2007: atmospheric fingerprinting of pinene enantiomers | 2010: pinenes considered as renewable alternative to fuel | 2014: engineering of pinene-producing E. coli.

As one of the metabolites responsible for the smell of conifers (Schreiner et al. 2018), alpha-pinene is a fitting choice for our festive Metabolite of the month. This chiral molecule has two enantiomers that are found in varying proportions in different plants, as does its isomer, beta-pinene (Stephanou 2007).

Pinenes are unsaturated monoterpenes characterized by two rings fused to each other, making them quite reactive when released in the atmosphere. For instance, photooxidation of pinenes generates the metabolite 3-hydroxyglutaric acid (Claeys et al. 2007). Despite the clue in their name, their synthesis is not limited to pine trees and occurs in many plant species and some microorganisms.

A 2010 study identified beta-pinene as a potential renewable energy source, with properties comparable to those of jet fuel (Harvey et al. 2010). To enable industrial production of pinenes, bacterial strains were engineered to synthesize pinene by expressing pinene synthase and geranyl diphosphate synthase genes (Sarria et al. 2014). Beta-pinene was also used as a substrate to synthesize a high molecular weight polymer of interest for optoelectronics (Satoh et al. 2014; Winnacker 2018).

Pinenes also serve many endogenous functions in plants, with some interesting applications for human health, as discussed below.

Biosynthesis vs. dietary uptake

In plants, pinene biosynthesis starts with the activation of isoprene units that exist in two forms that react together to form geranyl pyrophosphate (GPP). GPP is transformed to its isomer linaloyl pyrophosphate, which undergoes cyclization and a nucleophilic attack, leading to a pinane cation intermediate. Alpha-pinenes are synthesized by methylene proton elimination while beta-pinenes arise from methyl proton elimination (Nyamwihura et al. 2022). Pinenes also serve as intermediates in the synthesis of other plant metabolites such as carvone (a common component of essential oils used in the food industry).

In human males, ingestion of oils containing pinenes resulted in absorption of alpha- and beta-pinene, with both metabolites detectable in plasma after 24 hours (Papada et al. 2020). A 2012 study showed that alpha-pinene and other terpenes were detectable in the plasma and milk of goats after ingestion, suggesting that these metabolites may be useful in tracing the consumption of certain foods by farm animals (Poulopoulou et al. 2012). However, terpene levels in cheese made from these goats’ milk were found to vary, which may limit their use as a feed tracer in processed milk products.

Alpha-pinene functions in plants

Pinenes appear to serve several functions in the plants that synthesize them. Studies have shown that pinenes help protect plants from pests, such as the red turpentine beetle, (Dendroctonus valens) (Xu et al. 2016) and the white pine weevil (Pissodes strobi) (McKay et al. 2003). The study by McKay et al. describes how traumatic resin ducts form in the Sitka spruce (Picea sitchensis) upon attack by pests that activate the tree’s terpenoid defense systems.

Pinenes also play a role in plant-to-plant communication. The release of pinenes into the atmosphere is light- and temperature-dependent (Stephanou 2007), and headspace exposure to these pinenes can cause strong reactions. For example, when Arabidopsis thaliana is exposed to a mixture of alpha and beta-pinenes, this triggers the plant’s defense responses, accumulation of reactive oxygen species, and changes in gene expression that are consistent with systemic acquired resistance (Riedlmeier et al. 2017). Thus, pinenes and other monoterpenes are infochemicals, supporting plant-to-plant signaling and propagating defense signals between neighboring plants.

Lastly, pinenes influence the growth of their host plant. In Cicer arietinum, alpha-pinene increases solute leakage from roots and increases the levels of proline, malondialdehyde and hydrogen peroxide, inhibiting radicle growth (Singh et al. 2006). Beta-pinene has been found to inhibit germination in several weed species (Chowhan et al. 2013).

Alpha-pinene activity in animals

Pinenes are not only relevant to plant biology.They have been found to have several properties that are of interest in human health and disease. Pinenes have been studied for their antimicrobial properties (Da Rivas et al. 2012). They have also been described as having anticoagulant, antitumor, antimalarial, antioxidant, anti-inflammatory, and analgesic (Salehi et al. 2019). Some of these effects were uncovered through the study of active ingredients in the plants used in traditional Chinese medicine. For example, a 2011 study showed that alpha-pinene derivatives isolated from Angelica sinensis inhibited platelet aggregation and exhibited weak antithrombin activity (Yang et al. 2011).

