The 5 Best Prebiotic Foods that Boost Beneficial Microbes!

Your gut hosts trillions of microbes, including bacteria, fungi, and viruses, collectively known as your gut microbiome. While certain microbes are linked to diseases, other beneficial gut bacteria are extremely beneficial as they help you digest your food, strengthen the immune system, and reduce inflammation, among various other functions.

The health of your gut microbiome is largely dependent on what you feed it. But what exactly keeps these helpful microbes alive? Read on to find out how prebiotics nourishes healthy gut bacteria which improves your gut health, creative ways to include them in your diet, their health benefits, and more.

What are Probiotics?

To understand prebiotics, you have to know what probiotics are. Probiotics are strains of good bacteria (and sometimes yeast), a majority of which are found in your colon, but they are also found in the mouth, nose, lungs, vagina, and on skin. In fact, it has been estimated that bacterial cells outnumber the human cells in your body.

Several kinds of beneficial bacteria are present in the human body, but lactobacillus and bifidobacteria are the most common and well-researched species. These bacteria are also present in foods, including kefir, kimchi, miso, yogurt, kombucha tea, and pickles, as well as in supplements. You can find out more Probiotic Foods from this list.

Probiotics are incredibly important in maintaining a healthy gut by encouraging the growth of healthy gut flora. And since your digestive system has a profound effect on your other body, probiotics indirectly influence many functions in your body.

What are Prebiotics?

There are two types of dietary fibers – soluble and insoluble. Prebiotics are insoluble fibers present in plant-based foods. Humans lack the enzymes to break down these fibers, but the friendly microbes in your gut don’t let any food go to waste. Prebiotics serves as nourishment to good gut bacteria and stimulates their growth. These bacteria ferment the prebiotic fibers and release short-chain fatty acids (SCFAs), such as butyrate, propionate, and acetate.

SCFAs play a major role in the maintenance of the integrity of the gut barrier as they are the energy source for the epithelial cells (colonocytes) in your gut. Butyrate alone provides 70% of the energy to colonocytes and serves as their primary energy source.

SCFAs also aid in mucus production and help maintain the thickness of the intestinal barrier, which is the first line of defense that separates the gut lining from its external environment. It allows the passage of nutrients, solutes, and water, and prohibits the flux of toxins and pathogens. Without this mucosal layer, harmful bacteria and toxins can penetrate the intestinal barrier and cause serious damage. In addition to this, SCFAs may reduce the risk of obesity, type 2 diabetes, heart disease, inflammatory diseases, and certain other conditions.

Unlike probiotics, prebiotics is not naturally present in the body and you need to consume them from your diet. Including a variety of prebiotic sources in your diet ensures there is enough substrate for different types of species, as they may have unique nutritional needs. Also read: Pre and Probiotics: How do they differ in Action?

Best Prebiotic Foods you should Eat

Prebiotics are naturally found in many high-fiber foods and they are also available in supplement form which helps increase healthy gut bacteria for good gut health. Here are some of the best sources of prebiotics that you must include in your diet.  

1. Chicory root
   Chicory root contains the prebiotic fiber inulin, which:
   • Promotes the growth of healthy bacteria in the gut,
   • Helps slow down digestion,
   • Regulates blood sugar levels,
   • And relieves constipation, among various other health benefits.
     
2. Asparagus
   • Asparagus isnaturally high in inulin, xylooligosaccharides (XOS), and antioxidants that fight off harmful free radicals in the body.
   • These prebiotic fibers help improve your digestive health, optimize your insulin levels, and reduce inflammation in the body.
     
3. Garlic
   • Garlichelps regulate cholesterol, reduces oxidative stress, and has excellent anti-inflammatory and anti-tumor properties.
   • It helps lower blood sugar levels and cleans your digestive tract by flushing out toxins.
     
4. Onions
   Onions are great sources of fructooligosaccharides (FOS) and inulin.
   • FOS helps break down fats and strengthens immunity.
   • It is also rich in antioxidants and has antibiotic and anticancer properties.
   • Additionally, onions can prevent plaque buildup in your arteries.
     
5. Bananas
   Bananas are high in vitamins, minerals, and soluble fibers, as well as small amounts of inulin.
   • Underripe bananas contain resistant starches that have prebiotic properties.
   • In addition, their high-fiber content keeps you full for longer.
     
6. Cocoa
   • Cocoa isconsidered a prebiotic as it promotes the growth of good bacteria and inhibits the growth of harmful bacteria in the gut.
   • It is high in polyphenols that have anti-inflammatory and antioxidant effects.
     
7. Flaxseeds
   • Flaxseeds contain prebiotics that helps regulate your bowel movements and relieve digestion problems.
   • They are also high in omega-3 fats, which are important for a healthy gut.
   • Additionally, they have phenolic antioxidants that also regulate your glucose levels and have anti-cancer effects.
     
