Simultaneous extraction and quantitative analysis of S-Methyl-l-Cysteine Sulfoxide, sulforaphane and glucosinolates in cruciferous vegetables by liquid chromatography mass spectrometry.

Sulfur containing compounds including glucosinolates (GLS), sulforaphane (SFN) and S-methyl-l-cysteine sulfoxide (SMCSO) have been proposed to be partly responsible for the beneficial health effects of cruciferous vegetables. As such, greater understanding of their measurements within foods is important to estimate intake in humans and to inform dietary intervention studies. Herein is described a simple and sensitive method for simultaneous analysis of 20 GLS, SFN and SMCSO by liquid chromatography mass spectrometry. Analytes were effectively retained and resolved on an Xbridge C18 column. Detection can be achieved using high resolution or unit resolution mass spectrometry; the latter making the method more applicable to large studies. Quantitative analysis using calibration standards was demonstrated for 10 GLS, SFN and SMCSO. A further 10 GLS were tentatively identified using high resolution mass spectrometry. The use of surrogate GLS standards was shown to be unreliable, with closely related GLS displaying significantly different ionisation efficiencies.

Lipidomic features of honey bee and colony health during limited supplementary feeding.

Honey bee nutritional health depends on nectar and pollen, which provide the main source of carbohydrates, proteins and lipids to individual bees. During malnutrition, insect metabolism accesses fat body reserves. However, this process in bees and its repercussions at the colony level are poorly understood. Using untargeted lipidomics and gene expression analysis, we examined the effects of different feeding treatments (starvation, sugar feeding and sugar + pollen feeding) on bees and correlated them with colony health indicators. We found that nutritional stress led to an increase in unsaturated triacylglycerols and diacylglycerols, as well as a decrease in free fatty acids in the bee fat body. Here, we hypothesise that stored lipids are made available through a process where unsaturations change lipid's structure. Increased gene expression of three lipid desaturases in response to malnutrition supports this hypothesis, as these desaturases may be involved in releasing fatty acyl chains for lipolysis. Although nutritional stress was evident in starving and sugar-fed bees at the colony and physiological level, only starved colonies presented long-term effects in honey production.

La salud nutricional de la abeja melífera depende del consumo de néctar y polen, que proporcionan la principal fuente de carbohidratos, proteínas y lípidos. En un estado de desnutrición, el metabolismo de los insectos accede a las reservas del cuerpo graso. Sin embargo, en la abeja melífera, este proceso y sus repercusiones a nivel de la colonia, no se han comprendido con claridad. Utilizando lipidómica global y análisis de expresión genética, examinamos los efectos de diferentes tratamientos alimenticios en las abejas (inanición, únicamente azúcar y azúcar + polen) y los correlacionamos con indicadores de salud de la colonia. Encontramos un aumento en triacilgliceroles y diacilgliceroles insaturados y una disminución en los ácidos grasos libres en el cuerpo graso de abejas desnutridas. Hipotetizamos que estas insaturaciones en los lípidos modifican su estructura, tornándolos accesibles. Respaldamos esta hipótesis con la elevada expresión genética observada en tres desaturasas de lípidos durante desnutrición. Estas desaturasas podrían estar involucradas en la liberación de cadenas de ácidos grasos para la lipólisis. El estrés nutricional fue evidente tanto en abejas y colonias en estado de inanición y alimentadas con azúcar. Sin embargo, únicamente las colonias en estado de inanición presentaron efectos negativos a largo plazo en la producción de miel.

Effect of fire on characteristics of dissolved organic matter in forested catchments in the Mediterranean biome: A review.

