Organisms are host to their memes, and to the genes of their gut bacteria
Unless the gut bacteria where somehow only transmitted from say mother to children.
That is certainly not how most human gut bacteria work!
But where does this leave "driving genes" - alleles that help themselves rather than the bearer.
Yes, some animal genes can act like parasites. Most animal genes are not like that, though!
After all to consider regular usage the mitochondria - rest of cell relationship is often considered a symbiosis.
Yes, that is still reasonable - mitochondria have different genetic interests to the host cells - e.g. they want to kill males. If that was the context, the term "symbiosis" would be fine.
"Host" terminology is still quite stretch, IMO. Symbiosis takes place when different types of creature live together. Cloned somatic cells are better regarded as being part of the same organism. The genes are not really in a symbiotic relationship with the "host" - there is only one creature involved here.
The jacket text for Keith Stanovich's The Robot's Rebellion sums up the book well:
The book is an excellent introduction to the first stage of Yudkowskian philosophy: We are robots in a mechanistic universe running on a swiss army knife of cognitive modules. But at least we finally noticed we're robots, and we can use the skills of rationality to hop off our habit treadmills and pursue our values instead. These values are complex and often arbitrary, but we can use our reflective capacities to extrapolate our values based on "higher-order" desires, a desire for preference consistency, and other considerations. All this is argued for at length in Stanovich's book. The only thing missing is a discussion of what to do about all this when AI arrives.