To circumvent the potential irreversible risks to cells posed by permanent genetic modifications, this study developed a copper-inducible system for dynamically regulating gene editing efficiency of Yarrowia lipolytica. By combining promoters pMT2 or enhanced pUAS16MT2 with genes scRAD52, scRAD59, and ylRAD52, homologous recombination efficiency was raised from 21.4% to 56.4%, while maintaining a transformation efficiency of 75±5 CFU/OD600. Employing a homology-mediated end joining strategy further improved DNA fragment integration efficiency from 15% to approximately 60%. Subsequently, the engineered chassis was subsequently applied to investigate stable conjugated linolenic acid (CLNA) production. Transcriptomic analysis and combinatorial gene knockouts identified POX2, POX3, and POX5 as key acyl-CoA oxidases involved in β-oxidation of long-chain fatty acids. A triple knockout strain increased extracellular lipid content by 64.19%, with POX5 playing a critical role in lipid-rich environments. Consequently, the CLNA degradation rate reduced from 92.9% to 19.2%, and final CLNA yield of muti-copy strains reached to 5.2g/L. In summary, this study establishes a tunable gene editing system for Y. lipolytica and provides an effective engineering strategy for high-value lipid production.

Integrated analysis of transcriptome and metabolomic uncover molecular mechanisms of ovarian aging in laying hens.

The effects of dietary supplementation with conjugated linoleic acid (CLA) on broiler duck growth performance and the quality of dry-cured products were investigated. Ten days preslaughter with the supplementation of 2 mL/d CLA was more economical and effective. This feeding protocol did not affect growth performance, with CLA accumulation amounting to 3.61 g/100 g. Histopathological observation of tissue morphology revealed that CLA alleviated intestinal damage with no adverse morphological changes in the heart, spleen, liver, or pancreas. Gut microbiota analysis demonstrated that the beneficial Megamonas increased and the pathogenic Streptococcus and Escherichia-Shigella reduced with the supplementation of CLA. Processing broiler ducks into dry-cured products resulted in no significant change in the CLA content. Additionally, CLA had no notable influence on the lipid oxidation or shelf life of dry-cured ducks. These findings indicate that dietary CLA does not impair dry-cured duck quality, supporting the development of functional CLA-enriched meat products.

This study aims to comprehensively analyze the role of metabolic signatures in rheumatoid arthritis (RA). A total of 599 samples, including fecal (n = 206), plasma (n = 206), and peripheral blood mononuclear cell (PBMC) samples (n = 187), were collected from 443 individuals with RA, systemic lupus erythematosus, and controls. Fecal, plasma and PBMC samples were subjected to 16S rRNA sequencing, liquid chromatography-tandem mass spectrometry, RNA sequencing and 4D DIA proteomics, respectively. A collagen-induced arthritis mouse model was used to investigate the role of the metabolite conjugated linoleic acid (CLA) in experimental arthritis. An RA clinical cohort (n = 26) was recruited to validate the potential role of CLA as an adjunct to conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) therapy. Multi-omics analysis revealed comprehensive alterations in metabolic signatures (metabolism-related molecules, metabolites, and metabolic pathways) in RA. Lipid metabolism pathways, particularly linoleic acid metabolism, appear to play a significant regulatory role in RA progression. Metabolites and molecules involved in linoleic acid metabolism were significantly associated with clinical phenotypes in RA patients. In animal experiments, CLA reduced arthritis scores, swollen joint counts, histopathological scores, and inflammatory levels. Finally, CLA supplementation accelerated the reduction of inflammatory levels in RA patients receiving csDMARDs therapy. These findings reveal lipid metabolism as a druggable axis, position dietary CLA as an adjunct to improve outcomes in RA, and offer a new avenue to enhance remission rates.

