Branched chain fatty acids are constituents of the normal healthy newborn gastrointestinal tract

Structural characterization of fatty acid anions via gas-phase charge inversion using Mg(tri-butyl-terpyridine)2 2+ reagent ions

RATIONALE

Free fatty acids and lipid classes containing fatty acid esters are major components of lipidome. In the absence of a chemical derivatization step, FA anions do not yield all of the structural information that may be of interest under commonly used collision-induced dissociation (CID) conditions. A line of work that avoids condensed-phase derivatization takes advantage of gas-phase ion/ion chemistry to charge invert FA anions to an ion type that provides the structural information of interest using conventional CID. This work was motivated by the potential for significant improvement in overall efficiency for obtaining FA chain structural information.

METHODS

A hybrid triple quadrupole/linear ion-trap tandem mass spectrometer that has been modified to enable the execution of ion/ion reaction experiments was used to evaluate the use of 4,4',4″-tri-tert-butyl-2,2':6',2″-terpyridine (ttb-Terpy) as the ligand in divalent magnesium complexes for charge inversion of FA anions.

RESULTS

Mg(ttb-Terpy)2 2+ complexes provide significantly improved efficiency in producing structurally informative products from FA ions relative to Mg(Terpy)2 2+ complexes, as demonstrated for straight-chain FAs, branched-chain FAs, unsaturated FAs, and cyclopropane-containing FAs. It was discovered that most of the structurally informative fragmentation from [FA-H + Mg(ttb-Terpy)]+ results from the loss of a methyl radical from the ligand followed by radical-directed dissociation (RDD), which stands in contrast to the charge-remote fragmentation (CRF) believed to be operative with the [FA-H + Mg(Terpy)]+ ions.

CONCLUSIONS

This work demonstrates that a large fraction of product ions from the CID of ions of the form [FA-H + Mg(ttb-Terpy)]+ are derived from RDD of the FA backbone, with a very minor fraction arising from structurally uninformative dissociation channels. This ligand provides an alternative to previously used ligands for the structural characterization of FAs via CRF.

Quantifying acyl-chain diversity in isobaric compound lipids containing monomethyl branched-chain fatty acids

Compound lipids comprise a diverse group of metabolites present in living systems, and metabolic- and environmentally-driven structural distinctions across this family is increasingly linked to biological function. However, methods for deconvoluting these often isobaric lipid species are lacking or require specialized instrumentation. Notably, acyl-chain diversity within cells may be influenced by nutritional states, metabolic dysregulation, or genetic alterations. Therefore, a reliable, validated method of quantifying structurally similar even-, odd-, and branched-chain acyl groups within intact compound lipids will be invaluable for gaining molecular insights into their biological functions. Here we demonstrate the chromatographic resolution of isobaric lipids containing distinct combinations of straight-chain and branched-chain acyl groups via ultra-high-pressure liquid chromatography (UHPLC)-mass spectrometry (MS) using a C30 liquid chromatography column. Using metabolically-engineered adipocytes lacking branched-keto acid dehydrogenase A (Bckdha), we validate this approach through a combination of fatty acid supplementation and metabolic tracing using monomethyl branched-chain fatty acids and valine. We observe resolution of numerous isobaric triacylglycerols and other compound lipids, demonstrating the resolving utility of this method. This approach strengthens our ability to quantify and characterize the inherent diversity of acyl chains across the lipidome.

Gas-Phase Ion/Ion Reactions to Enable Radical-Directed Dissociation of Fatty Acid Ions: Application to Localization of Methyl Branching

Methyl branching on the carbon chains of fatty acids and fatty esters is among the structural variations encountered with fatty acids and fatty esters. Branching in fatty acid/ester chains is particularly prominent in bacterial species and, for example, in vernix caseosa and sebum. The distinction of branched chains from isomeric straight-chain species and the localization of branching can be challenging to determine by mass spectrometry (MS). Condensed-phase derivatization strategies, often used in conjunction with separations, are most commonly used to address the identification and characterization of branched fatty acids. In this work, a gas-phase ion/ion strategy is presented that obviates condensed-phase derivatization and introduces a radical site into fatty acid ions to facilitate radical-directed dissociation (RDD). The gas-phase approach is also directly amenable to fatty acid anions generated via collision-induced dissociation from lipid classes that contain fatty esters. Specifically, divalent magnesium complexes bound to two terpyridine ligands that each incorporate a ((2,2,6,6-tetramethyl-1-piperidine-1-yl)oxy) (TEMPO) moiety are used to charge-invert fatty acid anions. Following the facile loss of one of the ligands and the TEMPO group of the remaining ligand, a radical site is introduced into the complex. Subsequent collision-induced dissociation (CID) of the complex exhibits preferred cleavages that localize the site(s) of branching. The approach is illustrated with iso-, anteiso-, and isoprenoid branched-chain fatty acids and an intact glycerophospholipid and is applied to a mixture of branched- and straight-chain fatty acids derived from Bacillus subtilis.

Fatty acid isomerism: analysis and selected biological functions

The biological functions of fatty acids and the lipids in which they are esterified are determined by their chain length, double bond position and geometry and other structural motifs such as the presence of methyl branches. Unusual isomeric features in fatty acids of human foods such as conjugated double bonds or chain branching found in dairy products, some seeds and nuts, and marine foods potentially have important effects on human health. Recent advancements in identifying fatty acids with unusual double bond positions and pinpointing the position of methyl branches have empowered the study of their biological functions. We present recent advances in fatty acid structural elucidation by mass spectrometry in comparison with the more traditional methods. The double bond position can be determined by purely instrumental methods, specifically solvent-mediated covalent adduct chemical ionization (SM-CACI) and ozone induced dissociation (OzID), with charge inversion methods showing promise. Prior derivatization using the Paternò-Büchi (PB) reaction to yield stable structures that, upon collisional activation, yield the double bond position has emerged. The chemical ionization (CI) based three ion monitoring (MRM) method has been developed to simultaneously identify and quantify low-level branched chain fatty acids (BCFAs), unattainable by electron ionization (EI) based methods. Accurate identification and quantification of unusual fatty acid isomers has led to research progress in the discovery of biomarkers for cancer, diabetes, nonalcoholic fatty liver disease (NAFLD) and atherosclerosis. Modulation of eicosanoids, weight loss and the health significance of BCFAs are also presented. This review clearly shows that the improvement of analytical capacity is critical in the study of fatty acid biological functions, and stronger coupling of the methods discussed here with fatty acid mechanistic research is promising in generating more refined outcomes.

Dietary sources of branched-chain fatty acids and their biosynthesis, distribution, and nutritional properties

Branched-chain fatty acids (BCFAs) consist of a wide variety of fatty acids with alkyl branching of methyl group. The most common BCFAs are the types with one methyl group (mmBCFA) on the penultimate carbon (iBCFA) or the antepenultimate carbon (aiBCFA). Long-chain mmBCFAs are widely existing in animal fats, milks and are mostly derived from bacteria in the diet or animal digestive system. Recent studies show that BCFAs benefit human intestinal health and immune homeostasis, but the connection between their content, distribution in the human and their nutritional functions are not well established. In this paper, we reviewed BCFAs from various dietary sources focused on their molecular species. The BCFAs biosynthesis in bacteria, Caenorhabditis elegans, mammals and their distribution in human tissues are summarized. This paper also discusses the nutritional properties of BCFAs including influences on intestinal health, immunoregulatory effects, anti-carcinoma, and anti-obesity activities, by highlighting the most recent research progress.

Branched-Long-Chain Monomethyl Fatty Acids: Are They Hidden Gems?

