The Microbiome and Health

What is Microbiome?

Consider a crowded city on a weekday morning, with people trying to get to work or appointments. Imagine this on a microscopic scale, and you’ll get a sense of what the microbiome within our bodies looks like, with trillions of microorganisms (also known as microbiota or microbes) from thousands of different species. These involve fungi, parasites, and viruses in addition to bacteria. These “bugs” coexist comfortably in a healthy person, with the greatest numbers occurring in the small and large intestines, but also throughout the body. Since it plays so many important roles in facilitating the smooth daily operations of the human body, the microbiome can sometimes be  referred to as a supporting organ.

Each individual has a microbiota network that is completely unique to them and is defined by their DNA. Microorganisms are first encountered as an infant, in the birth canal during labor, and in the mother’s breast milk. The microorganisms to which the infant is exposed are solely determined by the species contained in the mother. Later on, exposure to the environment and diet will alter one’s microbiome, making it either beneficial to one’s health or putting one at risk for disease.

Microbes that are both beneficial and potentially harmful make up the microbiome. The majority are symbiotic (meaning they support both the human body and the microbiota) and a small number are pathogenic (promoting disease). Pathogenic and symbiotic microbiota coexist peacefully in a safe body.

Dysbiosis happens when the equilibrium is disrupted, which can be caused by infectious diseases, certain diets, or long-term use of antibiotics or other bacteria-killing drugs. As a consequence, the body’s susceptibility to disease could increase.

How Microbiomes Benefit Your Health ?

Microbiota boost the immune system, break down potentially harmful food compounds, and synthesize vitamins and amino acids such as B vitamins and vitamin K. The main enzymes that are necessary for us to make the vitamin B12, for example, are only found in bacteria (not plants or animals).

Sugars, including table sugar and lactose (milk sugar) are rapidly absorbed in the upper portion of the small intestine.  More complex carbohydrates like starches and fibers are more difficult to digest and can end up in the large intestine. The microbiota contains important digestive enzymes that aid in the breakdown of these substances.

Additionally, short chain fatty acids (SCFA) are generated when indigestible fibers are fermented, and they can be used by the body as a food source as well as play a role in muscle function and probably the prevention of chronic diseases including cancer and bowel disorders.

SCFA have been shown to be effective in the treatment of ulcerative colitis, Crohn’s disease and antibiotic-associated diarrhea in clinical trials.

A healthy person’s microbiota can also protect them from pathogenic organisms that enter the body by consuming or eating infected water or food.

Prevotella, Ruminococcus, Bacteroides, and Firmicutes are large families of bacteria living in the human gut. The anaerobic bacteria Peptostreptococcus, Bifidobacterium, Lactobacillus and Clostridium live in the colon, which has a low oxygen atmosphere.

These microbes are thought to prevent harmful bacteria from overgrowing by vying for nutrients and attachment sites on the mucous membranes of the intestine, which is a major site of immune function and antimicrobial protein development.

Probiotics role in the microbiome 

How do we ensure that we have enough or the right types of microbiota if they are so important to our health? Probiotics may be common to you, and you may even be using them. These are either foods that naturally contain microbiota or supplement pills with live active bacteria that are marketed to help with digestion.

Sales of probiotic supplements surpassed $35 billion in 2015, and are expected to reach $65 billion by 2024. They are part of a multibillion-dollar industry that’s constantly changing in response to new studies.

While published research is contradictory, Dr. Allan Walker, Professor of Nutrition at Harvard Chan School of Public Health and Harvard Medical School, claims that probiotic supplements can be beneficial in some circumstances.

He also mentions instances where probiotics may be beneficial, such as minimizing the severity of diarrhea following pathogen exposure or replenishing normal bacteria in the intestine after a patient has taken antibiotics. “These are all situations where there is a disruption of equilibrium within the intestine,” Walker stresses.  If you’re dealing with a stable adult or older child who isn’t on antibiotics, I don’t believe that giving them a probiotic would make a significant difference in their overall health”.

Probiotics are not supervised by the Food and Drug Administration because they are supplements rather than foods. This means that a probiotic pill may not contain the quantities specified on the label or even guarantee that the bacteria are alive and active at the time of use unless the supplement company voluntarily discloses details on safety, such as bearing the USP seal, which offers standards for quality and purity.                                                       

Does your diet affect your microbiome?

Diet, in addition to family genes, climate, and drug usage, has a significant impact on the types of microbiota that reside in the colon.  All of these factors combine to produce a microbiome that is unique to each person. The type and amount of microbiota in the intestines are influenced by a high-fiber diet in particular.

Enzymes from the microbiota in the colon will break down and ferment dietary fiber. Fermentation results in the release of short chain fatty acids (SCFA). This reduces the pH of the colon, affecting the microbiota present and their ability to thrive in this acidic environment.

Some dangerous bacteria, such as Clostridium difficile, are inhibited by the lower pH. SCFA are being studied for their wide-ranging health effects, such as stimulating immune cell function and maintaining normal blood glucose and cholesterol levels.

Inulin, resistant starches, gums, pectins, and fructooligosaccharides are examples of indigestible carbohydrates and fibers that endorse increased SCFA levels. Since they feed our beneficial microbiota, these fibers are often referred to as prebiotics. While prebiotic fibers can be found in supplements, prebiotics can also be found naturally in a variety of foods.

Raw versions of garlic, onions, leeks, asparagus, Jerusalem artichokes, dandelion greens, bananas, and seaweed include the largest numbers. Prebiotic fibers can be found in a variety of foods, including fruits, tomatoes, beans, and whole grains including wheat, oats, and barley.

Be aware that consuming a lot of prebiotic foods, particularly if you start eating them all at once, can cause gas production (flatulence) and bloating. Individuals with gastrointestinal sensitivities, such as irritable bowel syndrome, should start with small quantities of these foods to see how they respond. Tolerance can improve with continued use, resulting in fewer side effects.

If you don’t have any food sensitivities, it’s important to transition to a high-fiber diet gradually because a low-fiber diet will reduce the amount of beneficial microbiota while also encouraging the growth of pathogenic bacteria that thrive in a less acidic setting.

Probiotic foods contain beneficial live microbiota, which can change one’s microbiome further. Fermented foods such as kefir, yogurt with live active cultures, pickled vegetables, tempeh, kombucha tea, kimchi, miso, and sauerkraut fall into this category.

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