Piperine improved the safety of swallow by : ( a ) reducing the prevalence of unsafe swallows by -@ % ( P = @ ) at @ M and -@ % ( P < @ ) at @ mM , and the severity score of the penetration-aspiration scale from @ @ to @ @ ( P = @ , @ mM ) ; and ( b ) shortening the time to laryngeal vestibule closure from @ @ to @ @ s with @ M piperine ( P < @ ) and from @ @ to @ @ s with @ mM piperine ( P < @ ) .