10 lessons from "The Good Gut"

​If you eat, I recommend you read this post, or this book! Authors Justin and Erica Sonnenburg of Stanford University explore the role the microbiota has in determining whether we are healthy or sick, fit or obese, happy or sad. Read on for 10 things I learned and think you should know so that we can all take better care of ourselves and our children.

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 1. We all have a microbiota that we should care about. Trillions of bacterial microbes find homes in our ears and mouths, on our skin, and in every other orifice on our bodies. Most of them live in our digestive tract, or gut. Many of these microbes are beneficial and essential for our health (like strains of Lactobacillus and Bifidobacterium), and some are pathogens (like Salmonella, Vibrio cholera, Clostridium difficile). We have no choice but to coexist with all of them, so it is important we establish a symbiotic alliance with them.

Your microbiota is not just a collection of loitering bacteria. These microbes have important biological tasks like tuning our immune system, helping us fend off disease causing bacteria, and regulating our metabolism. The science is showing that these microbes can profoundly change the trajectory of our health, for better or for worse. In mice studies, researchers have found that when implanting the microbiota of obese mice into lean "germ free" mice with no previous microbiota, the lean mice began to gain weight, even with their diet and exercise controlled. Studies also demonstrate that children with Autism Spectrum Disorder typically have a gut microbiota that deviates from what is considered normal. There is also a "gut-brain axis." The state of our microbiota has implications far beyond the gut. 

2. Your microbiota is an ecosystem where diversity matters, a lot. A variety of microbe species is your best defense against system collapse. If species are lost, a variety of unfortunate things can happen: your gut may not be able to absorb the nutrients it needs, your immune response could go into hyper-drive and cause autoimmune responses, or a pathogen could opportunistically invade and take over.

A number of factors lead to microbiota diversity loss. First, a diet lacking consumption of fibrous plants and food-borne microbes (the good kind from fermented foods). If you eat lots of pizza, fries, and processed foods, you will not be feeding the species of microbes that thrive on more nutritional food, and they will be relegated to feed on intestinal mucus (which can cause a variety of issues) or even face extinction. Second, antibiotics decimate the microbiota. While these medications usually do take out the bad guys, they also "set fire" to our ecosystem. This cripples our resident beneficial microbes, and only a few things are left to survive. A microbiota with fewer members is at much higher risk of getting overcome by even a small dose of bad pathogens.

Luckily, research shows the microbiota has the potential to adjust quickly to diet changes. So, over time, you can re-build your bacterial army by eating naturally fermented live cultures from yogurt, pickles, sauerkraut, kimchee, miso, tempeh, and kombucha, as well as consuming lots of foods high in dietary fiber. The microbes we want to thrive love to feed on complex carbohydrates from fruits, vegetables, legumes, and unrefined whole grains. Time to spend way more time in the produce section, and forego the bakery.

3. Our microbiota is constantly talking with with the part of the immune system located in the intestine. These "conversations" help our body discriminate between harmless foreign entities like a cashew, and harmful ones like Salmonella from contaminated meat. Obviously, we want our immune system to be able to respond accordingly. The microbiota helps train the immune system to build these distinctions, and instruct the systemic immune system that circulates our whole body on what to do. So, the gut microbiota pretty much operates the "dial" that controls the sensitivity or responsiveness of the entire immune system. Having this capability means that the gut could also misdirect the immune system. If messages are misinterpreted, the immune system may respond too fast or too vigorously. This is why auto-immune responses happen.

4. As our environment and food become more sanitized, we lose exposure to the microbes we need to occupy our immune system, translating into immunological problems. Most microbes are not intended to cause harm, but they will "tickle" the immune system. This revs up our "immune engine" without creating a noticeable or harmful response. Mini immune responses are part of maintaining a healthy immune system, and they depend upon regular interaction with microbes.  If we bathe in anti-bacterial soap and use hand sanitizer all the time, we encounter fewer microbes and reduce our immune system's workload. So, it is beneficial for your kids to play in dirt (that is not chemically treated), to have a dog, and to go easy on the Clorox and Dial.

5. The nurturing of the microbiota begins at birth. A vaginal delivery is ideal for jump-starting a child's microbiota health, as it exposes the infant to the set of bacteria nature intended. Breastfeeding is also invaluable, as it offers both prebiotics and probiotics from the mother that help nurture a healthy microbiota in a growing child. Probiotic supplementation can be helpful for infants who were born prematurely or via c-section (but be sure to speak with a pediatrician first).

