The Hidden Driver of SIBO and Chronic Gut Dysfunction: Bile Acid Malabsorption, Dysbiosis, and the Mitochondrial Cascade — Part VI: Investigation, Mechanistic Analysis, and Targeted Intervention

The Missing Diagnostic Step: Fecal Bile Acid Analysis Conventional gastroenterology does not routinely measure fecal or serum bile acid concentrations, bile acid composition, or secondary-to-primary bile acid ratios. This is a diagnostic void. A complete investigation in SIBO should include: 1. Fecal Bile Acid Panel Total bile acid concentration Primary bile acid concentration (cholic acid, chenodeoxycholic acid) Secondary bile acid concentration (deoxycholic acid, lithocholic acid, secondary bile acids) Ratio of secondary to primary bile acids Fecal bile acid loss rate (if 24-hour collection possible) Interpretation: In dysbiosis-driven bile acid malabsorption, you expect to see: Elevated total fecal bile acids (due to increased hepatic synthesis and reduced reabsorption) Elevated primary bile acid fraction (indicating failed conversion) Depressed secondary bile acid fraction (indicating absent bacterial enzymatic activity) Low or inverted secondary-to-primary ratio (in healthy states, secondary &gt; primary; in dysbiosis, the ratio inverts) 2. Serum Bile Acid Panel Fasting serum bile acids (normally 3&#8211;12 &#956;M) 2-hour postprandial serum bile acids If possible, individual bile acid species profiling Elevated fasting serum bile acids (&gt;10 &#956;M) suggest impaired ileal reabsorption, impaired return to the liver, or dysbiosis-driven loss of hepatic regulation. This i