocea) Fed with a High Level of Clostridium autoethanogenum Protein

An 8-week growth experiment was conducted to investigate effects of tributyrin (TB) supplementation on growth performance, intestinal digestive enzyme activity, antioxidant capacity, and inflammation-related gene expression of juvenile large yellow croaker (Larimichthys crocea) (initial weight of 12.90 ± 0.02 g) fed diets with high level of Clostridium autoethanogenum protein (CAP). In the negative control diet, 40% fish meal was used as the major source of protein (named as FM), while 45% fish meal protein of FM was substituted with CAP (named as FC) to form a positive control diet. Based on the FC diet, grade levels of 0.05%, 0.1%, 0.2%, 0.4%, and 0.8% tributyrin were added to formulate other five experimental diets. Results showed that fish fed diets with high levels of CAP significantly decreased the weight gain rate (WGR) and specific growth rate (SGR) compared with fish fed the FM diet (P < 0.05). WGR and SGR were significantly higher than in fish fed diets with 0.05% and 0.1% tributyrin that fed the FC diet (P < 0.05). Supplementation of 0.1% tributyrin significantly elevated fish intestinal lipase and protease activities compared to FM and FC diets (P < 0.05). Meanwhile, compared to fish fed the FC diet, fish fed diets with 0.05% and 0.1% tributyrin showed remarkably higher intestinal total antioxidant capacity (T-AOC). Malondialdehyde (MDA) content in the intestine of fish fed diets with 0.05%-0.4% tributyrin was remarkably lower than those in the fish fed the FC diet (P < 0.05). The mRNA expressions of tumor necrosis factor α (tnfα), interleukin-1β (il-1β), interleukin-6 (il-6), and interferon γ (ifnγ) were significantly downregulated in fish fed diets with 0.05%-0.2% tributyrin, and the mRNA expression of il-10 was significantly upregulated in fish fed the 0.2% tributyrin diet (P < 0.05). In regard to antioxidant genes, as the supplementation of tributyrin increased from 0.05% to 0.8%, the mRNA expression of nuclear factor erythroid 2-related factor 2 (nrf2) demonstrated a trend of first rising and then decreasing. However, the mRNA expression of Kelch-like ECH-associated protein 1 (keap1) was remarkably lower in fish fed the FC diet than that fed diets with tributyrin supplementation (P < 0.05). Overall, fish fed tributyrin supplementation diets can ameliorate the negative effects induced by high proportion of CAP in diets, with an appropriate supplementation of 0.1%.

Effects of lysophospholipids and multi-enzymes on growth performance, antioxidant capacity, intestinal health, and cecal microflora of male cherry valley ducks

Improvement of nutrient utilization to promote growth performance is always pursued in poultry. In this study, a total of 360 1-d-old male ducklings was randomly assigned to 3 treatments in terms of diet treatment groups. Three treatments were as follows: basal diet (Con group) or basal diet supplemented with 300 mg/kg multi-enzymes (ENZ group) or 500 mg/kg lysophospholipids (LPL group). On day 42, ducks were slaughtered for samplings. The results revealed that supplementary LPL improved the body weight (BW) at day 14 and average daily gain (ADG) during days 1 to 14 and improved the feed conversion rate (FCR) for the overall period (P < 0.05) by improving nutrient utilization of dry matter and ether extract (P < 0.05) compared with the Con group. Dietary ENZ improved the FCR from days 15-42 and 1-42, and nitrogen utilization (P < 0.05) compared with the Con group. Jejunal villus height and villus height/crypt depth ratio were higher (P < 0.05) in the LPL group and tended to be higher (P < 0.1) in the ENZ group compared to the Con group. Supplementation with either LPL or ENZ reduced interleukin-1β concentration in jejunal mucus (P < 0.05). Both LPL and ENZ enhanced serum total superoxide dismutase activity (P < 0.05), whereas only supplementation with LPL elevated total antioxidant capacity (P < 0.05). In terms of cecal microbiota, microbial richness tended to be reduced by LPL, with low observed-OTUs and Chao1 (0.05 < P < 0.1). Supplementation with ENZ led to higher abundances of cellulolytic bacteria such as Fibrobacterota, [Eubacterium]_xylanophilum_group, and Bifidobacterium. Overall, both LPL and ENZ improved FCR, which may be relevant to ameliorative intestinal health, overall antioxidant ability, and cecal microbiome.

