What products are you looking to take?
Why do you want to take these?
Do you have any medical problems?
What symptoms does the weak digestive system give you?
What have you tried so far?
The first thing with excess gas and bloating is to consider products that help specifically with those and I recommend peppermint tea after meals. You can also purchase concentrated peppermint oil capsules if you prefer.
Probiotics still do not have a lot of clinically proven evidence of effectiveness however they are very popular and should not cause any adverse effects.
I would not recommend that you take 'digestive enzymes' as your body should be able to make enough. Sometimes making changes to your diet can make a difference too. Small regular meals which are not spicy or oily would be the first thing. Avoid alcohol and caffeine too. If you take a lot of fiber then make sure that you drink plenty of water.