A Portfolio Analysis of Nutritional Biomarkers in NIH- and NHLBI-funded Research, 2008–2020

Nutrition biomarkers are important in elucidating disease risks and severity, as surrogate markers of nutritional status, and provide objective measures of dietary intake. This study analyzed grants that investigated nutritional biomarkers and were funded between 2008 and 2020 by the National Heart, Lung, and Blood Institute (NHLBI) and across the National Institutes of Health (NIH). Data were extracted using the NIH iSearch portfolio analysis platform to curate grant applications to the NIH and NHLBI. Keywords included nutrition or diet, followed by omics, metabolomics, lipidomics, proteomics, transcriptomics, genomics, and epigenomics. Funded and unfunded nutri-omics grants were separated and examined for keywords for total expenditures, Research, Condition, and Disease Categorization (RCDC) categories, administering Institute, fiscal year, Early-Stage Investigator eligibility, and organization. Citation and publication data stemming from each awarded grant were collated using iCite. The total number of NIH- and NHLBI-funded grants in nutri-omics biomarkers was 1,143 and 95, respectively from 2008–2020. Total dollar amount of NIH-funded grants in nutri-omics biomarkers increased from $15M in 2008 to $59.5M in 2019 and declined to $47M in 2020. NHLBI funded grants increased substantially during the same years from $1.8M in 2008 to $7.5M in 2020. During the 12-year period, the proportion of ESI grants among funded grants increased by about 10-fold across NIH and 2-fold for NHLBI. There was an increase in the number of NHLBI research publications (500%) and relative citation ratios (RCR) (150%). Funded grants were concentrated along the East and West coasts of the United States. Major foam tree topics from NHLBI-administered nutri-omics grants included cardiovascular disease, dietary patterns, obesity, human genome, risk factors, microbiome, TMAO (trimethyl amine oxide), and fatty acids. The analysis indicated increased funding in nutri-omics biomarkers. However, major gaps remain in topics categorized as nutrition biomarkers in NHLBI- and NIH-funded grants. More research is needed to characterize and examine novel biomarkers in NIH-funded grants. Not applicable.