Observational reports suggest that supplementation that increases citric acid cycle intermediates via anaplerosis may have therapeutic advantages over traditional medium-chain triglyceride (MCT) treatment of long-chain fatty acid oxidation disorders (LC-FAODs) but controlled trials have not been reported. The goal of our study was to compare the effects of triheptanoin (C7), an anaplerotic seven-carbon fatty acid triglyceride, to trioctanoin (C8), an eight-carbon fatty acid triglyceride, in patients with LC-FAODs.A double blinded, randomized controlled trial of 32 subjects with LC-FAODs (carnitine palmitoyltransferase-2, very long-chain acylCoA dehydrogenase, trifunctional protein or long-chain 3-hydroxy acylCoA dehydrogenase deficiencies) who were randomly assigned a diet containing 20% of their total daily energy from either C7 or C8 for 4 months was conducted. Primary outcomes included changes in total energy expenditure (TEE), cardiac function by echocardiogram, exercise tolerance, and phosphocreatine recovery following acute exercise. Secondary outcomes included body composition, blood biomarkers, and adverse events, including incidence of rhabdomyolysis.Patients in the C7 group increased left ventricular (LV) ejection fraction by 7.4% (p = 0.046) while experiencing a 20% (p = 0.041) decrease in LV wall mass on their resting echocardiogram. They also required a lower heart rate for the same amount of work during a moderate-intensity exercise stress test when compared to patients taking C8. There was no difference in TEE, phosphocreatine recovery, body composition, incidence of rhabdomyolysis, or any secondary outcome measures between the groups.C7 improved LV ejection fraction and reduced LV mass at rest, as well as lowering heart rate during exercise among patients with LC-FAODs.Clinicaltrials.gov NCT01379625.

The valorization of volatile fatty acids into microbial lipids by the oleaginous yeast Yarrowia lipolytica was investigated. Therefore, a two-stage fed-batch strategy was designed: the yeast was initially grown on glucose or glycerol as carbon source, then sequential additions of acetic acid under nitrogen limiting conditions were performed after glucose or glycerol exhaustion. The typical values obtained with an initial 40 g/L concentration of glucose were close to 31 g/L biomass, a lipid concentration of 12.4 g/L, which correspond to a lipid content of the biomass close to 40%. This cultivation strategy was also efficient with other volatile fatty acids (butyric and propionic acids) or with a mixture of these three VFAs. The lipids composition was found quite similar to that of vegetable oils. The study demonstrated the feasibility of simultaneous biovalorization of volatile fatty acids and glycerol, two cheap industrial by-products.Copyright © 2012 Elsevier Ltd. All rights reserved.

