Prebiotics are the food that grows and sustains the good bacterial colonies.
In my clinic, I almost always recommend prebiotics to clients when trying to increase good bacteria in the gut; sometimes, I recommend prebiotics instead of probiotics.”
Why? Research has shown that once we stop taking a probiotic, the number of good bacteria inevitably returns to pre-probiotic levels. Essentially, our gut bacteria diversity and numbers are set by the time we’re adults. However, there are a few things we can do to change these set points and increase our bacterial diversity and the number of colonies in our gut. When we take prebiotics, good bacterial colonies become more plentiful. More good bacteria equals better health.
Of course taking probiotics, if done correctly, remains important. I still use them with my patients with good success. As my last article pointed out, however picking the correct strains are important. See my article, “Probiotics: Wasting Your Money?”.
What is a prebiotic? A prebiotic is a non-digestible food ingredient (usually fiber or starch) which promotes the growth and activity of health-promoting microorganisms / bacteria (such as bifidobacteria and lactobacilli) in the intestines.
Research has shown prebiotics contribute to the integrity of the gut barrier, promote normal colon transit time, improve nutrient absorption, strengthen the immune system (in the gut and systemically), and modulate blood sugar and lipid levels. Thus, prebiotics have shown to have diverse effects on health, including:
- gut health maintenance
- colitis prevention
- cancer inhibition
- immune-potentiation
- cholesterol removal
- reduction of cardiovascular disease
- prevention of obesity and constipation
- restoration of the vaginal ecosystem
Prebiotics occur naturally in many foods, however, eating them raw can be important.
Prebiotic Foods:
- Acacia gum (or gum arabic)
- Raw chicory root
- Raw Jerusalem artichoke
- Raw dandelion greens
- Raw garlic
- Raw leek
- Raw onion
- Cooked onion
- Raw asparagus
- Raw Wheat bran
- Baked wheat flour
- Raw Banana
- Mexican yams
- Human milk
- Colostrum
I suggest getting 12 grams of prebiotic fiber / carbohydrate per day. Though it’s difficult to get some of these prebiotics into our diet, there are good supplements we can take. Just as with probiotics, taking a random product might not be the best idea. Knowing the different kinds of prebiotics, targeting your specific condition, and understanding which bacteria you are trying to grow is helpful.
Here are some prebiotics that I use in my clinic. More are consistently emerging with ongoing research.
Inulin-type fructans. Fructans are found in wheat, onions, asparagus, bananas, garlic, artichokes, and leeks. Chicory root is a major commercial source. These prebiotics mostly feed the Bifidobacterium family of bacteria, but also increase numbers of Lactobacillus and the important butyrate-producing Eubacterium and Roseburia species.
Galactooligosaccharides is found in human and cow’s milk and selectively augments Bifidobacterium and Lactobacillus.
Lactulose is a galacto-fructose made by the isomerization of lactose. It increases Bifidobacterium and Lactobacillus numbers, and reduces the bad bacteria, Clostridium perfringens, Bacteroides, Enterobacteriaceae, and Streptococcus populations.
Beta-Glucan are non-digestible polysaccharides. They are found in cereals, yeast (e.g. brewer’s yeast), mushrooms, seaweeds and some bacteria. Of note, different types of beta-glucans produce different effects on the body. Effects may include:
- immune stimulation
- anti-tumor properties
- blood cholesterol lowering capacity
- inhibiting the early stages of atherosclerosis
Larch Arabinogalactan (Larix occidentals) is a fiber that ferments in the intestine and increases the good bacteria, such as Lactobacillus, as well as other beneficial effects on the digestive tract health. This fiber is used for a wide range of immune disorders. Clinically I often use it to:
- prevent and treat the common cold and flu
Larch has a wide range of conditions it can benefit, for example:
- H1N1 (swine) flu
- Ear infections in children
- HIV/AIDS.
- Liver cancer
- Hepatic encephalopathy, (a brain condition caused by liver damage).
- Lowers cholesterol
Guar Gum: Diabetes & Blood Sugar Levels
Guar gum increases both Bifidobacteria and Lactobacillus, and helps to reduce symptoms of Irritable Bowel Syndrome (IBS). It also increases immune function. Further effects include:
- Reduction of fasting blood glucose
- Improvement in glycemic control
- Reduction of insulin requirements in insulin-dependent diabetics
- Reduction of LDL cholesterol
Here is a summary of some of the current research and recommendations for specific conditions and the prebiotics used to address them.
Normalize bowel transit time
- 20 gm/day inulin (elderly)
- 20 gm/day lactulose (healthy subjects)
- 2 gm/day xylooligosaccharides (pregnant woman)
Improve mineral absorption:
- 10 gm/day inulin-type fructan (postmenopausal women)
- 10 gm/day lactulose (postmenopausal women)
- 8 gm/day inulin-type fructans (pubertal males and females)
Favorably influence blood lipids
- 7-20 gm/day inulin-type fructans (healthy, type-2 diabetic, hyperlipidemic subjects)
Increase pathogen resistance
- 15 gm/day inulin and inulin-type fructans (healthy subjects)
- 20 gm/day lactulose (healthy subjects)
- 1 gm/dL galactooligosaccharides/inulintype fructans (9:1) (infants)
Enhance systemic immunity
- 8 gm/day inulin-type fructans (elderly)
- 8 gm/L galactooligosaccharides/inulintype fructans (9:1) (infants)
Attenuate GI inflammation
- 15 gm/day inulin-type fructans (Crohn’s disease patients)
- 12 gm/day inulin-type fructan (ulcerative colitis patients)
(Recommendations from Klaire Labs)
Questions:
When should I take prebiotics?
Prebiotics should be taken with a meal.
Do I need to take probiotics with prebiotics?
No. Prebiotics have been shown to have beneficial effects when taken alone. However, pairing the right prebiotic with the correct probiotic is best. To review how to pick a good probiotic see my previous article, “Probiotics: Wasting Your Money?”
Do prebiotics cause side-effects?
Some people have discomfort / bloating when they start taking prebiotics. Therefore, one should start slowly. If this does not remedy the situation, then consult your health practitioner and consider conditions such as small intestinal bacterial overgrowth (SIBO).
How do you know if you need prebiotics?
Prebiotics essentially come from fiber. It is my clinical opinion that almost everyone could benefit from additional fiber. For example, a modern westerner may eat 20-25 grams of fiber a day, whereas ancestral humans ate ~125 grams a day. Imagine hunters and gathers finding wild vegetables, I imagine they ate even the stalks, which are full of fiber.
This said, I do not know of any test or set of symptoms pointing the need for prebiotics. Yet anyone with compromised health, and those who want to stay healthy may benefit from taking prebiotics.
It is best to consult with a healthcare professional to know how you may benefit and to discern which prebiotic is best for you.
I would love to hear any questions or comments. In health, Jason…


