Vitamin D
Vitamin D is best known for its role in bone strength and immunity, but it also appears to have a direct impact on your gut bacteria. One study in particular sheds light on this and shows that vitamin D can help heal your gut and improve digestive symptoms, such as bloating and abdominal pain.
The study showed that vitamin D supplementation significantly changed the composition of the gut microbiota, primarily by decreasing the relative abundance of Firmicutes and increasing Bacteroidetes.
L-Glutamine
L-glutamine is a nonessential amino acid, meaning your body can produce it and doesn’t need to get it from food. It’s an important fuel source for intestinal and immune cells, and research suggests it can help prevent and treat leaky gut.
Glutamine may boost the production of tight junction proteins, which protect the intestinal walls from permeability. One study found that when glutamine was combined with a low FODMAP diet for irritable bowel syndrome, it helped reduce bloating and diarrhoea in 88% of patients.
Probiotics
The bacteria that live in your gut — called your microbiome — are the foundation for a healthy digestive tract. But when you get a stomach virus, have diarrhea or take antibiotics, the bacteria can become unbalanced, leaving pathogenic or bad bacteria to outnumber the good ones. Probiotics can help replenish the gut flora and may also improve immune function.
Prebiotics
Prebiotics are food for the bacteria in your gut, and they help keep them healthy. They can be eaten in a variety of foods or taken as a supplement. Probiotics introduce new strains of good bacteria, while prebiotics nourish the existing microbes and support their growth. Prebiotics can also enhance immune system function, reduce inflammation and prevent gastrointestinal issues like constipation.
The best prebiotics are soluble fibers called inulin and fructooligosaccharides (FOS). Inulin-rich foods include chicory root, Jerusalem artichokes, onions and garlic. Foods high in FOS include bananas, asparagus and wheat bran.