Prebiotics - Definition, Sources & Benefits
The microbes in the digestive tract are recognized as playing an important role in health and as a trigger for many health issues. There are trillions of microorganisms that are inhabitants of the human gastrointestinal tract, the gut microbiota includes both good and bad bacteria. The healthiest gut microbiome is diverse and is mainly comprised of good bacteria. The modern-day highly processed foods, fried foods (cooked in saturated and trans fats), excessive meat-eating, alcohol consumption, consumption of foods packed with added sugars, artificial sweeteners, and caffeinated beverages promote the growth of harmful gut bacteria, turn the diverse gut microbiome into a dysbiosis (reduction in microbial diversity and imbalance in the microflora) and a loss of beneficial bacteria. There is growing evidence that dysbiosis of the gut microbiome can cause digestive issues, such as inflammatory bowel disease, diarrhea, constipation, bloating, obesity, leaky gut syndrome, and diabetes. The bad bacteria may reproduce in our body and release toxins that can damage body tissue, and cause immune degradation.
Owing to these concerns, there is a growing recognition of the role of diet in modulating the composition of gut microbiota, which in turn has a great impact on health.
Diet, particularly, macronutrients has a major role in tuning the gut microbiome. While the number of microbes varies along the length of the GI tract, the majority of the microbes are found within the large intestine where they contribute to the fermentation of undigested food components, especially fiber.
In this article, we’ll discuss the potential benefits of prebiotics to modify gut microbial populations.
While the best-known method of maintenance of diverse gut microbiota is by keeping the harmful bacteria at bay through the use of probiotic foods, prebiotic foods are often underappreciated.
WHAT ARE PREBIOTICS?
Gut microbiota affects intestinal functions, such as metabolism and integrity of the intestine. If probiotics are the beneficial/friendly bacteria living inside our gut, prebiotics serves as fuel for the beneficial bacteria. Prebiotics are non-digestible food ingredient (fiber) that beneficially affects the host by selectively stimulating the growth and activity of the limited number of bacteria in the colon, and confer a health benefit.
While all prebiotics are classified as fiber, not all fibers are prebiotics. The soluble fibers can be fermented by gut bacteria to produce beneficial compounds like vitamins (like K, B12, and Folate), short-chain fatty acids which have an important role in the maintenance of health. These short chain fatty acids diffuse to blood circulation and can affect not only the gastrointestinal tract but also distant site organs. The insoluble fiber is not fermentable, they pass through the GI tract unchanged, add bulk to the stool, and helps the food to pass more quickly through the stomach and small intestine.
Fructans (which include inulin, fructooligosaccharides (FOS), and oligofructose), galactooligosaccharides (GOS), and trans-galacto-oligosaccharides, starch and glucose-derived oligosaccharides (resistant starch or RS) are the major types of prebiotics that naturally exist in foods.
WHAT ARE THE BEST PREBIOTIC FOODS AROUND AND HOW CAN THEY SUPPORT THE HEALTH OF YOUR GUT?
Prebiotics are naturally found in dietary food products like oat bran, barley, flax seeds, nuts (almonds, pistachios), lentils, beans, peas, onion, garlic, seaweeds, leeks, asparagus, beets, green bananas, tomato, rye, dandelion greens, chicory root, chickpeas, cabbage, custard apple, watermelon, grapefruit, apples, berries, kiwi fruit, seaweeds, microalgae. These foods support the growth of good bacteria which can produce short-chain fatty acids. Because of their low concentration in foods, prebiotics is manufactured industrially using lactose, sucrose, and starch as raw material.
WHY CONSUME PREBIOTICS?
- Antibiotics, inorganic food, consumption of animal foods, junk or processed foods, poor sleep cycles, and alcohol consumption, cause imbalance in the gut flora. The food that we consume daily is stunted with prebiotic content. A gluten-free and low-carb diet reduces the intake of prebiotics, with a resultant risk of dysbiosis.
- Lack of enough prebiotics can lead to a weakened immune system, and a poor digestive system, leading to the growth of pathogens. They promote the growth of beneficial bacteria without feeding the bad ones.
- Prebiotics target the beneficial bacteria that can favourably alter the microbiome and reduce levels of potentially pathogenic gastrointestinal microorganism levels.
- When gut microbes metabolize prebiotics, they produce short-chain fatty acids like butyrate, propionate, and acetate. These short chain fatty acids nourish the cells that line the gut and has been associated with reducing the risk of certain cancer (like colorectal cancer).
- Short-chain fatty acids can act as signals to communicate with the brain.
- Prebiotics enhance the number of probiotics which can lead to fecal bulking, improved bowel movements, may relieve digestive distress like constipation, diarrhea, may control serum lipids, blood glucose, may support calcium, magnesium absorption, immunomodulation, decreased inflammation.
HOW MUCH FIBER SHOULD WE INTAKE PER DAY?
25-38g/day should be your recommended fiber intake.
PREBIOTICS Vs PROBIOTICS
- Probiotics are live, good gut bacteria found in food and supplements. Prebiotics are non-living, non-digestible plant fibers.
- Probiotics feed on prebiotics. Prebiotics serve as food for probiotics.
- Probiotics are used up in the stomach and small intestine. Prebiotics reach the hindgut, they are resistant to digestion in the stomach and small intestine.
- Probiotics restore the balance of gut flora. Prebiotics help probiotics grow and flourish in the gut.
- Probiotics promote a healthy digestive tract and immune system. Prebiotics support healthy digestion and immune function.
- Probiotics (either in food or supplements) are fragile, vulnerable to heat, and may be killed over time. Prebiotics can survive heat, cold, and stomach acid.
- Good Sources of Probiotics: Yogurt, Kefir, buttermilk, kimchi, cheese, tempeh, kombucha
- Good Sources of Prebiotics: Garlic, leeks, whole wheat, fruits, vegetables, legumes
- Examples of Prebiotics - Lactobacillus, Bacteroides, Clostridium, Streptococcus, Bifidobacterium, Escherichia, Ruminicoccus.
The health of our gut is closely tied to many bodily functions, if probiotics are seeds of our gut garden, prebiotics water them, therefore, prebiotic + probiotic = better overall gut health.
Making a healthy change in your diet is all you need to boost your prebiotic and probiotic intake.