As summer winds down and we move into fall and cooler weather, we also move into cold and flu season. It’s not the temperature that brings on the coughs and sniffles, it’s that we have more opportunities to pick up germs as we spend more time inside with other people (and our kids are back in school and bring home even more germs to share with the rest of the family).
So how can we stay healthy through the cold months? Hygiene and cleanliness are certainly the first line of defense, but we can also reinforce our own internal systems to withstand any tiny invaders that get past our hand sanitizer. Good nutrition in general will certainly strengthen our resistance to them, but maintaining a healthy gut may be the most important way we can help avoid illness.
Our bodies - our digestive systems in particular - are hosts to trillions of microbial cells, collectively called the microbiome. Ever since we discovered that they were there we have been trying to kill them off. Sanitation has obviously been one of the most beneficial discoveries for human survival, and yet it turns out that not all of our microscopic passengers are bad for us. In fact we can’t survive without many of them. Good bacteria are key to digesting food and perform many essential functions for us. We are only just beginning to learn the extent of their effects on us, but it is estimated that 70-85% of our immune system is controlled by the microbes in our digestive system. The gut is the gateway between the outside world and our internal systems. We accidentally ingest small amounts of potentially bad agents on a regular basis, but the good bacteria in a healthy microbiome will fend off bad bacteria and viruses that find their way in .
So how do we keep our microbiomes happy? By populating our guts with both the good bacteria and the things the good bacteria like to eat (so they’ll stick around). Eating fermented foods is the perfect way to do both things! Some of the good bacteria that our guts need are the same ones that perform fermentation for us, so when we eat fermented foods we consume the beneficial microbes and their food.
In addition to delivering helpful microbes to our guts, fermented foods have the additional benefit of containing nutrients that are more bioavailable. During fermentation the living bacteria break down food components, making the nutrients easier to absorb.
Fermented foods are delicious and among the healthiest gifts you can give your digestive and immune systems. Find these great foods in the refrigerated section of your local store, and check for the “live cultures” statement on the label. Or learn to make your own sauerkraut or kimchi! There are many great books that teach fermentation, or look for a class near you.
Have a safe and healthy autumn! De Kivit S, Tobin MC, Forsyth CB, Keshavarzian A, Landay AL. Regulation of Intestinal Immune Responses through TLR Activation: Implications for Pro- and Prebiotics. Frontiers in Immunology. 2014;5:60. doi:10.3389/fimmu.2014.00060