Pinenes are also studied for their effects on cancer and cancer therapies. Both alpha- and beta-pinenes have shown synergistic antitumor effects with paclitaxel in the treatment of non-small-cell lung carcinoma (Zhang et al. 2015). Interestingly, in a murine model, exposure to a fragrant environment rich in alpha-pinene prior to and after tumor implantation resulted in 40% smaller tumors, increased plasma leptin levels, and neurological and immune differences compared to mice who were not exposed to alpha-pinene (Kusuhara et al. 2019).

In various models, pinenes were also shown to increase the skin penetration of drugs (Almirall et al. 1996), provide anti-inflammatory effects via inhibition of mitogen-activated protein kinases (MAPK) and nuclear factor-kappa B (NF-κB) in macrophages (Kim et al. 2015), influence vascular tone (Jin et al. 2023), and have a protective effect on the gastrointestinal tract (Marcelo de Almeida et al. 2015).

Alpha-pinene in the atmosphere

Researchers collect samples of the air over forests to identify the enantiomeric composition of the volatile compounds emitted by trees. A 2007 comparison of the ambient air over tropical (South America) and boreal (Northern Europe) forests showed that (-) alpha-pinene and (+) beta-pinene were predominant in the tropical forest while (+) alpha-pinene and (-) beta-pinene were predominant in the boreal forest (Williams et al. 2007). These results indicate a fingerprint-like profile of pinene enantiomers between different ecosystems and raise questions about the effects of such enantiomeric mixtures in the atmosphere.

To continue learning about seasonal metabolites, read our article on cinnamaldehyde.

References

Almirall M. et al.: Effect of d-limonene, alpha-pinene and cineole on in vitro transdermal human skin penetration of chlorpromazine and haloperidol. (1996) In Arzneimittel-Forschung | Available online at https://pubmed.ncbi.nlm.nih.gov/8842336/

Chowhan, N. et al.: β-Pinene inhibited germination and early growth involves membrane peroxidation. (2013) In Protoplasma http://doi.org/10.1007/s00709-012-0446-y

Claeys M. et al.: Hydroxydicarboxylic acids: markers for secondary organic aerosol from the photooxidation of alpha-pinene. (2007) Environmental Science & Technology | http://doi.org/10.1021/es0620181

Da Rivas S. et al.: Biological activities of α-pinene and β-pinene enantiomers. (2012) In Molecules 17 | http://doi.org/10.3390/molecules17066305

Harvey B. et al.: High-Density Renewable Fuels Based on the Selective Dimerization of Pinenes. (2010) Energy Fuels 24 | http://doi.org/10.1021/ef900799c

Jin L. et. al.: Endothelial-dependent relaxation of α-pinene and two metabolites, myrtenol and verbenol, in isolated murine blood vessels. In American journal of physiology. (2023) Heart and circulatory physiology 325 | http://doi.org/10.1152/ajpheart.00380.2023

Kim D. et al.: Alpha-Pinene Exhibits Anti-Inflammatory Activity Through the Suppression of MAPKs and the NF-κB Pathway in Mouse Peritoneal Macrophages. (2015) The American journal of Chinese medicine 43 | http://doi.org/10.1142/S0192415X15500457

Kusuhara M. et al.: (2019): A Fragrant Environment Containing α-Pinene Suppresses Tumor Growth in Mice by Modulating the Hypothalamus/Sympathetic Nerve/Leptin Axis and Immune System.(2019) Integrative cancer therapies 18 | http://doi.org/10.1177/1534735419845139

Marcelo de Almeida P. et al.: Gastroprotective effect of alpha-pinene and its correlation with antiulcerogenic activity of essential oils obtained from Hyptis species. (2015) In Pharmacognosy Magazine | Available online at https://phcog.com/article/view/2015/11/41/123-130

McKay S. et al.: Insect attack and wounding induce traumatic resin duct development and gene expression of (-)-pinene synthase in Sitka spruce. (2003) Plant physiology | http://doi.org/10.1104/pp.103.022723

Nyamwihura R. et al.: The pinene scaffold: its occurrence, chemistry, synthetic utility, and pharmacological importance. (2022) RSC advances | http://doi.org/10.1039/d2ra00423b

Papada E. et al.: An Absorption and Plasma Kinetics Study of Monoterpenes Present in Mastiha Oil Humans. (2020) Foods 9 | http://doi.org/10.3390/foods9081019

