"Feeding Microbes"

We are not human. Well, we are a little bit human; 10% to be exact. The other 90% of us is made up of microbes. I needed to unlearn much of what I thought I knew about human life after I researched gut health and the human microbiome. (The microbiome is the collective term for all the microorganisms that colonize the human body.) The term “gut microbiome” refers to the trillions of microorganisms and their genes that live in your colon. Were you aware you do not live alone? You are a type of superorganism, a collective of species.

Where did all these microorganisms come from? We’ve been collecting them since birth. Babies born vaginally acquire vaginal microbes from their mother. Then, if a baby is breast-fed, he or she receives daily doses of health-promoting microbes. Interestingly, breast milk contains not only food for the infant, but it contains “food” for the gut microbes! Human milk oligosaccharides (HMO) are a substantial component of breast milk. Babies are unable to digest these complex sugar molecules, so the HMOs pass through to the digestive tract, where they feed beneficial microbes and also help to eliminate pathogenic bacteria. [1] Since these HMOs are not even digestible by babies, they are absolutely designed for the microbes. Human milk is perfectly formulated!

There are 100 trillion microbes, most of which are bacteria, living in you. We also play host to viruses, fungi, and archaea. These microbes are not living rent-free in us. We enjoy a symbiotic relationship. Some of the important functions they have include making “Vitamin B12, which is essential for our brain function” (made by Klebsiella) and “Bacteroides shapes the intestine’s wall.” [2] Other benefits microbiotas bestow are to aid digestion of fibrous food, regulate our metabolism, detoxify harmful chemicals we ingest, and regulate our immune systems.

Humans depend on the microbiome for the critical function of improving their immune system. So everyone stays happy and healthy if functions are normal. However, if imbalances occur in microbiota, it can contribute to the development of disease (pathogenesis). These diseases include “inflammatory bowel disease, antibiotic-associated diarrhea, and asthma, and [microbes] may even play role in autism spectrum disorders…and Parkinson’s disease.” [3] 

Researchers are currently exploring the question of whether a proper balance in the microbiota determines mental health. A link to depression from an imbalance has already been established. Drugs routinely given for depression boost serotonin, previously thought to reside in the brain. Today we know that “95% of the body’s serotonin is actually contained in specialized cells in the gut.” These cells are influenced by what we eat as well as chemicals released from gut microbes. Therefore, gut microbes “mediate how food affects mental well-being and important brain functions.” [4]

Formerly, the brain was considered entirely independent of the digestive system. Now, however, scientists “know that these two organs are intricately connected with each other. Recent studies suggest that in close interactions with its resident microbes, the gut can influence our basic emotions, our pain sensitivity, and our social interactions!” [5] The phrase to base a decision “on gut feelings” is more biological accurate than we may have imagined. The communication between the gut and the brain is a contributing factor in making some of our decisions.

The mind-gut connection is a matter of much curiosity, research, and debate. The idea that microbes are dictating our mood, behavior, and even affecting our decisions has not been readily accepted. It sounds like science fiction and leaves us with philosophical questions about our personhood. It was news to me that my gut microbes were “talking” to my immune system—or more scientifically, communicating chemically.

“The gut is connected to the brain through thick nerve cables that can transfer information in both directions and through communication channels that use the bloodstream.” [6] Some of the gut signals to the brain generate gut sensations such as the fullness after a meal, nausea, and even feelings of well-being, Some familiar phrases turn out to actually accurately reflect our gut’s response to the messages our brain sends back such as “butterflies in my stomach” or “my stomach is tied in knots.”

A strong correlation has been established between a permeable gut (“leaky gut”) and depression. In these cases, the bacterium leaks out into the bloodstream. Even more serious mental disorders are linked to the microbiome. For example, schizophrenia seems to be induced by having a lack of normal gut bacteria, thus affecting brain development. Therefore, both your brain and mood are impacted by your microbes. [7]

Many of the suggestions having a consensus on how to improve the gut microbiome are already included in guidelines for general good health. That is, get sufficient sleep, keep hydrated, and eat a wide variety of fruits and vegetables. There are some foods which are especially beneficially for gut health, though. One is turmeric, due to its main component, curcumin which exhibits microbiome balancing activity. Also, food containing probiotics such as plain yogurt adds virus-fighting good bacteria. Other ingredients for increasing gut health: probiotics, B-complex vitamins, vitamins C, D, and K2, as well as Zinc, selenium, and Green Tea (to help bring zinc into the cell). [8] 

