35 Powerful Foods That Feed the Good Bacteria in Your Gut

2. Onions: The Digestive Enhancer

Onions are an incredibly rich source of prebiotic fiber, making them one of the best foods for feeding beneficial gut bacteria. They contain fructooligosaccharides (FOS), a specialized fiber that nourishes probiotic strains like Bifidobacteria, helping them thrive and outcompete harmful bacteria. FOS also enhances the production of short-chain fatty acids (SCFAs), which help maintain gut lining integrity, reduce inflammation, and promote overall digestive comfort. Onions also boast powerful antioxidants and flavonoids, particularly quercetin, which has been shown to reduce oxidative stress and support gut barrier function. This is especially beneficial for people who experience digestive discomfort, bloating, or food sensitivities, as onions help soothe the gut lining and promote regular digestion. For maximum gut-healing benefits, incorporate both raw and cooked onions into your diet. Raw onions contain higher concentrations of prebiotics, while cooked onions are easier to digest and still provide gut-friendly benefits. Add them to salads, stir-fries, soups, or roasted dishes to support gut balance and microbial diversity.