Poulopoulou I. et.al.: Transfer of orally administered terpenes in goat milk and cheese. (2012) Asian-Australas J Anim Sci 25 | http://doi.org/10.5713/ajas.2012.12165

Riedlmeier M. et al.: Monoterpenes Support Systemic Acquired Resistance within and between Plants. (2017) The Plant cell | http://doi.org/10.1105/tpc.16.00898

Salehi B. et al.: Therapeutic Potential of α- and β-Pinene: A Miracle Gift of Nature. (2019) Biomolecules | http://doi.org/10.3390/biom9110738

Sarria, S. et al.: Microbial synthesis of pinene. (2014) ACS Synthetic Biology | http://doi.org/10.1021/sb4001382

Satoh K. et al.: Sustainable cycloolefin polymer from pine tree oil for optoelectronics material: living cationic polymerization of β-pinene and catalytic hydrogenation of high-molecular-weight hydrogenated poly(β-pinene). (2014) Polym. Chem. | http://doi.org/10.1039/C3PY01320K

Schreiner L. et al.: Resolving the smell of wood – identification of odour-active compounds in Scots pine (Pinus sylvestris L.). (2018) Sci Rep 8 (1), p. 8294. | http://doi.org/10.1038/s41598-018-26626-8

Singh H. et al.: alpha-Pinene inhibits growth and induces oxidative stress in roots. (2018) Annals of botany | http://doi.org/10.1093/aob/mcl213

Stephanou E.G.: Atmospheric chemistry: a forest air of chirality. (2007) Nature | http://doi.org/10.1038/446991a

Williams J. et.al.: Mirror image hydrocarbons from Tropical and Boreal forests. (2007) Atmos. Chem. Phys.| http://doi.org/10.5194/acp-7-973-2007

Winnacker M.: Pinenes: Abundant and Renewable Building Blocks for a Variety of Sustainable Polymers. (2018) Angewandte Chemie (International ed. in English) | http://doi.org/10.1002/anie.201804009

Xu, L. et al.: Pine Defensive Monoterpene α-Pinene Influences the Feeding Behavior of Dendroctonus valens and Its Gut Bacterial Community Structure. (2016) International Journal of Molecular Sciences | http://doi.org/10.3390/ijms17111734

Yang N. et al.: Two new α-pinene derivatives from Angelica sinensis and their anticoagulative activities. (2011) Fitoterapia | http://doi.org/10.1016/j.fitote.2011.02.007

Zhang Z. et al.: Synergistic antitumor effect of α-pinene and β-pinene with paclitaxel against non-small-cell lung carcinoma (NSCLC). (2015) Drug research | http://doi.org/10.1055/s-0034-1377025

Industrial livestock farming is expanding worldwide as demand for meat and other animal products continues to increase. Herd size, room to roam, and feeding practices differ considerably from traditional animal husbandry, to maximize productivity per animal. This high-performance farming leads to massive health problems in livestock, including metabolic and infectious diseases. Improving the health of farm animals and early diagnosis of diseases extends their productive life span and reduces costs.

By providing a readout of the effect of exposure to different genetic and environmental conditions, metabolomics is a promising tool to predict, prevent, diagnose, and treat diseases in farm animals. Farmers can optimize the amount and composition of feed and supplements to avoid metabolic disorders and related infectious diseases, and increase fertility and breeding success. Production traits such as growth rate, fat deposition, and milk yield and quality can be maximized. It may also be possible to reduce the need for antibiotics, which reduces costs and improves product quality for the end consumers. Overall, metabolomics is essential for advancing sustainable, productive animal husbandry and welfare by contributing to the assessment of farm animal health.

A link between feeding and diseases

Over-conditioning of dairy cows due to grain-rich feeding in industrial farming causes severe diseases, including fatty liver, diabetes, and mastitis as a sonsequence of chronic inflammation and immune deficiency. Early metabolic changes such as increased circulating levels of branched-chain amino acids, lipids, and tryptophan metabolites, and reduced levels of biogenic amines, are frequently detectable even before onset of the disease.

This applies not only to cows, but also to other animals and humans, which highlights the extensive conservation of key metabolic pathways across species (Peregrín-Alvarez et al. 2009), and speaks to the direct relationship between animal and human health. Hence, human health profits from the understanding, detection, and curation of metabolic diseases in animals, and vice versa. The interdisciplinary “One Health” initiative (One Health: It’s for All of Us 2021) aims to integrate and translate knowledge between studies on animal, human and ecosystem health.

