Effects of Liquid Diet Administration Routes and Types of Dietary Fiber Pectin on Fecal Characteristics and Gut Microbiota in Rats

Why It Matters

Understanding route‑specific and fiber‑specific impacts can guide safer enteral feeding protocols and reduce dysbiosis‑related complications in vulnerable patients.

Key Takeaways

• Duodenostomy feeding increased cecal weight and reduced microbiota diversity.
• Low‑methoxyl pectin improved fecal consistency across all administration routes.
• LMP raised Firmicutes and lowered Enterobacteriaceae relative abundances.
• Gastrostomy showed higher plasma endotoxin than oral feeding but lower than duodenostomy.
• Body weight gains were highest in LMP groups regardless of route.

Pulse Analysis

Enteral nutrition is a cornerstone for patients who cannot eat orally, yet the choice of delivery method—nasogastric tube, gastrostomy or duodenostomy—can profoundly affect gut physiology. Recent clinical observations link tube feeding to reduced microbial diversity and increased pathogenic bacteria, but mechanistic data have been scarce. By employing a controlled rat model, researchers isolated the effects of three distinct routes, revealing that duodenostomy, which bypasses the stomach, leads to larger cecal contents, elevated endotoxin levels and a shift toward Proteobacteria, suggesting slower transit and heightened inflammatory risk.

The study also dissected the role of dietary fiber, focusing on two pectin variants. Low‑methoxyl pectin (LMP) formed calcium‑mediated gels in the acidic stomach, increasing luminal viscosity and promoting water retention. Across all feeding routes, LMP consistently enhanced stool form, boosted alpha‑diversity indices and favored Firmicutes while suppressing Enterobacteriaceae—key markers of a healthier microbiome. In contrast, high‑methoxyl pectin (HMP) and pectin‑free diets failed to deliver these benefits, underscoring the importance of fiber chemistry, not just quantity, in shaping microbial ecosystems during enteral feeding.

For clinicians, these findings suggest that selecting a feeding route that preserves gastric processing, combined with LMP‑enriched formulas, could mitigate dysbiosis, lower endotoxin translocation, and support better nutritional outcomes. Future translational work should evaluate LMP’s impact in human cohorts, explore optimal dosing, and assess long‑term effects on immune function and liver health. Integrating fiber‑type considerations into enteral nutrition protocols may become a new standard for reducing complications in intensive care and chronic disease settings.