Yogurt is great, especially if you get the right yogart like you said. Make sure the label states that it contains live and active cultures. There is also Soy Yogurt for those that are lactose intolerant that offer the same calories, protein & probiotics as many other yogurts. Don't neglect other fermented foods though, like sauerkraut, pickles, kefir, fermented soy products, etc.
Probiotic supplements are also great and many have thousands to millions of more strains of bacteria than yogurt. However, some probiotics (in any form) may do more harm than good if you have certain issues. Some strains of probiotics may not be right for you when others are if you have irritable bowel syndrome or other digestive issues. With some people, probiotics make the person bloated and gassy, and with other people, it relieves them from being bloated and gassy. It's a crazy mixed up world. Lol. But a lot of websites say that if you're farting enough, you have a happy gut. Lol
"Side effects: Probiotics are considered safe overall for healthy people; short-term side effects may include mild gas and bloating. But keep in mind that if they do have physiological effects, these may not always be good effects. Some may, at least in theory, overstimulate the immune system or adversely affect metabolic pathways such as carbohydrate metabolism. If you are immune-compromised, have certain bowel problems or are seriously ill in other ways, avoid probiotics unless your doctor has okayed their use. Probiotics should be used cautiously by pregnant women, infants and young children and never given to premature infants."
http://www.berkeleywellness.com/suppleme...s-and-cons
http://www.everydayhealth.com/digestive-...ogurt.aspx