BackgroundThere are few data concerning the risk of contamination of enteral feeding systems via gastrostomy in children, and none for conditions that pertain to home‐based care.MethodsTo investigate the risk of contamination of enteral feeding systems during the home‐based care of 20 children receiving gastrostomy tube feeding, five samples were taken for analysis: two samples before the enteral feeding period (gastrostomy, enteral feeding system) and three after this period (gastrostomy, distal giving set, liquid remained in container). Microorganisms were identified and counted. Different factors were studied to elucidate their role in bacterial colonization: acid suppressive therapy, gastrostomy tube or button, hanging feeding time, rate of enteral feeding, gastric pullulation and retrograde contamination, manipulation error, and use of open or closed enteral feeding systems.ResultsOvergrowth was defined as a microorganismal load exceeding 10 4 colony‐forming units (cfu)/mL. Overgrowth was present in 85% of gastrostomy samples before enteral nutrition started. Most microorganisms belonged to gastric flora. Some bacteria had an environmental origin or derived from cutaneous flora. Forty‐five percent of the lines showed overgrowth at the end of enteral nutrition period, mainly with the same microorganism found in the gastrostomy. Closed enteral bags remained sterile, even if manipulation error occurred. Duration, rate of enteral feeding, and acid suppression treatment were not risk factors for overgrowth.ConclusionsRetrograde contamination of gastrostomy feeding systems occurs frequently. The preferential use of closed enteral feeding systems is recommended for home‐based enteral nutrition programs.