Fires in forested catchments pose a water contamination risk from fire-derived dissolved organic matter (DOM). Fire events are expected to increase under a projection of warmer and drier climatic conditions; therefore, understanding the consequences of fire-derived DOM is critical for water supply and management of drinking water and catchments. This paper addresses how fire regime - the intensity, severity and frequency of fires - influences DOM quantity and composition in surface waters in forested catchments, and how long it takes for water quality to recover to pre-fire levels. A review of post-fire studies in Mediterranean regions reporting on DOM related parameters has been conducted. The literature shows that post-fire DOM composition and reactivity is different from DOM generated under processes of biological degradation, and hence our reliance on DOM 'bulk properties' and surrogate DOM bulk parameters may not provide sufficient information to deal with the potential complexity of the organic compounds produced by a catchment fire. Appropriate measures are important to adequately operate conventional water treatment facilities, for example. Critical parameters for the effects of burning include the alteration of DOM composition, aromaticity, and the relative amounts of labile/recalcitrant organic components. The literature shows mixed information for the influence of both burn severity and fire intensity, on these parameters, which indicates DOM response to fire is highly variable. For fire frequency, the evidence is more unequivocal, indicating that frequent fires change the composition of DOM to components that are less bioavailable, and elevate the degree of aromaticity, which may be detrimental to water quality. In addition, and in general terms, the more recent the fire, the more aromatic and humified DOM components are found, and vice versa. The recovery of surface water quality to pre-fire conditions was variable, with no safe temporal thresholds suggested in the literature. In some cases, fire-induced changes in DOM composition were observable up to 16 years post-fire. The lack of clearly observed trends in post-fire DOM with fire regimes could be attributed to numerous factors such as limited long-term and event-based observations, experimental design challenges, and site-specific biological, physical and hydrological factors. The application of terminologies used to describe fire regimes such as burn severity and fire intensity also creates challenges in comparing the outcomes and results from numerous studies.

Sensitive and quantitative determination of short-chain fatty acids in human serum using liquid chromatography mass spectrometry.

Short-chain fatty acids (SCFAs) are increasingly being monitored to elucidate the link between gut health and disease. These metabolites are routinely measured in faeces, but their determination in serum is more challenging due to their low concentrations. A method for the determination of eight SCFAs in serum is described here. High-resolution mass spectrometry and gas chromatography were used to identify the presence of isomeric interferences, which were then overcome through a combination of chromatographic separation and judicious choice of MS fragment ion. The SCFAs were derivatised to form 3-nitrophenylhydrazones before being separated on a reversed-phase column and then detected using liquid chromatography tandem mass spectrometry (LC-QQQ-MS). The LODs and LOQs of SCFAs using this method were in the range 1 to 7 ng mL-1 and 3 to 19 ng mL-1, respectively. The recovery of the SCFAs in serum ranged from 94 to 114% over the three concentration ranges tested.

Data supporting development and validation of liquid chromatography tandem mass spectrometry method for the quantitative determination of bile acids in feces.

Measuring bile acids in feces has an important role in disease prevention, diagnosis, treatment, and can be considered a measure of health status. Therefore, the primary aim was to develop a sensitive, robust, and high throughput liquid chromatography tandem mass spectrometry method with minimal sample preparation for quantitative determination of bile acids in human feces applicable to large cohorts. Due to the chemical diversity of bile acids, their wide concentration range in feces, and the complexity of feces itself, developing a sensitive and selective analytical method for bile acids is challenging. A simple extraction method using methanol suitable for subsequent quantification by liquid chromatography tandem mass spectrometry has been reported in, "Extraction and quantitative determination of bile acids in feces" [1]. The data highlight the importance of optimization of the extraction procedure and the stability of the bile acids in feces post-extraction and prior to analysis and after several freeze-thaw cycles.

Detecting Sex-Related Changes to the Metabolome of a Critically Endangered Freshwater Crayfish During the Mating Season.