ObjectiveEndometriosis (EM) is a chronic gynecological condition of unclear etiology, with evidence suggesting a link between metabolite levels and EM risk. A two-sample Mendelian randomization (MR) approach was used to explore the association between 233 metabolites and EM.MethodsUsing publicly available genetic data, we conducted a bidirectional two-sample MR analysis to assess the associations between metabolites and EM. Sensitivity analyses were performed to test robustness and pleiotropy, with Bonferroni correction applied for significance.ResultsMR analysis suggested that genetically elevated diacylglycerol levels were significantly associated with increased EM risk (odds ratio [OR], 1.225; P=1.16×10−7), corresponding to a 22.5% increase in risk per standard deviation increase in genetically predicted diacylglycerol levels, and remained significant after Bonferroni correction. Nominally significant associations were observed for several other metabolites; lower ratios of 3-hydroxybutyrate and saturated fatty acids to total fatty acids and of total cholesterol to total lipids in very low-density lipoproteins were associated with a higher EM risk (OR, 0.863; P=0.015; OR, 0.865; P=0.030; OR, 0.855; P=1.51×10−4). Reverse MR analysis showed that increased levels of conjugated linoleic acid (CLA) and tyrosine and the CLA to total fatty acid ratio exhibited nominal associations with EM (OR, 1.026; P=0.043; OR, 1.036; P=3.33×10−4; OR, 1.026; P=0.045). No significant heterogeneity or pleiotropy was observed.ConclusionThis study provides evidence of an association between specific metabolites, especially diacylglycerol, and EM risk, enhancing our understanding of the metabolic profile associated with EM.

Conjugated linoleic acid (CLA) is a dietary lipid that modulates host–microbiota–immune interactions, yet its mechanistic impact on mucosal defense remains unclear. Here, we show that oral CLA supplementation enhances resistance to Salmonella Typhimurium infection and is associated with coordinated changes in gut microbial composition and mucosal immune responses. CLA-enriched commensals, including Dubosiella and Lactobacillus, were associated with increased production of CLA-derived oxylipins and activation of immune surveillance genes. Functionally, CLA pretreatment reduced Salmonella colonization, preserved epithelial integrity, and decreased neutrophilic inflammation without direct antibacterial effects. Single-cell RNA sequencing of ileal intraepithelial lymphocytes revealed that CLA predominantly reprogrammed intestinal CD8⁺ T cells toward an oxidative phenotype and enhanced effector activity. ATAC-seq revealed increased chromatin accessibility at loci associated with metabolic regulation, consistent with transcriptional reprogramming toward oxidative fitness. Mechanistically, CLA directly activated PPARγ signaling to promote mitochondrial biogenesis, oxidative phosphorylation, and the production of IFN-γ and granzyme B in CD8⁺ T cells; pharmacologic inhibition of PPARγ attenuated these effects both in vitro and in vivo. Notably, depletion of CD8⁺ T cells eliminated CLA-mediated protection and abolished early restriction of bacterial dissemination at Peyer’s patches and mesenteric lymph nodes. Although CLA enhanced CD8⁺ T-cell effector programs, antibiotic depletion and fecal microbiota transplantation experiments demonstrated that an intact gut microbiota is necessary for effective protection in vivo. Together, these findings identify CLA as a dietary modulator that strengthens mucosal resistance to Salmonella by promoting PPARγ-mediated metabolic reprogramming and enhanced effector fitness in intestinal CD8⁺ T cells.

Amyotrophic lateral sclerosis (ALS) is a progressive and fatal motor-neuron disorder strongly linked to oxidative stress. The degenerative process gradually impairs motor-neurons function and leads to loss of homeostasis and integrity of skeletal muscle. Current therapies provide limited benefit, as the disease entails multiple pathological mechanisms. Among these, reduced activity of the nuclear factor erythroid 2–related factor 2 (Nrf2) has been observed, an effect that may compromise cellular antioxidant responses, inflammatory control, and mitochondrial biogenesis. In this preclinical study, we investigated the effects of conjugated linoleic acid (CLA), a natural and well-tolerated Nrf2 activator, by analysing the antioxidant enzymes gene expression in skeletal muscle of SOD1-G93A mice. CLA supplementation significantly enhanced the expression of key Nrf2 target genes, including G6PDX and NQO1 – which respectively encode for glucose-6-phosphate dehydrogenase and NADPH-quinone oxidoreductase – supporting NADPH production and redox balance. Additionally, CLA increased transcription of PPARGC1A, which encodes the peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), a known enhancer of Nrf2 transcription and pathway activation. These findings suggest that dietary CLA may strengthen antioxidant defences and offer support as a nutritional adjuvant in early ALS stages, potentially enhancing the overall effectiveness of current treatments. Funded by European Union-Next Generation EU project PRIN-PNRR 2022.

