From Circulating Short‐Chain Fatty Acids to an Actionable Gut–Liver–Circulatory Phenotype in Fontan Circulation

“We were very interested in reading the article by Shah et al. that investigates the association between circulating SCFAs and adverse hemodynamic and clinical outcomes among patients with Fontan circulation. We believe that the study contributes to the existing literature regarding the gut–liver–heart axis and provides relevant information. Nevertheless, several flaws should be mentioned.”

“We sincerely thank Dr. Chen for the thoughtful commentary on our recent study evaluating circulating straight- and branched- chain short- chain fatty acids (SCFAs) in adults with Fontan circulation. We appreciate the emphasis placed on the complexity of interpreting circulating microbial metabolites and agree that plasma SCFAs should not be considered direct surrogates of intestinal microbial production. Rather, they represent the net result of microbial metabolism, intestinal barrier function, portal transport, hepatic extraction, systemic shunting, and peripheral utilization.”