Captive breeding is a vital tool in the conservation of highly endangered species, as it is for the Margaret River hairy marron, Cherax tenuimanus, from the south west of Australia. A close relative, Cherax cainii, has almost completely displaced C. tenuimanus in the wild and is a successful aquaculture species, whereas C. tenuimanus has performed poorly in captivity. We used untargeted liquid chromatography-mass spectrometry to obtain metabolomic profiles of female and male C. tenuimanus held in controlled aquarium conditions during their reproductive period. Using repeated haemolymph sampling we tracked the metabolomic profiles of animals just prior to and for a period of up to 34 days after pairing with a similar sized potential mate. We identified 54 reproducible annotated metabolites including amino acids, fatty acids, biogenic amines, purine and pyrimidine metabolites and excretion metabolites. Hierarchical clustering analysis distinguished five metabolite clusters. Principal component-canonical variate analysis clearly distinguished females from males, both unpaired and paired; similar trends in profile changes in both sexes after pairing; and a striking shift in males upon pairing. We discuss three main patterns of metabolomic responses: differentiation between sexes; reactive responses to the disturbance of pairing; and convergent response to the disturbance of pairing for males. Females generally had higher concentrations of metabolites involved in metabolic rate, mobilisation of energy stores and stress. Responses to the disturbance of pairing were also related to elevated stress. Females were mobilising lipid stores to deposit yolk, whereas males had a rapid and strong response to pairing, with shifts in metabolites associated with gonad development and communication, indicating males could complete reproductive readiness only once paired with a female. The metabolomic profiles support a previously proposed potential mechanism for displacement of C. tenuimanus by C. cainii in the wild and identify several biomarkers for testing hypotheses regarding reproductive success using targeted metabolomics.

Extraction and quantitative determination of bile acids in feces.

With rapid advances in gut microbiome research, fecal bile acids are increasingly being monitored as potential biomarkers of diet related disease susceptibility. As such, rapid, robust and reliable methods for their analysis are of increasing importance. Herein is described a simple extraction method for the analysis of bile acids in feces suitable for subsequent quantification by liquid chromatography and tandem mass spectrometry. A C18 column separated the analytes with excellent peak shape and retention time repeatability maintained across 800 injections. The intra-day and inter-day precision and accuracy was greater than 80%. Recoveries ranged from 83.58 to 122.41%. The limit of detection and limit of quantification were in the range 2.5-15 nM, respectively. The optimized method involved extracting bile acids from wet feces with minimal clean up. A second aliquot of fecal material was dried and weighed to correct for water content. Extracting from dried feces showed reduced recovery that could be corrected for by spiking the feces with deuterated standards prior to drying. Storage of the extracts and standards in a refrigerated autosampler prior to analysis on the LC-MS is necessary. Multiple freeze-thaws of both extracts and standards lead to poor recoveries for some bile acids. The method was successfully applied to 100 human fecal samples.

Phenolic composition of 91 Australian apple varieties: towards understanding their health attributes.

INTRODUCTION: Apples, an important contributor to total dietary phenolic intake, are associated with cardiovascular health benefits. Determining the phenolic composition of apples, their individual variation across varieties, and the phenolic compounds present in plasma after apple consumption is integral to understanding the effects of apple phenolics on cardiovascular health. METHODS: Using liquid chromatography we quantified five important polyphenols and one phenolic acid with potential health benefits: quercetin glycosides, (-)-epicatechin, procyanidin B2, phloridzin, anthocyanins, and chlorogenic acid, in the skin and flesh of 19 apple varieties and 72 breeding selections from the Australian National Apple Breeding program. Furthermore, we measured the phenolic compounds in the plasma of 30 individuals post-consumption of an identified phenolic-rich apple, Cripp's Pink. RESULTS: Considerable variation in concentration of phenolic compounds was found between genotypes: quercetin (mean ± SD: 16.1 ± 5.9, range: 5.8-30.1 mg per 100 g); (-)-epicatechin (mean ± SD: 8.6 ± 5.8, range: 0.2-19.8 mg per 100 g); procyanidin B2 (mean ± SD: 11.5 ± 6.6, range: 0.5-26.5 mg per 100 g); phloridzin (mean ± SD: 1.1 ± 0.6, range: 0.3-4.3 mg per 100 g); anthocyanins (mean ± SD: 1.8 ± 4.4, range: 0-40.8 mg per 100 g); and chlorogenic acid (mean ± SD: 11.3 ± 9.9, range: 0.4-56.0 mg per 100 g). All phenolic compounds except chlorogenic acid were more concentrated in the skin compared with flesh. We observed a significant increase, with wide variation, in 14 phenolic compounds in plasma post-consumption of a phenolic-rich apple. CONCLUSION: This information makes an important contribution to understanding the potential health benefits of apples.

