From a Scientific American online release:
One of the immune system’s jobs is to protect us from harmful bacterial. And the beneficial organisms that we refer to as probiotics contribute to this effort in a number of ways. In the gut, a robust population of beneficial bacteria can help crowd out harmful bacteria, making it harder for them to thrive. In addition, probiotic bacteria can influence the activity of our own immune cells, regulating inflammation, barrier function, and cell-to-cell signaling.
One way to foster healthy intestinal bacteria is to eat more of the foods these bugs like to eat—namely, fiber. Increasing your intake of plant fibers from vegetables, fruits, legumes, whole grains, nuts, and seeds is like filling a bird-feeder with the kind of seeds that the beautiful songbirds you want attract like best. If you feed them, they will come!
And if we want to attract a lot of different types of songbirds—er, bacteria—then we want to put out a variety of foods. That means you don’t just want to get all your fiber from a single source, such as a fiber supplement. You want to get it fiber from lots of different kinds of vegetables, fruits, legumes, grains, nuts and seeds.
To read more: https://www.scientificamerican.com/article/are-probiotics-safe-for-your-immune-system/?utm_source=newsletter&utm_medium=email&utm_campaign=weekly-review&utm_content=link&utm_term=2019-11-13_top-stories&spMailingID=60991971&spUserID=MjUxMzc4MzQ1MzMyS0&spJobID=1761811419&spReportId=MTc2MTgxMTQxOQS2