Metabolic Signatures of Extreme Longevity in Northern Italian Centenarians Reveal a Complex Remodeling of Lipids, Amino Acids, and Gut Microbiota Metabolism

<div><p>The aging phenotype in humans has been thoroughly studied but a detailed metabolic profiling capable of shading light on the underpinning biological processes of longevity is still missing. Here using a combined metabonomics approach compromising holistic ¹H-NMR profiling and targeted MS approaches, we report for the first time the metabolic phenotype of longevity in a well characterized human aging cohort compromising mostly female centenarians, elderly, and young individuals. With increasing age, targeted MS profiling of blood serum displayed a marked decrease in tryptophan concentration, while an unique alteration of specific glycerophospholipids and sphingolipids are seen in the longevity phenotype. We hypothesized that the overall lipidome changes specific to longevity putatively reflect centenarians' unique capacity to adapt/respond to the accumulating oxidative and chronic inflammatory conditions characteristic of their extreme aging phenotype. Our data in centenarians support promotion of cellular detoxification mechanisms through specific modulation of the arachidonic acid metabolic cascade as we underpinned increased concentration of 8,9-EpETrE, suggesting enhanced cytochrome P450 (CYP) enzyme activity. Such effective mechanism might result in the activation of an anti-oxidative response, as displayed by decreased circulating levels of 9-HODE and 9-oxoODE, markers of lipid peroxidation and oxidative products of linoleic acid. Lastly, we also revealed that the longevity process deeply affects the structure and composition of the human gut microbiota as shown by the increased extrection of phenylacetylglutamine (PAG) and p-cresol sulfate (PCS) in urine of centenarians. Together, our novel approach in this representative Italian longevity cohort support the hypothesis that a complex remodeling of lipid, amino acid metabolism, and of gut microbiota functionality are key regulatory processes marking exceptional longevity in humans.</p> </div

Markers of longevity as per ¹H-NMR urine profiling.

<p>Bar plots indicating mean (relative concentration) ±standard error. PAG = Phenylacetylglutamine, PCS = p-cresol-sulfate, 2HB = 2-hydroxybenzoate. All significantly regulated metabolites and statistical changes are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056564#pone.0056564.s014" target="_blank">Table S12</a>. Significant differences were assessed by Mann-Whitney U test where ***p<0.001.</p

Spearman correlation map between urine markers of longevity (PAG = phenylacetylglutamine, PCS = p-cresol sulfate, 3-HB = 3-hydroxybenzoate) and order/genus-like bacterial phylogroups.

<p>Blue denotes negative correlation, orange denotes positive correlation, and black denotes no correlation.</p

Differences in metabolic profiles as displayed by LC/MS-MS targeted approach between centenarian's offspring (46 subjects average age 68.4 yrs) and offspring of non long-lived parents (42 subjects average age 70.7 yrs).

<p>Bar plots indicating mean (µM) ±standard error. All significantly regulated metabolites and statistical changes are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056564#pone.0056564.s011" target="_blank">Table S9</a>. Significant differences were assessed by Mann-Whitney U test where *p<0.05., **p<0.01, ***p<0.001.</p

Demographic characteristics of the recruited age cohorts.

<p>Values are presented as mean ±SD with the range in parentheses.</p

Metabolic signature of aging and longevity in serum as per LC/MS eicosanoids profiling.

<p>Reported is median value in ng/100 µl serum among the three age groups. Blue denotes negative/decreased concentration, orange denotes positive/increased correlation, black denotes no changes. All significantly regulated metabolites are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0056564#pone.0056564.s008" target="_blank">Table S6</a>.</p