Novel lipid emulsion for total parenteral nutrition based on 18-carbon n-3 fatty acids elicits a superior immunometabolic phenotype in a murine model compared with standard lipid emulsions

Pathogenesis and Management of Intestinal Failure-Associated Liver Disease

Long-term parenteral nutrition (PN) has considerably improved the management of intestinal failure (IF) in children and adults, particularly those with short bowel syndrome; however, it carries a significant risk of hepatotoxicity, specifically, intestinal failure-associated liver disease (IFALD), also known as PN-associated liver disease. This review provides an update on the latest understanding of IFALD pathogenesis, emerging therapies, and ongoing challenges in the management of this complication. A number of factors are associated with the development of IFALD. PN lipid emulsions, phytosterol exposure, bacterial dysbiosis, an altered gut-liver axis, and episodes of sepsis disrupt bile acid homeostasis and promote liver inflammation in the active phase of IFALD, favoring the development of PN-associated cholestasis (PNAC) and the more chronic form of steatohepatitis with fibrosis. Based on the identification of pathophysiological pathways, potential therapies are being studied in preclinical and clinical trials, including lipid emulsion modifications; targeted therapies such as Farnesoid X receptor (FXR) and liver receptor homolog 1 (LRH-1) agonists, tumor necrosis factor inhibitors, glucagon-like peptide-2 analogs; microbiome modulation; and supplementation with choline and antioxidants. In conclusion, the pathogenesis of IFALD is complex, and PN dependence and liver injury remain challenging, particularly in patients with IF who cannot advance to enteral nutrition and be weaned off PN.

Comprehensive quantification of C4 to C26 free fatty acids using a supercritical fluid chromatography-mass spectrometry method in pharmaceutical-grade egg yolk powders intended for total parenteral nutrition use

Free fatty acids (FFAs) are important energy sources and significant for energy transport in the body. They also play a crucial role in cellular oxidative stress responses, following cell membrane depolarization, making accurate quantification of FFAs essential. This study presents a novel supercritical fluid chromatography-mass spectrometry (SFC-MS) method using selected ion recording in negative electrospray ionization mode, enabling rapid quantification of 31 FFAs within 6 min without derivatization. FFAs are identified and quantified using an HSS C18 SB column and a secondary mobile phase consisting of methanol with formic acid by detecting their [M - H]- ions. Calibration curves showed strong linearity (R2 ≥ 0.9910), spanning 1000-12,000 ng/mL for short-chain FFAs and 50-1200 ng/mL for medium- and long-chain FFAs. The method achieves detection limits as low as 1 ng/µL for short-chain FFAs and 0.05 pg/µL for other FFAs per on-column injection. The method demonstrated high accuracy and precision, with bias and coefficients of variation maintained below 15% across five quality control levels. Freeze-thaw and autosampler stability studies confirmed the behavior of matrix-matched standards under optimal storage conditions. The validated method was applied to the analysis of pharmaceutical-grade egg yolk powders, using 13 deuterated FFAs as internal standards (IS) in comparison with heptadecanoic acid (C17:0). Significant variations in FFA quantification using two different IS approaches underscore the importance of selecting an appropriate IS. In summary, this study introduces a reliable and validated SFC-MS method for analyzing FFAs ranging from C4 to C26, requiring minimal sample preparation.

The Novel Lipid Emulsion Vegaven Is Well Tolerated and Elicits Distinct Biological Actions Compared With a Mixed-Oil Lipid Emulsion Containing Fish Oil: A Parenteral Nutrition Trial in Piglets

BACKGROUND

Vegaven is a novel lipid emulsion for parenteral nutrition (PN) based on 18-carbon n-3 (ω-3) fatty acids, which elicits liver protection via interleukin-10 (IL-10) in the murine model of PN.

OBJECTIVES

In a preclinical model of PN in neonatal piglets, Vegaven was tested for efficacy and safety and compared with a mixed-oil lipid emulsion containing fish oil (SMOFlipid).

METHODS

Male piglets 4-5 d old were randomly allocated to isocaloric isonitrogenous PN for 14 d, which varied only by the type of lipid emulsion (Vegaven, n = 8; SMOFlipid, n = 8). Hepatic IL-10 tissue concentration served as primary outcome. Secondary outcomes were organ weights, bile flow, blood analyses, plasma insulin and glucagon concentrations, insulin signaling, proinflammatory cytokines, tissue lipopolysaccharide concentrations, and fatty acid composition of phospholipid fractions in plasma, liver, and brain.

RESULTS

Total weight gain on trial, organ weights, and bile flow were similar between the Vegaven and the SMOFlipid group. Vegaven elicited higher hepatic IL10 (Δ = 148 pg/mg protein; P < 0.001) and insulin receptor substrate-2 amounts (Δ = 0.08 OD; P = 0.012). Plasma insulin concentrations (Δ = 1.46 mU/L; P = 0.003) and fructosamine (glycated albumin, Δ = 12.4 μmol/g protein; P = 0.003) were increased in SMOFlipid as compared with those of Vegaven group, indicating insulin resistance. Higher hepatic injury markers were observed more frequently in the SMOFlipid group than those in the Vegaven group. Lipopolysaccharide, tumor necrosis factor-α, and IL-6 concentrations increased in pancreatic and brain tissues of SMOFlipid-treated compared with those in the Vegaven-treated piglets. Insulin signaling reduced in the brains of SMOFlipid-treated piglets. Vegaven and SMOFlipid elicited distinct fatty acid profiles in the phospholipid fractions of the rapidly growing brains but showed similar accretion of docosahexaenoic acid and arachidonic acid after 2 wk of PN.

