I am by no means an expert (not a great start to a comment I realise), but from what I've read about it (e.g. in Sapiens by Harari) hunter gathers typically did have a diverse diet. In fact it's hard to imagine they wouldn't. For a start, different foods obviously have different availibility with the seasons. And, as the name suggests, there was typically a hunter/gatherer split (along gender lines) and hunting has this very bimodal distribution of getting a big kill that lasts for days or getting nothing at all, so the balance between the two is very variable. As for the content of both what is gathered and what is hunted, that varies a lot due to both natural variation (a natural forest isn't just filled with a single type of tree) and desire for variation. The desire for variation presumably evolved from both the nutritional benefit of having a varied diet and the fragility of relying on a single food source - if you don't learn how to hunt more than one type of animal then you'll end up starving if their numbers dwindle (e.g. because you hunted them too much).
> coevolved with a microbiome that relied on a very homogeneous diet
Did he go through specific examples? The Hadza only eat five foods and have a diet that's significantly less varied that modern society. I'll see if I can find counter-examples.
However I will say, even though the Hadza only eat five foods, they eat everything in the animal including the organs, which definitely adds variation.
I am by no means an expert (not a great start to a comment I realise), but from what I've read about it (e.g. in Sapiens by Harari) hunter gathers typically did have a diverse diet. In fact it's hard to imagine they wouldn't. For a start, different foods obviously have different availibility with the seasons. And, as the name suggests, there was typically a hunter/gatherer split (along gender lines) and hunting has this very bimodal distribution of getting a big kill that lasts for days or getting nothing at all, so the balance between the two is very variable. As for the content of both what is gathered and what is hunted, that varies a lot due to both natural variation (a natural forest isn't just filled with a single type of tree) and desire for variation. The desire for variation presumably evolved from both the nutritional benefit of having a varied diet and the fragility of relying on a single food source - if you don't learn how to hunt more than one type of animal then you'll end up starving if their numbers dwindle (e.g. because you hunted them too much).
> coevolved with a microbiome that relied on a very homogeneous diet
... so this unlikely to start with.