The study protocol for a pseudo-randomised pre-post designed controlled intervention trial to study the effects of a 7-week cooking program on self-efficacy and biomarkers of health: the ECU lifestyle and biomarkers get connected study (ECULABJMOF) including the Jamie's Ministry of Food WA participant experience.

BACKGROUND: Australia, like other nations, has experienced a shift in dietary patterns away from home cooking of nutritious foods, towards a reliance on pre-prepared convenience meals. These are typically energy-dense, nutrient-poor and contribute to the rising prevalence of obesity and chronic disease burden. The aims of this study were to evaluate whether a community-based cooking program instigated a change to participants' skills, attitudes, knowledge, enjoyment and satisfaction of cooking and cooking confidence (self-efficacy). METHODS: The pseudo-random, pre-post study design consisted of an intervention and a control group. Participant recruitment and group allocation was based on their program start dates. Intervention participants were surveyed three times (baseline, 7 weeks and 6 months) and the control group were surveyed at baseline and 5 weeks. All participants were registered via an online website and were 18 years or over. Upon consent, participants were offered four levels of commitment, defined by different assessments. The minimum participation level included an online survey and levels 2, 3 and 4 involved attendance at a clinic with increasing functional, anthropometric and biomarker measurements. Primary endpoints were participants' cooking confidence as a proxy for self-efficacy. Secondary endpoints were dietary intake, physical activity levels, body composition, anthropometry, blood, urine and faecal biomarkers of systemic, physical and mental health. DISCUSSION: The community cooking program provided participants with information and advice on food sourcing, preparation and nutrition to improve home cooking skills. The study was designed to explore whether food literacy programs are efficacious in improving participant physical health and well-being in order to combat the rise in obesity and diet-related disease. It will support future use of public health cooking program initiatives aimed at improving food literacy, self-efficacy and physical and mental health. The extensive data collected will inform future research into the relationship between diet, the gut-microbiota and human health. TRIAL REGISTRATION: Retrospectively registered on 16.08.2019 with the Australian New Zealand Clinical Trials Registry (ANZCTR). ACTRN12619001144101 . Protocol version 4.

A randomised controlled crossover trial investigating the short-term effects of different types of vegetables on vascular and metabolic function in middle-aged and older adults with mildly elevated blood pressure: the VEgetableS for vaScular hEaLth (VESSEL) study protocol.

BACKGROUND: A diet rich in fruits and vegetables is recommended for cardiovascular health. However, the majority of Australians do not consume the recommended number of vegetable servings each day. Furthermore, intakes of vegetables considered to have the greatest cardiovascular benefit are often very low. Results from prospective observational studies indicate that a higher consumption of cruciferous vegetables (e.g. broccoli, cabbage, cauliflower) is associated with lower cardiovascular disease risk. This may be due to the presence of specific nutrients and bioactive compounds found almost exclusively, or at relatively high levels, in cruciferous vegetables. Therefore, the aim of this randomised controlled crossover trial is to determine whether regular consumption of cruciferous vegetables results in short-term improvement in measures related to cardiovascular disease risk, including ambulatory blood pressure, arterial stiffness, glycaemic control, and circulating biomarkers of oxidative stress and inflammation. METHODS: Twenty-five participants (50-75 years) with mildly elevated blood pressure (systolic blood pressure 120-160 mmHg) will complete two 2-week intervention periods in random order, separated by a 2-week washout period. During the intervention period, participants will consume 4 servings (~ 300 g) of cruciferous vegetables per day as a soup (~ 500-600 mL/day). The 'control' soup will consist of other commonly consumed vegetables (potato, sweet potato, carrot, pumpkin). Both soups will be approximately matched for energy, protein, fat, and carbohydrate content. All measurements will be performed at the beginning and end of each intervention period. DISCUSSION: The findings of this study will provide evidence regarding the potential cardiometabolic health benefits of cruciferous vegetables, which may contribute to the revision of dietary and clinical guidelines. TRIAL REGISTRATION: The trial was registered with the Australian New Zealand Clinical Trial Registry on 19th September 2019 (ACTRN12619001294145).