One of the most common cattle health issues resulting from grain-rich feeding is acidosis. The accumulation of acids in the rumen leads to dysbiosis of the gut microbiome, increased rumen permeability, and systemic inflammation (Nagaraja et al. 2007). Animals suffering from chronic inflammation or metabolic disorders are more susceptible to infections due to an impaired immune response. Early detection and treatment of inflammation and metabolic diseases can prevent subsequent infections.

Mastitis, the inflammation of the udder caused by infection of the mammary gland, is the second most important reason for culling of dairy cows with a very high economic impact (Zwierzchowski et al. 2020). Indeed, cows affected with subacute ruminal acidosis (SARA) have been shown to exhibit higher levels of acute phase protein and altered plasma metabolomes when experiencing acute mastitis (Humer et al. 2018).

Fatty liver impairs health status, decreases productivity, reduces fertility, and shortens the lifespan of farm animals. Despite the high prevalence and economic burden of hepatic lipidosis, only biopsy has been proven as a reliable diagnostic tool. However, identification of novel metabolic biomarkers in urine, feces, or blood would be a non- or minimally invasive way to improve the prevention or diagnosis of disorders like fatty liver. In dairy cows, a panel of 29 serum metabolites was shown to differentiate healthy controls from subjects with different disease states of hepatic lipidosis (Imhasly et al. 2014). Subjects with fatty liver disease had decreased levels of glycine, glutamine, and almost all phosphatidylcholines and sphingomyelins.

How to use metabotypes

The metabolome holds information about how different biochemical pathways respond to dietary or environmental conditions. With this information, individuals can be grouped based on similarities in their metabolic phenotype. This practice is referred to as metabotyping.

For example, a study from 2016 found that a novel metabotype of periparturient cows, characterized by long-chain acylcarnitines and biogenic amines, is associated with a productive life span. Increased levels of carnitine and acylcarnitines may indicate properly functioning mitochondria, while reduction of the kynurenine/tryptophan ratio along with higher levels of carnosine, sarcosine, and spermidine point to anti-inflammatory, anti-oxidative, and anti-ageing states (Huber et al. 2016). Identifying biomarkers of metabotypes in this way can help to predict the risk of metabolic dysfunctions and select appropriate interventions to extend the productive life of farm animals.

Metabotyping has also been used to identify screening markers for postpartum ketosis risk in dairy cows. Ketosis is a metabolic disease with a prevalence of up to 40% in dairy cows, and causes vague clinical symptoms like anorexia, loss of body condition, and impaired productiveness. The formation of ketone bodies, including acetone, acetoacetate, and beta-hydroxybutyrate, reflects the hepatic conversion of circulating free fatty acids into glucose via gluconeogenesis.

Characterizing metabolic patterns in dairy cows revealed several metabotypes, based on changes in amino acids, glycerophospholipids, sphingolipids, acylcarnitines, and biogenic amines in serum of prepartum dairy cows that developed ketosis after parturition. (Zhang et al. 2017). Two sets of predictive biomarker models and one set of diagnostic biomarkers with high sensitivity and specificity were identified, providing new insights into the pathology and diagnosis of ketosis.

Finding alternative feeding strategies to improve animal health

To avoid feeding-related metabolic and infectious diseases, the farming industry needs alternatives to conventional feeding practices. Considering that the metabolome directly reflects feed intake and physiological processes, discovery of metabolic biomarkers associated with health and productivity are key to find appropriate feeding alternatives (Hao et al. 2021). A study in growing pigs showed that partial or complete replacement of a conventional protein source by insect meal feeding does not have any adverse effects on the metabolism (Meyer et al. 2020).

Implications for pet health

In accordance with the One Health concept, companion animals suffer from the same lifestyle-related problems as farm animals and humans, due to a combination of overfeeding and reduced physical activity. In fact, more than 50% of cats and dogs in the US are overweight or obese. Importantly, obesity enhances the susceptibility for severe metabolic disorders like diabetes, which impair life quality and shorten life span. Analysis of saliva from obese dogs revealed a strong association between 27 metabolites and insulin resistance. Thus, the salivary metabolome is a valuable source of biomarkers for obesity, insulin resistance, and related complex conditions (Muñoz-Prieto et al. 2021).