Microbial oils are sustainable alternatives to petroleum for the production of chemicals and fuels. Oleaginous yeasts are promising source of oils and Yarrowia lipolytica is the most studied and engineered one. Nonetheless the commercial production of biolipids is so far limited to high value products due to the elevated production and extraction costs. In order to contribute to overcoming these limitations we exploited the possibility of secreting lipids to the culture broth, uncoupling production and biomass formation and facilitating the extraction. We therefore considered two synthetic approaches, Strategy I where fatty acids are produced by enhancing the flux through neutral lipid formation, as typically occurs in eukaryotic systems and Strategy II where the bacterial system to produce free fatty acids is mimicked. The engineered strains, in a coupled fermentation and extraction process using alkanes, secreted the highest titer of lipids described so far, with a content of 120% of DCW.Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Milk odd- and branched-chain fatty acids (OBCFA) are largely derived from bacteria leaving the rumen, which has encouraged research on their use as biomarkers of rumen function. Targeted research has examined relationships between these fatty acids (FA) and dietary components, but interactions between the effects of lipids and other nutrients on milk OBCFA are not well characterized yet. Furthermore, factors controlling milk OBCFA in sheep are largely unknown. Thus, the present meta-analysis examined relationships between diet composition and milk OBCFA using a database compiled with lot observations from 14 trials in dairy ewes fed lipid supplements. A total of 47 lots received lipid supplements, whereas their respective controls (27 lots) were fed the same basal diets without lipid supplementation. Relationships between milk OBCFA and dietary components were first assessed through a principal component analysis (PCA) and a correlation analysis. Then, responses of milk OBCFA to variations in specific dietary components (selected on the basis of the PCA) were examined in more detail by regression analysis. According to the loading plot, dietary unsaturated C18 FA loaded opposite to major milk OBCFA (e.g., 15:0, 15:0 anteiso, and 17:0) and were strongly correlated with principal component 1, which described 46% of variability. Overall, regression equations supported this negative, and generally linear, relationship between unsaturated C18 FA levels and milk OBCFA. However, the influence of C20-22 n-3 polyunsaturated FA and saturated FA was more limited. The PCA also suggested that dietary crude protein is not a determinant of milk OBCFA profile in dairy ewes, but significant relationships were observed between some OBCFA and dietary fiber or starch, consistent with a potential role of these FA as biomarkers of rumen cellulolytic and amylolytic bacteria. In this regard, regression equations indicated that iso FA would show opposite responses to increasing levels of acid detergent fiber (positive linear coefficients) and starch (negative linear coefficients). Lipid supplementation would not largely affect these associations, supporting the potential of OBCFA as noninvasive markers of rumen function under different feeding conditions (i.e., with or without lipid supplementation). Because consumption of these FA may have nutritional benefits for humans, the use of high-fiber/low-starch rations might be recommended to maintain the highest possible content of milk OBCFA in dairy sheep.Copyright © 2020 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Fatty acids (FAs) have been postulated to impact adiposity, but few epidemiological studies addressing this hypothesis have been conducted. This study investigated the association between serum phospholipid FAs (S-PLFAs) and indicators of obesity. BMI and waist-to-hip ratio (WHR) were collected from 372 healthy Mexican women included as controls in a case-control study. S-PLFA percentages were determined through gas chromatography. Desaturation indices, SCD-16, SCD-18, FA desaturase (FADS)1, and FADS2, biomarkers of endogenous metabolism, were proxied respectively as 16:1n-7/16:0, 18:1n-9/18:0, 20:4n-6/20:3n-6, and 22:6n-3/20:5n-3. Multiple linear regressions adjusted for relevant confounders and corrected for multiple testing were conducted to determine the association between S-PLFA, desaturation indices, and indicators of adiposity. SCD-16 (β = 0.034, = 0.001, q = 0.014), palmitoleic acid (β = 0.031, = 0.001, q = 0.014), and dihomo-γ-linolenic acid (β = 0.043, = 0.000, q = 0.0002) were positively associated with BMI. Total n-6 PUFAs (β = 1.497, = 0.047, q = 0.22) and the ratio of n-6/n-3 PUFAs (β = 0.034, = 0.040, q = 0.19) were positively associated with WHR, while odd-chain FAs (pentadecanoic and heptadecanoic acid) showed negative associations with all the adiposity indicators. In conclusion, increased endogenous synthesis of palmitoleic acid and a high n-6/n-3 ratio are associated with increased adiposity, while odd-chain FAs are associated with decreased adiposity. Further studies are needed to determine the potential causality behind these associations.Copyright © 2017 by the American Society for Biochemistry and Molecular Biology, Inc.

Acne is a common skin affliction that involves excess sebum production and modified lipid composition, duct blockage, colonization by bacteria, and inflammation. Acne drugs target one or more of these steps, with antibiotics commonly used to treat the microbial infection for moderate to severe cases. Whilst a number of other acne therapies are purported to possess antimicrobial activity, this has been poorly documented in many cases. We conducted a comparative analysis of the activity of common topical acne drugs against the principal etiological agent associated with acne: the aerotolerant anaerobic Gram-positive organism Propionibacterium acnes (recently renamed as Cutibacterium acnes). We also assessed their impact on other bacteria that could also be affected by topical treatments, including both antibiotic-sensitive and antibiotic-resistant strains, using broth microdilution assay conditions. Drugs designated specifically as antibiotics had the greatest potency, but lost activity against resistant strains. The non-antibiotic acne agents did possess widespread antimicrobial activity, including against resistant strains, but at substantially higher concentrations. Hence, the antimicrobial activity of non-antibiotic acne agents may provide protection against a background of increased drug-resistant bacteria.

