[speedy-learner]

I am a beginner level Spanish learner and found this text which talks about dietary needs. I just wanted to check how natural sounding it is.

In particular, I am not sure about Son alérgicos al trigo, a su harina y al gluten. I thought a su means to their so I don't quite understand the sentence structure. Thanks for any help!

We are vegetarian
Somos vegetarianos

We don’t eat meat, cow, fish, horse or chicken or animal broth.
No comemos ningún tipo de carne: ternera, pescado, caballo, pollo u otros animales.

Does that contain meat? Has it been prepared in animal broth?
¿Este plato contiene carne? ¿Se ha preparado con caldo de animales?

They are allergic to wheat, wheat flour and gluten. They absolutely must not eat it. If they eat it by mistake, they will become ill.
Son alérgicos al trigo, a su harina y al gluten. Tienen absolutamente prohibido tomarlos. Si por error se los toman, se pondrán muy enfermos.

Do you have a gluten free, vegetarian burger? That is, with no gluten, meat, cow, fish, horse or chicken.
¿Tiene una hamburguesa vegetariana sin gluten? Quiero decir: sin gluten ni ningún tipo de carne, como vaca, pescado, caballo o pollo.

Does this Cheese have animal rennet?
¿Este queso contiene cuajo animal?


Suitable for a Celiac
apta para un Celíaco

They are Celiac
Son celíacos