Furthermore, metabolites, especially those of the gut microbiome, are important mediators of the gut-brain and gut-immune axis. Modulating the interaction between these organs might improve chronic inflammatory states. Inflammatory bowel disease (IBD) is a chronic gastrointestinal inflammation, leading to diarrhea, vomiting, and weight loss. Hydrolyzed diet alone or in combination with pre- and probiotics significantly increased lipids in serum of dogs with IBD, leading to the amelioration of clinical signs (Ambrosini et al. 2020). Finally, various factors of pet health, from dietary interventions over microbiome to pharmacological treatments can be monitored by metabolomics.

If you want to gain a complete picture of health and disease in livestock and companion animals, have a look at the different application areas of metabolomics or continue to read on animal health.

References

Ambrosini Y. et al.: Treatment With Hydrolyzed Diet Supplemented With Prebiotics and Glycosaminoglycans Alters Lipid Metabolism in Canine Inflammatory Bowel Disease. (2020) Frontiers in Veterinary Science | https://doi.org/10.3389/fvets.2020.00451

Hao D. et al.: Overview of Metabolomic Analysis and the Integration with Multi-Omics for Economic Traits in Cattle. (2021) Metabolites | https://doi.org/10.3390/metabo11110753

Huber K. et al.: Metabotypes with properly functioning mitochondria and anti-inflammation predict extended productive life span in dairy cows. Scientific Reports, 6, 24642. | https://doi.org/10.1038/srep24642

Humer E. et al.: Innate immunity and metabolomic responses in dairy cows challenged intramammarily with lipopolysaccharide after subacute ruminal acidosis. (2018) Animal | https://doi.org/10.1017/S1751731118000411

Imhasly S. et al.: Metabolomic biomarkers correlating with hepatic lipidosis in dairy cows. (2014) BMC Veterinary Research | https://doi.org/10.1186/1746-6148-10-122

Meyer S.et al.: Comprehensive evaluation of the metabolic effects of insect meal from Tenebrio molitor L. In growing pigs by transcriptomics, metabolomics and lipidomics. (2020) Journal of Animal Science and Biotechnology | https://doi.org/10.1186/s40104-020-0425-7

Muñoz-Prieto A. et al.: Evaluation of Changes in Metabolites of Saliva in Canine Obesity Using a Targeted Metabolomic Approach. (2021) Animals : An Open Access Journal from MDPI | https://doi.org/10.3390/ani11092501

Nagaraja T. et al.: Acidosis in feedlot cattle. The Veterinary Clinics of North America. (2007) Food Animal Practice | https://doi.org/10.1016/j.cvfa.2007.04.002

One Health: It’s for All of Us (2021) FDA | https://www.fda.gov/animal-veterinary/animal-health-literacy/one-health-its-all-us

Peregrín-Alvarez J. et al.: The conservation and evolutionary modularity of metabolism. (2009) Genome Biology | https://doi.org/10.1186/gb-2009-10-6-r63

Zhang G. et al.: Metabotyping reveals distinct metabolic alterations in ketotic cows and identifies early predictive serum biomarkers for the risk of disease. (2017) Metabolomics | https://doi.org/10.1007/s11306-017-1180-4

Zwierzchowski G. et al.: Mass-spec-based urinary metabotyping around parturition identifies screening biomarkers for subclinical mastitis in dairy cows. (2020) Research in Veterinary Science | https://doi.org/10.1016/j.rvsc.2020.01.001

For example, Pelvic Organ Prolapse (POP) and Porcine Reproductive Respiratory Syndrome (PRRS) each lead to the loss of hundreds of millions of dollars annually in the United States alone. Here, we look at two recent publications which use different metabolomic approaches to investigate these diseases, with a view to finding new ways to treat disease and reduce the economic burden. The first uses a hypothesis-driven approach to investigate POP, and the second uses a hypothesis-generating metabolomics approach for PRRS.

Circulating biomarkers associated with pelvic organ prolapse risk in late gestation sows

POP occurs when pelvic organs shift away from their normal location. Typically, this occurs around the time of birth, often resulting in the death of the piglets and requiring the sow to be euthanized. The cause remains unclear. In a recent study, researchers from Iowa and Nebraska performed total blood-count analysis and investigated the role of inflammation-related protein biomarkers, such as C-reactive protein (CRP) and tumor necrosis factor alpha (TNF-alpha), and steroid hormone profiles in sows with a presumed low, medium or high risk for POP.