Branched-long-chain monomethyl fatty acids (BLCFA) are consumed daily in significant amounts by humans in all stages of life. BLCFA are absorbed and metabolized in human intestinal epithelial cells and are not only oxidized for energy. Thus far, BLCFA have been revealed to possess versatile beneficial bioactivities, including cytotoxicity to cancer cells, anti-inflammation, lipid-lowering, reducing the risk of metabolic disorders, maintaining normal β cell function and insulin sensitivity, regulation of development, and mitigating cerebral ischemia/reperfusion injury. However, compared to other well-studied dietary fatty acids like eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), BLCFA has received disproportionate attention despite their potential importance. Here we outlined the major food sources, estimated intake, absorption, and metabolism in human cells, and bioactive properties of BLCFA with a focus on the bioactive mechanisms to advocate for an increased commitment to BLCFA investigations. Humans were estimated to absorb 6-5000 mg of dietary BLCFA daily from fetus to adult. Notably, iso-15:0 inhibited the growth of prostate cancer, liver cancer and T-cell non-Hodgkin lymphomas in rodent models at the effective doses of 35-105 mg/kg/day, 70 mg/kg/day, and 70 mg/kg/day, respectively. Feeding formula prepared with 20% w/w BLCFA mixture to neonatal rats with enterocolitis mitigated the intestine inflammation. Iso-15:0 at doses of 10, 40, and 80 mg/kg relieved brain ischemia/reperfusion injury in rats. In the future, it is crucial to conduct research to establish the epidemiology of BLCFA intake and their impacts on health outcomes in humans as well as to fully uncover the underlying mechanisms for their bioactivities.

Protect the Microbiome: Be HOLISTIC

The newborn who requires intensive care hospitalization is forced into an external environment that can negatively impact the developing microbiome. The NICU nurse has a unique role that affects, and may even protect, the development of the newborn microbiome through daily nursing care. The purpose of this article is to inform neonatal nurses regarding common nursing interventions that can positively or negatively impact the developing microbiome. Evidence-based practices are presented and bundled to describe their impact the neonatal microbiome.

Bacillus Subtilis (BG01-4TM) Improves Self-Reported Symptoms for Constipation, Indigestion, and Dyspepsia: A Phase 1/2A Randomized Controlled Trial

BACKGROUND

Functional gastrointestinal disorders (FGIDs) are common, difficult-to-manage conditions. Probiotics are emerging as a dietary component that influence gastrointestinal (GI) health. We conducted a double-blinded randomised controlled trial of a proprietary strain of deactivated Bacillus subtilis (BG01-4™) high in branched-chain fatty acids (BCFA) to treat self-reported FGID.

METHODS

Participants (n = 67) completed a four-week intervention of BG01-4™ (n = 34) or placebo (n = 33). The Gastrointestinal Symptom Rating Scale (GSRS) served as the outcome measure, collected prior to, at two weeks, and at four weeks after completion of the intervention.

RESULTS

At four weeks, one of three primary outcomes, constipation in the experimental group, was improved by 33% compared to placebo (15%); both other primary outcomes, Total GSRS and diarrhoea, were significantly improved in both the experimental and placebo groups (32%/26% and 20%/22%, respectively). The pre-planned secondary outcome, indigestion, was improved at four weeks (32%) but compared to the placebo (21%) was not significant (p = 0.079). Exploratory analysis, however, revealed that clusters for constipation (18% improvement, p < 0.001), indigestion (11% improvement, p = 0.04), and dyspepsia (10% improvement, p = 0.04) were significantly improved in the intervention group compared to the placebo.

CONCLUSIONS

These initial findings suggest that in people with self-reported FGID, BG01-4™ improves specific symptoms of constipation and related GI dysfunction. Longer-term confirmatory studies for this intervention are warranted.

TRIAL REGISTRATION

This study was registered prospectively (25 October 2021) at the Australian New Zealand Clinical Trials Registry (ACTRN12621001441808p).

The Low-FODMAP Diet, IBS, and BCFAs: Exploring the Positive, Negative, and Less Desirable Aspects-A Literature Review

The literature about the association of branched short-chain fatty acids (BCFAs) and irritable bowel syndrome (IBS) is limited. BCFAs, the bacterial products of the catabolism of branched-chain amino acids, are proposed as markers for colonic protein fermentation. IBS is a gastrointestinal disorder characterized by low-grade inflammation and intestinal dysbiosis. The low-FODMAP diet (LFD) has increasingly been applied as first-line therapy for managing IBS symptoms, although it decreases the production of short-chain fatty acids (SCFA), well known for their anti-inflammatory action. In parallel, high protein consumption increases BCFAs. Protein fermentation alters the colonic microbiome through nitrogenous metabolites production, known for their detrimental effects on the intestinal barrier promoting inflammation. Purpose: This review aims to explore the role of BCFAs on gut inflammation in patients with IBS and the impact of LFD in BCFAs production. Methods: A literature search was carried out using a combination of terms in scientific databases. Results: The included studies have contradictory findings about how BCFAs affect the intestinal health of IBS patients. Conclusions: Although evidence suggests that BCFAs may play a protective role in gut inflammation, other metabolites of protein fermentation are associated with gut inflammation. Further research is needed in order to clarify how diet protein composition and, consequently, the BCFAs are implicated in IBS pathogenesis or in symptoms management with LFD+.

Evaluation of Four Multispecies Probiotic Cocktails in a Human Colonic Fermentation Model

Bacteriotherapy represents an attractive approach for both prophylaxis and treatment of human diseases. However, combining probiotic bacteria in "cocktails" is underexplored, despite its potential as an alternative multi-target therapy. Herein, three-strain probiotic mixtures containing different combinations of Bacillus (Bc.) coagulans [ATB-BCS-042], Levilactobacillus (Lv.) brevis [THT 0303101], Lacticaseibacillus (Lc.) paracasei [THT 031901], Bacillus subtilis subsp. natto [ATB-BSN-049], Enterococcus faecium [ATB-EFM-030], and Bifidobacterium (Bf.) animalis subsp. lactis [THT 010802] were prepared. Four cocktails (PA: Bc. coagulans + Lv. brevis + Lc. paracasei, PB: Bc. subtilis subsp. natto + Lv. brevis + Lc. paracasei, PC: E. faecium + Lv. brevis + Lc. paracasei, PD: Bc. coagulans + Lv. brevis + Bf. animalis subsp. lactis) were tested using a short-term (72 h) simulation of the human colonic microbiota in a final dose of 6 × 109 CFU. All these probiotic mixtures significantly increased butyrate production compared to the parallel control experiment. PA and PB promoted a bifidogenic effect and facilitated lactobacilli colonization. Furthermore, reporter gene assays using the AhR_HT29-Lucia cell line revealed that fermentation supernatants from PA and PB notably induced AhR transactivity. Subsequent examination of the metabolic outputs of PA and PB in intestinal epithelial models using cell culture inserts suggested no significant impact on the transepithelial electrical resistance (TEER). Assessment of the expression of proinflammatory and anti-inflammatory cytokines, as well as AhR-related target genes in the Caco-2 cell monolayers indicated that PB's metabolic output upregulated most of the measured endpoints. This in vitro investigation evaluated the potential impact of four multispecies probiotic mixtures in the human colonic microbiota and identified a promising formulation comprising a combination of Bc. subtilis subsp. natto, Lv. brevis, and Lc. paracasei as a promising formulation for further study.

Fasting and non-fasting plasma levels of monomethyl branched chain fatty acids: Implications for maple syrup urine disease

The branched-chain amino acids (BCAA) leucine, valine, and isoleucine provide precursors for monomethyl branched-chain fatty acids (BCFA). Established reference ranges for BCFAs are lacking. In maple syrup urine disease (MSUD), a rare inborn error of BCAA metabolism, the endogen production is impaired and MSUD patients are treated with a low protein (low BCAA) diet. The protein restriction may affect the dietary intake of BCFA, depending on the dietary choices made. Patients with MSUD are prescribed a more or less protein-restricted diet depending on the severity of the disease. The combination of a protein-restricted diet and subsequent impaired endogenous synthesis may render MSUD patients sensitive to BCFA deficiency, with yet unknown implications. To investigate the possibility of lower circulatory BCFA levels in MSUD that favors dietary BCFA supplementation, we first established fasting-state reference ranges for selected BCFAs and saturated/unsaturated fatty acids in plasma. Then, the effect of fasting on BCFA levels was evaluated by comparing the distribution in a fasting versus a non-fasting cohort. To test the hypothesis that BCFA deficiency could contribute to MSUD pathophysiology, we recruited patients with intermittent, intermediate, and classical form of MSUD and analyzed the corresponding BCFA z-scores. None of the BCFA species had |z-scores| > 2 relative to the reference range. Our findings do not support the requirement of BCFA supplementation in MSUD patients. The origin of BCFAs is discussed. Impaired capacity to synthesize BCFA do not manifest as reduced plasma levels in MSUD, suggesting that endogenous synthesis is dispensable for plasma levels.

