Occasional gastrointestinal symptoms are common in the otherwise healthy population. Most symptoms respond to dietary changes presumably via changes in the gut microbiota. Evidence shows that diet has a major impact on the gut microbiota and overall gastrointestinal health, and dietary interventions, such as consuming probiotics, especially Bifidobacterium, and the low oligo-, di-, and monosaccharide and polyol (FODMAP) diet, are recommended for different disorders. Physical activity may also improve the gut microbiota composition and appears to reduce digestive complaints, yet many studies analyzing the effects of diet and lifestyle are limited.