Follow Your Gut

BY BRIANNE COHEN Gut

Bacteria, viruses and fungi…oh my! Hundreds of trillions of these microbes live in the human gut; not exactly as part of the body, but in a symbiotic relationship with it. This ecosystem of the digestive tract and the microbes it hosts is called the gut microbiome.

Hippocrates, the father of modern medicine, reportedly stated that “all diseases begin in the gut.” Though nobody knows for sure that he said these words 2,500 years ago, it’s true that a flourishing microbiome is key to good health. According to researchers at U.C. Davis, microbes are integral to the basic functions of digestion and nutrient absorption, as well as bolstering the body’s defenses against disease, including cancer and obesity. A healthy microbiome can even influence mental health, via a system called the gut-brain axis.

Each of us possess our own unique microbiome. Development begins at birth and is impacted by a host of factors, including where you live, your race and socioeconomic status and, especially, what you eat. A breast-fed infant develops a different microbiome than a formula-fed infant! All this individuality accounts for our varying reactions to food and medication.

As long as the gut microbiome is in homeostasis - with beneficial bacteria flourishing and pathogen growth suppressed - the body can thrive. Problems arise when there is an overgrowth, or disproportionate amount, of microbes. Imbalances can occur as a result of medication, illness or excessive dietary sugar, and can wreak havoc on your health.

Fermented foods have been around for thousands of years, in every corner of the world. The ancients used fermentation as a food preservation method. The concept is simple: raw ingredients, like dairy or vegetables, are combined with microorganisms, like bacteria or yeast. As the food ferments, beneficial bacteria flourishes and suppresses the growth of pathogens. When we eat naturally fermented foods with live or active cultures, we also reap the benefits. The very same chemical processes that quash harmful microbes in food also impede their overgrowth in our gut.

Cultured food is also fermented but differs in that a starter culture is used to initiate the fermentation process. A starter culture is a preparation consisting of specific microbes in known proportions. One example is sourdough starter, which is used when making sourdough bread. Even though the dough is fermented, heat will destroy the bacteria during the baking process. Despite this, sourdough bread is considered healthful because the initial fermentation process makes nutrients more bioavailable.

Fermented foods should be eaten daily! Luckily, there are many naturally fermented foods to choose from. Some examples are:

Fermented dairy products: yogurt, kefir and traditional buttermilk. Some cheeses are also fermented. Look for unpasteurized varieties that have been aged for six months or more, including feta and parmigiana.

Fermented soy products: tempe and miso Probiotics are live microorganisms that, under the right conditions, take root and flourish in the digestive tract. Certain strains of probiotics work in specific ways. For example, a course of antibiotics indiscriminately targets both pathogens and beneficial bacteria in the gut. In this case, the probiotic Lactobacillus can help prevent antibiotic-associated diarrhea. Likewise, the strain Saccharomyces boulardi can help prevent Clostridium difficile (C-diff), also associated with antibiotic use. This type of targeted supplementation helps bolster healthfulness by keeping bacteria in balance.

Should your microbiome require assistance, there are an endless array of probiotic supplements ready to come to the rescue. Global sales of probiotics are expected to reach about $70 billion by 2023.

Are these products really a cure-all, or can we do better by changing what we eat? Research shows that a robust gut microbiome supports health, but there is scant evidence that probiotic supplements benefit healthy individuals, according to a study published in the journal Genome Medicine. Despite these findings, many people buy the products, relying on marketing hype that promises improved digestion or immunity. Even if a formulation contains active cultures, there is no assurance that they will thrive in the gut. That’s why tweaking one’s diet to include pre- and probiotic foods is the best way to support a healthy microbiome.

Fermented and cultured foods are great sources of probiotics. Here in the U.S., the most-widely recognized probiotic food is yogurt, but its less well-known cousin, kefir, provides a more potent source. Other fermented foods include kimchi, sauerkraut, miso and tempe, as well as the beverages kombucha and traditional buttermilk, which has earned the moniker “Grandma’s probiotic.” Always look for the words live and active cultures on the label.

Prebiotics are just as important to microbiome health. These are non-digestible fibers that pass through the stomach and settle in the large intestine. Once there, prebiotics work to maintain the intesti-

nal walls, which provide an optimum growing surface for probiotics. Not all dietary fiber is prebiotic, nor is all prebiotic fiber alike. For example, barley and oats are high in beta-glucan, fruit contains pectin, onions and Jerusalem artichokes are rich in inulin, and bananas and legumes contain resistant starch. All of these are different types of prebiotic fiber, and they each stimulate microbial growth. Unfortunately, the Standard American Diet is sorely deficient in fiber, with about 90 percent of both adults and children consuming less than the recommended 25 to 38 grams per day for women and men, respectively. Increased fiber consumption sustains a healthy microbiome and is best attained by eating a wide variety of whole, high-fiber foods. Many people recognize the health benefits of probiotics but are unaware that prebiotic fiber is also necessary. Without this fiber, the microbiome cannot flourish.

Postbiotics are the current focus of gut health research. To best understand them, it helps to visualize the game of Pacman. In this analogy, probiotics are the yellow munchers and prebiotics are the little white pucks. (Quick trivia: Pacman was originally called Puckman). As we know, the muncher eats as many pucks as possible. What we don’t see in the game are the by-products of all this munching. These by-products are called postbiotics, and they are potent compounds. Postbiotics have anti-inflammatory properties and provide essential nutrients like vitamin K, amino acids and a host of B vitamins, as well. We will be hearing a lot more about the benefits of postbiotics in the future.

Gut health is all about balance. Even “good” bacteria can experience overgrowth and throw the microbiome out of whack. If you take probiotic supplements, moderation is advised. However, do not bank your health on them; food sources of both pre- and probiotics are better processed and utilized by the body.

Support your gut with a diverse diet, abundant in fresh, raw fruits and vegetables, as well as a variety of whole grains. This will encourage your microbiome to flourish and thrive! Get your probiotics from regular consumption of cultured and fermented foods. Allow your body to do its job with healthy food, and you will reap the benefits.

Cooking does kill microbes, and this holds true for baking, pasteurization or any heat process. However, previously fermented foods like sourdough bread still have health benefits. During the proofing process, bacteria from the starter culture partially breaks down nutrients, making them more bio-available and the resulting bread easier to digest.

It’s true that wine is fermented! The fermenting microbes convert the grape sugars into alcohol, transforming the juice into wine. A recent study published in Food Microbiology found that probiotic strands of bacteria were able to be isolated in red wine. An earlier study published in The American Journal of Clinical Nutrition showed that moderate consumption of red wine contributes to a larger percentage of beneficial gut bacteria. All this, and antioxidants, too!

While oats are a superlative source of prebiotics, it is only one type of non-digestible fiber. Different strains of probiotic bacteria require specific types of non-digestible fiber to help create a diverse range of postbiotic metabolites! This is why eating a variety of fiber sources is important. Your diet should include an array of whole grains, as well as fruits and vegetables, preferably eaten raw.