Association of circulating branched chain fatty acids with insulin sensitivity and beta cell function in the PROMISE cohort

Branched chain fatty acids (BCFAs) are mainly saturated fatty acids with a methyl branch on the penultimate or antepenultimate carbon atom. While BCFAs are endogenously produced via the catabolism of branched chain amino acids, the primary exogenous source of BCFAs in the human body is via the diet, including dairy products. Recently, BCFAs have been identified as having a potentially protective role in the etiology of cardiometabolic disorders although current literature is limited. We aimed to investigate the longitudinal associations of circulating BCFAs across four serum pools with insulin sensitivity, beta cell function, and glucose concentrations in the PROMISE Cohort. Estimates of insulin sensitivity were assessed using Matsuda's insulin sensitivity index (ISI) and the homeostasis model assessment of insulin sensitivity (HOMA2). Estimates of beta cell function were determined using the insulinogenic index divided by HOMA insulin resistance and the insulin secretion-sensitivity index-2 (ISSI-2). Baseline serum samples were analyzed for BCFAs using gas-chromatography flame ionization detection. Longitudinal associations were determined using generalized estimating equations. In the free fatty acid (FFA) pool, iso15:0 and anteiso15:0 were positively associated with logHOMA2 (iso15:0 logHOMA2-%S: β = 6.86, 95% CI: [1.64, 12.36], p < 0.05, anteiso15:0 logHOMA2-%S: β = 6.36, 95% CI: [0.63, 12.42], p < 0.05) while anteiso14:0 was inversely associated with measures of insulin sensitivity (iso14:0 logHOMA2-%S: β = -2.35, 95% CI: [-4.26, -0.40], p < 0.05, logISI: β = -2.30, 95% CI: [-4.32, -0.23], p < 0.05, anteiso14:0 logHOMA2-%S: β = -4.72, 95% CI: [-7.81, -1.52], p < 0.05, logISI: β = -6.13, 95% CI: [-9.49, -2.66], p < 0.01). Associations in other pools were less consistent. We identified the potential importance of specific BCFAs, specifically iso14:0, anteiso14:0, iso15:0, anteiso15:0, in cardiometabolic phenotypes underlying type 2 diabetes.

Attempts to limit sporulation in the probiotic strain Bacillus subtilis BG01-4TM through mutation accumulation and selection

The use of bacterial spores in probiotics over viable loads of bacteria has many advantages, including the durability of spores, which allows spore-based probiotics to effectively traverse the various biochemical barriers present in the gastrointestinal tract. However, the majority of spore-based probiotics developed currently aim to treat adults, and there is a litany of differences between the adult and infant intestinal systems, including the immaturity and low microbial species diversity observed within the intestines of infants. These differences are only further exacerbated in premature infants with necrotizing enterocolitis (NEC) and indicates that what may be appropriate for an adult or even a healthy full-term infant may not be suited for an unhealthy premature infant. Complications from using spore-based probiotics for premature infants with NEC may involve the spores remaining dormant and adhering to the intestinal epithelia, the out-competing of commensal bacteria by spores, and most importantly the innate antibiotic resistance of spores. Also, the ability of Bacillus subtilis to produce spores under duress may result in less B. subtilis perishing within the intestines and releasing membrane branched-chain fatty acids. The isolate B. subtilis BG01-4^TM is a proprietary strain developed by Vernx Biotechnology through accumulating mutations within the BG01-4^TM genome in a serial batch culture. Strain BG01-4^TM was provided as a non-spore-forming B. subtilis , but a positive sporulation status for BG01-4^TM was confirmed through in vitro testing and suggested that selection for the sporulation defective genes could occur within an environment that would select against sporulation. The durability of key sporulation genes was ratified in this study, as the ability of BG01-4^TM to produce spores was not eliminated by the attempts to select against sporulation genes in BG01-4^TM by the epigenetic factors of high glucose and low pH. However, a variation in the genes in isolate BG01-4-8 involved in the regulation of sporulation is believed to have occurred during the mutation selection from the parent strain BG01-4^TM. An alteration in selected sporulation regulation genes is expected to have occurred from BG01-4^TM to BG01-4-8, with BG01-4-8 producing spores within 24 h, ~48 h quicker than BG01-4^TM.

Monomethyl branched-chain fatty acids-a pearl dropped in the ocean

As an emerging group of bioactive fatty acids, monomethyl branched-chain fatty acids (mmBCFAs) have sparked the interest of many researchers both domestically and internationally. In addition to documenting the importance of mmBCFAs for growth and development, there is increasing evidence that mmBCFAs are highly correlated with obesity and insulin resistance. According to previous pharmacological investigations, mmBCFAs also exhibit anti-inflammatory effects and anticancer properties. This review summarized the distribution of mmBCFAs, which are widely found in dairy products, ruminants, fish, and fermented foods. Besides, we discuss the biosynthesis pathway in different species and detection methods of mmBCFAs. With the hope to unveil their mechanisms of action, we recapitulated detailed the nutrition and health benefits of mmBCFAs. Furthermore, this study provides a thorough, critical overview of the current state of the art, upcoming difficulties, and trends in mmBCFAs.

Monomethyl branched-chain fatty acids: Health effects and biological mechanisms

Branched-chain fatty acids (BCFA) are a group of lipids that are widely present in various organisms; they take part in numerous biochemical processes and affect multiple signaling pathways. However, BCFA are not well explored in terms of their effects on human health. Recently, they have been gaining interest, especially in relation to various human diseases. This review describes the occurrence of BCFA, their dietary sources, their potential health effects, and the current state of knowledge concerning their mechanism(s) of action. Many studies have been conducted so far in cellular and animal models, which reveal potent anti-cancer, lipid lowering, anti-inflammatory and neuroprotective actions. Research in humans is scarce. Therefore, further studies on animals and humans should be performed to confirm and expand these findings, and improve our understanding of the potential relevance of BCFA to human health and disease.

Hepatic and serum branched-chain fatty acid profile in patients with nonalcoholic fatty liver disease: A case-control study

OBJECTIVE

Alterations in the hepatic lipidome are a crucial factor involved in the pathophysiology of nonalcoholic fatty liver disease (NAFLD). The aim of this study was to evaluate the serum and hepatic profile of branched-chain fatty acids (BCFAs) in patients with different stages of NAFLD.

METHODS

This was a case-control study performed in 27 patients without NAFLD, 49 patients with nonalcoholic fatty liver, and 17 patients with nonalcoholic steatohepatitis, defined by liver biopsies. Serum and hepatic levels of BCFAs were analyzed by gas chromatography-mass spectrometry. The hepatic expression of genes involved in the endogenous synthesis of BCFAs was analyzed by real-time quantitative polymerase chain reaction (RT-qPCR).

RESULTS

A significant increase in hepatic BCFAs was found in subjects with NAFLD compared with those without NAFLD; no differences were observed in serum BCFAs between study groups. Trimethyl BCFAs, iso-BCFAs, and anteiso-BCFAs were increased in subjects with NAFLD (either nonalcoholic fatty liver or nonalcoholic steatohepatitis) compared with those without NAFLD. Correlation analysis showed a relationship between hepatic BCFAs and the histopathological diagnosis of NAFLD, as well as other histological and biochemical parameters related to this disease. Gene expression analysis in liver showed that the mRNA levels of BCAT1, BCAT2, and BCKDHA were upregulated in patients with NAFLD.

CONCLUSIONS

These results suggest that the increased production of liver BCFAs might be related to NAFLD development and progression.

