Genomics in Personalized Nutrition: Can You “Eat for Your Genes”?

Genome-wide single nucleotide polymorphism (SNP) data are now quickly and inexpensively acquired, raising the prospect of creating personalized dietary recommendations based on an individual’s genetic variability at multiple SNPs. However, relatively little is known about most specific gene–diet interactions, and many molecular and clinical phenotypes of interest (e.g., body mass index [BMI]) involve multiple genes. In this review, we discuss direct to consumer genetic testing (DTC-GT) and the current potential for precision nutrition based on an individual’s genetic data. We review important issues such as dietary exposure and genetic architecture addressing the concepts of penetrance, pleiotropy, epistasis, polygenicity, and epigenetics. More specifically, we discuss how they complicate using genotypic data to predict phenotypes as well as response to dietary interventions. Then, several examples (including caffeine sensitivity, alcohol dependence, non-alcoholic fatty liver disease, obesity/appetite, cardiovascular, Alzheimer’s disease, folate metabolism, long-chain fatty acid biosynthesis, and vitamin D metabolism) are provided illustrating how genotypic information could be used to inform nutritional recommendations. We conclude by examining ethical considerations and practical applications for using genetic information to inform dietary choices and the future role genetics may play in adopting changes beyond population-wide healthy eating guidelines

Influence of Storage Conditions and Preservatives on Metabolite Fingerprints in Urine

Human urine, which is rich in metabolites, provides valuable approaches for biomarker measurement. Maintaining the stability of metabolites in urine is critical for accurate and reliable research results and subsequent interpretation. In this study, the effect of storage temperature (4, 22, and 40 °C), storage time (24 and 48 h), and use of preservatives (boric acid (BA), thymol) and para-aminobenzoic acid (PABA) on urinary metabolites in the pooled urine samples from 20 participants was systematically investigated using large-scale targeted liquid chromatography tandem mass spectrometry (LC-MS/MS)-based metabolomics. Statistical analysis of 158 reliably detected metabolites showed that metabolites in urine with no preservative remained stable at 4 °C for 24 and 48 h as well as at 22 °C for 24 h, but significant metabolite differences were observed in urine stored at 22 °C for 48 h and at 40 °C. The mere addition of BA caused metabolite changes. Thymol was observed to be effective in maintaining metabolite stability in urine in all the conditions designed, most likely due to the inhibitory effect of thymol on urine microbiota. Our results provide valuable urine preservation guidance during sample storage, which is essential for obtaining reliable, accurate, and reproducible analytical results from urine samples

Identification of Plasma Glycosphingolipids as Potential Biomarkers for Prostate Cancer (PCa) Status

Prostate cancer (PCa) is the most common male cancer and the second leading cause of cancer death in United States men. Controversy continues over the effectiveness of prostate-specific antigen (PSA) for distinguishing aggressive from indolent PCa. There is a critical need for more specific and sensitive biomarkers to detect and distinguish low- versus high-risk PCa cases. Discovery metabolomics were performed utilizing ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS) on plasma samples from 159 men with treatment naive prostate cancer participating in the North Carolina-Louisiana PCa Project to determine if there were metabolites associated with aggressive PCa. Thirty-five identifiable plasma small molecules were associated with PCa aggressiveness, 15 of which were sphingolipids; nine common molecules were present in both African-American and European-American men. The molecules most associated with PCa aggressiveness were glycosphingolipids; levels of trihexosylceramide and tetrahexosylceramide were most closely associated with high-aggressive PCa. The Cancer Genome Atlas was queried to determine gene alterations within glycosphingolipid metabolism that are associated with PCa and other cancers. Genes that encode enzymes associated with the metabolism of glycosphingolipids were altered in 12% of PCa and >30% of lung, uterine, and ovarian cancers. These data suggest that the identified plasma (glyco)sphingolipids should be further validated for their association with aggressive PCa, suggesting that specific sphingolipids may be included in a diagnostic signature for PCa.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Trends in Size Class Distribution, Recaptures, and Abundance of Juvenile Green Turtles ( Chelonia mydas

Despite great advances in the understanding of marine turtle biology over the past 60 yrs, there is still a paucity of demographic data on the juvenile stage of their life history. These data are required to adequately predict population trends for these long-lived marine turtle species. In the early 1990s, juvenile green turtles (Chelonia mydas) were observed in the Trident Turning Basin at Port Canaveral, Brevard County, Florida. We began a study in 1993 to assess the species composition, size class distribution, and degree of residency of the marine turtles utilizing this man-made embayment as developmental habitat. The results of the first 18 yrs of that study are related here. Juvenile green turtles constituted 99.4% of the marine turtle captures. Straight carapace lengths (SCL) of turtles ranged from 20.0 to 52.0 cm with a mean of 31.7 cm, smaller than those observed in other known green turtle developmental habitats in Florida. The mean SCL of the green turtles in the basin has declined over the course of the study. Although initially there was a high recapture rate of turtles tagged in the basin, that rate declined significantly along with the size of the turtles at their most recent recapture and the interval of time between their first capture and most recent recapture. We attribute these declines to the increase in the number of juvenile green turtles recruiting to developmental habitats along Florida\u27s east coast and to the limited forage available in the basin. Population surveys over the past 13 yrs of the study yielded estimates that ranged from 27 to 224 green turtles in the basin, with a mean estimate of 61±10 turtles. The results of this study illustrate the value of long-term monitoring projects in understanding both juvenile green turtle habitat preferences and sea turtle population dynamics. © Chelonian Research Foundation