While complete blood count and inflammatory markers revealed mostly small to moderate changes, there was a 25.8% increase in Lipopolysaccharide-binding protein (LBP) in high-risk sows compared to low-risk sows. The statistically strongest differences (P ≤ 0.02) were observed for steroid hormones such as androgens and estrogens. While the exact biological relevance for steroid hormones in POP could not fully be elucidated in this paper, the relationship between increased hormones and increased LBP suggests a possible involvement of bacterial infection or host-microbial immune interaction. These findings could help identify effective mitigation strategies.

Fetal Metabolomic Alterations Following Porcine Reproductive and Respiratory Syndrome Virus Infection

PRRS is caused by a viral infection and can lead to reproductive failure in sows, weak piglets, and severe respiratory disease in weaning pigs. Unlike the hypothesis-driven approach showcased in the POP article, researchers in this experiment employed a broader metabolomics method using the AbsoluteIDQ® p180 kit and nuclear magnetic resonance (NMR) in fetal serum samples. The intention was to develop hypotheses to explain why some piglets escape infection which is fatal in others – even within the same litter.

Piglets from non-inoculated mothers (the controls) and uninfected piglets from inoculated mothers had similar metabolic profiles, but with differing levels of alpha-aminoadipic acid. This indicates a fetal response to the mother’s infection, even without contracting the infection. Infected fetuses showed a larger variability in their metabolome and larger deviation from controls. Out of 15 relevant metabolites, kynurenine and alpha-aminoadipic acid were found to be most relevant, with alpha-aminoadipic acid appearing to correlate most strongly with disease severity.

The infected group did not separate completely from uninfected fetuses in multivariate analysis, which probably reflects the heterogeneity seen in infection outcomes. Finally, fetuses with intrauterine growth restriction (IUGR) appear to be somewhat protected from adverse outcomes. IUGR fetuses differ from normally developing fetuses mainly by the levels of (in part essential) amino acids, as well as selected phosphatidylcholines and lyso-phosphatidylcholines. These differences probably represent a blunted response to infection due to placental inefficiency.

The study reveals mechanisms associated with the susceptibility for and progression of PRRS. It also shows how a targeted approach covering a broad spectrum of metabolites can be used in hypothesis-generating research. This could yield biomarkers and potential targets for improving outcomes, and reduce economic losses associated with health risks in animal breeding.

Metabolomics has been applied in various fields within animal husbandry and animal health, from the prediction of the healthy life span of animals, to studies on the metabolic effects of feed strategies. For more examples how metabolomics has been applied in such contexts, go to https://biocrates.com/category/animal-health/

1. Kiefer ZE, Studer JM, Chipman AL, et al.: Circulating biomarkers associated with pelvic organ prolapse risk in late gestation sows. (2021) Journal of Animal Science | https://doi.org/10.1093/jas/skab207
2. Malgarin CM, MacPhee DJ, Harding JCS.: Fetal Metabolomic Alterations Following Porcine Reproductive and Respiratory Syndrome Virus Infection. (2020) Frontiers in Molecular Biosciences | https://doi.org/10.3389/fmolb.2020.559688

In dairy cows, proper nutrition around the time of calving is crucial to ensure optimal milk production. Research has shown that lactation is supported by the release of fatty acids from storage in adipose tissue, providing an energy source for the liver and other peripheral organs. Many hormonal factors play a role in regulating this process, including growth hormone and insulin signaling.

A previous metabolomic study demonstrated that over-conditioned cows were less able to adapt metabolically to the sudden increase in milk yield after calving. Combining body condition score (BCS) – used to classify dairy cows- and metabolomics, cows with a high BCS (HBCS) could be predicted to have a normal or a high BCS, resulting in one of two metabotypes: HBCS-predicted high (HBSC-PH) or -predicted normal (HBCS-PN).

In this recent article, the authors combined metabolomics of muscle tissue with transcriptomics of adipose tissue to investigate the mechanisms related to lipogenesis in these two HBCS metabotypes. They also applied this to normal BCS cows predicted to have a normal BCS (NBCS-PN).

Their findings show that before giving birth, transcriptomic profiles clearly separated HBCS-PH from the other phenotypes, with an increase in the expression of several genes related to lipogenesis. After giving birth, this effect was no longer visible. Metabolomics, however, could distinguish HBCS-PH from both HBCS-PN and NBCS-PN cows after birth based on the levels of serotonin and short- and long-chain acylcarnitines.