Goat milk powder supplemented with branched-chain fatty acid: influence on quality and microstructure

BACKGROUND

Branched-chain fatty acid (BCFA) is effective in preventing and helping to treat neonatal necrotizing enterocolitis. It is essential to supplement goat-milk powder for formula-fed preterm infants with BCFA. In this study, the quality and microstructures of milk powders supplemented with different concentrations of BCFA were evaluated, using goat milk powder without BCFA as the control group (CG).

RESULTS

In comparison with the CG, goat milk powder supplemented with BCFA exhibited smaller fat globules and a significant drop in overall particle size. During 16 weeks of storage, BCFA-supplemented groups showed suitable moisture content and viscosity and good solubility. The BCFA also helped reduce the number of folds on the surface of the milk powder particles.

CONCLUSION

The findings of this study indicate that goat milk powders with BCFA exhibit differences in quality and microstructure in comparison with ordinary goat milk powder, which is relevant for the future development and application of BCFA in foods. © 2022 Society of Chemical Industry.

Effects of direct-fed Bacillus subtilis and Bacillus licheniformis on production performance and milk fatty acid profile in dairy cows

The aim of the study was to determine the effect of a Bacillus-based direct-fed microbial on performance of mid-lactating Holstein dairy cows and on their milk fatty acid composition. Six multiparous cows fitted with a rumen cannula were used in a randomized replicated crossover design. Cows received 200 g/d of either whey powder as a control or BioPlus 2B (Chr. Hansen), a commercial direct-fed microbial providing Bacillus subtilis and Bacillus licheniformis, representing a daily dose of 6.4 × 10¹¹ cfu, and using whey powder as a carrier. The 2 experimental periods lasted 14 d and were separated by a 7-d washout interval. Samples were collected on d 0, 13, and 14 of each period. Data from d 0 were used as covariate. Significance was declared at P ≤ 0.05 and tendency at 0.05 <P ≤ 0.10. There was a 10-fold increase in the relative concentration of bacteria from the Bacillus subtilis group in the rumen when feeding direct-fed Bacillus compared with control. Treatment did not affect ruminal pH, NH₃-N, or concentrations of acetate, propionate, and butyrate. However, direct-fed Bacillus increased ruminal concentrations of isovalerate and isobutyrate (tendency). Treatments did not affect lactation performance. Supplying direct-fed Bacillus enhanced milk relative concentration of anteiso 13:0 by 27.3% and of anteiso 15:0 by 6.5% and tended to increase concentrations of iso 14:0 (+41.8%) relative to control. When expressed on a yield basis, direct-fed Bacillus increased the secretion of anteiso 13:0 and decreased that of 11:0, 15:0, 17:0 (tendency), and cis-9 17:1. These variations, although limited in magnitude, indicate that milk branched-chain fatty acid composition is sensitive to ruminal microbiota modifications without changes in chemical composition of the diet.

Impact of Thin Meconium on Delivery and Early Neonatal Outcomes

Several reports regarding the effects of thin meconium on maternal and neonatal outcomes are contradictory. This study evaluated the risk factors and obstetrical outcomes during deliveries complicated with thin meconium. This retrospective cohort study included all women with a singleton pregnancy, who underwent trial of labor >24 weeks of gestation, in a single tertiary center, over a six-year period. Obstetrical, delivery, and neonatal outcomes were compared between deliveries with thin meconium (thin meconium group) to deliveries with clear amniotic fluid (control group). Included in the study were 31,536 deliveries. Among them 1946 (6.2%) were in the thin meconium group and 29,590 (93.8%) were controls. Meconium aspiration syndrome was diagnosed in eight neonates in the thin meconium group and in none of the controls (0.41%, p < 0.001). In multivariate logistic regression analysis, the following adverse outcomes were found to be independently associated with increased odds ratio (OR) for thin meconium: intrapartum fever (OR 1.37, 95% CI 1.1-1.7), instrumental delivery (OR 1.26, 95% CI 1.09-1.46), cesarean delivery for non-reassuring fetal heart rate (OR 2.0, 95% CI 1.68-2.46), and respiratory distress requiring mechanical ventilation (OR 2.06, 95% CI 1.19-3.56). Thin meconium was associated with adverse obstetrical, delivery, and neonatal outcomes that should receive extra neonatal care and alert the pediatrician.

Association of branched chain fatty acids with cardiometabolic disorders in humans: a systematic review

CONTEXT

Despite advances in treatments for cardiometabolic disorders such as type 2 diabetes mellitus and obesity, the increasing frequency of these conditions is of major clinical and public health concern. Therefore, primary prevention including diet and lifestyle approaches continues to play a key role in risk reduction. Meta-analyses of prospective cohort studies have documented inverse associations of dairy consumption with the incidence of different cardiometabolic disorders. Dairy is the largest dietary contributor of branched chain fatty acids (BCFAs), which have been suggested to not only serve as biomarkers of dairy consumption but may also have bioactive properties contributing to reducing the risk of cardiometabolic outcomes. To date, however, the literature on this topic has not been systematically reviewed.

OBJECTIVE

The aim here was to report the results of a systematic review of the association of BCFAs with cardiometabolic disorders in humans.

DATA SOURCES

Search terms were developed and run through the Ovid MEDLINE, Ovid Embase, and the Cochrane Library databases.

DATA EXTRACTION

Articles were selected on the basis of prespecified inclusion criteria and assessed for risk of bias by independent reviewers.

RESULTS

Four studies (n = 2 cross sectional; n = 1 randomized feeding trial and n = 1 pre-post study) were identified. Two studies reported significant inverse associations between serum BCFAs and insulin resistance, triglycerides and/or body mass index. One study identified an inverse association between adipose tissue monomethyl BCFAs and skeletal muscle insulin resistance. In contrast, the randomized feeding trial reported no significant differences to stool BCFA concentrations or body mass index in obese participants following assignment to fruit-vegetable or whole-grain diet groups compared with a refined-grain control group.

CONCLUSIONS

Current evidence suggests beneficial associations of circulating BCFAs with cardiometabolic risk phenotypes, although data in human participants are limited, indicating that additional research is required.

PROSPERO REGISTRATION NO

CRD42021224975.

Changes in milk fat globule physical properties and milk fatty acid composition throughout the lactation cycle of Laoshan goat

The objective of this study was to investigate the effect of lactation stage on the physical properties of milk fat globules (MFGs) and profiles of milk fatty acids (FAs) of milk from Laoshan dairy goats. Goat colostrum and milk samples were collected on days 1, 3, 30, 90, 150, and 240 postpartum. Milk fat content was found to significantly decrease during the first 90 d of lactation and increase thereafter as lactation progressed (P < 0.01). Average area particle size and volume particle size of MFGs showed trends similar to those of the milk fat content of goat milk with the extension of lactation, and the lowest levels were 2.39 μm and 3.97 μm on day 90, respectively (P < 0.01). The zeta-potential of MFGs significantly increased before 30 d of lactation, with a slight drop on day 90. It increased thereafter and tended to stabilize in the late stages of lactation (P < 0.01). The content of several saturated fatty acids (SFAs) (C10:0-C16:0) in early lactation, especially in colostrum, was lower than that in other stages of lactation (P < 0.05). Branched-chain fatty acids of the iso and anteiso series, including C13:0 anteiso, C15:0 anteiso, and C15:0 iso, were observed at high contents in mid-lactation goat milk (P < 0.01). As lactation progressed (3 d to 240 d), the content of SFAs significantly increased (P < 0.01), while the content of monounsaturated fatty acids and polyunsaturated fatty acids significantly decreased (P < 0.05). Furthermore, the content of C18:0 significantly increased during the first 30 d of lactation and decreased thereafter as lactation progressed (P < 0.01). Our results indicated that lactation stage has a pronounced effect on the physical properties of MFGs and the FA profiles of goat milk.