Conjugated linolenic acids (CLnAs) are emerging as promising agents to trigger ferroptosis, a cell death driven by excessive lipid peroxidation, in cancer cells. Given the aggressive nature and treatment resistance of malignant melanoma, exploring CLnAs as therapeutic agents may offer a novel strategy to overcome these challenges. Here, we investigated the toxicity of four CLnA isomers on human (A375, WM266.4) and zebrafish (ZMEL1) melanoma cell lines. We observed a dose-dependent reduction in cell viability across all three tested cell lines. While human melanoma cells were more sensitive to CLnAs than ZMEL1 cells, treatment with ferroptosis inhibitors mitigated cell death in all models, confirming ferroptosis as the consistent primary mechanism of cell death. In addition, chemical inhibitors of ACSL4 and GPX4 modulated CLnA toxicity, further substantiating the ferroptotic mechanism by highlighting the role of these key regulators. Furthermore, fatty acid analysis revealed that CLnAs were effectively incorporated into phospholipids, generating substrates for lethal lipid peroxidation. At the transcriptional level, CLnA treatment significantly upregulated the pro-ferroptotic gene acsl4a in ZMEL1 cells. Overall, our study identifies specific CLnAs as potent ferroptosis inducers in both human and zebrafish melanoma cells and underscores the translational relevance of the zebrafish model based on a shared ferroptotic mechanism.

Abstract BACKGROUND Conjugated linoleic acid (CLA), particularly the bioactive isomers c9,t11‐CLA, and t10,c12‐CLA, has garnered substantial attention in food, nutraceutical, and pharmaceutical fields due to its diverse physiological benefits. However, the efficient synthesis of CLA with high selectivity toward bioactive isomers and satisfactory yield remains a challenge in homogeneous catalytic systems. RESULTS We systematically investigated the effects of key reaction parameters – including temperature, time, catalyst dosage, and alcohol‐to‐oil ratio – on the conversion of linoleic acid (LA) and the selectivity of target CLA isomers in a homogeneous base‐catalyzed isomerization process. The chemical composition and structural characteristics of the resulting CLA products were comprehensively characterized via Fourier transform infrared spectroscopy (FT‐IR), ultraviolet–visible spectroscopy (UV‐visible), gas chromatography (GC), and gas chromatography–mass spectrometry (GC–MS). Four CLA isomers were identified, namely c9,t11‐CLA, t10,c12‐CLA, t10,t12‐CLA, and t9,t11‐CLA, with the bioactive c9,t11‐CLA and t10,c12‐CLA as the predominant components. Through univariate optimization combined with parallel validation experiments, the optimal reaction conditions were determined as follows: stirring rate of 800 r/min, reaction temperature of 185 °C, reaction time of 4.5 h, catalyst (Sodium ethoxide) dosage of 30 wt%, and alcohol (Ethylene glycol) ‐to‐oil ratio of 10 mL/g. Under these optimized conditions, the relative content of bioactive CLA isomers reached nearly 90% – a performance that outperforms many conventional homogeneous catalytic systems for LA isomerization. CONCLUSION This study provides a systematic and scalable approach for the efficient synthesis of high‐purity, bioactive‐enriched CLA, offering valuable insights into the rational design of homogeneous catalytic processes for lipid modification and meeting the industrial demand for high‐quality CLA products. © 2026 Society of Chemical Industry (SCI).

The milk metabolite profiles of dairy cows during the dry-off and peripartum periods were investigated using 1H NMR combined with chemometric analysis to evaluate the effects of different dry-off management strategies. Milk samples were collected 14 days before dry-off (T0) and 28 days after calving (T1) from cows receiving an internal teat sealant combined with intramammary antibiotics (CTR), an internal teat sealant alone (SIG), or an internal teat sealant associated with dietary supplementation of lyophilized Aloe arborescens (ASIG). Analysis of both aqueous and organic milk extracts revealed no significant metabolite differences among treatment groups. In contrast, a clear discrimination was detected between samples collected at T0 and T1. Aqueous extracts at T0 were characterized by higher levels of choline, butyrate, branched-chain amino acids, and N-acetylated compounds, whereas T1 samples exhibited higher levels of saccharides, citrate, phosphorylcholine, and galactose-1-phosphate. Organic extracts at T0 showed higher concentrations of conjugated linoleic acids (CLAs) and caproleic acid. These findings indicated that the physiological stage of the cows had a more pronounced impact on milk metabolite composition than the dry-off treatments, with no detrimental effects on milk composition or overall metabolite balance.

