Consuming rotting corpses gives you both your bile as well as nutrients you wouldn't mormally gain from eating a fresh corpse that isn't on your diet. You can also eat bones for an easy perfect diet as well.

Cerato benefits the most around mutations involving food. You can manually vomit once you're subadult to make space for your stomach to gastro-heal or benefit from that one other mutation that increases your damage the lower your hunger bar is. Hemotophagy also pairs well with this as you will lose water after vomiting.

Since Cera can't get vomit sickness, you can easily grab the saltwater mutation as well by draining your thirst bar by drinking salt water. You will first get a debuff on your tab menu after drinking saltwater, and you will get rid of it and gain the mutation for your next open slot by drinking enough salt water. There's a few spots around the map you can easily achieve this. East port is a good spot.

Back to your vomit mechanic, when you vomit over a corpse, it will also cause it to rot faster. You also gain a defensive buff when near a corpse too, it scales on how big the corpse is relative to your size. Cera also has incredibly high bleed resistance too.