Long-term Paleolithic diet is associated with lower resistant starch intake, different gut microbiota composition and increased serum TMAO concentrations.

BACKGROUND: The Paleolithic diet is promoted worldwide for improved gut health. However, there is little evidence available to support these claims, with existing literature examining anthropometric and cardiometabolic outcomes. OBJECTIVE: To determine the association between dietary intake, markers of colonic health, microbiota, and serum trimethylamine-N-oxide (TMAO), a gut-derived metabolite associated with cardiovascular disease. DESIGN: In a cross-sectional design, long-term (n = 44, > 1 year) self-reported followers of a Paleolithic diet (PD) and controls (n = 47) consuming a diet typical of national recommendations were recruited. Diets were assessed via 3-day weighed diet records; 48-h stool for short chain fatty acids using GC/MS, microbial composition via 16S rRNA sequencing of the V4 region using Illumina MiSeq. TMAO was quantified using LC-MS/MS. RESULTS: Participants were grouped according to PD adherence; namely excluding grains and dairy products. Strict Paleolithic (SP) (n = 22) and Pseudo-Paleolithic (PP) (n = 22) groups were formed. General linear modelling with age, gender, energy intake and body fat percentage as covariates assessed differences between groups. Intake of resistant starch was lower in both Paleolithic groups, compared to controls [2.62, 1.26 vs 4.48 g/day (P < 0.05)]; PERMANOVA analysis showed differences in microbiota composition (P < 0.05), with higher abundance of TMA-producer Hungatella in both Paleolithic groups (P < 0.001). TMAO was higher in SP compared to PP and control (P < 0.01), and inversely associated with whole grain intake (r = - 0.34, P < 0.01). CONCLUSIONS: Although the PD is promoted for improved gut health, results indicate long-term adherence is associated with different gut microbiota and increased TMAO. A variety of fiber components, including whole grain sources may be required to maintain gut and cardiovascular health. CLINICAL TRIAL REGISTRATIONS: Australian and New Zealand Clinical Trial Registry (ANZCTRN12616001703493).

Characterizing the Composition of the Pediatric Gut Microbiome: A Systematic Review.

The consortium of trillions of microorganisms that live inside the human gut are integral to health. Little has been done to collate and characterize the microbiome of children. A systematic review was undertaken to address this gap (PROSPERO ID: CRD42018109599). MEDLINE and EMBASE were searched using the keywords: "healthy preadolescent children" and "gut microbiome" to 31 August 2018. Of the 815 journal articles, 42 met the inclusion criteria. The primary outcome was the relative abundance of bacteria at the phylum, family, and genus taxonomic ranks. α-diversity, short chain fatty acid concentrations, diet, 16S rRNA sequencing region, and geographical location were documented. The preadolescent gut microbiome is dominated at the phylum level by Firmicutes (weighted overall average relative abundance = 51.1%) and Bacteroidetes (36.0%); genus level by Bacteroides (16.0%), Prevotella (8.69%), Faecalibacterium (7.51%), and Bifidobacterium (5.47%). Geographic location and 16S rRNA sequencing region were independently associated with microbial proportions. There was limited consensus between studies that reported α-diversity and short chain fatty acids. Broadly speaking, participants from non-Western locations, who were less likely to follow a Westernized dietary pattern, had higher α-diversity and SCFA concentrations. Confirmatory studies will increase the understanding of the composition and functional capacity of the preadolescent gut microbiome.

