Photobiomodulation Strengthens Muscles via Its Dual Functions in Gut Microbiota

Area of Science:

• Exercise Physiology
• Mitochondrial Biology
• Microbiome Research

Background:

• Photobiomodulation therapy (PBMT) is known to alleviate fatigue and improve mitochondrial function.
• However, its effects on physical performance are modest when applied only to peripheral muscles like the thighs.

Purpose of the Study:

• To investigate the efficacy of non-invasive abdominal PBMT in enhancing endurance and mitigating exercise-induced physiological stress.
• To explore PBMT's impact on gut epithelial integrity, microbiota composition, and mitochondrial bioenergetics.

Main Methods:

• Subjects underwent graded treadmill tests under anaerobic stress with combined abdomen-and-legs PBMT or sham treatment.
• Mitochondrial structure and mass in leg muscles were assessed.
• Gut microbiota composition, short-chain fatty acid (SCFA) levels, and other metabolites were analyzed in fecal and circulating samples.
• Ex vivo assays and a lactic acidosis model were used to evaluate PBMT effects under specific stress conditions.

Main Results:

• Combined abdomen-and-legs PBMT nearly doubled time to exhaustion compared to sham treatment, with sustained benefits.
• PBMT preserved mitochondrial cristae and mass in key leg muscles, showing a significant increase over sham.
• Abdominal PBMT maintained gut phyla diversity, enriched SCFA-producing bacteria, reduced pathobionts, and increased beneficial metabolites like butyrate and spermidine.
• PBMT accelerated recovery in a lactic acidosis model and reduced associated physiological stress.

Conclusions:

• Brief, non-invasive abdominal PBMT is a potent non-invasive modality for enhancing physical endurance.
• PBMT effectively preserves gut epithelial integrity, modulates the gut microbiota, and supports mitochondrial function during intense exercise.
• These findings highlight the translational potential of abdominal PBMT for performance enhancement, rehabilitation, and managing conditions linked to gut dysbiosis and mitochondrial dysfunction.