Probiotics are the good bacteria that colonize the gastrointestinal tract. They are easily outnumbered and taken over by pathogenic kinds of bacteria, yeast, and fungi leading to many health complications including leaky gut syndrome.
Proper gut flora maintenance is an absolute cornerstone of good health. It is important to constantly supply the gut flora with beneficial bacteria in the form of probiotics. To start with, there are many good probiotics you can find in pill form. It is important to try to find one that has at least ten billion species. You should take the probiotics on an empty stomach. When you take them with food, the active acid in your stomach will dissolve some of the active ingredients. You can take them either right before bed, or right as you wake up.
Our ancestors had diets rich in probiotics and never had to take any supplementation. They achieved this richness of bacterial cultures through fermented foods. Fermented foods are an ancient way to preserve harvest before refrigeration and were a daily addition to meals. You can find some fermented foods at the grocery as they are gaining in popularity. For example, sauerkraut from Germany, kimchi from Korea, and kombucha originally from China, yogurt, and kefir, are all rich sources of probiotics. Kim chi and sauerkraut are usually cabbage based but can include all kinds of vegetables. In fact, you can easily ferment any kind of vegetable you would like. You don’t have to have any starter bacterial culture, the natural bacteria in the air and on the food will help the fermentation process. If you are interested in at home fermentation, there are many helpful guides on the internet. Kombucha is a fermented tea drink that is easily brewed at home, but you do need a starter culture. The culture full of beneficial bacteria will consume the sweet tea until it tastes slightly sour.
All of these rich probiotic foods that were consumed daily added a large spectrum of bacterial species to our ancestor's gastrointestinal tracts. If you find these items at the market or are interested in making some at home, it will greatly improve your health.