That's an interesting statement.
Yes, it is. What's even more interesting is that FMT is now standard practice in the NHS in my country for C-Diff infections/overgrowth, as the eficacy is proven to be superior to antibiotics (which ironically is often the cause of the condition in the first place). There are also countless ancedotal reports and case studies indicating various benefits from it, including people recovering partially or fully from all kinds of ailments. However, much more research is needed before any useful theoretical conclusions and practical applications can be made for use beyond C-Diff treatment. Whatever the case, there is a lot of signal there for scientists to work with.
Do you think humans have a soul and/or free will? What even are those things? Is the soul and free will related to mental health?
Soul and free will are more religious and philosophical questions. I understand various concepts of it from several different religious points of view, but don't necessarily subscribe to any particular one. I have no idea of it's relationship to mental health. But, back on the topic of consciousness; evolutionary biologist Bret Weinstein has some interesting concepts regarding consciousness as an emergent phenomena, but not on an individual level as most would understand it, he comes at it as being a potentially collective evolutionary emergence...
I've always liked the saying, regarding the mystery of consciousness, that human beings are more than the sum of their parts. I'm not an ideologically driven materialist, so am not drawn to or convinced by the reductionist arguments of such, and I'm also open to the immaterial although not a believer in the unproven. I think the true nature of consciouness is far beyond the scope of current human understanding to fully, or even partially, grasp and explain, which is one of the reasons it can be so inceredibly fascinating a subject.