Michael Lohan, Kate Major Lose Custody of Kids

Michael Lohan and Kate Major just got shut down by a judge, who has awarded custody of their 2 children to Michael's mother ... TMZ has learned.

TMZ broke the story ... the Florida Dept. of Children and Families took the kids last week and placed them in foster care after the Dept. obtained a video showing Michael and Kate in a blowout fight in front of 2-year-old Landon and 10-month-old Logan. Michael's mother was given temporary guardianship.

Michael and Kate showed up in court today but a judge was unmoved by their pleas to regain custody. Michael's mom will care for the kids and Michael and Kate can only see their children with a DCF monitor.