Highlights
• Lactose-free milk powder could alleviate diarrhea symptoms but not affect normal growth in both antibiotic-associated diarrhea rats and children.
• Lactose-free milk powder promoted the recovery of gut barrier integrity.
• Lactose-free milk powder played a vital role in regulating gut microbial structure and diversity.
• Lactose-free milk powder enhanced the production of short chain fatty acids.