Long-chain fatty acid oxidation disorders (LC-FAOD) can cause cardiac hypertrophy and cardiomyopathy, often presenting in infancy, typically leading to death or heart transplant despite ongoing treatment. Previous data on triheptanoin treatment of cardiomyopathy in LC-FAOD suggested a clinical benefit on heart function during acute failure. An additional series of LC-FAOD patients with critical emergencies associated with cardiomyopathy was treated with triheptanoin under emergency treatment or compassionate use protocols. Case reports from 10 patients (8 infants) with moderate or severe cardiomyopathy associated with LC-FAOD are summarized. The majority of these patients were detected by newborn screening, with follow up confirmatory testing, including mutation analysis; all patients were managed with standard treatment, including medium chain triglyceride (MCT) oil. While on this regimen, they presented with acute heart failure requiring hospitalization and cardiac support (ventilation, ECMO, vasopressors) and, in some cases, resuscitation. The patients discontinued MCT oil and began treatment with triheptanoin, an investigational drug. Triheptanoin is expected to provide anaplerotic metabolites, to replace deficient TCA cycle intermediates and improve effective energy metabolism. Cardiac function was measured by echocardiography and ejection fraction (EF) was assessed. EF was moderately to severely impaired prior to triheptanoin treatment, ranging from 12-45%. Improvements in EF began between 2 and 21days following initiation of triheptanoin, and peaked at 33-71%, with 9 of 10 patients achieving EF in the normal range. Continued treatment was associated with longer-term stabilization of clinical signs of cardiomyopathy. The most common adverse event observed was gastrointestinal distress. Of the 10 patients, 7 have continued on treatment, 1 elected to discontinue due to tolerability issues, and 2 patients died from other causes. Two of the case histories illustrate that cardiomyopathy may also develop later in childhood and/or persist into adulthood. Overall, the presented cases suggest a therapeutic effect of triheptanoin in the management of acute cardiomyopathy associated with LC-FAOD.Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Dietary odd-chain saturated fatty acids (OCFAs) are present in trace levels in dairy fat and some fish and plants. Higher circulating concentrations of OCFAs, pentadecanoic acid (C15:0) and heptadecanoic acid (C17:0), are associated with lower risks of cardiometabolic diseases, and higher dietary intake of OCFAs is associated with lower mortality. Population-wide circulating OCFA levels, however, have been declining over recent years. Here, we show C15:0 as an active dietary fatty acid that attenuates inflammation, anemia, dyslipidemia, and fibrosis in vivo, potentially by binding to key metabolic regulators and repairing mitochondrial function. This is the first demonstration of C15:0's direct role in attenuating multiple comorbidities using relevant physiological mechanisms at established circulating concentrations. Pairing our findings with evidence that (1) C15:0 is not readily made endogenously, (2) lower C15:0 dietary intake and blood concentrations are associated with higher mortality and a poorer physiological state, and (3) C15:0 has demonstrated activities and efficacy that parallel associated health benefits in humans, we propose C15:0 as a potential essential fatty acid. Further studies are needed to evaluate the potential impact of decades of reduced intake of OCFA-containing foods as contributors to C15:0 deficiencies and susceptibilities to chronic disease.

Fatty acids (FA) in bovine milk derive through body mobilization, de novo synthesis or from the feed via the blood stream. To be able to digest feedstuff, the cow depends on its rumen microbiome. The relative abundance of the microbes has been shown to differ between cows. To date, there is little information on the impact of the microbiome on the formation of specific milk FA. Therefore, in this study, our aim was to investigate the impact of the rumen bacterial microbiome on milk FA composition. Furthermore, we evaluated the predictive value of the rumen microbiome and the host genetics on the composition of individual FA in milk.Our results show that the proportion of variance explained by the rumen bacteria composition (termed microbiability or [Formula: see text]) was generally smaller than that of the genetic component (heritability), and that rumen bacteria influenced most C15:0, C17:0, C18:2 n-6, C18:3 n-3 and CLA cis-9, trans-11 with estimated [Formula: see text] ranging from 0.26 to 0.42. For C6:0, C8:0, C10:0, C12:0, C16:0, C16:1 cis-9 and C18:1 cis-9, the variance explained by the rumen bacteria component was close to 0. In general, both the rumen microbiome and the host genetics had little value for predicting FA phenotype. Compared to genetic information only, adding rumen bacteria information resulted in a significant improvement of the predictive value for C15:0 from 0.22 to 0.38 (P = 9.50e-07) and C18:3 n-3 from 0 to 0.29 (P = 8.81e-18).The rumen microbiome has a pronounced influence on the content of odd chain FA and polyunsaturated C18 FA, and to a lesser extent, on the content of the short- and medium-chain FA in the milk of Holstein cattle. The accuracy of prediction of FA phenotypes in milk based on information from either the animal's genotypes or rumen bacteria composition was very low.

Branched-chain fatty acids (BCFA) are encountered in Gram-positive bacteria, but less so in other organisms. The bacterial BCFA in membranes are typically saturated, with both odd- and even-numbered carbon chain lengths, and with methyl branches at either the ω-1 () or ω-2 () positions. The acylation with BCFA also contributes to the structural diversity of microbial natural products and potentially modulates biological activity. For the tunicamycin (TUN) family of natural products, the toxicity toward eukaryotes is highly dependent upon -acylation with -2,3-unsaturated BCFA. The loss of the 2,3-unsaturation gives modified TUN with reduced eukaryotic toxicity but crucially with retention of the synergistic enhancement of the β-lactam group of antibiotics. Here, we infer from genomics, mass spectrometry, and deuterium labeling that the -2,3-unsaturated TUN variants and the saturated cellular lipids found in TUN-producing are derived from the same pool of BCFA metabolites. Moreover, non-natural primers of BCFA metabolism are selectively incorporated into the cellular lipids of TUN-producing and concomitantly produce structurally novel -branched TUN -acyl variants.

