Mixed: human and animal research · review
Guimaraes GNF et al., Biomedicines 2025
A systematic review of abdominal photobiomodulation (PBM, light applied to the belly) and the gut-brain axis found only 9 studies: 5 small human studies (1 pilot RCT, case series, a single case report, and overlapping reports from one 12-patient Parkinson's cohort) and 4 animal studies. The only RCT (53 people with Alzheimer's disease, head plus abdomen device) did not improve its primary cognitive score. The evidence is early and mostly preclinical; the review's own 'favorable recommendation' wording goes beyond its data.
Source: Abdominal Photobiomodulation and the Gut-Brain Axis: A Systematic Review of Mechanistic and Translational Evidence. Guimaraes GNF, dos Santos Cardoso F, Gamboa L, Barrett DW, Gonzalez-Lima F. Biomedicines. 2025;13(12):3042. doi:10.3390/biomedicines13123042. PMID:41463053. PMCID:PMC12730906. Published 2025-12-11. Full text read (PMC); Supplementary Tables S1/S2 not read (study details taken from the main-text Results)
Verified research card EL-20261018-08