The X Factor UK runner-up was under Barlow's tutelage during last year's talent contest, and he explained that the Take That frontman still contacts him despite his busy schedule.
He told BBC Breakfast: "He's a busy man, he always makes time for me. It meant a lot to me that he stuck with me after the show. I see quite a lot of him."
Gary Barlow wrote the track 'Feel Like I Feel' for Collins's debut self-titled album, which he described as his "favourite" song on the LP.
Collins added that his album would make the "perfect" soundtrack to the summer months due to its "uplifting" nature.
"All the music on the album is uplifting, and it's great for the summer. I want people to dance while doing the ironing."
> Marcus Collins releases behind-the-scenes look at 'Mercy' video
He also said that he is "proud" of his career so far after originally thinking that it would only be a "pipe dream".
"Some people would say to me, 'It's just a pipe dream', and to a certain extent I thought the same. But I proved a lot of people wrong and I'm really proud of myself."
Collins was recently rumoured to be close to facing the axe from his record label.
He recently told Digital Spy that there's "plenty to come" for his music career.
Marcus Collins releases 'Mercy' on June 3. Watch the official music video below: