I am currently 7 months into my PhD. I did my masters working with gut bacteria and I really enjoy it, but I'm now doing a PhD in a completely different area of research. I am really unhappy with my work and I find it really hard to motivate myself and I am simply not interested in the topic of my research. I have seen another PhD which is advertised at the same university I am currently at and it is working with gut bacteria/microbiome which I have been interested in for years and completed my masters inI I was wondering if anyone knows if it is even possible to apply for another PhD if I quit the one I am already doing? And if there would be any chance of me even getting an interview if they knew I had already quit one?

I have already met the supervisor of the PhD informally and he also assessed my masters project presentation.I was wondering if it would be a good idea to email him mentioning all this and potentially meeting him to have a chat? But I am worried that I may not get a second chance of getting onto a PhD if I have quit one in the past. I imagine it would look really bad to potential supervisors.

Any advice would be massively appreciated!

Heard from lots of seniors that the PI is the single most important for a PhD. A good PI will show the fun in the topic and teaches you a lot by demonstrating how to interpret the data and in discussion. Back this up with my personal experience. In fact, even if your work on a very interesting topic, it can be a disaster if the group is not working as a team, and you cant have the best of everything. So, I'd choose the team than the project.

Yes, this is possible. A friend of mine did something similar. She made sure she guaranteed funding / had secured the new PhD opportunity before actually quitting the old one. If she hadn't made certain she had the new opportunity, I don't think she'd have left the old one. I believe she did this by managing to be quite open and having a conversation with the new potential supervisor about the situation, and discussing her interest in doing a project with them. She may have even identified funding options in advance, or she may have asked them about funding. Basically, she got them on board and the rest went smoothly. Let me know if you want me to ask her anything.