Higo Blog

A Google Search yielded this page. Like natto in Japan, British children are fed this stuff at an early age, so they aquire the taste after rigorous feeding regimens. Natto is typically served as a condiment to rice, as Marmite generally tops toast (the most popular carbohydrate eaten with every meal in said countries).
In the Marmite page, this is a suggestion of a possible use for this particular "savoury spread":
...Marmite is very effective as a topical ointment in the treatment of haemorrhoids.
And I'll leave it at that...