8. Seaweed
   • Seaweed ishighly nutritious and contains polysaccharides such as fucoidans, carrageenans, and agars that support your gut health and boost your immunity.
   • It is also a great source of antioxidants and soluble fiber.
     
9. Legumes
   Legumes contain resistant starch, galactooligosaccharides (GOS), and soluble fiber. Dry, uncooked legumes contain about 20-30% resistant starch.
   • They have anti-carcinogenic properties and anti-inflammatory properties.
   • They also help regulate blood glucose and cholesterol levels.
     
10. Green Leafy Vegetables
    • Green leafy vegetablescontain a special type of prebiotic sulfoquinovose, which acts as a source of hydrogen sulfide for the gut.
    • It helps good bacteria flourish and outgrow the harmful ones through the secretion of bactericides.
      
11. Apples
    • Apples contain polyphenols and pectin, which is a soluble fiber, but it has prebiotic effects as it is not digested by human saliva or gastric acid.
    • Pectin helps to suppress fat accumulation and reduce inflammation in the body.
      
12. Barley
    • Barley is an ideal source of beta-glucan, a prebiotic fiber that has been shown to reduce bad cholesterol levels and helps prevent cardiovascular diseases.
    • It improves your metabolism by increasing insulin sensitivity and regulating your blood glucose levels.

Top 5 Ways to Eat More Prebiotics

We often tend to overlook the fiber content in our diets, especially as we are used to eating out and consuming heavily processed foods. By becoming more aware of your options and ways to use them, you can reap the benefits of prebiotics and still enjoy your meals.

Here are some easy ways to incorporate more prebiotics into your diet.

1. Add garlic, onions, scallions, and shallots to your dishes.
   Although all vegetables are healthy, certain vegetables provide unique benefits. Species of the Allium family, garlic, onions, scallions (spring onions), and shallots are high in sulfur compounds, which add a lot of flavor and aroma to your dishes, making them great additions to your recipes. Some of these compounds break down upon cooking and their taste becomes milder. Additionally, these vegetables are natural sources of fructans, a type of prebiotic. It is known to improve calcium absorption and increase bone density.
   • Add scallions to your soups, stews, salads, omelets, and stir-fries.
   • Add generous amounts of onion and garlic to your curries. Season your food with dried onion and garlic (look for additive-free variants)
   • Garnish your finished recipes with caramelized onions or chopped scallion for an added kick of flavor.
     
2. Add underripe bananas to your smoothies
   While you may be used to adding ripe bananas to your smoothies, underripe bananas contain much more prebiotic fiber than ripe bananas and also add more texture to your smoothies. Green bananas have 70-80% resistant starch but as they ripen, they tend to lose a lot of their probiotic effects as the resistant starch is converted into sugars, even though the rest of the nutritional value remains the same. Resistant starch is also known to help in weight management, prevent obesity, regulate blood sugar levels, and promote satiety. Besides, it is a great way to use up green bananas that won’t ripen. Also, learn why bananas are good for Leaky Gut.
   
   Try preparing a flavourful smoothie by blending Greek yogurt, 1 frozen underripe banana, and 1 tbsp. of chia seeds, cocoa powder, and peanut butter, a pitted date (optional), and some milk to achieve the right consistency.
   
   However, it is important to note that people with latex allergies should avoid green bananas as they contain a similar protein to that found in latex.
   
   
3. Add flaxseeds and chia seeds to your cereals and smoothies
   Flaxseeds and chia seeds are known to be highly nutritious and are great sources of prebiotics.
   • Chia seeds are loaded with antioxidants and alpha-linolenic acid (ALA), a type of omega-3 fatty acid known to lower blood pressure and improve cardiovascular health.
   • Flaxseeds, on the other hand, can reduce the risk of certain types of cancers and help decrease cancer mortality. Researchers attribute it to their lignan content, a polyphenolic compound highly abundant in flaxseeds.
     
     Both flaxseeds and chia seeds can be added to your smoothies and cereals. You can sneak flaxseeds into a variety of dishes without altering their taste. These include dips, salads, and sandwiches. Chia seeds are highly versatile and have a tendency to form a viscous gel in the presence of water, due to their high soluble fiber content. You can add chia seeds to some milk and add some flavoring of your choices like vanilla extract, cinnamon, and some honey. Let it set for at least 2 hours in the fridge and enjoy a wholesome chia pudding.
     
4. Substitute meat with legumes once in a while
   Legumes, such as black beans, chickpeas, and pulses are not just great plant-based protein sources, but they are also high in prebiotic fibers. These prebiotic fibers stimulate the growth of bifidobacteria in the gut, which are thought to relieve constipation and lower blood lipid levels. Moreover, plant-based proteins can reduce the risk of coronary heart disease.
   