Alzheimer’s disease (AD) is a major global health challenge, characterized by accumulation of amyloid plaques and neurofibrillary tangles. On account of this, PUFA have gained a major therapeutic strategy which plays role on Alzheimer’s disease by contributing effects as neuroprotective, anti-oxidant and anti-inflammatory properties. Among this, we review the dual effects of omega-6 fatty acid in relation to AD and performed the literature survey in databases like PubMed, google scholar and found that 30 articles were addressed the effect of omega-6 fatty acid in AD. Arachidonic Acid (ARA) and Linoleic Acid (LA) are central to the brain development and function. In that ARA contributes to the generation of pro-inflammatory mediators such as COX and LOX enzymes, which is responsible for the generation of pro-inflammatory cytokines, various in vivo and invitro studies have been reported that by inhibiting specific enzyme such as LOX and COX, the release of ARA can be stopped which prevent the generation of pro-inflammatory mediators. while, in some human studies have reported that circulating the higher ARA can produce the better cognitive outcomes and significantly reduce the dementia risk. In contrast to ARA, another acid such as LA have contributed to the anti-inflammatory properties and the reduced LA level may decrease the cognitive function and its isomer Conjugated linoleic acid (CLA) have also gained interesting therapeutic role as it has effect on the reduction of Aβ accumulation and tau phosphorylation, therefore it results in the uptake of anti-inflammatory cytokines and suppresses the inflammation. The derivative of LA such as Gamma Linoleic Acid (GLA) has inhibit the NF-kB which reduce the pro-inflammatory cytokines and also the MAPK signaling protect neurons from the amyloid toxicity. The balance of omega-3/omega-6 ratio (specifically AA: DHA) have been detected for the early AD biomarker. The therapeutic conclusion states that central target is not omega-6 fatty acids themselves but the metabolic pathway, future directions will focus on the metabolic pathway and which omega-6 will produce the anti-inflammatory effect and also the randomized controlled trials to establish the causal effects.

It is generally suggested that milk and milk products reduce the risk of colorectal cancer (CRC). While there is some controversy over specific sites affected throughout the colon and the benefits of specific dairy foods (DFs), there is a general consensus that calcium intake is the main mechanism of the cancer-reducing effects. This opinion may be sidelined by several other mechanisms. There is also a potentially important compensatory mechanism in populations with adult genetic lactase deficiency. The microbiome changes occur through a process of adaptation to continued lactose consumption. The bacterial blooms consist largely of Bifidobacterial species. These bacteria may exert anti-neoplastic effects and also increase the capacity of persons with adapted lactase insufficiency to consume dairy products. Bacterial metabolism thus provides a second pathway for lactose digestion. Since the use of Mendelian randomization (MR) accuracy disallow two different pathways for the genetic variable, this process constitutes a horizontal pleiotropy. This narrative review using articles from PubMed and Google Scholar will discuss different nutrients and mechanisms in milk and milk products that are involved in anti-neoplastic effects. The impact of adult lactase deficiency and continued dairy consumption on the microbiome, and its contribution to colorectal cancer reduction, is highlighted. The conclusions from this review are that calcium has multifaceted mechanisms of anti-carcinogenesis, but other nutrients, such as conjugated linoleic acid (CLA), lactoferrin, and folate in the dairy matrix, could also contribute. In lactase non-persistent (LNP) populations adapted to dairy foods, a bifidogenic bloom in the microbiome may add additional anti-neoplastic effects and /or increase dairy food consumption. We argue that predictions of colon cancer effects from dairy foods may be inaccurate, and that evaluating both populations together may confound outcomes.

Conjugated linoleic acid (CLA) is produced by bacterial biohydrogenation in the rumen of cattle, fulfills various biological functions, and is known for anti-obesity, anti-inflammation, anti-cancer, and other beneficial effects. It has numerous isomers, of which cis-9,trans-11 CLA accounts for 80% of total CLA, followed by trans-10,cis-12 CLA (t10,c12 CLA), with distinct molecular structures, oxidation efficiencies, activities, and functions. Different effects were observed, when isomers were individually supplemented in livestock nutrition. Currently, CLA is supplemented into the diets of dairy cows to improve the energy balance, and avoid negative effects of energy loss during the transition period. Furthermore, t10,c12 CLA was shown to reduce subcutaneous fat and to improve intramuscular fat (IMF) content in the carcasses of ruminants and pigs. Increasing the IMF content without increasing other fat depots and without compromising feed efficiency is an important goal in beef production. However, inconsistent and conflicting results were reported partly based on different study designs. This review aims to summarize studies on CLA supplementation in cattle, focusing on t10,c12 CLA and the effects of the dose, time, and method of supplementation on energy balance, milk yield and body composition, as well as on individual cells in vitro. This may improve our understanding of energy-saving and repartitioning effects of CLA in cattle.