Simultaneous quantitative analysis of polyphenolic compounds in human plasma by liquid chromatography tandem mass spectrometry.

A diet rich in polyphenolic compounds has recognized health benefits, and as such is routinely monitored as part of dietary intervention studies. A method for the simultaneous determination of 36 phenolic compounds, including phenolic acids and flavonoids, using liquid chromatography and tandem mass spectrometry is described here. The target analytes were quantified based on their specific mass spectral fragments using a selected reaction monitoring approach. A C18 column with embedded aromatic functionality ensured separation of all phenolic compounds studied which included several pairs of isomers. Sample preparation involved the use of ß-glucuronidase to release the phenolic compounds from their conjugated forms. The intra-day and inter-day precision and accuracy was less than 7% for all phenolic compounds studied. Recoveries, where plasma was spiked with three different concentrations of the analytes, ranged from 95-115%. The limits of detection and quantification were 0.23-3.89 and 1.15-7.79 nM, respectively. The method was successfully applied to real samples and the range reported for each phenolic compound, with the exception of hydroferulic acid, nordihydroguaiaretic acid, methylgallate, and m-coumaric acid, was at least an order of magnitude higher than the limit of quantification for the method.

The Not-so-Sterile Womb: Evidence That the Human Fetus Is Exposed to Bacteria Prior to Birth.

The human microbiome includes trillions of bacteria, many of which play a vital role in host physiology. Numerous studies have now detected bacterial DNA in first-pass meconium and amniotic fluid samples, suggesting that the human microbiome may commence in utero. However, these data have remained contentious due to underlying contamination issues. Here, we have used a previously described method for reducing contamination in microbiome workflows to determine if there is a fetal bacterial microbiome beyond the level of background contamination. We recruited 50 women undergoing non-emergency cesarean section deliveries with no evidence of intra-uterine infection and collected first-pass meconium and amniotic fluid samples. Full-length 16S rRNA gene sequencing was performed using PacBio SMRT cell technology, to allow high resolution profiling of the fetal gut and amniotic fluid bacterial microbiomes. Levels of inflammatory cytokines were measured in amniotic fluid, and levels of immunomodulatory short chain fatty acids (SCFAs) were quantified in meconium. All meconium samples and most amniotic fluid samples (36/43) contained bacterial DNA. The meconium microbiome was dominated by reads that mapped to Pelomonas puraquae. Aside from this species, the meconium microbiome was remarkably heterogeneous between patients. The amniotic fluid microbiome was more diverse and contained mainly reads that mapped to typical skin commensals, including Propionibacterium acnes and Staphylococcus spp. All meconium samples contained acetate and propionate, at ratios similar to those previously reported in infants. P. puraquae reads were inversely correlated with meconium propionate levels. Amniotic fluid cytokine levels were associated with the amniotic fluid microbiome. Our results demonstrate that bacterial DNA and SCFAs are present in utero, and have the potential to influence the developing fetal immune system.

Untargeted gas chromatography-mass spectrometry-based metabolomics analysis of kidney and liver tissue from the Lewis Polycystic Kidney rat.