   You can substitute meat with equal amounts of legumes in most recipes. You can make Bolognese sauce using lentils, prepare black bean tacos, or make falafel with chickpeas. You can also use them to make dips and salad dressings. The soluble fibers and resistant starches in legumes will make them much more filling.
   
   
5. Indulge guilt-free in Dark Chocolate
   Cocoa is one of the best sources of antioxidants one can find. One such antioxidant is polyphenol. Polyphenols are poorly absorbed by the human body but they can be broken down by friendly gut microbes. They also enhance your immune function, reduce inflammation, and improve brain functions by improving blood flow to your brain. Health experts recommend eating 25-50g of dark chocolate on a daily basis.
   
   Look for dark chocolates with at least 70% cocoa content. You may opt for variants sweetened using stevia or monk fruit or use raw cocoa powder in your recipes to avoid any artificial ingredients or additives.

Studies of Benefits of Prebiotics

1. A study was conducted on 80 volunteers to determine the effect of fructooligosaccharides (FOS) on the human gut microbiome. The treatment group was given three doses (2.5g, 5g, and 10g/day) of FOS, while the control group received a placebo. The microbial composition was determined through fecal samples at 9 time points.
   
   The study showed that FOS increased the abundance of Lactobacillus and Bifidobacterium as well as certain butyrate-producing microbes. Moreover, these benefits ceased when FOS was discontinued ^[1].
   
   
2. Another study was conducted on 255 children to determine the effectiveness and safety of apple pectin chamomile extract on acute diarrhea. The volunteers were either given apple pectin chamomile extract or a placebo.
   
   The study showed that apple pectin chamomile extracts significantly lowered stool frequency and were well tolerated among the treatment group ^[2].
   
   
3. A study was conducted on 32 participants to evaluate the effect of xylooligosaccharide (XOS) on the human gut microbiome. The participants were either given 1.4g or 2.8g XOS or a placebo daily for 2 weeks. This was followed by an 8-week intervention phase and a washout period of 2 weeks. Stool samples at baseline, at 4 and 8 weeks during the intervention, and after the washout phase.
   
   The study showed that XOS increased the abundance of bifidobacteria in the treatment group. Additionally, a dose of 2.8 g was substantially more effective than a dose of 1.4g per day ^[3].

Benefits of Prebiotics

1. Boosts Digestive Health
   Since prebiotics increases the number and diversity of healthy bacteria and helps improve your overall gut health, they are useful in treating digestive issues such as diarrhea, gas, and bloating. They also help in the elimination process and work to detoxify your body naturally. In addition, prebiotics has been shown to regulate the consistency and frequency of bowel movements.
   
   
2. Strengthens Immunity
   Your gut is responsible for producing 70-80% of your immune cells, which is heavily influenced by your gut microbiome. By stimulating the growth of beneficial bacteria, prebiotics help strengthens your immunity and reduce your risk of allergies. In addition to this, prebiotics directly stimulate your immune cells to make them resistant to infection.
   
   Moreover, prebiotics feeds nitrogen oxide-producing bacteria in your gut. Nitrogen oxide is an important vasodilator that increases blood flow to your gut.
   
   
3. Insulin Sensitivity
   The gut-brain axis modulates your blood sugar levels depending on the glycemic index of a food. The glycemic index is the measure of how quickly your blood sugar levels rise after consuming a particular food.
   
   Consuming a diet rich in prebiotics can improve your metabolic health and regulate your blood sugar levels and insulin sensitivity by improving the composition of your gut microbiome. Prebiotics also help improve glucose-stimulated insulin production, reduce fasting sugar, and improve glucose tolerance.
   
   
4. Control Cholesterol Levels
   Studies have shown that prebiotics can help increase good cholesterol (HDL) and reduces bad cholesterol (LDL) and triglyceride levels through various mechanisms. High levels of good cholesterol can help reduce the risk of stroke, heart disease, and blood clots.
   
   
5. Regulates Hormones
   Prebiotics can help reduce cortisol levels, which is the primary stress hormone. Too much cortisol causes your digestive system to shut down and causes a spike in your blood sugar levels, increasing your risk of type 2 diabetes and weight gain.
   
   Prebiotics also regulate the hormone leptin, which regulates energy levels and inhibits hunger so that the brain stops sending hunger signals when your body doesn’t need any more energy.
   
   
6. Helps in Weight Management
   Evidence suggests that prebiotics can delay gastric emptying and help you feel full for longer. They also help support healthy digestion and absorption of dietary fats, which may cause you to consume fewer calories.
   