Utilizing immobilized lipase for selective esterification in non-aqueous media: A strategy to enrich and purify conjugated linoleic acid isomers.

Dietary phytochemicals, primarily derived from grasses, legumes, and agro-industrial byproducts of plant origin, encompass distinct chemical classes such as polyphenols (including tannins, flavonoids, and other polyphenol compounds), saponins, organosulfur compounds, and essential oils (largely composed of terpenoids and phenylpropanoids). These compounds can function as rumen modifiers, antimethanogenic agents, anthelmintics, growth promoters, stress mitigators, and biopreservatives in ruminant production systems. Thus, they improve feed efficiency, nutrient utilization, and nitrogen retention while mitigating greenhouse gas emissions. In dairy systems specifically, phytogenic feedstuffs enhance milk yield and composition by enriching conjugated linoleic acids (CLAs), omega-3 fatty acids, and antioxidant compounds, leading to superior nutritional and oxidative stability. In meat production systems, they improve tenderness, flavor and shelf life through reduced oxidation and enhanced muscle metabolism. Despite these benefits, dose optimization, bio-efficacy, and species-specific responses remain critical research priorities. Use of phytogenic-based feeding strategies aligns with global sustainability goals by reducing reliance on feed additives, promoting environmentally resilient and circular food systems. This review synthesizes emerging evidence on the mechanisms, production outcomes, and functional benefits of dietary phytochemicals, providing a scientific framework for their strategic application in sustainable ruminant milk and meat production.

This study investigated the effects of supplementing 3% rapeseed oil or soybean oil in the diet during the late fattening period on intramuscular fat (IMF) deposition and fatty acid composition in beef cattle. In the preliminary cell experiment, rapeseed oil exhibited a superior effect in promoting the adipogenic differentiation of bovine skeletal muscle-derived cells compared with soybean oil (P < 0.05). In the animal experiment, beef cattle (n = 41) were randomly divided into 3 groups, which were supplemented with 3% soybean oil or 3% rapeseed oil or had no oil supplementation (control group). The results showed that both oils significantly increased IMF deposition (P < 0.001), and rapeseed oil exhibited a superior effect. It promoted endogenous synthesis of conjugated linoleic acid (CLA) (P < 0.001), enriched eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (P < 0.05), and reduced the n-6/n-3 ratio from 55.62 to 33.41 (P < 0.001) without affecting serum biochemical indicators. In contrast, soybean oil mainly increased n-6 fatty acids (P < 0.05). Mechanistically, cell inhibitor experiments revealed that rapeseed oil specifically activated phosphatidylinositol 3-kinase/protein kinase b/mammalian target of rapamycin (PI3K/AKT/mTOR) axis and upregulated the expression of key adipogenic transcription factors and fatty acid synthase (all P < 0.05), while soybean oil did not produce these effects. This result provides new insights for the enhancement of IMF deposition, optimization of fatty acid composition, and enrichment of CLA in beef and reveals the underlying molecular mechanisms involved.

Transcriptional regulation of the bbi gene in Bifidobacterium: Key factors controlling conjugated linoleic acid bioconversion.

Although conjugated linoleic acid (CLA) has attracted attention as a potent body fat-reducing agent, its detailed molecular mechanism of action remains obscure. Here, we evaluated the effect of short-term feeding of CLA on metabolism in adipose tissue of mice fed a high-fat diet. Mice were fed a high-fat diet for 8-wk to promote the accumulation of body fat, then divided into control and 1 % CLA groups and kept for 1-wk. CLA did not affect the weight of epididymal and perirenal adipose tissues. To detect the metabolic changes that precede the body fat-reducing effect of CLA, a comprehensive metabolite analysis in adipose tissue was performed using a capillary electrophoresis quadrupole time-of-flight system. Principal component analysis clearly showed differentiation in the pattern of quantitative data for metabolites between control and CLA groups. KEGG enrichment analysis of metabolites indicated the importance of three metabolite sets. Seventeen metabolites were significantly upregulated in the CLA group compared to the control and no metabolites were downregulated. Taken together, these changes in metabolite profile induced by CLA are indicative of early onset metabolic change, potentially leading to a reduction in adipose tissue mass.

The anti-cancer effects and mechanisms of conjugated fatty acids.

Co-culture with ethanol synergistically enhances CLA production. Ethanol increases membrane permeability, facilitating LA cellular uptake and its isomerization to CLA by LAI.