Level C· Early human research exploring benefitsProspective StudyEurope PMCOpen access

Exoproteome of calorie-restricted humans identifies complement deactivation as an immunometabolic checkpoint reducing inflammaging

Mishra M., Kim HH., Youm YH., Gonzalez-Hurtado E., Zaitsev K., Dlugos T.

Prospective Study, published in Nat Aging (2026) — summary generated from the PubMed abstract.

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Level C· Early human research exploring benefitsEvidence level of this study

Early human evidence such as case series or small samples is exploring possible benefits.

  • Level A · Stronger Clinical Evidence
  • Level B · Emerging clinical evidence with positive signals
  • Level C · Early human research exploring benefits
  • Level D · Scientific groundwork from lab and animal studies
  • Emerging · Emerging topic under active research
Read the A–D evidence level guide

This page is generated from the PubMed record. The Thai description is an automated summary of bibliographic fields and the abstract, not a full translation, and is not medical advice.

Study type
Prospective Study
Journal
Nat Aging (2026)
Reported sample size
—
Source database
Europe PMC
PMID
41974968
PMCID
PMC13190345
DOI
10.1038/s43587-026-01107-0
Citations
2

Abstract (original English)

Caloric restriction (CR) extends lifespan across diverse organisms, but the effects of CR on human aging and on healthspan are only beginning to be uncovered. In this study, we applied proteomics to plasma samples collected longitudinally from participants achieving, on average, 14% CR over 2 years as part of the CALERIE trial. We identified that inhibition of the complement pathway is linked to lower inflammaging. In humans, the C3a/C3 ratio was significantly lowered by CR, thus reducing inflammation emanating from three canonical complement pathways. Furthermore, circulating C3a is elevated during aging in humans and in mice; we identified a non-senescent age-associated macrophage subset that expands in visceral fat as the predominant source. In macrophages, C3a-C3AR1 autocrine signaling via extracellular signal-regulated kinase (ERK) regulates age-related inflammation. Intra-adipose administration of a C3a-specific neutralizing antibody reduced inflammaging in mice. In addition, fibroblast growth factor 21 (FGF21) overexpression and deficiency of phospholipase A2 group VII (PLA2G7/lp-PLA2), which enhance lifespan and healthspan in mice, lowered C3a in aging. Thus, complement C3a reduction is a metabolically regulated inflammatory checkpoint that can be harnessed to attenuate inflammaging.

What this study does not prove

  • • This study does not prove SVF is an approved treatment or a replacement for standard care.

Evidence level

Early human evidence such as case series or small samples is exploring possible benefits.

How we grade evidence
AnimalsMice, Inbred C57BLMice, KnockoutHumansMiceProteomeBody Mass IndexCaloric RestrictionComplement ActivationAging

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