Whether you are taking antibiotics, or just want to keep your intestines functioning properly, probiotics are an optimal choice. Probiotics can help to maintain a healthy balance of friendly bacteria in the intestines, keeping the digestive system in line. When using antibiotics, harmful bacteria sometimes kill off the friendly bacteria, a process that can cause an infection. You can find probiotics in many forms, such as probiotic capsules, which are available from reliable sellers on eBay. Examples of what you might find include capsules that have up to 20 billion live probiotic cultures, and are easy to swallow. Most capsules need to accompany a meal or large snack. If you prefer not to swallow pills, another option is probiotic powder, which comes in single-serve packets, along with containers. From vegetable probiotics, to ones that contain essential vitamins and nutrients, there are various products to consider. Convenient shipping options mean no long waits in line for your supplements.