CONCLUSIONS

Vegaven is well tolerated in this piglet model of PN, demonstrating distinct biological actions compared with SMOFlipid, namely lower liver, pancreas, and brain inflammation, enhanced insulin signaling, and improved whole body glucose control.

Size of lipid emulsion droplets influences metabolism in human CD4+ T cells

SCOPE

Triglyceride-based lipid emulsions are critical for total parenteral nutrition (TPN), but their long-term use has adverse effects, such as severe liver dysfunction necessitating improved formulations. This study compares the uptake mechanism and intracellular fate of novel glycerol-stabilized nano-sized lipid emulsions with conventional emulsions in CD4+ T cells, focusing on their impact on cellular metabolism.

METHODS AND RESULTS

Nanoemulsions were formulated with increased glycerol content. Uptake of emulsions in primary human CD4+ T cells was investigated using different endocytic blockers, then quantified by flow cytometry, and visualized by confocal microscopy. To investigate emulsion intracellular fate, fatty acids in membrane phospholipids were quantified by GC-MS/MS and cellular metabolism was assessed by Seahorse technology. Results show T cells internalize both conventional and nano-sized emulsions using macropinocytosis. Fatty acids from emulsions are stored as neutral lipids in intracellular vesicles and are incorporated into phospholipids of cellular membranes. However, only nanoemulsions additionally use clathrin-mediated endocytosis and deliver fatty acids to mitochondria for increased β-oxidation.

CONCLUSIONS

Size of lipid emulsion droplets significantly influences their uptake and subsequent metabolism in CD4+ T cells. Our results highlight the potential for improved nutrient utilization with nanoemulsions in TPN formulations possibly leading to less adverse effects.

Parenteral nutrition-associated liver injury: clinical relevance and mechanistic insights

Intestinal failure-associated liver disease (IFALD) is a relatively common complication in individuals receiving parenteral nutrition (PN). IFALD can be manifested as different types of liver injury, including steatosis, cholestasis, and fibrosis, and could result in liver failure in some cases. The onset and progression of IFALD are highly dependent on various patient and PN-related risk factors. Despite still being under investigation, several mechanisms have been proposed. Liver injury can originate due to caloric overload, nutrient deficiency, and toxicity, as well as phytosterol content, and omega-6 to omega-3 fatty acids ratio contained in lipid emulsions. Additional mechanisms include immature or defective bile acid metabolism, acute heart failure, infections, and sepsis exerting negative effects via Toll-like receptor 4 and nuclear factor κB inflammatory signaling. Furthermore, lack of enteral feeding, gut dysbiosis, and altered enterohepatic circulation that affect the farnesoid x receptor-fibroblast growth factor 19 axis can also contribute to IFALD. Various best practices can be adopted to minimize the risk of developing IFALD, such as prevention and management of central line infections and sepsis, preservation of intestine's length, a switch to oral and enteral feeding, cyclic PN, avoidance of overfeeding and soybean oil-based lipid formulations, and avoiding hepatotoxic substances. The present review thus provides a comprehensive overview of all relevant aspects inherent to IFALD. Further research focused on clinical observations, translational models, and advanced toxicological knowledge frameworks is needed to gain more insight into the molecular pathogenesis of hepatotoxicity, reduce IFALD incidence, and encourage the safe use of PN.

Effects of Bacillus coagulans TBC169 on gut microbiota and metabolites in gynecological laparoscopy patients

Objective

The primary objective of this study is to investigate the mechanism by which Bacillus coagulans TBC169 accelerates intestinal function recovery in patients who have undergone gynecological laparoscopic surgery, using metabolomics and gut microbiota analysis.

Methods

A total of 20 subjects were selected and randomly divided into two groups: the intervention group (n = 10) receiving Bacillus coagulans TBC169 Tablets (6 pills, 1.05 × 108 CFU), and the control group (n = 10) receiving placebos (6 pills). After the initial postoperative defecation, fecal samples were collected from each subject to analyze their gut microbiota and metabolic profiles by high-throughput 16S rRNA gene sequencing analysis and untargeted metabonomic.

Results

There were no statistically significant differences observed in the α-diversity and β-diversity between the two groups; however, in the intervention group, there was a significant reduction in the relative abundance of unclassified_Enterobacteriaceae at the genus level. Furthermore, the control group showed increased levels of Holdemanella and Enterobacter, whereas the intervention group exhibited elevated levels of Intestinimonas. And administration of Bacillus coagulans TBC169 led to variations in 2 metabolic pathways: D-glutamine and D-glutamate metabolism, and arginine biosynthesis.

