Yogurt

Yogurt (specifically the dairy kind) is rich in probiotics, which support your immune system and improve digestive health by maintaining levels of 'good bacteria in the gut. These good bacteria help break down lactose and improve symptoms of irritable bowel syndrome too. Besides supporting your digestive system, this will positively impact your brain, too. Scientific studies have shown a strong connection between gut health and brain health. That means, eating yogurt regularly can help with both cognitive function and mood.

Yogurt is probably the most popular probiotic and for good reason. It's made when good bacteria are added to milk, where they metabolize lactose to form lactic acid and other beneficial bugs. Look for yogurt labeled with the "Live & Active Cultures" seal, which guarantees 100 million probiotic cultures per gram. A quick look at the ingredients list will also show you if there are bacteria in the yogurt. Don't eat dairy? The probiotics in yogurt help digest some of the lactose (milk sugar) so if you're lactose-intolerant, you may be able to enjoy yogurt. Plus, many companies now make dairy-free and vegan yogurts that contain probiotics.