Probiotics 102: A “Deeper” Dive 2024 - Vitalitown Selfcare Center

In “Probiotic 101” we talked about the basics of what the microbiome was and what probiotics (and prebiotics) can do to support overall health. In this article, we are going to go a bit deeper into how this works and how (and what) you do can either support or harm the microbiome. A glossary of terms is included just to re-introduce and clarify some of the terms used.

The largest portion of the total microbiome is in the digestive tract, including the mouth. The skin has a large microbiome as well. The skin is actually the largest organ of the body, though we don’t often think of it as an organ! Finally, the vagina and placenta each have its own separate and unique microbiome.

Let’s look at the gut microbiome and what you can do—beyond taking probiotics—to KEEP that microbiome healthy so that YOU can stay healthy!

Glossary of Terms

Microbiome: The collection of microorganisms (bacteria, fungi, viruses, protozoa) found within the digestive system.
Inflammation: A normal and necessary part of the immune response which serves to alert the immune system of an infection or injury. The problem is not inflammation—the problem is when control of inflammation is lost.
Flora: Describes all the microorganisms in the gut.
Prebiotics: “Food” for the bacteria in the gut.
Probiotics: Live organisms that can provide health benefits when they colonize the gut.
Antioxidants: Substances found commonly in fruit and vegetables that “soak up” free radicals produced by cells as a normal consequence of normal metabolism. When free radicals are not absorbed, they can damage and kill the cells.

Supporting the Gut Microbiome

The gut microbiome can be almost as unique as a fingerprint! It can change, depending on diet, family history, environmental factors, age, culture, mental health, geographic location, and overall health. It can also change based on medication use.

Diet

The gut microbiome responds quickly to dietary changes—and there are distinct differences in the families of organisms found in the guts of vegetarians versus vegans versus individuals who eat both animal and plant products (omnivores).(1) Your diet is probably the single, most “controllable” factor for microbiome health. Taking a probiotic supplement can certainly help maintain a healthy gut microbiome—but taking a probiotic supplement without improving your diet won’t help much—because just as you have to properly feed your body, you have to properly feed your microbiome. The good news is that the same guidelines apply to a healthy body AND a healthy gut microbiome!

According to the Harvard School of Public Health, the single most important dietary factor in supporting a healthy microbiome is a high-fiber diet.(2) So, let’s dig a little deeper into the types of fiber found in various foods.

Eat Plenty of Fiber!

Broadly, food fiber—dietary fiber—can be divided into two types—fiber that is soluble in water and fiber that is insoluble in water.

Soluble fiber: turns into a sort of gel when it absorbs water and slows digestion. Can add bulk to stool, helping to prevent constipation and keep bowel movements regular and comfortable.

Slowing digestion can be helpful for preventing spikes in blood sugar—and can be critical for people with diabetes. It is also important in helping to prevent Soluble fiber also helps lower LDLcholesterol and total cholesterol by binding to it and allowing it to be excreted.
Soluble fiber also is a source of prebiotics—basically, nutrition for the microbiome.
Soluble fiber helps in weight management because it keeps you feeling fuller, longer and tends to help you eat smaller portions.
Sources of soluble fiber include whole grains like oats, beans, seeds, berries, vegetables, and Examples of soluble fiber include inulin oligofructose, mucilage, beta-glucans, psyllium, wheat dextrin, pectin, and gums like xanthum and guar gums.

Insoluble fiber: retains water without dissolving in it—helps prevent constipation, may lower the risk of some bowel conditions including diverticulitis, and, along with soluble fiber, lowers the risk of colorectal cancer.(3)

Sources of insoluble fiber often overlap with those of soluble fiber. Often, the more insoluble fiber is on the outside, skin, or rind of the food, while the more soluble fiber is found in the “core”. Examples of insoluble fiber include lignans, cellulose, and hemicellulose.

Current recommendations suggest that women should eat at least 21-25 grams of fiber every day while men should eat a bit more and aim for 32-38 grams of fiber every day. To give you an idea of what that means, one bowl of whole grain cereal has about 5 grams of fiber while a whole banana has 3 grams of fiber. 2 slices of whole grain bread have 4 grams, 2 cup of brown rice has 3.5 grams, and 1 cup of cooked beans has about 15-20 grams of fiber, depending on the bean. 1 cup of oatmeal has 4 grams and ½ cup of peas has 4.4 grams of fiber. A ½ cup of spinach has about 2 grams of fiber and a ½ cup of “standard” mixed vegetables has about 4 grams of fiber.