Conclusion

This study demonstrated that consuming Bacillus coagulans TBC169 after gynecological laparoscopic surgery might inhibit the proliferation of harmful Enterobacteriaceae; mainly influence 2 pathways including D-glutamine and D-glutamate metabolism, and arginine biosynthesis; and regulate metabolites related to immunity and intestinal motility; which can help regulate immune function, maintain intestinal balance, promote intestinal peristalsis, and thus accelerate the recovery of intestinal function.

Alternative sources of bioactive omega-3 fatty acids: what are the options?

PURPOSE OF REVIEW

The very-long chain (VLC) omega-3 polyunsaturated fatty acids (PUFAs) eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) promote optimal development, physiological function and healthy ageing and help to manage disease. EPA and DHA are sourced mainly from fish, which is not sustainable. This review explores alternative sustainable sources.

RECENT FINDINGS

Recent research confirms that higher intake and status of EPA and DHA are associated with health benefits including lower risk of incident type-2 diabetes and cardiovascular disease mortality. Meta-analyses confirm benefits of intravenous EPA and DHA in hospitalized adults. Algal oils and seed oils from some genetically modified (GM) plants are sources of EPA and DHA. An oil from GM camelina showed equivalence with fish oil in human trials. Ahiflower oil, a source of stearidonic acid, had biological effects in experimental studies that might translate into health benefits. An intravenous lipid emulsion based on Ahiflower oil has been tested in experimental research. Pine nut oil (PNO) is a source of pinolenic acid, which is not an omega-3 PUFA but has similar actions.

SUMMARY

Algal oils, oils from GM seed crops, Ahiflower oil and other sources of stearidonic acid, and nonomega-3 oils including PNO, are plant-sourced sustainable alternatives to fish-sourced VLC omega-3 PUFAs.

Oxylipin secretion by human CD3+ T lymphocytes in vitro is modified by the exogenous essential fatty acid ratio and life stage

Immune function changes across the life stages; for example, senior adults exhibit a tendency towards a weaker cell-mediated immune response and a stronger inflammatory response than younger adults. This might be partly mediated by changes in oxylipin synthesis across the life course. Oxylipins are oxidation products of polyunsaturated fatty acids (PUFAs) that modulate immune function and inflammation. A number of PUFAs are precursors to oxylipins, including the essential fatty acids (EFAs) linoleic acid (LA) and α-linolenic acid (ALA). LA and ALA are also substrates for synthesis of longer chain PUFAs. Studies with stable isotopes have shown that the relative amounts of LA and ALA can influence their partitioning by T lymphocytes between conversion to longer chain PUFAs and to oxylipins. It is not known whether the relative availability of EFA substrates influences the overall pattern of oxylipin secretion by human T cells or if this changes across the life stages. To address this, the oxylipin profile was determined in supernatants from resting and mitogen activated human CD3+ T cell cultures incubated in medium containing an EFA ratio of either 5:1 or 8:1 (LA : ALA). Furthermore, oxylipin profiles in supernatants of T cells from three life stages, namely fetal (derived from umbilical cord blood), adults and seniors, treated with the 5:1 EFA ratio were determined. The extracellular oxylipin profiles were affected more by the EFA ratio than mitogen stimulation such that n-3 PUFA-derived oxylipin concentrations were higher with the 5:1 EFA ratio than the 8:1 ratio, possibly due to PUFA precursor competition for lipoxygenases. 47 oxylipin species were measured in all cell culture supernatants. Extracellular oxylipin concentrations were generally higher for fetal T cells than for T cells from adult and senior donors, although the composition of oxylipins was similar across the life stages. The contribution of oxylipins towards an immunological phenotype might be due to the capacity of T cells to synthesize oxylipins rather than the nature of the oxylipins produced.

The Role of α-Linolenic Acid and Its Oxylipins in Human Cardiovascular Diseases

α-linolenic acid (ALA) is an essential C-18 n-3 polyunsaturated fatty acid (PUFA), which can be elongated to longer n-3 PUFAs, such as eicosapentaenoic acid (EPA). These long-chain n-3 PUFAs have anti-inflammatory and pro-resolution effects either directly or through their oxylipin metabolites. However, there is evidence that the conversion of ALA to the long-chain PUFAs is limited. On the other hand, there is evidence in humans that supplementation of ALA in the diet is associated with an improved lipid profile, a reduction in the inflammatory biomarker C-reactive protein (CRP) and a reduction in cardiovascular diseases (CVDs) and all-cause mortality. Studies investigating the cellular mechanism for these beneficial effects showed that ALA is metabolized to oxylipins through the Lipoxygenase (LOX), the Cyclooxygenase (COX) and the Cytochrome P450 (CYP450) pathways, leading to hydroperoxy-, epoxy-, mono- and dihydroxylated oxylipins. In several mouse and cell models, it has been shown that ALA and some of its oxylipins, including 9- and 13-hydroxy-octadecatrienoic acids (9-HOTrE and 13-HOTrE), have immunomodulating effects. Taken together, the current literature suggests a beneficial role for diets rich in ALA in human CVDs, however, it is not always clear whether the described effects are attributable to ALA, its oxylipins or other substances present in the supplemented diets.