Sadri H, Ghaffari MS, Schuh K, Koch C, Sauerwein H: Muscle metabolome and adipose tissue mRNA expression of lipid metabolism‑related genes in over‑conditioned dairy cows differing in serum-metabotype (2021) Sci Rep | https://doi.org/10.1038/s41598-021-90577-w

Probiotics are not only for humans. In the farm and food industries, the clever use of microorganisms (e.g. bacteria, yeast) as food supplements can also help enhance the health of livestock. Diana Luise and colleagues explored the use of Bacillus bacteria to combat enterotoxic ETEC E. Coli strains that are a persistent threat to piglets after weaning.

ETEC has been linked to the development of post-weaning diarrhea syndrome (PWDS) which can result in the death of piglets. The typical mitigation strategies for PWDS are to supplement food with antibiotics or zinc oxide (ZnO) to remove any trace of the dangerous pathogen. These strategies are, however, strongly criticized. Indeed, the systematic use of antibiotics in the food industry is a source of growing concern vis-à-vis antimicrobial resistance, while ZnO will be banned for use against PWDS in the EU from 2022 on. Thus, better strategies are needed to mitigate the risk of PWDS.

In this article, scientists from Italian and Danish institutions investigated the use of two strains of Bacillus bacteria to counteract the effect of ETEC on piglets after weaning. The piglets were either fed a basic diet or a basic diet supplemented with the antibiotic colistin (particularly effective against ETEC) or one of two Bacillus strains (B. amyloliquefaciens or B. subtilis). The researchers followed the effects of their food supplements on the digestion and overall health of piglets with several methods, including targeted metabolomics in plasma samples 1 day and 14 days after weaning. Metabolomic profiles showed similarities between the probiotic and antibiotic groups. The authors conclude on a promising note on the potential use of Bacillus bacteria to combat the effects of E. coli strains in post-weaning piglets.

To find out how targeted metabolomics can be applied in your field of research, visit our products page or contact us.

Diana Luise, Micol Bertocchi, Vincenzo Motta, Chiara Salvarani, Paolo Bosi, Andrea Luppi, Flaminia Fanelli, Maurizio Mazzoni, Ivonne Archetti, Giuseppe Maiorano, Bea K. K. Nielsen and Paolo Trevisi. Bacillus Sp. Probiotic Supplementation Diminish the Escherichia coli F4ac Infection in Susceptible Weaned Pigs by Influencing the Intestinal Immune Response, Intestinal Microbiota and Blood Metabolomics. J Anim Sci Biotech 2019 https://doi.org/10.1186/s40104-019-0380-3

Biogenic amines are nitrogenous metabolites related to amino acids with a broad range of physiological actions and diagnostic applications. Creatinine, a by-product of muscle metabolism, is perhaps the most famous biogenic amine and has been used for decades to monitor kidney function in the clinics.

In this study, Ghaffari and colleagues used targeted metabolomics to study animal health. They quantified 21 biogenic amines over a 19-week period in 2 groups of pregnant cows fed either a high- or low-energy diet prior to giving birth. This study design allowed to not only compare the metabolism of two groups with different adiposity levels, but also to follow temporal changes in each group around the time of birth. Metabolite levels were changed during the weeks leading to and following birth in both groups. In addition, the influence of the diet was clearly observed in serum with significant differences in creatinine, carnosine, putrescine, alpha-aminoadipic acid, hydroxyproline, and asymmetric dimethylarginine (ADMA) levels. The effect in muscle tissue was milder, with a notably lower amount of phenylethylamine (PEA) in cows fed the high-energy diet.

Beyond absolute concentrations, the authors also took advantage of the power of metabolite ratios, revealing interesting findings. In serum, the kynurenine/tryptophan ratio was higher in the more adipose cows after giving birth. While little is known on the relevance of this ratio to animal health, elevated kynurenine and kynurenine/tryptophan ratio in the blood have been associated with obesity-linked inflammation in humans.

If you want to know more about the use of metabolite sums and ratios in modern biomedicine, check out MetaboINDICATOR™, the new software tool for improved metabolomics data analysis and interpretation.

Ghaffari, M. H.; Sadri, H.; Schuh, K.; Dusel, G.; Frieten, Dörte; Koch, C. et al. (2019): Biogenic amines: Concentrations in serum and skeletal muscle from late pregnancy until early lactation in dairy cows with high versus normal body condition score. Journal of dairy science DOI: 10.3168/jds.2018-16034.