Butyric acid and GABA — a supplement for the gut and nerves, or an empty promise?

Aim of the study: Gamma-aminobutyric acid (GABA) is a key neurotransmitter implicated in the development of stress, anxiety, sleep-related disorders, and heart rate (HR) responses. Heart-rate variability (HRV), modulated by the sympathetic and parasympathetic branches of the autonomic nervous system (ANS), provides insight into cardiac autonomic control and cardiovascular health.

Results: An improved emotional response was also observed, characterized by reduced negative affect. GABA supplementation improved depression scores, as measured by the Depression, Anxiety, and Stress Scale (DASS-21). Notably, HRV increased, attributed to greater dominance of the parasympathetic autonomic nervous system. After 90 days of supplementation, GABA led to notable improvements in heart rate variability, emotional response, depression symptoms, and sleep efficiency.

Aim of the study: The gut microbiome has emerged as a potential target for the treatment of cardiovascular disease. Ischemia/reperfusion (I/R) after myocardial infarction is a serious complication, and it remains unclear whether certain gut bacteria could be used as a treatment.

Results: Mechanistically, GABA administered by gavage reduced the number of proinflammatory macrophages in I/R hearts, and it no longer protected the heart from I/R injury when macrophages were depleted. In vitro studies using LPS-stimulated bone marrow-derived macrophages (BMDM) further showed that GABA inhibits the polarization of macrophages toward the proinflammatory M1 phenotype by preventing lysosomal leakage and NLRP3 inflammasome activation. Together, this study shows that preventive oral administration of L. reuteri or its metabolite GABA reduces macrophage-mediated heart inflammation and thus alleviates cardiac dysfunction after I/R, providing a new preventive strategy for mitigating acute ischemic heart injury.

Aim of the study: Dietary supplementation with sodium butyrate or bovine colostrum modulates the gut-liver axis in weaned piglets. Sodium butyrate had beneficial effects on liver function and lipid parameters, while also inhibiting inflammation and helping maintain the intestinal barrier.

Results: Significant increases were detected in acetic acid (p = 0.003) and in butyric, isobutyric, and valeric acids (p = 0.014, p = 0.024, and p = 0.038, respectively). Supplementation with sodium butyrate and dried bovine colostrum also increased hepatic concentrations of macro- and microelements in piglets in the experimental groups. Genomic analyses suggest that sodium butyrate modulates hepatic metabolic and inflammatory pathways by downregulating PPAR (peroxisome proliferator-activated receptor) and SIRT3 (sirtuin 3) expression and reducing TNF (tumor necrosis factor) gene expression, highlighting its potential role in regulating lipid metabolism, oxidative stress, and inflammation in a porcine model. Overall, the results indicate that both supplements may help modulate gut microbial activity and liver metabolism in weaned piglets.