DIVISION OF AGRICULTURE RESEARCH & EXTENSION University of Arkansas System Family and Consumer Sciences FSFCS93

Gut Microbiome: An Overview

Jamie I. Baum, PhD Gut Microbiota What is the role of the Assistant Professor ­ Gut microbiota, sometimes gut microbiome? Nutrition called gut flora, is the name given to The gut microbiome plays many

the microbe populations living in our roles in the body (1): intestines (1). Our gut microbiota It helps the body to digest Rosemary Rodibaugh, • contains tens of trillions of micro­ certain foods that the stomach PhD Professor ­ Nutrition organisms, which includes at least and small intestine have not been 1,000 different species of bacteria able to digest. containing over three million genes. It helps with the production of • Our gut microbiota can weigh up to some vitamins (B and K). 4.5 pounds. One­third of our gut micro­ It plays an important role in the • biota is shared among most people, immune system, performing a while two­thirds of our gut microbiota barrier effect. are unique to each of us, just like A healthy and balanced gut • fingerprints (1). See Table 1 for microbiota is key to ensuring beneficial and harmful bacteria (2). proper digestive functioning.

Table 1. Beneficial and How does the gut Harmful Bacteria (2) microbiome develop?

Species Beneficial Harmful The development of the gut microbiota starts at birth. The

Bifidobacterium + newborn’s digestive tract is quickly colonized by microorganisms from Eubacterium + the mother (vaginal, fecal, skin, Lactobacillus + breast, etc.), the environment in Clostridium + which the delivery takes place, the air, etc. From the third day, the Shigella + composition of the intestinal flora is Veillonella + directly dependent on how the infant is fed: breastfed babies’ gut micro­

Gut Microbiome biota, for example, is mainly domi­ nated by Bifidobacteria, compared to The microbiome is the combined Arkansas Is babies nourished with infant formu­ genetic material of all the micro­ las. Scientists consider that by the Our Campus organisms that live inside and on the age of three, microbiota becomes human body. We have about 10 times stable and similar to that of adults, as many microbial cells as human continuing its evolution at a steadier Visit our web site at: cells (3). s .uada rate throughout life (1). http ://www.uaex .edu

University of Arkansas, United States Department of Agriculture, and County Governments Cooperating probiotics. Prebiotics are natural, nondigestible foods How does the gut microbiome evolve? that promote the growth of beneficial or ‘good’ bacteria The composition of our microbiota evolves over harmful ones in your gut. Prebiotics include throughout our entire life, from birth to old age, and fructooligosaccharides, such as inulin, and galac­ is the result of different environmental influences (1), tooligosaccharides, which are found in fruits and such as our diet. vegetables. Table 2 has a list of foods that contain

prebiotics and probiotics. It is estimated that around How does the food we eat influence 4 million U.S. adults (approximately 1.6 percent of the U.S. population) have used probiotics or prebiotics in the gut microbiome? the last 30 days (5). The food we eat plays an essential role in maintaining the diversity and proper functioning of our gut microbiota. When talking about gut micro­ Table 2: Foods containing prebiotics and probiotics biota, it could be said that “we are what we eat,” as Prebiotics Probiotics what we consume also feeds the hundreds of trillions of bacteria living in our digestive system. For this Bananas Yogurt reason, a varied and balanced diet is essential. Onions Kefir

Prebiotics and probiotics are two of the most widely Garlic Aged cheeses studied elements in the field of gut microbiota. Both Asparagus Miso soup

Artichokes Pickled fruit or vegetables have effects that are considered beneficial for the gut Soybeans Tempeh (fermented soybeans) microbiota (1). How long does it take for your diet to Kimchi (Korean pickled cabbage) change your gut microbiome? A recent study suggests Whole­grain foods that it only takes three to four days (4)! Leeks Sourdough bread Peas Sauerkraut Chicory Beer Why is the gut microbiome Berries Kiwifruit important? Honey The gut microbiome is associated with both health and disease, and research has found links between the bacterial population in our gut and the References 1. Gut Microbiota Info: Public Information Service from European following diseases: asthma, autism, cancer, celiac Society of Neurogastroenterology and Motility; disease, colitis, diabetes, eczema, heart disease, [cited 2017 January 31]. Available from malnutrition, multiple sclerosis and obesity. However, http://www.gutmicrobiotaforhealth.com/en/about­gut­ more research is needed to define the exact role the microbiota­info/ . 2. Wessel, J.J. Prebiotics, Probiotics and Synbiotics: Functional gut microbiome plays in the development or Foods. AbbottNutritionHealthInstitute.org, pages 1­6. prevention of these diseases. 3. Yang, J. The Human Microbiome Project: Extending the definition of what constitutes a human: National Human Genome Research Institute; 2012 [cited 2017 January 31]. Available from https://www.genome.gov/27549400/the­human­ What kind of foods are linked to a microbiome­project­extending­the­definition­of­what­ constitutes­a­human/. healthy gut? 4. Turnbaugh, P.J., V.K. Ridaura, J.J. Faith, F.E. Rey, R. Knight There are two types of foods that are linked to a and J.I. Gordon. The effect of diet on the human gut healthy gut: probiotics and prebiotics. Probiotics are microbiome: a metagenomic analysis in humanized gnotobiotic live microorganisms that are intended to have health mice. Sci Transl Med. 2009;1(6):6ra14. doi: 10.1126/ scitranslmed.3000322. PubMed PMID: 20368178; PMCID: benefits. Products that are sold as probiotics include PMC2894525. foods such as yogurt. Prebiotics are not the same as 5. Probiotics [cited 2017 January 27]. Available from https://nccih.nih.gov/health/probiotics.

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DR. JAMIE I. BAUM is assistant professor ­ nutrition with the Department urtherance Issued in f of Cooperative Extension work, Acts of May 8 and of Food Science, University of Arkansas System Division of Agriculture in June 30, 1914, in cooperation with the U.S. Department of Agric ulture, Fayetteville. DR. ROSEMARY RODIBAUGH is professor ­ nutrition with Director, Cooperative Extension Service, University of Arkansas. The the University of Arkansas System Division of Agriculture in Little Rock. U niversity of Arkansas System Division of Agriculture offers all its E xtension and Research programs and services without regard to race, color, sex, gender identity, sexual orientation, national origin, religion, age, disa bility, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action/Equal FSFCS93­PD­4­2017N O pportunity Employer.