Dietary lysolecithin supplementation improves growth performance of weaned piglets via improving nutrients absorption, lipid metabolism, and redox status

Lysolecithin is widely used as emulsifier to improve the digestibility and retention of fat. The current study aimed to investigate the effects of dietary lysolecithin supplementation on growth performance, nutrients absorption, lipid metabolism, and redox status of weaned pigs. A total of 60 weaned piglets were assigned into 2 dietary treatments in a randomized complete block design, receiving basal diet with 0 or 1,000 mg/kg lysolecithin for a period of 28 d. Each dietary treatment had 10 replicates with 3 piglets per replicate. Growth performance and fecal score were monitored during trial. Samples of blood, ileum, and liver tissues were collected and analyzed for serology, intestinal histomorphology, and lipid metabolism-related gene and protein expressions. Dietary lysolecithin supplementation increased average daily gain (+15%, P < 0.05) and tended to increase average daily feed intake (+14%, P = 0.08) in overall experimental period. At final, the average body weight of piglets in lysolecithin group was 10% greater than that of control group (P = 0.09). In addition, dietary lysolecithin supplementation improved the ability of nutrients absorption as indicated by the higher d-xylose level in plasma (P < 0.05). Moreover, piglets from lysolecithin group had higher concentration of high-density lipoprotein (P < 0.05), but lower triglyceride (P < 0.05) in plasma. The inclusion of lysolecithin in diet increased the level of reduced glutathione (GSH) and GSH to oxidized glutathione (GSSG) ratio in plasma and liver (P < 0.05), but attenuated the levels of malondialdehyde and GSSG in ileum (P < 0.05). The upregulation of lipogenesis-related genes (FAS and ACC), downregulation of lipolysis (PNPLA2 and PABP1), and lipid mobilization (PGC-1α and SRIT1) genes were observed in lysolecithin relative to control piglets. Compared with control group, dietary lysolecithin supplementation upregulated protein expressions of GPX4, SREBP1, and LPL in liver and LPL in ileum (P < 0.05). Collectively, our study indicates that dietary lysolecithin supplementation improved growth performance of weaned piglets, which may be associated with the improved nutrients absorption, redox status, and lipid metabolism.

Effects of Lysophosphatidylcholine on Intestinal Health of Turbot Fed High-Lipid Diets

An 8-week feeding trial was conducted, where turbot were fed four experimental diets, containing different LPC levels (0%, 0.1%, 0.25%, and 0.5%, named LPC0, LPC0.1, LPC0.25, and LPC0.5, respectively). The intestinal morphology results showed that there were no widened lamina propria and mixed inflammatory cells in the LPC-supplemented groups. Dietary LPC remarkably decreased the expression of TLRs (TLR3, TLR8, TLR9, and TLR22), MyD88, and signaling molecules (NF-κB, JNK, and AP-1). Similarly, diets with LPC supplementation markedly depressed the gene expression of NF-κB and JNK signaling pathway downstream genes (TNF-α, IL-1β, Bax, Caspase9, and Caspase-3). Furthermore, dietary LPC modified the intestinal microbial profiles, increasing the relative abundance of short-chain fatty acids-producers, lactic acid bacteria, and digestive enzyme-producing bacteria. Predictive functions of intestinal microbiota showed that turbot fed LPC diets had a relatively higher abundance of functions, such as lipid metabolism and immune system, but a lower abundance of functions, such as metabolic diseases and immune system diseases. The activities of intestinal acid phosphatase and alkaline phosphatase were also increased by dietary LPC. In conclusion, LPC supplementation could regulate the intestinal mucosal barrier via the TLR signaling pathway and alter the intestinal microbiota profile of turbot fed high-lipid diets.