While you might hear the word bacteria and associate it with something negative, there are many beneficial bacteria that our digestive system needs to stay healthy. The bacterial composition of your gut is very important to not only your digestion, but also to your health in general. Maintaining a proper balance of bacteria in your gastrointestinal system means increasing the beneficial, “good” bacteria while decreasing the harmful, “bad” bacteria. Probiotics and prebiotics are both ways to help keep this balance. But what is the difference between prebiotics vs probiotics?

Probiotics

These are live bacteria that have a beneficial effect on the body when ingested. When these bacteria get to the digestive system, they colonize and flourish, limiting the concentration of harmful bacteria. They may also influence enzyme activity to help aid digestion.[1] Probiotics can be ingested either through a supplement or through foods with live cultures such as fermented foods. 

Probiotics have many benefits:

• They improve digestion and fight diarrhea.[2]
• They enhance immune function.[2,3,4]
• They benefit lipid metabolism.[2,5]
• They have antioxidant properties [5,6,7] and exhibit anti-cancer effects.[2,7]
• They have wide ranging effects that can benefit lung, skin, and joint health.[2]

Prebiotics

These are not bacteria—they are the food that probiotics need to thrive. They are non-digestible carbohydrates that can be fermented by the intestinal bacteria, resulting in the selective growth and activity of good bacteria.[8] Essentially, prebiotics help the beneficial gut microbiota grow. Prebiotics could be thought of as fertilizer for gut bacteria.

Prebiotics come in the form of specific dietary fibers, such as inulin and oligofructose. They are not digested by the intestinal tract, but instead are fermented in the colon by the bacterial community there.[8] As they are dietary fibers, prebiotics increase bowel movement frequency, can help with constipation, and have a positive impact on the mucosa of the large intestine.[8]

Prebiotics have a positive effect on a variety of conditions.

• They improve symptoms associated with irritable bowel syndrome (IBS) and irritable bowel disease (IBD).[9,10]
• They protect against colon cancer development.[9,10]
• They enhance absorption of certain minerals, including calcium, magnesium, and possibly iron.[1,3, 8, 9]
• They promote weight loss and prevent obesity by enhancing the feeling of satiety.[10]
• They lower certain risk factors for cardiovascular disease[10] by possibly decreasing blood lipid levels.[1]

Synbiotics

A third term has been used to describe a combination of probiotics and prebiotics, in which there is a true symbiosis between the two. Synbiotics are mixtures of probiotics and prebiotics, which are potentially beneficial because they can help improve the survival of the live bacteria in dietary supplements when they reach the gastrointestinal tract. Some researchers warn, however, that many products that claim they are synbiotics may not actually have the correct balance and composition of probiotics and prebiotics to actually have these effects.[8]

How can you increase your consumption of probiotics and prebiotics?

Probiotics are available as a supplement, or you can increase your intake through eating more fermented foods. Prebiotics are found naturally in many fibrous foods, including wheat, onions, bananas, honey, garlic, leeks, chicory root, asparagus, Jerusalem artichokes, oats, and soybeans.[1,10]

While there are many beneficial effects of prebiotics, it is important to diversify your intake by eating a variety of sources, and to not overdo it – excess quantities can produce symptoms like flatulence and diarrhea because of high fiber intake. Between 10 and 20 g of oligofructose or inulin (both prebiotics) are considered to be without side effects.[8]

Share your experience

Do you take a probiotic or do you eat prebiotic-rich foods? What effects have you seen on your health? Share your experience in the comments section below.

[1] J Ren Nutr. 2002 Apr;12(2):76-86.

[2] J Appl Microbiol. 2006 Jun;100(6):1171-85.

[3] Best Pract Res Clin Gastroenterol. 2013 Feb;27(1):139-55.

[4] Crit Rev Food Sci Nutr. 2014;54(7):938-56.

[5] J Med Food. 2013 Mar;16(3):223-9.

[6] Food Chem. 2012 Dec 1;135(3):1914-9.

[7] Food Microbiol. 2011 Aug;28(5):1062-71.

[8] Adv Biochem Eng Biotechnol. 2008;111:1-66.

[9] Br J Nutr. 2010 Aug;104 Suppl 2:S1-63.

[10] Nutrients. 2013 Apr 22;5(4):1417-35.