It's not one I eat particularly, but bread has been mentioned recently in another thread.
For alternatives though
Hovis Nimble is 37g per 100g, but only 8.1g per slice
Warburtons wholemeal (400g) is 37.8g per 100g, but only 9g per slice
They are not seeded, but smaller slices, but still quite reasonable.
Livlife, if you can find it, it used to be in Waitrose, and occasionally in a few other supermarkets intermittently is
10.2g per 100g, 3.4g per slice.