An exercise-inducible metabolite that suppresses feeding and obesity.
Level 5 - mechanism / opinion, no new human data
Preclinical animal and bench research with descriptive human biomarker validation
PubMed 35705806 · doi:10.1038/s41586-022-04828-5
What was done
Researchers investigated the biosynthetic pathway and physiological function of N-lactoyl-phenylalanine (Lac-Phe) during exercise. In diet-induced obese mice, they measured the effects of pharmacological Lac-Phe administration on food intake, movement, energy expenditure, adiposity, body weight, and glucose homeostasis, as well as the effects of genetic ablation of Lac-Phe biosynthesis during exercise training. They also evaluated activity-induced circulating Lac-Phe levels in humans and racehorses.
What was found
No quantitative values or effect sizes are reported in the abstract. Directionally, exercise stimulated Lac-Phe production synthesized by CNDP2+ cells. In diet-induced obese mice, pharmacological Lac-Phe reduced food intake without altering movement or energy expenditure, and chronic administration decreased adiposity, reduced body weight, and improved glucose homeostasis. Genetic ablation of Lac-Phe biosynthesis increased food intake and obesity following exercise. Activity-inducible increases in circulating Lac-Phe were confirmed in humans and racehorses.
Why it matters
This work identifies Lac-Phe as a conserved exercise-inducible signaling metabolite that regulates food intake and energy balance, revealing a molecular mechanism for exercise-mediated appetite suppression.
Limits
The abstract provides no sample sizes, participant demographics, dosage details, or numerical effect sizes. Direct causal effects of Lac-Phe on appetite suppression and weight loss were tested only in mice; human and equine data were limited to observational biomarker measurements after exertion.
Cited by
- supports Jonathan Long's laboratory identified Lac-Phe (lactate-phenylalanine), an amino acid conjugated to lactate that spikes during extreme bursts of muscle activity in sprinter dogs, racehorses, and human sprinters, and mediates exercise-induced benefits.