What foods will help in increasing gut microbe
Foods containing probiotics such as yogurt, kefir, cottage cheese, cheddar cheese, sauerkraut, kombucha, pickled vegetables, kimchi, miso, and tempeh. Foods high in fiber are also important. Fiber can be found in whole grains, and vegetables and plants particularly in the skin like apples, berries, etc
Eat more fiber. That’s it. Probiotics are fine if you like it, but all you need to do is regularly provide the prebiotic that feeds the good gut bacteria (fiber) and the rest will take care of itself.
As stated by u/Baseball_bossman, fermented foods help increase microbiota.
Other than that and increasing your intake of plant-based foods for their fiber, resistant starch, prebiotic, and/or polyphenol content, there’s not much else you can do.