Polycystic kidney disease (PKD) encompasses a spectrum of inherited disorders that lead to end-stage renal disease (ESRD). There is no cure for PKD and current treatment options are limited to renal replacement therapy and transplantation. A better understanding of the pathobiology of PKD is needed for the development of new, less invasive treatments. The Lewis Polycystic Kidney (LPK) rat phenotype has been characterized and classified as a model of nephronophthisis (NPHP9, caused by mutation of the Nek8 gene) for which polycystic kidneys are one of the main pathologic features. The aim of this study was to use a GC-MS-based untargeted metabolomics approach to determine key biochemical changes in kidney and liver tissue of the LPK rat. Tissues from 16-week old LPK (n = 10) and Lewis age- and sex-matched control animals (n = 11) were used. Principal component analysis (PCA) distinguished signal corrected metabolite profiles from Lewis and LPK rats for kidney (PC-1 77%) and liver (PC-1 46%) tissue. There were marked differences in the metabolite profiles of the kidney tissues with 122 deconvoluted features significantly different between the LPK and Lewis strains. The metabolite profiles were less marked between strains for liver samples with 30 features significantly different. Five biochemical pathways showed three or more significantly altered metabolites: transcription/translation, arginine and proline metabolism, alpha-linolenic and linoleic acid metabolism, the citric acid cycle, and the urea cycle. The results of this study validate and complement the current literature and are consistent with the understood pathobiology of PKD.

A Paleolithic diet lowers resistant starch intake but does not affect serum trimethylamine-N-oxide concentrations in healthy women.

The Paleolithic diet excludes two major sources of fibre, grains and legumes. However, it is not known whether this results in changes to resistant starch (RS) consumption. Serum trimethylamine-N-oxide (TMAO) is produced mainly from colonic fermentation and hepatic conversion of animal protein and is implicated in CVD, but changes in RS intake may alter concentrations. We aimed to determine whether intake of RS and serum concentrations of TMAO varied in response to either the Paleolithic or the Australian Guide to Healthy Eating (AGHE) diets and whether this was related to changes in food group consumption. A total of thirty-nine women (mean age 47 (sd 13) years, BMI 27 (sd 4) kg/m2) were randomised to AGHE (n 17) or Paleolithic diets (n 22) for 4 weeks. Serum TMAO concentrations were measured using liquid chromatography-MS; food groups, fibre and RS intake were estimated from weighed food records. The change in TMAO concentrations between groups (Paleolithic 3·39 µm v. AGHE 1·19 µm, P = 0·654) did not reach significance despite greater red meat and egg consumption in the Paleolithic group (0·65 serves/d; 95 % CI 0·2, 1·1; P <0·01, and 0·22 serves/d; 95 % CI 0·1, 0·4, P <0·05, respectively). RS intake was significantly lower on the Paleolithic diet (P <0·01) and was not associated with TMAO concentrations. However, the limited data for RS and the small sample size may have influenced these findings. While there were no significant changes in TMAO concentrations, increased meat consumption and reduced RS intake warrant further research to examine the markers of gastrointestinal health of Paleolithic diet followers and to update Australian food databases to include additional fibre components.

Development and validation of a simple LC-MS/MS method for the simultaneous quantitative determination of trimethylamine-N-oxide and branched chain amino acids in human serum.

Serum branched chain amino acids and trimethylamine-N-oxide are monitored as potential indicators of diabetes and cardiovascular health respectively. A rapid method for their simultaneous determination using liquid chromatography and tandem mass spectrometry is described here. Branched chain amino acids and trimethylamine-N-oxide were quantified based on their specific MS/MS fragments using a selected reaction monitoring approach. A number of columns were tested for their ability to separate the analytes. A C18-PFP column separated the analytes in just 4 minutes, and resulted in excellent peak shape and retention time repeatability, and was therefore chosen as the optimal column. A second column, the Intrada Amino Acid column, was chosen for comparison and validation experiments as it provided an orthogonal separation mechanism. The intra-day and inter-day precision and accuracy were less than 12% for trimethylamine-N-oxide and less than 6% for the branched chain amino acids. Recoveries, where serum was spiked with three different concentrations of the analytes, ranged from 97 to 113%. The LODs and LOQs for trimethylamine-N-oxide were 1 and 6 ng/mL, for leucine and isoleucine were 4 and 8 ng/mL, and for valine were 5 and 15 ng/mL, respectively. The C18-PFP column method was validated using the Intrada Amino Acid column method and percentage agreement for all four analytes was within 10%. Sample preparation was minimal, and use of labelled internal standards accounted for matrix effects. The method was successfully applied to human plasma samples. Graphical abstract ᅟ.