Exogenous propionate is incorporated in vivo by Escherichia coli as a primer to produce lipids with fatty acids of odd chain lengths. This provides a method for the specific labeling of the three terminal carbons in the fatty acyl chains of phospholipids.

Conjugated linoleic acids (CLAs) have been found to have beneficial effects on human health when used as dietary supplements. However, their availability is limited because pure, chemistry-based production is expensive, and biology-based fermentation methods can only create small quantities. In an effort to enhance microbial production of CLAs, four genetically modified strains of the oleaginous yeast Yarrowia lipolytica were generated. These mutants presented various genetic modifications, including the elimination of β-oxidation (pox1-6∆), the inability to store lipids as triglycerides (dga1∆ dga2∆ are1∆ lro1∆), and the overexpression of the Y. lipolytica ∆12-desaturase gene (YlFAD2) under the control of the constitutive pTEF promoter. All strains received two copies of the pTEF-oPAI or pPOX-oPAI expression cassettes; PAI encodes linoleic acid isomerase in Propionibacterium acnes. The strains were cultured in neosynthesis or bioconversion medium in flasks or a bioreactor. The strain combining the three modifications mentioned above showed the best results: when it was grown in neosynthesis medium in a flask, CLAs represented 6.5% of total fatty acids and in bioconversion medium in a bioreactor, and CLA content reached 302 mg/L. In a previous study, a CLA degradation rate of 117 mg/L/h was observed in bioconversion medium. Here, by eliminating β-oxidation, we achieved a much lower rate of 1.8 mg/L/h.

One of the most promising alternatives to petroleum for the production of fuels and chemicals is bio-oil based chemistry. Microbial oils are gaining importance because they can be engineered to accumulate lipids enriched in desired fatty acids. These specific lipids are closer to the commercialized product, therefore reducing pollutants and costly chemical steps. Yarrowia lipolytica is the most widely studied and engineered oleaginous yeast. Different molecular and bioinformatics tools permit systems metabolic engineering strategies in this yeast, which can produce usual and unusual fatty acids. Usual fatty acids, those usually found in triacylglycerol, accumulate through the action of several pathways, such as fatty acid/triacylglycerol synthesis, transport and degradation. Unusual fatty acids are enzymatic modifications of usual fatty acids to produce compounds that are not naturally synthetized in the host. Recently, the metabolic engineering of microorganisms has produced different unusual fatty acids, such as building block ricinoleic acid and nutraceuticals such as conjugated linoleic acid or polyunsaturated fatty acids. Additionally, microbial sources are preferred hosts for the production of fatty acid-derived compounds such as γ-decalactone, hexanal and dicarboxylic acids. The variety of lipids produced by oleaginous microorganisms is expected to rise in the coming years to cope with the increasing demand.Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Triacylglycerols (TAGs) are valuable versatile compounds that can be used as metabolites for nutrition and health, as well as feedstocks for biofuel production. Although is the favored microbial cell factory for industrial production of biochemicals, it does not produce large amounts of lipids and TAGs comprise only ~1% of its cell dry weight. Here, we engineered to reorient its metabolism for overproduction of TAGs, by regulating lipid droplet associated-proteins involved in TAG synthesis and hydrolysis. We implemented a push-and-pull strategy by overexpressing genes encoding a deregulated acetyl-CoA carboxylase,, as well as the last two steps of TAG formation: phosphatidic phosphatase () and diacylglycerol acyltransferase (), ultimately leading to 129 mg∙gCDW of TAGs. Disruption of TAG lipase genes,, and sterol acyltransferase gene increased the TAG content to 218 mg∙gCDW. Further disruption of the beta-oxidation by deletion of, as well as glycerol-3-phosphate utilization through deletion of, did not affect TAGs levels. Finally, disruption of the peroxisomal fatty acyl-CoA transporter led to accumulation of 254 mg∙gCDW. The TAG levels achieved here are the highest titer reported in, reaching 27.4% of the maximum theoretical yield in minimal medium with 2% glucose. This work shows the potential of using an industrially established and robust yeast species for high level lipid production.