Diet, feeding route may influence bile acids in dysphagia

Diet type and feeding route may affect gastric bile acid concentrations in pediatric patients with oropharyngeal dysphagia who are at high risk for bile acid–related aerodigestive complications, according to findings published in Clinical Gastroenterology and Hepatology.

In an interview with GI & Hepatology News, lead author Rachel Rosen, MD, MPH, of Boston Children’s Hospital, noted, “We have been worried about bile acid reflux for a long time,” explaining that in vitro studies have linked it to gastric, esophageal, laryngeal, and lung inflammation. “We are excited that this study finally opens the door to modulate bile acids using nutritional interventions," she added.

When asked about key clinical takeaways, Dr. Rosen and corresponding author Bridget M. Hron, MD, MMSc, also of Boston Children’s Hospital, stated that

Gastric and lung bile acid concentrations were associated with increased all-cause and respiratory hospitalizations, reported Dr. Rosen and corresponding author

, also of Boston Children’s Hospital. Higher gastric bile acid concentrations correlated with higher lung bile acid concentrations and increased neutrophilic inflammation in the lungs.

Bile acid exposure in the stomach and lungs appeared to be modulated by diet type (regular oral diet, commercial formula, or blenderized tube feeds) and feeding route (oral, gastrostomy, or gastrojejunostomy feeds), with gastric feeds — particularly blenderized — associated with lower gastric bile acids and lung neutrophils.

“The bottom-line takeaway is that bile acid reflux — not just acid reflux — appears to be an important and modifiable driver of aerodigestive disease,” they said.

Study details

The prospective cohort study recruited 141 children (69 orally fed; 43 fed via gastrostomy; and 29 fed via gastrojejunostomy) with oropharyngeal dysphagia and respiratory symptoms undergoing aerodigestive testing. Gastric (n = 131) and lung (n = 113) bile acid concentrations were measured using liquid chromatography–mass spectrometry.

In a subgroup of patients receiving enteral feeding (n = 16 [9 with formula and 7 with blenderized tube feeds]), serum 7α-hydroxy-4-cholesten-3-one (C4) levels — a marker of bile acid synthesis rate that increases with greater fecal bile losses — were assessed.

The study aimed to assess how enteral tube feeding type affects gastric bile acid concentrations, evaluate the influence of dietary differences on these concentrations, and determine whether enteral feed type is associated with serum C4 levels.

Results

Patients fed orally exhibited higher gastric bile acid concentrations than those who were fed through enteral tubes. The investigators reported that gastric bile acid was strongly and significantly correlated with lung bile acids in patients fed via blenderized tube feeds (r = 0.57) but not in those who received formula (r = 0.34) or oral feeding (r = −0.02).

Lower lung bile acid concentrations were significantly correlated with reduced lung neutrophil counts (r = 0.39), investigators reported. Neutrophil levels also varied significantly by diet, with bronchoalveolar lavage neutrophils highest in formula-fed patients (7.5%), followed by oral diets (5%), and lowest with blenderized diets (0%).

Gastric and lung bile acid levels, analyzed by quartile, were reported to be strong and significant predictors of hospitalization rates.

"This study is exciting from a mechanistic perspective because it shows that the relationship between gastric and lung bile acids could be modulated by blenderized tube feeds, and that lung inflammation may be lower with these feeds, all likely contributing to improved outcomes," said Dr. Hron.

Serum C4 levels did not support excessive bile acid loss with blenderized tube feeds (2.3 [blenderized] vs 18.1 [formula] ng/mL), noted investigators.

Implications 

In the interview, Dr. Rosen and Dr. Hron noted that current reflux management strategies may warrant reconsideration, as standard therapies such as proton pump inhibitors do not address bile acid reflux. Although no commercially available treatments specifically target bile acid reflux, they suggested that nutritional interventions — particularly in patients at risk for aspiration-related lung disease — may help modify aerodigestive outcomes.

Postpyloric feeds, often used to prevent lung disease, were noted by Dr. Rosen to “not help reduce gastric bile acids, which means that may not be a panacea for patients with aspiration-related lung disease.” She and Dr. Hron highlighted blenderized feeds as a potential therapeutic option for many patients who are fed by enteral tubes, suggesting that reduced lung bile acid exposure with this approach could translate to lower hospitalization rates.

"Blenderized tube feeds have become a mainstay of nutritional management for children with medical complexity, and we are really interested in learning exactly why they are associated with improved outcomes," said Dr. Hron.

Dr. Rosen and Dr. Hron cautioned that while their findings suggest associations between diet, gastric and lung bile acid concentrations, and hospitalizations, causality cannot be established from the present study. Although blenderized tube feeds have been shown to improve outcomes in this and other studies, their use remains limited in practice due to availability constraints and the need for close dietetic support, which may not be accessible in all clinical settings. Future prospective studies may help clarify the relationship between upper gastrointestinal bile tract sequestration and improved aerodigestive outcomes.

The authors reported no conflicts of interest.