From Thyroid to Stress: 13 Hidden Reasons Behind Unexplained Weight Gain

Sometimes the problem starts in the gut. An overgrowth of bacteria in the small intestine can cause bloating, abdominal discomfort, diarrhea, and even sudden weight gain. The gut relies on a careful balance of beneficial and harmful bacteria, and when this balance shifts, digestion and nutrient absorption suffer. Treatment may include antibiotics and dietary changes to restore microbial harmony.