The short answer, maybe! It’s somewhat personal and specific to your body as to whether or not blackberries in general will cause gas and bloating. If you are juicing blackberries, the same rules apply.
Blackberries are rich in fiber and antioxidants which makes them a fantastic, healthy snack, but many concerns surround the consumption of blackberries in the way of gas, bloating, diarrhea and general digestive issues.
If you have salicylate sensitivity or your body has trouble processing gas forming foods in general, you may want to limit the amount of blackberries in your diet, but in general blackberries do not produce an above average amount of gas when being digested. This applies to eating whole blackberries and also when juicing them and drinking the actual blackberry juice.