The Impact of Diet and Enteral Tube Type on Gastric Bile Acid Concentrations and Pulmonary Outcomes.

BACKGROUND & AIMS: Bile acid reflux has been implicated as a cause for esophagitis, pulmonary fibrosis, and other aerodigestive disorders. The goal of this study was to determine the relationship between gastric and lung bile acid concentrations and if diet was a modifiable risk factor to reduce bile acid reflux.

METHODS

We prospectively recruited children with oropharyngeal dysphagia and respiratory symptoms undergoing aerodigestive testing. Gastric and, when available, lung bile acid concentrations were quantified using liquid chromatography-mass spectrometry. In a subgroup of enterally fed patients, serum 7α-hydroxy-4-cholesten-3-one (C4) levels were measured.

RESULTS

In this prospective cohort of 141 participants, gastric bile acids concentrations were highest in those fed orally compared with enteral tubes (P = .008). Gastric bile acid was a strong predictor of lung bile acids in children receiving blenderized tube feeds (r = 0.57; P = .03), but not formula (r = 0.34; P = .09), or oral feeds (r = -0.02; P = .89). Low lung bile acid concentration predicted low neutrophil counts in the lung (r = 0.39; P = .003), as did use of blenderized tube feeds (oral, 5 [interquartile range (IQR), 26]; formula, 7.5 [IQR, 37.5]; blenderized, 0 [IQR, 0]; P = .008). Quartile gastric and lung bile acids were strong predictors of hospitalization rates (P< .001 for both). Serum C4 levels, a surrogate for bile acid synthesis rate, did not support evidence of excessive bile acid loss with blenderized tube feeds (blenderized, 2.3 [IQR, 11.3] vs formula, 18.1 [IQR, 34.8] ng/mL; P = .03).

CONCLUSIONS

For patients at high risk for bile acid-related aerodigestive complications, tube and diet type may affect gastric bile acid concentrations, in turn impacting important clinical outcomes of hospitalization rates and airway inflammation.