Gastroenterologist Dr. Palaniappan Manickam emphasizes that sleep is crucial for gut health, not optional. He explains that sleep is an active phase for metabolic repair, hormone resetting, and gut healing. Poor sleep disrupts gut microbes, reduces beneficial bacteria, increases hunger, and raises risks for diabetes, obesity, and heart disease. Dr. Manickam advises prioritizing sleep, suggesting that fixing sleep quality is fundamental for diet and exercise to be effective.