BACKGROUND/AIMS: Lactose-free milk (LFM) is available for nutrient supply for those with lactose intolerance (LI). However, there are no consistent results of the efficacy of LFM in LI subjects. We aimed to examine the changes of gastrointestinal (GI) symptoms and hydrogen breath test (HBT) values after ingestion of lactose contained milk (LCM) vs. LFM. METHODS: From May 2015 to September 2015, thirty-five healthy adults with history of LCM-induced GI symptoms were recruited at a tertiary hospital. For the diagnosis of LI, HBT with LCM 550 mL (lactose 25 g) was performed every 20 minutes for 3 hours. The test was defined as "positive" when H2 peak exceeded 20 ppm above baseline values (DeltaH2>20 ppm). When the subjects are diagnosed as LI, the second HBT using LFM 550 mL (lactose 0 g) was performed 7 days later. Subjects were asked to complete a questionnaire about the occurrence and severity of GI symptoms. RESULTS: Among a total of 35 subjects, 31 were diagnosed with LI at first visit, and their LCM-related symptoms were abdominal pain (98.6%), borborygmus (96.8%), diarrhea (90.3%), and flatus (87.1%). The DeltaH2 value in subjects taking LCM (103.7+/-66.3 ppm) significantly decreased to 6.3+/-4.9 ppm after ingesting LFM (p<0.0001). There were also significant reduction in total symptom scores and the severity of each symptom when LCM was changed to LFM (p<0.0001). CONCLUSIONS: This is the first report that LFM reduce LCM-related GI symptoms and H2 production in Korean adults. LFM can be an effective alternative for LCM in adults with LI.
Abdominal Pain/pathology ; Adult ; Aged ; Animals ; Asian Continental Ancestry Group ; Breath Tests ; Diarrhea/pathology ; Female ; Humans ; Hydrogen/metabolism ; Lactose/chemistry/metabolism ; Lactose Intolerance/*diagnosis ; Male ; Middle Aged ; Milk/chemistry ; Republic of Korea ; Severity of Illness Index ; Surveys and Questionnaires ; Tertiary Care Centers