The recommended adult dose is one capsule per day for 2-6 months depending on your level of dysbiosis - ratio of bad to good gut bacteria. If you're dealing with an acute or chronic condition (or traveling out of the country), it's perfectly safe to take more than 1 per day. Be sure to take the capsules together and after your largest meal. After 6 months, a maintenance dose of 2-4 capsules per week is recommended for ongoing gut protection.
Keep in mind that taking more than 1 per day can result in bacterial die-off reactions which can be unpleasant, but is a great sign the product is working. Die-off can cause symptoms such as gas/bloating, headaches, diarrhea/constipation, skin eruptions, etc. Simply reduce or skip your dose until symptoms subside.