Thursday, December 20, 2018

What Are Prebiotics?

By now, most people are well-aware that foods rich in dietary fiber and the benefits of  probiotics offers a long list of benefits and are absolutely essential to overall health. Nonetheless, prebiotic foods are still largely under-appreciated and often lacking in the typical American diet. Unfortunately, this can result in serious issues like indigestion, inflammation, impaired immunity, weight gain and an increased risk for many chronic conditions.
While probiotic foods play a key role in gut health and overall well-being, prebiotics help “feed” the probiotics to bump up the health benefits even more. By pairing both together with a nutritious diet and healthy lifestyle, you can amplify the incredible health-promoting properties of these powerful ingredients.

 But what are prebiotics

By definition, prebiotics are a type of non-digestible fiber compound. Just like other high-fiber foods, prebiotic compounds pass through the upper part of the gastrointestinal tract and remain undigested because the human body can’t fully break them down. Once they pass through the small intestine, they reach the colon, where they’re fermented by the gut microflora. (1)
Prebiotics are best known as a type of dietary fiber called “oligosaccharides.” Today, when researchers refer to “fiber,” they’re speaking about not just one substance, but a whole group of different chemical compounds found in foods, including fructo-oligosaccharides, other oligosaccharides (prebiotics), inulin and polysaccharides.
Originally, prebiotics weren’t classified as prebiotic fiber compounds, but recent research has shown us that these compounds behave the same way as other forms of fiber. Today, prebiotic carbohydrates that have been evaluated in humans largely consist of fructans and galactans, both of which are fermented by anaerobic bacteria in the large intestine. (2)

Prebiotics vs. Probiotics vs. Postbiotics

So what’s the difference between prebiotics, probiotics and postbiotics and how they can each affect health?
Prebiotics are substances that are fermented by the beneficial bacteria in the gut and used as a source of fuel to help enhance gut flora health. Probiotics, on the other hand, are live microorganisms that can confer health benefits to the host ranging from improved immunity to better brain function. (3) Postbiotics, meanwhile, are the byproducts of bacterial fermentation in the colon.
To break down all the scientific jargon and put it simply, prebiotics “feed” the probiotics, or beneficial bacteria in your gut, and end up producing a byproduct called postbiotics. All three boast an extensive array of health benefits and work together to boost both digestive and overall health.

How Prebiotics Work Together with Probiotics to Improve Health

While probiotic benefits have become more widely known in recent years, especially with the growing popularity of fermented foods like sauerkraut, kombucha and kimchi, prebiotics still remain under the radar. All types of fiber that we get from eating whole, plant foods play a major role in nutrient absorption, gut and digestive health. Prebiotics, together with probiotics, open the door for heightened levels of health in general, so nearly everyone can afford to include them in their diets more often.
As prebiotics make their way through the stomach without being broken down by either gastric acids or digestive enzymes, they bring about positive changes in the digestive tract and organs. Essentially, prebiotic compounds become nutrient sources, or “fuel,” for the beneficial bacteria housed within your gut.
Prebiotics work together with probiotics (selectively fermented ingredients that produce gut-friendly bacteria) to allow specific changes to take place, both in the composition and activity of the gastrointestinal system. They play a fundamental role in preserving health by maintaining balance and diversity of intestinal bacteria, especially by increasing the presence of “good bacteria,” such as Lactobacilli and Bifidobacteria. (2)
Because the health of our gut is closely tied to many other bodily functions, prebiotics and probiotics together are important for battling inflammation and lowering overall disease risk.
Upping your intake of prebiotics has been linked to a long list of powerful benefits, including (4):
    • lower risk for cardiovascular disease
    • healthier cholesterol levels
    • better gut health
    • improved digestion
    • lower stress response
    • better hormonal balance
    • higher immune function
    • lower risk for obesity and weight gain
    • lower inflammation and autoimmune reactions

    Benefits of Prebiotics

  • Better Gut Health and Improved Digestion
  • Enhanced Immune Function
  • Lower Inflammation
  • Reduced Risk of Heart Disease
  • Aids in Weight Loss
  • Protects Bone Health
  • Regulates Hormone Levels and Mood

