Gut microbiome × endurance — Veillonella metabolizes lactate to propionate (landmark)
Key Findings
Marathon runners: Veillonella relative abundance increased post-marathon; a Veillonella atypica strain was isolated from their stool
Inoculation (gavage) of this strain into mice significantly increased exhaustive treadmill run time (magnitude not given in the abstract)
Veillonella uses lactate as its sole carbon source; shotgun metagenomics in a cohort of elite athletes found every gene of a major lactate→propionate pathway at higher relative abundance post-exercise
13C3-labelled lactate in mice: serum lactate crosses the epithelial barrier into the gut lumen
Intrarectal instillation of propionate alone reproduced the run-time gain seen with V. atypica gavage → propionate mediates the benefit
Model: exercise → lactate into blood → into the gut → Veillonella → propionate → improved run time
Practical Application
Meta-omics of marathon runners and elite athletes plus mouse experiments: Veillonella rose after a marathon, its lactate→propionate genes rose after exercise, and gavaging the isolated V. atypica strain — or propionate alone — into mice significantly lengthened treadmill run time; lactate was shown to cross from blood into the gut. A mechanism, not a ready protocol: commercial Veillonella probiotics have no proven efficacy in humans yet
Not from this paper, and not supported by any entry in the base: "support the microbiome" advice (diverse fibre, fermented foods). The study tested no food or fibre intervention in humans, and SYNTH-08 states that no entry supports a stool test, a "diversity" target or fermented-food quotas — do not prescribe them from this entry. Antibiotics are a medical decision, not a training one
Dovetails with lactate metabolism (lactate is not "waste" but a substrate — see REF-172, REF-491-496)
Limitations
Causality shown in MICE (gavage, propionate instillation); direct transfer to a human athlete is not proven by RCT
The human part is observational (association of Veillonella enrichment with the marathon / post-exercise state)
Veillonella probiotic supplements in humans have no proven ergogenic effect yet
Individual microbiome variability is enormous
How this entry was checked and changed
Why this level
regraded 2026-09-27 from A: the human part is an observational association (marathon runners, elite-athlete cohort); the causal part is in mice
Content correction 2026-09-27
"+13% time to exhaustion running" -> the abstract says only "significantly increased exhaustive treadmill run time"; the figure removed.
Level A -> B per KB-LEVEL-RUBRIC (human part observational/correlational; causal part animal data). Lead bullet now states the human-observational vs mouse-causal split.
Added the abstract's elite-athlete metagenomic cohort and the 13C-lactate tracer finding.
2026-10-01: the fermented-food / 'support the microbiome' advice is relabelled as supported neither by this paper (human part observational, causal part in mice, no dietary intervention) nor by any entry in the base, in line with SYNTH-08; the Applicability line no longer offers it as a rationale.