In order to understand why eating fermented foods is beneficial, we have to understand how they affect our bodies. There is a lot of talk these days about microbes and bacteria—how some of them are good, while others are not. The truth is that the human body has evolved over millions of years in the presence of microbes and has thus, developed a harmonious relationship with them. In fact, there are roughly 10 trillion cells in the human body, but our bodies host 10 times that amount of bacterial cells!
Microbes inhabit nearly every part of our bodies, with the exception of muscle tissues, the brain, and blood. They are found everywhere else. While it may sound creepy to have all of these organisms on us and inside of us, without microbes, we could not live! They help our bodies with many functions that are required to sustain life: they provide us with vitamins and minerals; they create an environment unfriendly to harmful microbes by essentially hogging all the nutrients or altering the environment; they regulate the functions of our digestive tracts, and help to strengthen our immune systems.
The immune system is one of the most complicated systems of triggers, responses, chemicals, and signals in our bodies. We are being constantly bombarded by microbes looking for a new host to multiply in and conquer. They attack from the air, our food, and our water. They are very opportunistic and will establish themselves anywhere they can find a suitable environment. For that reason, our friendly microbes act as obstacles to harmful microbes. Almost all microbes love mucus membranes (such as sinuses, gut, and mouth) and our skin. This is why we have billions of good bacteria at these most common points of entry—to keep harmful bacteria out.
Because this book focuses on food, we should discuss the major microflora of the gut. Our intestines host the most extensive populations of microbes in the body. They are broken into four groups, which will be discussed briefly. But, the intestinal flora serve as more than sentries: they also play very important roles in our daily lives.
We often think that the nutrients in the foods we eat are immediately broken down and absorbed after being dissolved by stomach acid. This belief isn’t quite accurate. Once the sludge of highly acidic stomach contents moves into the small intestine, the bacteria there go to work. They consume the acidic mush, and it is their by-products—the actual forms of nutrients our bodies require—which are absorbed. As the sludge moves through the small intestine, the pH rises and becomes less acidic. This creates a different environment for other microbes to perform their jobs. It is this highly specialized (and synchronized) process that produces the nutrients our bodies need.
But gut microbes do other things, too. Some manufacture vitamins (like the B-complex) that we cannot obtain any other way. They protect the intestinal lining from any invading harmful microbes. Some secrete antiviral and anti-inflammatory substances that assist our immune system responses. They can neutralize dangerous chemicals, such as nitrites, from food. And some even draw the calcium out of dairy products.
As mentioned earlier, the four main types of intestinal flora are Bifidobacteria, Lactobacilli, ingested microbes, and fungi. The first two groups are essential for good health, while the ingested microbes are often harmful. And the fungi, like yeast and mold, can be beneficial or detrimental, depending on their numbers and strains.
Bifidobacteria consists of about thirty species found extensively in the gut (as well as other places). They help prevent pathological (harmful) bacteria from colonizing the gut. They also regulate and bolster the immune system. Many fermented foods are rich in Bifidobacteria, such as kefir and yogurt, sauerkraut, and the beverage kombucha.
Lactobacilli are found in every mucus membrane and are also very prevalent in the small intestine. They produce lactic acid, and for this reason, some strains populate the vagina: they keep the pH low (acidic) to create an unfriendly environment for harmful and virulent microbes. But, Lactobacilli do more than just produce acid. In the gut, they produce antiseptic substances that limit the presence of harmful microbes. They also produce proteins which are involved in the immune response in that they seek out and destroy foreign microbes. Many fermented foods contain Lactobacilli.
Ingested microbes can include any number of harmful bacteria from the environment or from improperly cooked or stored food. In individuals with healthy populations of microflora, these pathogens cannot increase to such numbers to pose a threat. However, in individuals with weak immunity or poor microflora, these nasty microbes can establish colonies and cause serious health problems.
Many fungi are fine in balanced amounts. They are found everywhere in nature. Some strains of yeast are known to pose health risks, but others are beneficial, like the strains that ferment food. Molds are also fungi, and they often reside on food and plants. Some molds are famous for spoiling foods, while others, like Penicillium are beneficial for their antibacterial properties. Some cheeses get their flavor from beneficial molds. Some molds also produce the chemicals that can be used to make bread.
Now that you understand what is present in your gut, let’s take a look at what can upset the balance. One of the biggest challenges for our natural systems come from an invention intended to help: antibiotics. Antibiotics are not selective, and they will kill any susceptible microbe. If you take amoxicillin for a sinus infection, the same antibiotic will also kill your gut flora, which will throw your internal ecosystems off balance. Have you ever noticed having an upset stomach, gas, and/or diarrhea when you take antibiotics? Guess what—your intestinal microflora are out of balance! The best thing you can do is to resupply your body with “good” microbes by eating foods rich in Bifidobacteria and Lactobacilli. This will prevent any opportunistic and harmful bacteria from flourishing, in addition to making your belly feel better!
An improper microflora balance can also cause vitamin and mineral deficiencies, affecting vitamins A, B, C and D, essential fatty acids, magnesium, zinc, and calcium, just to name a few. Fermented food not only offers beneficial microbes, but it is also rich in the nutrients and minerals that our bodies require to function healthily.