Microbial regulation of offspring diseases mediated by maternal-associated microbial metabolites

The microbiota plays a crucial role in individuals’ early and long-term health. Previous studies indicated that the microbial regulation of health may start before birth. As the in utero environment is (nearly) sterile, the regulation is probably be originated from maternal microbiota and mediated by their metabolites transferred across the placenta. After the birth, various metabolites are continuously delivered to offspring through human milk feeding. Meanwhile, some components, for example, human milk oligosaccharides, in human milk can only be fermented by microbes, which brings beneficial effects on offspring health. Hence, we speculated that human milk-derived metabolites may also play roles in microbial regulation. However, reports between maternal-associated microbial metabolites and offspring diseases are still lacking and sparsely distributed in several fields. Also, the definition of the maternal-associated microbial metabolite is still unclear. Thus, it would be beneficial to comb through the current knowledge of these metabolites related to diseases for assisting our goals of early prediction, early diagnosis, early prevention, or early treatment through actions only on mothers. Therefore, this review aims to present studies showing how researchers came to the path of investigating these metabolites and then to present studies linking them to the development of offspring asthma, type 1 diabetes mellitus, food allergy, neonatal necrotizing enterocolitis, or autism spectrum disorder. Potential English articles were collected from PubMed by searching terms of disease(s), maternal, and a list of microbial metabolites. Articles published within 5 years were preferred.

Identification of Monomethyl Branched-Chain Lipids by a Combination of Liquid Chromatography Tandem Mass Spectrometry and Charge-Switching Chemistries

While various mass spectrometric approaches have been applied to lipid analysis, unraveling the extensive structural diversity of lipids remains a significant challenge. Notably, these approaches often fail to differentiate between isomeric lipids─a challenge that is particularly acute for branched-chain fatty acids (FAs) that often share similar (or identical) mass spectra to their straight-chain isomers. Here, we utilize charge-switching strategies that combine ligated magnesium dications with deprotonated fatty acid anions. Subsequent activation of these charge inverted anions yields mass spectra that differentiate anteiso-branched- from straight-chain and iso-branched-chain FA isomers with the predictable fragmentation enabling de novo assignment of anteiso branch points. The application of these charge-inversion chemistries in both gas- and solution-phase modalities is demonstrated to assign the position of anteiso-methyl branch-points in FAs and, with the aid of liquid chromatography, can be extended to de novo assignment of additional branching sites via predictable fragmentation patterns as methyl branching site(s) move closer to the carboxyl carbon. The gas-phase approach is shown to be compatible with top-down structure elucidation of complex lipids such as phosphatidylcholines, while the integration of solution-phase charge-inversion with reversed phase liquid chromatography enables separation and unambiguous identification of FA structures within isomeric mixtures. Taken together, the presented charge-switching MS-based technique, in combination with liquid chromatography, enables the structural identification of branched-chain FA without the requirement of authentic methyl-branched FA reference standards.

Towards engineered yeast as production platform for capsaicinoids

Capsaicinoids are bioactive alkaloids produced by the chili pepper fruit and are known to be the most potent agonists of the human pain receptor TRPV1 (Transient Receptor Potential Cation Channel Subfamily V Member 1). They are currently produced by extraction from chili pepper fruit or by chemical synthesis. Transfer of the biosynthetic route to a microbial host could enable more efficient capsaicinoid production by fermentation and may also enable the use of synthetic biology to create a diversity of new compounds with potentially improved properties. This review summarises the current state of the art on the biosynthesis of capsaicinoid precursors in baker's yeast, Saccharomyces cerevisiae, and discusses bioengineering strategies for achieving total synthesis from sugar.

Early life host-microbe interactions in skin

Our skin is the interface through which we mediate lifelong interactions with our surrounding environment. Initial development of the skin's epidermis, adnexal structures, and barrier function is necessary for normal cutaneous microbial colonization, immune development, and prevention of disease. Early life microbial exposures can have unique and long-lasting impacts on skin health. The identity of neonatal skin microbes and the context in which they are first encountered, i.e., through a compromised skin barrier or in conjunction with cutaneous inflammation, can have additional short- and long-term health consequences. Here, we discuss key attributes of infant skin and endogenous and exogenous factors that shape its relationship to the early life cutaneous microbiome, with a focus on their clinical implications.

Fatty acid profile characterization in colostrum, transition milk, and mature milk of primi- and multiparous cows during the first week of lactation

The specific fatty acid (FA) profile of colostrum may indicate a biological requirement for neonatal calves. The objective of this study was to characterize the FA profile and yields in colostrum, transition milk, and mature milk in primiparous (PP) and multiparous (MP) cows. Colostrum was milked from 10 PP and 10 MP Holstein cows fed the same pre- and postpartum rations. Milkings (M) 2 to 5 and 12 were respectively termed transition and mature milk. Overall, short-chain FA (C4:0 and C6:0) were 61 and 50% lower in colostrum than mature milk, respectively. A parity by milking interaction was also present, with higher C4:0 for PP cows at M2 and for MP cows at M12. Additionally, higher concentrations of C6:0 were present for PP cows at M2 through M4 and for MP cows at M12. Palmitic (C16:0) and myristic (C14:0) acids were 38% and 19% higher in colostrum than mature milk, respectively. However, total saturated FA remained relatively stable. Branched-chain FA were 13% lower in colostrum than mature milk and higher in PP than MP cows throughout the milking period. The proportion of trans-monounsaturated FA (MUFA) was 72% higher in PP cows throughout the milking period, as well as 13% lower in colostrum than mature milk. In contrast, cis-MUFA and total MUFA were not affected by milking nor parity. Linoleic acid (LA) was 25% higher in colostrum than transition and mature milks, but α-linolenic acid (ALA) did not differ. Consequently, the ratio of LA to ALA was 29% higher in colostrum than mature milk and 33% higher in MP cows. Linoleic acid was also 15% higher in MP cows, whereas ALA was 15% higher in PP cows. Conjugated linoleic acid (CLA, cis-9,trans-11) was 2.7-fold higher in PP cows, and no differences between colostrum and mature milk were detected. Overall, polyunsaturated FA (PUFA) from the n-6 and n-3 series were over 40% higher in colostrum compared with transition and mature milk. Milking by parity interactions were present for arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and total n-3 PUFA, translating to higher proportions in PP cows in M1 to M3, whereas proportions remained relatively stable throughout the milking period in MP cows. Despite increasing milk yields throughout the subsequent milkings, higher yields of EPA, ARA, DPA, and DHA were present in colostrum than in mature milk. Greater proportions and yields of n-3 and n-6 FA in colostrum may translate to specific requirements for newborn calves. Differences were also observed between PP and MP cows and may reflect different nutrient requirements and partitioning.

Content of Health-Promoting Fatty Acids in Commercial Sheep, Cow and Goat Cheeses

The study aimed to examine samples of different market original sheep cow and goat cheeses, in respect of the content and profile of FA with special emphasis on health-promoting FA. The content of fatty acids in the examined cheeses was highly differentiated and depended on the sort and type of cheese. The content of fatty acid groups in milk fat varied within the limits: SFA, 55.2–67.2%; SCSFA, 10.9–23.4%; BCFA, 1.6–2.9%; MUFA, 15.2–23.4%; PUFA, 1.9–4.3%; trans-MUFA, 1.8–6.0%; and CLA, 1.0–3.1%. From among the examined cheeses, the seasonal sheep cheeses (Oscypek) and mountain cow cheeses were characterized by the highest content of health-promoting fatty acids. The content of health-promoting fatty acids in the fat fraction of these cheeses was CLA 2.1–3.1%, trans-MUFA 3.5–6%, BCFA 2.7–2.9%, and SCSFA 12–18%.