   Additionally, steady blood sugar levels help stabilize your appetite and reduce food cravings, especially for foods high in simple carbohydrates and other sugars.
   
   Furthermore, the polyphenols in certain prebiotic sources can help alleviate metabolic syndrome and decrease body fat, especially around the waist.
   
   
7. Supports Bone Health
   By stimulating the proliferation of friendly gut microbes, prebiotics help in the production of certain metabolites that are beneficial for bone health. These microbes also decrease inflammatory mediators in the bone marrow, which play a critical role in regulating bone homeostasis.
   
   Additionally, prebiotics increase calcium metabolism, reduce bone resorption, and promote osteoblast proliferation and maturation, improving osteoporosis.
   
   
8. Helps Recover from Gastrointestinal Disorders
   Prebiotics adds bulk to your stool and promotes the movement of food through your gastrointestinal (GI) tract. They’re beneficial for people suffering from constipation or irregular bowel movements.
   
   The short-chain fatty acids produced through fermentation are highly anti-inflammatory and are beneficial for people with inflammatory bowel disease (IBD). In addition, prebiotics favorably alter the composition of the gut bacteria to help fight pathogens.

What happens when you are not incorporating Prebiotic Foods into your diet?

Not consuming enough prebiotic-rich foods can cause you to lose out on a slew of health benefits. Prebiotics are required for a well-balanced gut microbiome as they selectively feed the friendly microbes in the gut.

• When you don’t consume enough prebiotics, you lose the abundance and diversity of gut bacteria. Probiotics play a major role in maintaining a healthy gut microbiome as it feeds beneficial gut bacteria. Without prebiotics, bad bacteria over-populate your gut and create a microbial imbalance in the gut, which essentially affects your entire body.
  
  
• Moreover, the soft and bulky texture of prebiotics help prevents the production of hard stools.
  
  
• A lack of enough prebiotics affects gut motility and may lead to constipation.

You must include prebiotics in your diet daily to maintain their benefits in the long run, it can be either in the form of foods or supplements, read more about the Top 10 Supplements with Pre and Probiotic Content in them. Experts recommend getting at least 38g of fiber daily for men and at least 25g of fiber for women.

Potential Side Effects

Prebiotics are generally well tolerated by most adults, but this may not always be the case. People with gut issues such as irritable bowel syndrome (IBS), small intestinal bacterial overgrowth (SIBO), FODMAP intolerance, or any other gastrointestinal disorder, should avoid consuming prebiotics until they have fully recovered since the lack of enough good bacteria in the colon or excessive fermentation can cause uncomfortable symptoms, such as gas, bloating, and abdominal pain.

When you start eating more prebiotics, start small and gradually increase your intake as this gives your digestive system time to adjust.

Your body works on a circadian rhythm and so do the gut microbes. This means that gut microbes are more active during day time. Therefore, you want to avoid eating a lot of legumes or cruciferous vegetables before going to bed.

Conclusion

Prebiotic fibers are a type of dietary fiber that is not digested in the small intestine and travels straight to the colon where they are fermented by friendly bacteria. Prebiotic foods help increase the growth of beneficial bacteria in the gut, which play a major role in keeping your gut healthy. The by-products released on fermentation of prebiotics by the gut bacteria are beneficial for the gut in many ways. Prebiotics has also been shown to regulate many bodily functions and help reduce the risk of certain cancers and other diseases.

We often tend to overlook dietary fiber in our diets, even though it is one of the most important nutrients you can eat. Consuming prebiotic foods doesn’t have to be boring. With a variety of foods to choose from, you can eat a diverse diet and experiment to see what works best for you, you can also explore the List of Digestive Superfoods. While prebiotics is best consumed raw, you can get a majority of prebiotic benefits by using them in your cooking. That being said, people with gastrointestinal disorders should avoid loading up on prebiotics.

References

1. Tandon, D., Haque, M.M., Gote, M. et al. A prospective randomized, double-blind, placebo-controlled, dose-response relationship study to investigate efficacy of fructooligosaccharides (FOS) on human gut microflora. Sci Rep 9, 5473 (2019).
   
   
2. Becker B, Kuhn U, Hardewig-Budny B. Double-blind, randomized evaluation of clinical efficacy and tolerability of an apple pectin-chamomile extract in children with unspecific diarrhea. Arzneimittelforschung. 2006;56(6):387-93. doi: 10.1055/s-0031-1296739. PMID: 16889120.
   
   
3. Finegold SM, Li Z, Summanen PH, Downes J, Thames G, Corbett K, Dowd S, Krak M, Heber D. Xylooligosaccharide increases bifidobacteria but not lactobacilli in human gut microbiota. Food Funct. 2014 Mar;5(3):436-45. doi: 10.1039/c3fo60348b. PMID: 24513849.