1. Better Gut Health and Improved Digestion

Prebiotics work to stimulate the growth of beneficial bacteria (often called “probiotics”) that colonize our gut microflora. Since they act like food for probiotics, prebiotic compounds help balance harmful bacteria and toxins living in the digestive tract, which has numerous health implications, including improving digestion. Research has shown that higher intakes of prebiotics foods can increase numerous probiotic microorganisms, including Lactobacillus rhamnosus GG, L. reuteri, bifidobacteria, and certain strains of L. casei or the L. acidophilus-group. (5)
The beneficial bacteria in your gut uses the indigestible fiber content from the foods that you eat as a source for their own survival. As your gut bacteria metabolize otherwise non-digestible fibers from foods, they produce short-chain fatty acids, which are compounds that boast a wide range of benefits.
One of these beneficial fatty acids is called butyric acid, which improves the health of the intestinal lining. Short-chain fatty acids also help regulate electrolyte levels in the body to promote proper digestion, support regularity, and relieve digestive issues like diarrhea and constipation. (6, 7)
Changes in the gut microbiota composition are classically considered as one of the many factors involved in the development of either inflammatory bowel disease or irritable bowel syndrome. A 2012 report published in The Journal of Nutrition reported that prebiotics, along with probiotics, can help treat many digestive problems, including (8):
  • diarrhea (especially after taking antibiotics)
  • certain intestinal infections and chronic disorders like Crohn’s disease and ulcerative colitis
  • symptoms of irritable bowel syndrome (IBS)
  • inflammatory bowel disease
  • leaky gut

2. Enhanced Immune Function

Many human studies have demonstrated that consuming prebiotic-containing food products can result in significant changes in the composition of the gut microbiome that help improve immunity. (9) This “prebiotic effect” has been associated with improvements in biomarkers and activities of the immune system, including reduced levels of certain cancer-promoting enzymes and bacterial metabolites in the gut. (10)
According to a report in The British Journal of Nutrition, prebiotics can help improve poop frequency and consistency, reduce the risk of gastroenteritis and infections, enhance overall health and decrease the incidence allergy symptoms. (9) Prebiotics and probiotics also help boost immunity by improving nutrient absorption and lowering the pH in the gut to block the growth of potential pathogens and harmful bacteria.
Prebiotics may help enhance immunity by providing fuel for your gut bacteria. This could be beneficial in the treatment of a wide range of conditions, including viral infections, allergies, eczema and intestinal disorders. (11) Plus, some studies have even reported a reduction in the incidence of tumors and cancer cells after eating foods with a prebiotic effect. (9)

3. Lower Inflammation

Prebiotics can help lower inflammation, which is believed to be one of the root causes of many chronic diseases, including our nation’s No. 1 killer: heart disease. (12) In fact, people consuming more prebiotics and fiber tend to have healthier cholesterol levels and lower risk markers for cardiovascular diseases. (13)
Inflammation is also thought to contribute to many other chronic conditions as well, including diabetes, cancer and even obesity. Interestingly enough, it’s believed that prebiotics and probiotics contribute to improvements in metabolic processes that are tied to both obesity and type 2 diabetes. (14) Research also shows that a healthier gut environment can turn off autoimmune reactions, help the body metabolize nutrients more efficiently and modulate immune functions that control how and where the body stores fats (including in the arteries). (15)

4. Reduced Risk of Heart Disease

Consuming foods high in prebiotics can reduce glycation, which increases free radicals, triggers inflammation and lowers insulin resistance, all of which can contribute to heart disease. (16)
Prebiotics have cholesterol-lowering properties, which can aid in the prevention of heart disease as well as autoimmune disorders like arthritis. (10) They can also balance the body’s electrolyte and mineral levels, including potassium and sodium, which are responsible for controlling blood pressure.

5. Aids in Weight Loss

Recent data from both human and animal studies support the beneficial effects of particular prebiotics food products with better energy homeostasis, increased and decreased weight gain. (17) Higher intakes of all types of fiber are, in fact, linked to lower body weight and protection against obesity. (18)
A 2002 animal model published in The British Journal of Nutrition found that prebiotic foods promote a feeling of fullness, prevent obesity and spur weight loss. (19) Their effects on hormone levels are related to appetite regulation, with studies showing that animals given prebiotics produce less ghrelin, which is the the hormone responsible for stimulating hunger. (20)

6. Protects Bone Health

A 2007 study published in The Journal of Nutrition found that prebiotics enhance the absorption of minerals in the body, including magnesium, possibly iron and calcium. All of these are crucial for retaining strong bone bones and preventing fractures or osteoporosis. In one study, just eight grams of prebiotics a day was shown to have a big effect on the uptake of calcium in the body that led to an increase in bone density. (21)

7. Regulates Hormone Levels and Mood

Research regarding the “gut-brain connection” is still in its infancy, but it’s becoming clear that mood-related disorders like anxiety or depression are closely linked to gut health. Research suggests that your mood and hormonal balance are affected by a combination of factors that most definitely includes the state of the bacterial inhabitants living inside of your body. Your gut helps to absorb and metabolize nutrients from the foods you eat that ultimately are used to support neurotransmitter functions that create the hormones (like serotonin) that control your mood and help relieve stress. (22)
The final straw in triggering a mood-related disorder might be a series of misfiring neurotransmitters in parts of the brain that control fear and other emotions. These transmissions partly depend on the health of the human microbiome, so when the balance of gut bacteria isn’t working right, other biological pathways including hormonal, immunological or neuronal won’t work right either.
Recent studies have demonstrated that prebiotics have significant neurobiological effects in the human brain, including lowering cortisol levels and the body’s stress response. For example, a 2015 study published in Psychopharmacology explored the effects of two prebiotics on the secretion of the stress hormone cortisol and emotional processing in healthy adult volunteers. After volunteers received one of two prebiotics or a placebo daily for three weeks, the group receiving prebiotics showed positive changes in levels of cortisol, suggesting that it may be beneficial in the treatment of stress-related disorders. (23)

