Gut microbiome researcher and trained chef Emily Leeming is a fan of high-fiber pumpernickel bread.Bree DunbarGut health is a key cornerstone of our overall health as it can affect many bodily systems.A diet high in fiber, fermented foods, and polyphenols can help support a healthy gut microbiome.Emily Leeming, a gut health expert and dietitian, sees her breakfast as a chance to boost her fiber intake.A gut health scientist and dietitian shared the two breakfasts she often eats to help boost her gut microbiome.Gut health is a key cornerstone to overall health because it is thought to influence everything from the immune and endocrine systems to the brain, Emily Leeming, a gut microbiome researcher at King's College London and a former private chef, told Business Insider.