Localization of Intrachain Modifications in Bacterial Lipids Via Radical-Directed Dissociation

Intrachain modifications of membrane glycerophospholipids (GPLs) due to formation of the carbon-carbon double bond (C═C), cyclopropane ring, and methyl branching are crucial for bacterial membrane homeostasis. Conventional collision-induced dissociation (CID) of even-electron ions of GPL favors charge-directed fragmentation channels, and thus little structurally informative fragments can be detected for locating intrachain modifications. In this study, we report a radical-directed dissociation (RDD) approach for characterization of the intrachain modifications within phosphoethanolamines (PEs), a major lipid component in bacterial membrane. In this method, a radical precursor that can produce benzyl or pyridine methyl radical upon low-energy CID at high efficiency is conjugated onto the amine group of PEs. The carbon-centered radical ions subsequently initiate RDD along the fatty acyl chain, producing fragment patterns key to the assignment and localization of intrachain modifications including C═C, cyclopropane rings, and methyl branching. Besides intrachain fragmentation, RDD on the glycerol backbone produces fatty acyl loss as radicals, allowing one to identify the fatty acyl chain composition of PE. Moreover, RDD of lyso-PEs produces radical losses for distinguishing the sn-isomers. The above RDD approach has been incorporated onto a liquid chromatography-mass spectrometry workflow and applied for the analysis of lipid extracts from Escherichia coli and Bacillus subtilis.

Fatty acid profile characterization in colostrum, transition milk, and mature milk of primi- and multiparous cows during the first week of lactation

The specific fatty acid (FA) profile of colostrum may indicate a biological requirement for neonatal calves. The objective of this study was to characterize the FA profile and yields in colostrum, transition milk, and mature milk in primiparous (PP) and multiparous (MP) cows. Colostrum was milked from 10 PP and 10 MP Holstein cows fed the same pre- and postpartum rations. Milkings (M) 2 to 5 and 12 were respectively termed transition and mature milk. Overall, short-chain FA (C4:0 and C6:0) were 61 and 50% lower in colostrum than mature milk, respectively. A parity by milking interaction was also present, with higher C4:0 for PP cows at M2 and for MP cows at M12. Additionally, higher concentrations of C6:0 were present for PP cows at M2 through M4 and for MP cows at M12. Palmitic (C16:0) and myristic (C14:0) acids were 16% and 27% higher in colostrum than mature milk, respectively. However, total saturated FA remained relatively stable. Branched-chain FA were 13% lower in colostrum than mature milk and higher in PP than MP cows throughout the milking period. The proportion of trans-monounsaturated FA (MUFA) was 42% higher in PP cows throughout the milking period, as well as 15% lower in colostrum than mature milk. In contrast, cis-MUFA and total MUFA were not affected by milking nor parity. Linoleic acid (LA) was 13% higher in colostrum than transition and mature milks, but α-linolenic acid (ALA) did not differ. Consequently, the ratio of LA to ALA was 23% higher in colostrum than mature milk and 25% higher in MP cows. Linoleic acid was also 13% higher in MP cows, whereas ALA was 15% higher in PP cows. Conjugated linoleic acid (CLA, cis-9,trans-11) was 63% higher in PP cows, and no differences between colostrum and mature milk were detected. Overall, polyunsaturated FA (PUFA) from the n-6 and n-3 series were over 25% higher in colostrum compared with transition and mature milk. Milking by parity interactions were present for arachidonic acid (ARA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), and total n-3 PUFA, translating to higher proportions in PP cows in M1 to M3, whereas proportions remained relatively stable throughout the milking period in MP cows. Despite increasing milk yields throughout the subsequent milkings, higher yields of EPA, ARA, DPA, and DHA were present in colostrum than in mature milk. Greater proportions and yields of n-3 and n-6 FA in colostrum may translate to specific requirements for newborn calves. Differences were also observed between PP and MP cows and may reflect different nutrient requirements and partitioning.

Profiling of branched-chain fatty acids via nitroxide radical-directed dissociation integrated on an LC-MS/MS workflow

By coupling O-benzylhydroxylamine derivatization and tandem mass spectrometry, nitroxide radical-induced dissociation can be initiated via collisional activation which enables the analysis of methyl branching(s) in fatty acids.

The Role of Dietary Fats in the Development and Prevention of Necrotizing Enterocolitis

Necrotizing enterocolitis (NEC) is a significant cause of mortality and morbidity in preterm infants. The pathogenesis of NEC is not completely understood; however, intestinal immaturity and excessive immunoreactivity of intestinal mucosa to intraluminal microbes and nutrients appear to have critical roles. Dietary fats are not only the main source of energy for preterm infants, but also exert potent effects on intestinal development, intestinal microbial colonization, immune function, and inflammatory response. Preterm infants have a relatively low capacity to digest and absorb triglyceride fat. Fat may thereby accumulate in the ileum and contribute to the development of NEC by inducing oxidative stress and inflammation. Some fat components, such as long-chain polyunsaturated fatty acids (LC-PUFAs), also exert immunomodulatory roles during the early postnatal period when the immune system is rapidly developing. LC-PUFAs may have the ability to modulate the inflammatory process of NEC, particularly when the balance between n3 and n6 LC-PUFAs derivatives is maintained. Supplementation with n3 LC-PUFAs alone may have limited effect on NEC prevention. In this review, we describe how various fatty acids play different roles in the pathogenesis of NEC in preterm infants.

Monomethyl branched-chain fatty acid mediates amino acid sensing upstream of mTORC1

Animals have developed various nutrient-sensing mechanisms for survival under fluctuating environmental conditions. Although extensive cell-culture-based analyses have identified diverse mediators of amino acid sensing upstream of mTOR, studies using animal models to examine intestine-initiated amino acid sensing mechanisms under specific physiological conditions are lacking. Here, we developed a Caenorhabditis elegans model to examine the impact of amino acid deficiency on development. We discovered a leucine-derived monomethyl branched-chain fatty acid and its downstream metabolite, glycosphingolipid, which critically mediates the overall amino acid sensing by intestinal and neuronal mTORC1, which in turn regulates postembryonic development at least partly by controlling protein translation and ribosomal biogenesis. Additional data suggest that a similar mechanism may operate in mammals. This study uncovers an amino-acid-sensing mechanism mediated by a lipid biosynthesis pathway.

Branched-chain fatty acids in the vernix caseosa and meconium of infants born at different gestational ages

The functional lipid components found in breast milk, vernix caseosa, and meconium are Branched-chain Fatty Acids (BCFA). The goal of this study was to establish the existence of BCFA in vernix and meconium in infants born at different gestational ages. TLC plates and GC-MS were examined for the lipids in vernix caseosa and meconium. The results indicated that there were nine BCFA in vernix caseosa, including iso-12:0, anteiso-13:0, iso-14:0, iso-15:0, anteiso-15:0, iso-16:0, anteiso-17:0, iso-18:0, and iso-20:0. Five BCFA (iso-12:0, anteiso-13:0, iso-14:0, iso-15:0, and anteiso-15:0) were not contained in the meconium, suggesting that some of the BCFA may be digested and consumed by infants. In the vernix caseosa, the content of BCFA in triacylglycerol (TAG) and free fatty acid (FFA) was 15.59% and 11.82%, respectively. The vernix caseosa's wax ester fraction contained the highest content of BCFA, reaching up to 16.81%. The carbon chain length of fatty acids (FA) ranged from 12 to 24 in the vernix caseosa and 14 to 22 in meconium samples. The gestational age was likely to affect BCFA concentrations, with the vernix caseosa and meconium BCFA content being significantly higher in full-term infants than in preterm infants (p < .001). Further research is required into the relationship between BCFA and gut microbiotas.

Characterization of Fatty Acyl Modifications in Phosphatidylcholines and Lysophosphatidylcholines via Radical-Directed Dissociation

Phosphatidylcholines (PCs) are the major structural components of the plasma membrane of mammalian cells, while lysophosphatidylcholines (LPCs) are critical intermediates in lipid remodeling. Conventional tandem mass spectrometric (MSⁿ) methods via collision-induced dissociation (CID) are blind to intrachain modifications such as the location of the carbon-carbon double bond (C═C) and methyl branching point. In this study, we demonstrate that almost complete structural information can be inferred from a single MS² CID spectrum of the bicarbonate anion adducts of PC or LPC ([M + HCO₃]^-), including the identity of the headgroup, composition of fatty acyl chains, their sn-positions, the location of C═C, and the point of methyl branching in fatty acyls. We have integrated this MS² CID method onto liquid chromatography for the analysis LPCs in human plasma, revealing the existence of multiple sn-isomers, branched chain isomers, and C═C location isomers of LPC.