Limiting Sugars

You’ve probably heard it all before—limit your sugar intake to stay healthy. People drink diet soft drinks and all sorts of foods with sugar substitutes and artificial sweeteners added. These sugar alternatives may increase the risk of diabetes and may, in fact, damage or alter the microbiome.(4)(5)

First, not all “sugar” is created equal! There is a big difference, for example, between the everyday understanding of sugar and the nutritional understanding of sugar.

The everyday understanding of sugar usually is about table sugar, the standard white crystals you would use in cooking, baking, or adding to your coffee or tea. That kind of sugar is made up of two molecules of what a chemist would call a sugar—table sugar is made up of one molecule of glucose and one molecule of fructose. The glucose molecule is what is meant when a doctor says they want to see your levels of “blood sugar”. The fructose molecule is also known as fruit sugar and is chemically different from glucose. Table sugar is known as a simple sugar—it is made of two different types of sugar.

Complex sugars—which make up starches, carbohydrates, polysaccharides, and others—contain long strings or chains of single sugar molecules often arranged as layered chains or complicated webs. This is the form of “sugar” found in whole foods, while processed foods often contain added simple sugars.

Complex sugars present much less of a problem for overall health, weight management, and the health of the microbiome than simple sugars do.

Why? There are several reasons, but here are the three considered the most important:

Complex sugars take longer to digest and are more slowly absorbed. This avoids high spikes in blood sugar levels AND avoids deep lows in blood sugar levels. Avoiding both the highs and the lows is thought to be the best way to reduce the risk of diabetes and heart disease.(6)
Complex sugars, found in whole grains, fruits, vegetables, berries and other whole foods, help you in maintaining a healthy weight and support weight loss.(7)
Complex sugars can help support and maintain the health and function of your microbiome.(8)

Feed Your Microbiome!

Prebiotics are food for your microbiome—and an excellent way of supporting your microbiome is by eating prebiotic rich foods—and by replenishing your microbiome either by eating fermented foods or by regularly with probiotics. Inulin, a soluble fiber, is one of the most commonly found prebiotics in foods. Another common food-sources prebiotic is fructooligosaccharide (FOS).

Prebiotic-rich foods include:

Chicory root. Chicory root is high in inulin. Inulin promotes the microbiome, supports the immune function of the microbiome, and helps your body absorb minerals.
Dandelion greens (especially in the spring—yes, go out onto a lawn and just harvest the leaves!). Dandelion greens are rich in inulin—and tea made from these greens have e been traditionally used as a spring tonic.
Jerusalem artichoke. This vegetable is also known as sunroot, or sunchoke and doesn’t look anything like a regular artichoke—it is a tuber or root plant like a potato, carrot, or beet. It also contains inulin. Other tubers that supply prebiotics are yacon and jicama roots.
Garlic, onions, and leeks are from the same plant family (Allium). Both have antibiotic (killing off harmful bacteria while leaving the healthy parts of the microbiome alone), anti-inflammatory, antioxidant, and blood lipid lowering properties. Both garlic and onions contain FOS and inulin.
Asparagus contains inulin, other sources of fiber, vitamins, and minerals.
Whole grains such as barley, oats, and whole wheat. These whole grains contain beta-glucan, a soluble fiber that has been linked to appetite suppression, microbiome support, improvement of cellular sensitivity to glucose, and support of thyroid function. Beta-glucan has also been linked to the reduction of blood cholesterol and sugar levels.(9)
Remember the old saying, an apple a day keeps the doctor away? It is not clear that this has ever been tested (!) but apples, eaten with the rind intact, are loaded with pectin, a substance that acts as a prebiotic but also is associated with weight loss, decreased inflammation, and increased production of the short-chain fatty acid, butyrate, that not only acts as a prebiotic but also appears to act as an ANTIbiotic against disease-causing bacteria.(10)

Takeaways

Your microbiome will help take care of you, but in return, YOU have to take care of your microbiome! Take care of your microbiome by regularly re-supplying it with probiotics, feeding it with fiber and prebiotics, and protecting it by limiting simple sugars like table sugar.