It is not only important to consider what we do consume, it is essential to avoid certain things. For example, antibiotics can decimate helpful bacteria populations because they are broad spectrum, meaning they target broad swaths of normal microbiota. Antibiotics create an imbalance by suppressing the immune system’s ability to produce vitamin B, and they also reduce the protective mucous layer of the gut lining which protects it from potential antigens. Also harmful to gut health are processed foods with a lot of sugar because these feed pathogenic bacteria. Sugar-loving microbes in the gut along with the carbs that feed them can fuel colon cancer. Chlorinated or fluoridated water also negatively impacts our microbiome. Of course, we need to shun agricultural chemicals, especially glyphosate. Those who eat meat will want to avoid conventionally-raised meats where the animals are fed antibiotics and eat grains sprayed with glyphosate. For some, dietary changed may be required in order to restore a balanced and thriving colony of microbes that works in tandem with our human cells.

Gut health is not only affected by food choices. Stress also can impact your microbiome. Of course, long-term stress is harmful since it dramatically reduces the balanced biodiversity. Yet even stress that lasts a couple of hours begins to impact your microbiome. Stress also reduces the beneficial intestinal mucus secretions, increases intestinal permeability, and enables the expression of virulent bacteria! To improve gut health, exercise and try to avoid stress-inducing situations.

Maintaining a healthy gut is undoubtedly more challenging today than ever before. Within the last century, our diets have changed from food mainly sourced from local farms to overly-processed food. There are more environmental toxins to deal with now, too. And the prolific use of antibiotics is a major problem since they wipe out friendly gut flora. Another concern is that many people are unlikely to get good nutritional advice from their physicians. This is due to corporate medicine requiring doctors to see a certain number of patients per hour, leaving no time for nutritional counseling.

Even if the doctor has a thorough understanding of nutrition and suggests a life-style change, many patients are resistant—not willing to give up their French fries and treats. They may want the easy way out and believe that a pill is all they need. In this regard, Thomas Edison had a vision for what medical practice should be: “The doctor of the future will no longer treat the human frame with drugs, but rather will cure and prevent disease with nutrition.” Fortunately more doctors are embracing the understanding that health equals good nutrition and are adding dieticians to their clinical staff.   

No pill is going to solve pervasive and worsening health conditions. We need to begin to eat healthier which means consuming fiber for our gut health. Granted, there are fiber supplements available for occasional use if one has a specific, temporary problem, but they should not be relied upon as a source of fiber. Supplements don’t contain the same antioxidants, vitamins, and minerals as whole food does.

Hopefully, we will act upon the fact that our gut is not an isolated organ, but part of our whole system. Then we can begin to address health concerns in a holistic manner. What we eat impacts everything from our toes to our brain. We absolutely need to eat well to feed not only ourselves, but to keep our microbiome healthy. If you’ve ever had cancer or some other serious disease, I know you’ve realized (as I do) that good health is a treasure. Mahatma Gandhi words are truth: “It is health that is real wealth and not pieces of gold and silver.”

 

1 M. Lawson, I. J. O’Neill, M. Kujawska, et al. Breast milk-derived human milk oligosaccharides promote Bifidobacterium interactions within a single ecosystem. ISME J 14, 635–648 (2020). https://doi.org/10.1038/s41396-019-0553-2

2 Alanna Collen, 10% Human: How Your Body's Microbes Hold the Key to Health and Happiness (New York, NY: Harper Collins, 2015).

3 Collen

4 Collen

5 Collen

6 Emeran A. Mayer, The Mind-Gut Connection: How the Hidden Conversation within Our Bodies Impacts Our Mood, Our Choices, and Our Overall Health (New York, NY: Harper Wave, 2018).

7 Mayer

8 “10 Research-Backed Ways to Improve Gut Health,” Medical News Today (MediLexicon International), accessed October 8, 2020, https://www.medicalnewstoday.com/articles/325293.