If this is the same Gallup poll that had Trump's ratings all of a sudden jump five points to 49 in a manner of days, when his consistent and current ratings in other multiple polls have had him at never more than 44, then I would suspect that this poll is also not a reliable indicator. Although I haven't examined the methodology in this particular poll, many of these polls are conducted, at least partly, via landline numbers. Thus, there will be a natural skew to older, Trump-supporting voters.