I'm one of the twelve Americans who like Marmite, and I agree it's very nice on toast.

So I was sad to discover recently that Marmite's weird love-it-or-hate-it flavor is largely powered by free glutamic acids, better known as MSG. Naturally occurring, but still hard to tolerate. I suspect that free glutamic acids may be a causative factor in the panic attacks I'm subject to, so I sadly said goodbye to my jar of Marmite. I'll miss it.