Comparison of the effectiveness of oral lactase enzyme and lactose-free formula in the management of secondary lactose intolerance in persistent and severe persistent diarrhea.

OBJECTIVE: To compare the effectiveness of oral lactase enzyme versus lactose-free formula in the management of secondary lactose intolerance in persistent and severe persistent diarrhea. METHODS: This randomized controlled trial was conducted at the pediatric unit of Ziauddin University Hospital, Kemari, Karachi, Pakistan, from June, 2023 to July,2024. A total of 50 children were included in this study following the inclusion criteria of both genders aged 6-24 months and presented with persistent or severe persistent diarrhea due to secondary lactose intolerance. In Group-A, five drops of lactase enzyme (200 units lactase/drop)/ounce of milk were added 5-30 minutes before feeding, while in Group-B, lactose-free formula milk/diet was advised. They were monitored from day one through day five and assessed for outcome measures, comprising clinical (on day five) and laboratory assessments (stool pH and reducing substances on day six), success or failure, and duration of hospital stay (less or more than five days). RESULTS: In a total of 50 children, the median age was 11 (9-15.3) months. There were 30 (60.0%) children who presented with vomiting, while 14 (28.0%) had severe dehydration. At day five, lactase enzyme children showed significantly less episodes of diarrhea versus lactose free formula (20.0% vs. 48.0%, p=0.037), while all other complaints were statistically similar (p>0.05). The duration of hospital stay was significantly less among children in lactase enzyme group versus lactose free formula group (p=0.001). CONCLUSION: The effectiveness of lactase enzyme supplementation was better than lactose-free formula in children with persistent diarrhea due to secondary lactose intolerance.Clinical Trial Registration: NCT06827405 (https://clinicaltrials.gov).