Characterization of fecal branched-chain fatty acid profiles and their associations with fecal microbiota in diarrheic and healthy dairy calves

Branched-chain fatty acids (BCFA) have recently been reported to play a role in human gut health during early life. However, little information is available on the fecal BCFA profiles in young ruminants and whether they are associated with the development of neonatal calf diarrhea. The objectives of this study were to (1) characterize BCFA profiles in feces collected from young calves, (2) compare the fecal BCFA composition between diarrheic and nondiarrheic dairy calves, and (3) explore the potential relationships between BCFA and microbiota in the feces. A total of 32 male Holstein dairy calves (13 ± 3 d old) with the same diet management were grouped as diarrheic (n = 16) or healthy (n = 16) based on fecal score (determined by liquid fecal consistency with some solid particles); diarrhea cases were defined as fecal score ≥2 for at least 2 d. Fecal samples were collected on the seventh day after calf arrival, and the fecal BCFA and microbial profiles were assessed using gas chromatograph and amplicon sequencing, respectively. In total, 7 BCFA were detected in the feces of all dairy calves; however, the concentrations of fecal BCFA differed between diarrheic and nondiarrheic calves. Specifically, the concentrations of iso-C16:0, iso-C17:0, anteiso-C17:0, and total even-chain BCFA were significantly higher in the feces of diarrheic calves. When the associations between BCFA and bacteria were studied, the relative abundance of Eggerthella was positively correlated with the concentrations of iso-C16:0 (ρ = 0.67), iso-17:0 (ρ = 0.77), anteiso-C17:0 (ρ = 0.73), and iso-C18:0 (ρ = 0.65), whereas the relative abundance of Subdoligranulum was positively correlated with the concentrations of iso-C14:0 (ρ = 0.62), iso-C15:0 (ρ = 0.78), and anteiso-C15:0 (ρ = 0.63). Use of random forest algorithm showed that BCFA such as anteiso-C15:0, iso-C16:0, iso-C17:0, iso-C18:0, and total even-chain BCFA could be used as biomarkers to differentiate diarrheic calves from healthy ones. Our findings generated fundamental knowledge on the potential roles of BCFA in neonatal calf gut health. Follow-up studies with larger animal populations are warranted to validate the feasibility of using BCFA as indicators of health status in neonatal calves.

Very Long-Chain Branched-Chain Fatty Acids in Chia Seeds: Implications for Human Use

Dairy and fermented foods are common sources of dietary branched-chain fatty acids (BCFA) of chain lengths C13-C18 serving a putative prebiotic role and a component of human integument. Few studies have reported on nonfermented plant-derived BCFA in human diets or cosmetics. A three-ion monitoring method was adapted to confirm branch position of ultratrace (<0.01%, w/w) BCFA. We identified chia as a new source of BCFA with C15-C35 chain lengths. Surprisingly, even-numbered very long-chain BCFA (VLC BCFA), anteiso-22:0, anteiso-24:0, and anteiso-26:0 were unequivocally identified in natural products for the first time. Plant-derived BCFA are predominantly anteiso, in contrast with similar iso and anteiso levels in ruminant and fermented foods. Chia seeds contain 0.4% BCFA, w/w of total fatty acids, or 32 mg BCFA in a food serving, surpassing other plant oils. Topical administration of chia seed oil containing VLC BCFA may have a role in skin and hair functionality.

Short communication: Odd-chain and branched-chain fatty acid concentrations in bovine colostrum and transition milk and their stability under heating and freezing treatments

Although odd-chain fatty acids (OCFA) and branched-chain fatty acids (BCFA) are found in bovine milk and have some positive influences on human and animal health, their concentrations in bovine colostrum and transition milk have not been reported. In this study, we reported the OCFA and BCFA concentrations in colostrum and transition milk and their stability after heating or freezing treatments (or both), which are processes commonly applied in dairy calf management. Milk samples were collected from 12 Holstein dairy cows (6 primiparous and 6 multiparous) at the first milking (colostrum), fifth milking (transition milk), and ninth milking (mature milk) after calving, respectively, and were used for fatty acid analysis using gas chromatography. The sum concentration of OCFA and BCFA (termed OBCFA) was 134 mg/100 g of milk in the colostrum, which was 24% and 35% lower than that in the transition milk and mature milk, respectively. Among these fatty acids detected, C15:0 and C17:0 were the top 2 abundant fatty acids in all milk types, accounting for 20 to 25% and 21 to 24% of the total concentration of OBCFA, respectively. Additionally, anteiso-C17:0 was the most abundant BCFA, followed by iso-C17:0, anteiso-C15:0, iso-C16:0, iso-C15:0, iso-C18:0, and iso-C14:0 in 3 types of milk. Significant interactions between milk type and cow parity were observed for all OCFA and BCFA concentrations. The milk samples were also treated with heating (at 65°C for 60 min), freezing (at -20°C for 30 d), and heating and freezing (at 65°C for 60 min and then at -20°C for 30 d), and milk OCFA and BCFA concentrations were similar between these treatments. In conclusion, the OBCFA concentration was lower in colostrum, compared with transition and mature milks, and it remained stable after heating and freezing treatments.

Saturated Fats and Health: A Reassessment and Proposal for Food-Based Recommendations: JACC State-of-the-Art Review

The recommendation to limit dietary saturated fatty acid (SFA) intake has persisted despite mounting evidence to the contrary. Most recent meta-analyses of randomized trials and observational studies found no beneficial effects of reducing SFA intake on cardiovascular disease (CVD) and total mortality, and instead found protective effects against stroke. Although SFAs increase low-density lipoprotein (LDL) cholesterol, in most individuals, this is not due to increasing levels of small, dense LDL particles, but rather larger LDL particles, which are much less strongly related to CVD risk. It is also apparent that the health effects of foods cannot be predicted by their content in any nutrient group without considering the overall macronutrient distribution. Whole-fat dairy, unprocessed meat, and dark chocolate are SFA-rich foods with a complex matrix that are not associated with increased risk of CVD. The totality of available evidence does not support further limiting the intake of such foods.

Gas Chromatography Chemical Ionization Mass Spectrometry and Tandem Mass Spectrometry for Identification and Straightforward Quantification of Branched Chain Fatty Acids in Foods

Fatty acid analysis of food lipids containing branched chain fatty acids (BCFAs) are complex because of unavoidable gas chromatography (GC) co-elution. We demonstrate a method for convenient quantitative GC coupled to novel solvent-mediated chemical ionization (CI) mass spectrometry (MS) that enables resolution of co-eluting peaks by mass. The relevant masses yield uniform responses for C_14-20 normal fatty acids and BCFAs, eliminating the need for rare purified BCFA standards essential for unpredictable responses, as for electron ionization (EI). CI-tandem mass spectrometry analysis of MH⁺ yields fragments characteristic of the branch position. Application of the measurement to BCFAs in salami samples demonstrates consistent results for the novel method and EI-MS. A higher proportion of C_17-18 BCFAs was found in beef compared to milkfat, possibly indicative of fatty acid elongation, endogenous in the beef animal. This method enables straightforward structure elucidation and quantification of food BCFAs and similar chain length normal fatty acids without purified standards.

Effect of Rearing System on the Straight and Branched Fatty Acids of Goat Milk and Meat of Suckling Kids

Goat meat is considered healthy because it has fewer calories and fat than meat from other traditional meat species. It is also rich in branched chain fatty acids that have health advantages when consumed. We studied the effects of maternal milk and milk replacers fed to suckling kids of four breeds on the straight and branched fatty acid compositions of their muscle. In addition, the proximal and fatty acid compositions of colostrum and milk were studied. Goat colostrum had more protein and fat and less lactose than milk. Goat milk is an important source of healthy fatty acids such as C18:1 c9 and C18:2 n–6. Suckling kid meat was also an important source of C18:1c9. Dairy goat breeds had higher percentages of trans monounsaturated fatty acids (MUFAs) and most of the C18:1 isomers but lower amounts of total MUFAs than meat breeds. However, these dairy kids had meat with a lower percentage of conjugated linoleic acid (CLA) than meat kids. The meat of kids fed natural milk had higher amounts of CLA and branched chain fatty acids (BCFAs) and lower amounts of n–6 fatty acids than kids fed milk replacers. Both milk and meat are a source of linoleic, α-linolenic, docosahexaenoic, eicosapentaenoic and arachidonic fatty acids, which are essential fatty acids and healthy long-chain fatty acids.