IMass Time: The Future, in Future!

Joseph John Thomson discovered and proved the existence of electrons through a series of experiments. His work earned him a Nobel Prize in 1906 and initiated the era of mass spectrometry (MS). In the intervening time, other researchers have also been awarded the Nobel Prize for significant advances in MS technology. The development of soft ionization techniques was central to the application of MS to large biological molecules and led to an unprecedented interest in the study of biomolecules such as proteins (proteomics), metabolites (metabolomics), carbohydrates (glycomics), and lipids (lipidomics), allowing a better understanding of the molecular underpinnings of health and disease. The interest in large molecules drove improvements in MS resolution and now the challenge is in data deconvolution, intelligent exploitation of heterogeneous data, and interpretation, all of which can be ameliorated with a proposed IMass technology. We define IMass as a combination of MS and artificial intelligence, with each performing a specific role. IMass will offer advantages such as improving speed, sensitivity, and analyses of large data that are presently not possible with MS alone. In this study, we present an overview of the MS considering historical perspectives and applications, challenges, as well as insightful highlights of IMass.

The Microbiome of the Gastrointestinal Tract of a Range-Shifting Marine Herbivorous Fish.

Globally, marine species' distributions are being modified due to rising ocean temperatures. Increasing evidence suggests a circum-global pattern of poleward extensions in the distributions of many tropical herbivorous species, including the ecologically important rabbitfish Siganus fuscescens. Adaptability of a species to such new environments may be heavily influenced by the composition of their gastrointestinal microbe fauna, which is fundamentally important to animal health. Siganus fuscescens thus provides an opportunity to assess the stability of gastrointestinal microbes under varying environmental conditions. The gastrointestinal microbial communities of S. fuscescens were characterized over 2,000 km of Australia's western coast, from tropical to temperate waters, including near its current southern distributional limit. Sequencing of the 16S rRNA gene demonstrated that each population had a distinct hindgut microbial community, and yet, 20 OTUs occurred consistently in all samples. These OTUs were considered the 'core microbiome' and were highly abundant, composing between 31 and 54% of each population. Furthermore, levels of short chain fatty acids, an indicator of microbial fermentation activity, were similar among tropical and temperate locations. These data suggest that flexibility in the hindgut microbiome may play a role in enabling such herbivores to colonize new environments beyond their existing range.

Instability-Induced Pattern Transformation in Soft Metamaterial with Hexagonal Networks for Tunable Wave Propagation.

Instability-induced pattern transformations of the architectured multi-phase soft metamaterial under bi-axial compression were explored. The soft metamaterial is composed of two phases: a soft matrix and a reinforcing hexagonal network embedded in the matrix. Equi-biaxial loading is found to induce both micro- and macro- instabilities in the networked architecture. Two types of instability patterns were observed, dependent upon the architecture geometry and the material combination. The critical strain for triggering instability and the two resulting types of patterns was derived, and a theoretical criterion for the transition between the two patterns was determined. Type I patterns retain the original periodicity of the architecture but wrinkles the network walls whereas Type II patterns transform the overall periodicity of the architecture while bending the network walls. Elastic wave propagation analysis was performed for the two distinct patterns under both stressed and stress-free conditions: a change in band gaps is found for both instability-induced pattern transformations, but differs for each type due to their dramatic difference in structure transformation (i.e. Type I wall wrinkling vs. Type II periodicity switching). The distinguished mechanical behavior and the rich properties of this category of multi-phase soft metamaterial can be used to design new smart materials with switchable functionalities controllable by deformation.