To continue development of our kids' healthy gut community, it is critical we instill lifelong healthy eating habits in our children the moment we wean them to eating solid foods. The authors introduced their children to vegetables before fruits, and to real foods like oatmeal and meat. They discussed with their kids the importance of becoming "big and strong." They explained to their kids that the microbes in their colon that keep them healthy were "counting on them to send veggies down their way." Eating healthy food was the only option in their house. An example of a simple healthy modification you could make for your kids is nut butter sandwiches on whole wheat bread with fresh strawberry slices instead of jelly. Another, adding black beans to cheese quesadillas for extra protein and fiber. The book offers more menu ideas. The point is, the better you can start things off from the very beginning, the easier it will be for your child to maintain these habits and long-term good health.

6. You actually have a "gut-feeling," this is not just metaphorical. Your microbiota and brain are connected by an extensive network of neurons and a highway of chemicals and hormones that send messages. Communication between the brain and microbes on this highway travels both ways. So, microbes can affect mood and memory, and stress or depression can impact which microbes live in the gut. Depending on which types of microbes reside in the gut, the messages they send may also combine with a person's genetic predisposition to increase or decrease the chance that a behavior disorder manifests. Scientists are finding this link with ASD, schizophrenia, obsessive-compulsive disorder, and depression. This area of exploration is just opening, and looking very exciting!

7. Prebiotics are just as important as probiotics. Prebiotics are what feed the good gut bacteria. They are food-derived compounds that travel directly to the colon, and are fermented by the bacteria within the microbiota providing the nourishment to promote their growth and abundance. Inulin is the most common and commercially available prebiotic. It can be purchased as a supplement, but it is also naturally found in bananas, onions, Jerusalem artichokes (which I hear are super yummy!), garlic, leeks, and asparagus. When our gut bacteria ferments inulin, it produces short-chain fatty acids that can be absorbed for energy and protect our gut from inflammation. 

Probiotics are the "live cultures," or bacteria, found in fermented foods such as sauerkraut, cultured yogurt, kefir, miso, tempeh, kombucha, and kimchee. You can also purchase probiotic supplements. While many of this probiotic bacteria can survive in our gut, most are not well suited for the environment and they just pass through. Proponents of probiotics often recommend their regular consumption to ensure a steady stream of them. This can help "reinvigorate" our body's defenses against pathogens, especially in times when antibiotics may be needed. However, no human has the same microbiota, so predicting which strains of probiotic bacteria will be beneficial to each of us is difficult. It takes some trial and error.

8. Only you can keep your microbiota, and your child's microbiota, flourishing. Environment plays a huge role on our internal collection of bacteria, and we can shape that environment. Eating a highly nutritious and well-balanced diet is the best thing you can do. This means lots and lots of plants and fermented foods, every day. Long term dietary patterns are a major determinant of attaining and maintaining microbiota diversity. We can also strengthen our microbiota by encountering lots of microbes daily. Having a small garden or pots on your patio/deck is a great way to do this. Be sure to use organic soil free of herbicides, pesticides, and synthetic fertilizers. Encourage your kids to pull the weeds, play with the worms, or harvest the vegetables. Pets can also bring beneficial microbes they collect from outside into our homes. And we can also use less-toxic cleaners which will allow increased exposure to microbes, and may lessen the risk of a misfiring immune system. I now use Biokleen and Dr. Bronner's products.

9. You can assess the health of your microbiota. The biggest clue about what is happening to the microbiota is your stool. The ideal stool is smooth, soft, easy to pass, and comes out in one long snake-like piece. A lack of splash means you are on the right track! Additionally, you can have your microbiota tested. For $99 through American Gut, you can receive a sample kit, send in a sample, and get an idea of who is living in your gut. They even have package deals for multiple people. How cool! I have yet to do this, but plan on it.

10. Research is emerging, and much more is needed. But, it is clear that our bodies are complex ecosystems and all of its parts are interconnected. A disruption in the microbiota can cause a ripple effect through the whole body. Knowing this, we can make more informed choices of how we eat, what we pack in our kids' school lunches, what medications we take, and how we clean our homes in order to maximize the health and resiliency of our microbe residents, and ourselves.

Thanks for reading, and be well!

Resource: The Good Gut. Authors Justin Sonnenburg and Erica Sonnenburg. Forward by Andrew Weil.  Published 2015 by Penguin Press.