Sex- and Age-Related Metabolic Characteristics of Serum Free Fatty Acids in Healthy Chinese Adults

Free fatty acids (FFAs), also named nonesterified fatty acids, largely originate from the lipolysis of triacylglycerol stored in adipose tissue. Despite extensive research on sex- and age-dependent effects on lipolysis and lipid mobilization of adipose tissue, the primary differences in the metabolic characteristics of circulating FFAs among normal-weight healthy men and women during aging are still unclear. Here, we measured the concentrations of 45 FFAs in fasting sera of two Chinese community-based studies consisting of 201 metabolically healthy normal-weight adults to ascertain the associations of sex and age with FFA compositions and their upstream and downstream relations. Results showed greater conversions toward n-3 polyunsaturated fatty acids of docosahexaenoic acid and n-6 of docosapentaenoic acid from their precursors in women than in men. Meanwhile, there were significantly positive correlations between the concentrations of a panel of saturated fatty acids with straight chain or branched chain and age in women, whereas no association was found in men. These findings highlight that sex and age should be considered as the potential confounding factors in assessing the risk for metabolic disturbance using FFA biomarkers.

Branched chain fatty acid composition of yak milk and manure during full-lactation and half-lactation

BACKGROUND

Branched chain fatty acids (BCFA) are bioactive food compounds and are well known to be essential components of human, cow and caprine milk. In Qinghai-Tibet plateau, yaks are domesticated in large numbers and their milk in addition to meat are commercially important to millions of Tibetans and Chinese.

OBJECTIVE

We tested the hypotheses that concentrations of BCFA in yak milk and manure differ between lactation periods and evaluated gene expression levels of certain genes involved in the biosynthesis and elongation of fatty acids.

DESIGN

Fresh milk and manure were collected from each yak and their fatty acid compositions compared with emphasis on BCFA.

PARTICIPANTS/SETTING

Yak milk and manure samples from the full lactation (October, 2015) and half lactation periods (March, 2016) were collected and BCFA levels were analyzed in detail by GC-FID and structures verified by GC-EI-MS/MS. Gene expression studies were carried out by semi-quantitative real time PCR method.

STATISTICAL ANALYSES PERFORMED

The difference between full lactation and half lactation was tested using student's t-test. Linear regression model was modelled in Excel and its significance was tested by ANOVA. Statistical significance was determined by performing student's t-test for gene expression studies.

RESULTS

BCFA ranged from 3-6% of total fatty acids in yak milk samples. The half-lactation yak milk contained higher levels of BCFA (5.29 ± 0.53) than the full-lactation milk (4.00 ± 0.46). The total BCFA in yak manure was found to be 14.67 ± 1.21, high in anteiso-15:0 and anteiso-17:0. ELOVL1 enzyme involved in the elongation of saturated C18 to C26 acyl-CoA substrates and MCAT enzyme involved in the transfer of a malonyl group to the mitochondrial acyl carrier protein are significantly upregulated in full-lactation milk.

CONCLUSIONS

BCFA in yak manure especially anteiso BCFA are positively correlated with yak milk from the same animal, indicating that these BCFA come from dietary sources. Yak milk delivers 777 mg BCFA compared to 158 mg per cup of whole U.S. dairy milk. QTP herders known to consume up to 2 kg of yak yogurt take in an estimated 3,500-5,000 mg BCFA per day. We conclude that BCFA intake for yak milk consumers is among the highest known in the world, higher when drawn from half lactating yaks.

Combining Charge-Switch Derivatization with Ozone-Induced Dissociation for Fatty Acid Analysis

The specific positions of carbon-carbon double bond(s) within an unsaturated fatty acid exert a significant effect on the physical and chemical properties of the lipid that ultimately inform its biological function(s). Contemporary liquid chromatography-mass spectrometry (MS) strategies based on electrospray ionization coupled to tandem MS can easily detect fatty acyl lipids but generally cannot reveal those specific site(s) of unsaturation. Herein, we describe a novel and versatile workflow whereby fatty acids are first converted to fixed charge N-(4-aminomethylphenyl)pyridinium (AMPP) derivatives and subsequently subjected to ozone-induced dissociation (OzID) on a modified triple quadrupole mass spectrometer. The AMPP modification enhances the detection of fatty acids introduced by direct infusion. Fragmentation of the derivatized fatty acids also provides diagnostic fragment ions upon collision-induced dissociation that can be targeted in precursor ion scans to subsequently trigger OzID analyses in an automated data-dependent workflow. It is these OzID analyses that provide unambiguous assignment of carbon-carbon double bond locations in the AMPP-derivatized fatty acids. The performance of this analysis pipeline is assessed in profiling the patterns of unsaturation in fatty acids within the complex biological secretion vernix caseosa. This analysis uncovers significant isomeric diversity within the fatty acid pool of this sample, including a number of hitherto unreported double bond positional isomers that hint at the activity of potentially new metabolic pathways.

Iso- but Not Anteiso-Branched Chain Fatty Acids Exert Growth-Inhibiting and Apoptosis-Inducing Effects in MCF-7 Cells

The present study compared the growth-inhibitory effects of four common branched chain fatty acids (BCFAs) found in beef and dairy fats including iso 15:0, anteiso 15:0, iso 17:0, and anteiso 17:0. MCF-7 human breast cancer cells were exposed for 72 h to media containing increasing doses (50 to -400 μM) of the four BCFA. Cell viability was not affected by any of the BCFA treatments at doses less than 200 μM. Culturing cells with 200 μM of iso-15:0 or iso-17:0 reduced cell viability by 27 ± 2.8 and 43 ± 8.3% at 24 h, 35 ± 4.6 and 49 ± 9.1% at 48 h, and 44 ± 6.8 and 57 ± 8.8% at 72 h posttreatment. In contrast, culturing cells with 200 μM of anteiso-15:0 or anteiso-17:0 did not affect cell viability for any durations tested. The incorporation of iso 15:0 and iso 17:0 into cells (19.1 ± 1.3 and 21.2 ± 1.4 μmol/mg protein, respectively) was greater (P < 0.01) than that of anteiso 15:0 and anteiso 17:0 (11.8 ± 0.7 and 13.8 ± 0.8 μmol/mg protein, respectively). Iso-15:0 and iso-17:0 downregulated (P < 0.01) the expression of antiapoptotic Bcl-2 (0.71 ± 0.6-fold and 0.64 ± 0.09-fold, respectively) and upregulated (P < 0.01) the expression of proapoptotic Bax (1.72 ± 0.14-fold and 2.15 ± 0.24-fold, respectively) compared to the control, whereas their corresponding anteiso isomers did not affect the expression of any apoptosis-related genes. Our findings suggest that the branching structure influences anticarcinogenic effects of BCFAs, with iso being more potent than anteiso.

Biology of the vernix caseosa: A review

The vernix caseosa is a complex membranous structure comprising 80% water, 10% protein, and 10% lipids including barrier lipids such as ceramides, free fatty acids, phospholipids and cholesterol, synthesized partly by fetal sebaceous glands during the last trimester of pregnancy in an antero-posterior and dorsoventral manner. Because of its lipid content, vernix is hydrophobic and protects the skin from excessive water exposure during the development of the stratum corneum. The vernix caseosa has various functions during fetal transition from an intrauterine to an extrauterine environment, including lubrication of the birth canal during parturition, barrier function to prevent water loss, temperature regulation, for innate immunity and for intestinal development. This review discusses the evidence supporting the prenatal and postnatal functions of vernix caseosa, along with its structure, composition, and physical and biological characteristics. Understanding the biology of the vernix may facilitate improved care of preterm infants immediately post-partum.