Marcus Jordan appears to be making serious lifestyle changes following his recent legal troubles -- Michael's son says he celebrated 40 days of sobriety over the weekend ... months after he was arrested for DWI.
The 34-year-old former college basketball player shared the update on his Instagram Story on Sunday ... and it sure sounds like he's not turning back anytime soon, 'cause he's looking to add more days to that tally.
Jordan might be focusing on his wellness overall .