Atherosclerosis amelioration by allicin in raw garlic through gut microbiota and trimethylamine-N-oxide modulation.
Level 4 - case-series / case-control
Preclinical animal and in vitro research combined with an uncontrolled single-arm human pilot study.
PubMed 35087050 · doi:10.1038/s41522-022-00266-3
What was done
Researchers evaluated the effect of raw garlic juice and its active compound allicin on gut microbial conversion of L-carnitine to trimethylamine-N-oxide (TMAO) and atherosclerosis. The study tested allicin in L-carnitine-fed C57BL/6J mice and ApoE-/- mice, assessing serum TMAO, fecal microbiota, and aortic lesion area. In vitro and ex vivo assays examined γ-butyrobetaine and trimethylamine synthesis. Additionally, human subjects with high TMAO production consumed raw garlic juice for one week to assess changes in TMAO formation and gut microbiota composition.
What was found
No numerical values, effect sizes, or statistical metrics are reported in the abstract. In mice, allicin supplementation significantly reduced serum TMAO, decreased aortic lesions, and altered fecal microbiota. In vitro and ex vivo experiments showed inhibition of γ-butyrobetaine and trimethylamine production. In human subjects, one week of raw garlic juice intake reduced TMAO formation, increased gut microbial diversity, and increased relative abundances of beneficial bacteria.
Why it matters
This work identifies a potential mechanism by which allicin in raw garlic targets gut microbial metabolism to lower pro-atherogenic TMAO production.
Limits
The abstract provides no sample sizes for human or animal groups and omits all quantitative data and variance. The human evaluation was a short, one-week single-arm intervention without a control group or clinical cardiovascular endpoints.