Top Sources of Prebiotics

While probiotics are typically found in cultured and fermented foods like yogurt, kefir, kimchi and kombucha, prebiotics are typically found in certain vegetables, whole grains and sources of resistant starch such as under-ripe bananas.
A few of the best prebiotic-rich foods that you can add to your diet include:
  1. Acacia gum (or gum arabic)
  2. Raw chicory root
  3. Raw Jerusalem artichoke
  4. Raw dandelion greens
  5. Raw garlic
  6. Raw leeks
  7. Raw or cooked onions
  8. Raw jicama
  9. Raw asparagus
  10. Under-ripe bananas
  11. Yacon syrup
Some other sources include foods that contain isolated carbohydrates (galactooligosaccharides and transgalactooligosaccharides), such as raw honey, wheat dextrin,  psyllium husk, whole-grain wheat and whole-grain corn.
Need a few more ideas to help bump up your intake of prebiotics? Here are some tips to help you reap the rewards of these super healthy ingredients:
  • One of the most realistic and delicious ways to prebiotics to your meals is by including nutrition-packed onions. Onions, both cooked or raw, give plenty of flavor to your food and also provide immune-enhancing antioxidants. They contain a natural source of inulin, one type of good bacteria that fights indigestion. Use onions in savory dishes like sauces, salads, dips and soups or grilled on the BBQ.
  • Raw garlic is another easy prebiotic ingredient to use that offers loads of benefits. Not only can it help boost gut health, but it has also been shown to have powerful antifungal, antioxidant, anti-inflammatory, antiviral and anti-cancer properties. (24) Try using some in a tomato salad, dips, spreads or homemade hummus.
  • Nutrient-dense bananas that aren’t yet fully ripe contain the highest concentration of resistant starch and prebiotics. Look for bananas that are still greenish instead of bright yellow and spotted. While they won’t be as soft or sweet-tasting, they still work well in smoothies or even warmed up as a dessert.
  • Dandelion greens are another food that can be found in most grocery stores and nearly all health food stores. These leafy greens are a great source of prebiotics in addition to antioxidants, vitamins and minerals. Eat them raw by chopping them up finely and adding some to a salad or side dish.
  • If eating asparagus raw doesn’t initially appeal to you, try fermenting them. You can easily make homemade fermented asparagus (and many other veggies too) with just some salt and a mason jar. The same goes for jicama — either slice them thinly and throw them in a salad for some crunch, or try bringing out their natural flavors and probiotics by making cultured jicama sticks.
  • Jerusalem artichokes, often called sunchokes, are more similar to a root vegetable than the large green artichokes you’re probably familiar with. Try shredding them and sprinkling some on top of a salad, into a smoothie or into a dip. They have a mild flavor and blend easily with other tastes.
  • Chicory root is useful for baking since it binds ingredients together. It’s also a high-antioxidant food and great digestive cleanser. Some people use chicory when making homemade cultured veggies, like kimchi or sauerkraut. Chicory root is also used as a coffee substitute for those looking to cut their caffeine intake since its taste mimics that of coffee without any of the caffeine or acidity.
  • Acacia gum is used in a variety of products, including some supplements, powders and even ice cream. In herbal medicine, the gum is used to bind pills and lozenges and to stabilize emulsions. It’s possible to find powder acaia to add to smoothies in certain health food stores or online.

Prebiotic Supplements & Dosage

Some prebiotics are also added to some foods artificially and can often be found as dietary supplements, such as Prebiotin. While many food manufacturers now produce foods that are “high in fiber,” many use isolated fiber sources that are difficult to digest and some might even have mild laxative effects.
The best prebiotics come from whole food sources and foods containing prebiotics like raw chicory root or onions. Not only do these foods supply a concentrated amount of prebiotics, but they are also rich in other important vitamins, minerals and antioxidants that can help optimize your health.
That being said, if you’re unable to meet your needs through food alone, you may want to consider prebiotics supplements instead. Look for a supplement that contains real prebiotics instead of compounds with prebiotic-like effects and be sure to buy from a reputable retailer with high-quality standards as well.
Additionally, it’s important to stick to the recommended dosage to avoid adverse symptoms and gastrointestinal problems. You may also want to start with a low dose and gradually increase your intake to assess your tolerance and minimize the risk of side effects.

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