Erin Judge, RDN, LDN, CPT, who is a registered dietitian nutritionist, certified personal trainer, and founder of Gutivate, a virtual nutrition counseling practice for digestive disorders and gastrointestinal conditions is here to discuss the importance of gut health. Erin's expertise is in providing medical nutrition therapy for functional gut disorders with a patient-centered focus. She is proud of her work in education and advocacy for the IBS patient community through social media, as well as her work in providing resources for dietitians in the GI field.
You can connect with Erin on social media @erinjudge.rd or online at www.gutivate.com
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Health starts in the gut. This has been the theme of health research over the last 5-10 years, and the more researchers uncover about the gut, the more true this statement becomes.
Aside from the endless ads you get on social media or influencers sharing the next big product to “heal your gut,” what does gut health actually mean and how do you get there?
The goal of this article is to break this down into the core components of gut health, how to know they’re in a good place, and what science says actually helps.
Gut health means that each core function of the gut is working as it should in the absence of gastrointestinal (GI) disease or illness. The core functions of the gut include digestion and absorption of nutrients, removal of waste through stool, protection from pathogens and immune system function, and an effective gut environment including the makeup and function of gut microbes. (1)
The exact markers of a healthy gut will be unique to each person, based on where you are starting, what barriers may be in place including GI conditions, and your goals. The following are goals you can start with and personalize for yourself.
Digestion and absorption of nutrients: This process is crucial for the body to obtain what it needs for energy, growth, and maintenance of all bodily functions. (2)
Healthy and effective digestion and absorption means that the body is producing acids, enzymes, and bile to chemically break down nutrients in foods, then it’s transporting those nutrients to be used or stored for later use.
Signs that something might be wrong with digestion and absorption include persistent digestive symptoms (bloating, gas, abdominal pain, or indigestion), changes in bowel habits, unexplained weight changes, nutrient deficiencies, and food intolerances.
Removal of waste through stool: This process is important because there are byproducts of absorption and digestion that aren’t used by the body, as well as substances the body doesn’t need or could be harmful to the body. This includes nondigestible fibers, dead cells, unabsorbed water and bile, and pathogenic (aka harmful) bacteria.
If these byproducts aren’t removed by the body through the formation and release of stool, they would build up in the GI tract and can lead to complications including excess gas production, bloating, perforation of the bowels, disruption of the gut microbiome, and more.
Healthy and effective removal of waste looks like having 1-3 well-formed and satisfying bowel movements per day. These should be easy to pass and a smooth shape. Signs that something may be wrong would be incomplete bowel movements, too few or too many per day/week, poor consistency of either too hard or too soft, and difficulty to pass.
Protection from pathogens and immune system function: The gut acts as a physical barrier from everything that comes into the body through eating and breathing and the body itself. The gut barrier is responsible for keeping the things that could be harmful to the body, including pathogenic microbes and toxins, from entering the body and wreaking havoc on different organs and systems. The gut also includes many immune cells that are responsible for acting on harmful substances in order to prevent as much injury as possible.
Healthy and effective immune function in the gut includes very little gut permeability, meaning that the gut wall is properly allowing in nutrients while keeping out pathogens, as well as immune cell activation when needed for protection. (3)
Signs that something may be wrong is immune activation without the presence of harm, leading to unnecessary inflammation. In some cases this can also lead to food allergies and intolerances. Signs of increased gut permeability include digestive symptoms like bloating and altered bowel habits, as well as food intolerance. (4)
An effective gut environment: The gut is made up of microbes including bacteria, fungi, and yeasts that interact with one another and different systems in the body. This microbial community plays a crucial role in various aspects of human health, including digestion, immune function, and the synthesis of certain vitamins. (5)
An ideal gut environment includes an adequate amount and diversity of beneficial gut microbes. Signs of a healthy gut microbiome include regular bowel movements, diverse diet tolerance, stable weight, steady mental health, and absence of chronic digestive symptoms. Signs that something may be wrong in the gut environment is disruption of all the above. Poor immunity and increased allergies can also be a sign something is off. (6)
To support a healthy gut, it's important to maintain a balanced and varied diet of fiber-rich foods, as well as to avoid excessive use of antibiotics and other factors that can disrupt the microbial balance. Research from The American Gut Project shows that eating 30 different plant foods per week is associated with diversity of the gut microbiome, and that a diet rich in all plant foods can improve the markers reviewed above. (7)
This doesn’t mean that you have to eat a vegan diet, and instead means to focus on what you can add to your diet, including grains, legumes, fruits, vegetables, nuts, seeds, teas, herbs, and spices.
Probiotics, which are live beneficial bacteria, and prebiotics, which are substances that promote the growth of beneficial bacteria, can also be beneficial for maintaining a healthy gut microbiome. You can find probiotics through fermented foods, such as kefir, sauerkraut, and kimchi. You can find prebiotics through certain fiber-rich foods, which is another value of a diversity of plant sources in your diet. (7)
As you do focus on what to add to your diet, it can also help to reduce diet disruptors, including excess saturated fat, alcohol, and ultra processed foods. (8, 9)
In addition to your diet, you can support a healthy gut through adequate sleep of 7-9 hours per night, reduced stress, and consistent movement practices. (10, 11)
References:
- Hornbuckle WE, Simpson KW, Tennant BC. Gastrointestinal Function. Clinical Biochemistry of Domestic Animals. 2008:413–57. doi: 10.1016/B978-0-12-370491-7.00014-3. Epub 2008 Oct 22. PMCID: PMC7173558
- Goodman BE. Insights into digestion and absorption of major nutrients in humans. Adv Physiol Educ. 2010 Jun;34(2):44-53. doi: 10.1152/advan.00094.2009. PMID: 20522896.
- Kayama H, Okumura R, Takeda K. Interaction Between the Microbiota, Epithelia, and Immune Cells in the Intestine. Annu Rev Immunol. 2020 Apr 26;38:23-48. doi: 10.1146/annurev-immunol-070119-115104. PMID: 32340570.
- Saffouri GB, Shields-Cutler RR, Chen J, Yang Y, Lekatz HR, Hale VL, Cho JM, Battaglioli EJ, Bhattarai Y, Thompson KJ, Kalari KK, Behera G, Berry JC, Peters SA, Patel R, Schuetz AN, Faith JJ, Camilleri M, Sonnenburg JL, Farrugia G, Swann JR, Grover M, Knights D, Kashyap PC. Small intestinal microbial dysbiosis underlies symptoms associated with functional gastrointestinal disorders. Nat Commun. 2019 May 1;10(1):2012. doi: 10.1038/s41467-019-09964-7. PMID: 31043597; PMCID: PMC6494866.
- Chen Y, Zhou J, Wang L. Role and Mechanism of Gut Microbiota in Human Disease. Front Cell Infect Microbiol. 2021 Mar 17;11:625913. doi: 10.3389/fcimb.2021.625913. PMID: 33816335; PMCID: PMC8010197.
- Shu SA, Yuen AWT, Woo E, Chu KH, Kwan HS, Yang GX, Yang Y, Leung PSC. Microbiota and Food Allergy. Clin Rev Allergy Immunol. 2019 Aug;57(1):83-97. doi: 10.1007/s12016-018-8723-y. PMID: 30564985.
- McDonald D, Hyde E, Debelius JW, Morton JT, Gonzalez A, Ackermann G, Aksenov AA, Behsaz B, Brennan C, Chen Y, DeRight Goldasich L, Dorrestein PC, Dunn RR, Fahimipour AK, Gaffney J, Gilbert JA, Gogul G, Green JL, Hugenholtz P, Humphrey G, Huttenhower C, Jackson MA, Janssen S, Jeste DV, Jiang L, Kelley ST, Knights D, Kosciolek T, Ladau J, Leach J, Marotz C, Meleshko D, Melnik AV, Metcalf JL, Mohimani H, Montassier E, Navas-Molina J, Nguyen TT, Peddada S, Pevzner P, Pollard KS, Rahnavard G, Robbins-Pianka A, Sangwan N, Shorenstein J, Smarr L, Song SJ, Spector T, Swafford AD, Thackray VG, Thompson LR, Tripathi A, Vázquez-Baeza Y, Vrbanac A, Wischmeyer P, Wolfe E, Zhu Q; American Gut Consortium; Knight R. American Gut: an Open Platform for Citizen Science Microbiome Research. mSystems. 2018 May 15;3(3):e00031-18. doi: 10.1128/mSystems.00031-18. PMID: 29795809; PMCID: PMC5954204.
- Zhang M, Yang XJ. Effects of a high fat diet on intestinal microbiota and gastrointestinal diseases. World J Gastroenterol. 2016 Oct 28;22(40):8905-8909. doi: 10.3748/wjg.v22.i40.8905. PMID: 27833381; PMCID: PMC5083795.
- Bolte LA, Vich Vila A, Imhann F, Collij V, Gacesa R, Peters V, Wijmenga C, Kurilshikov A, Campmans-Kuijpers MJE, Fu J, Dijkstra G, Zhernakova A, Weersma RK. Long-term dietary patterns are associated with pro-inflammatory and anti-inflammatory features of the gut microbiome. Gut. 2021 Jul;70(7):1287-1298. doi: 10.1136/gutjnl-2020-322670. Epub 2021 Apr 2. PMID: 33811041; PMCID: PMC8223641.
- Sanford LD, Wellman LL, Ciavarra RP, Oldfield EC 4th, Shams R, Copare JL, Johnson DA. Differential Effect of Light and Dark Period Sleep Fragmentation on Composition of Gut Microbiome and Inflammation in Mice. Life (Basel). 2021 Nov 23;11(12):1283. doi: 10.3390/life11121283. PMID: 34947814; PMCID: PMC8709399.
- Gubert C, Kong G, Renoir T, Hannan AJ. Exercise, diet and stress as modulators of gut microbiota: Implications for neurodegenerative diseases. Neurobiol Dis. 2020 Feb;134:104621. doi: 10.1016/j.nbd.2019.104621. Epub 2019 Oct 16. PMID: 31628992.