KORN KURATED RESEARCH

The Benefits of Slime: Protect, Lubricate, Defend

Slimy foods might seem off-putting to some, but they play a vital role in our health, mirroring the essential functions of mucus in our gut. From protecting the stomach lining to supporting a healthy microbiome, mucus is our slimy friend. Let’s explore why embracing mucilaginous foods could be a game-changer for your digestive health.

I love slimy foods. They feel right. I know not everyone likes slime—some people even get grossed out by it. However, I want to convince you why you should embrace this type of food, or at least chew it a little, and why slime can be your friend. In these superb research articles, scientists have tackled why slimy innards, our guts, require slime (mucus). But first, a primer on mucus!

The mucus layer in the gut, throat, and intestines serves several crucial protective and functional roles across the digestive tract:

The mucus in the esophagus allows smooth passage of food and liquids to the stomach, reducing friction and preventing injury to the esophageal lining. It also protects the lining from damage due to acid reflux.   

In the stomach, the mucus layer protects the stomach lining from this acid, preventing damage and ulcer formation. It also contains bicarbonate ions that help neutralize stomach acid to protect stomach cells from acidity. 

In the intestines, mucus is a barrier against harmful substances, pathogens, and toxins that might enter with food and also helps lubricate the intestinal walls.

The mucus in the large intestine provides:

• Habitat for beneficial bacteria.
• A healthy microbiome and aiding digestion.
• Immunity.
• Overall gut health.

So consider our slimy friend's role to Protect, Lubricate, and Defend!

Enjoy the research articles below while you eat mucilaginous foods. Among my favorites are nopal, flax, chia seeds, plantains, sea moss, oats, okra, and, of course, our healing herbs, licorice, and Slippery Elm. The articles provide solid reviews of the importance of mucins and mucus for gut health.

Tags: mucins, mucus barrier, mucus layer, gastrointestinal tract, gut health, gut microbiota

Interested in Learning More?

• Course(s): Food as Medicine
• Course(s): Mental Health Disorders
• Book(s): Nutrition Essentials For Mental Health
• Book(s): The Good Mood Kitchen

Referenced Research Publications

Gut
2020, September 11
DOI: https://doi.org/10.1136/gutjnl-2020-322260

Mucus barrier, mucins and gut microbiota: the expected slimy partners?

Abstract

The gastrointestinal tract is often considered as a key organ involved in the digestion of food and providing nutrients to the body for proper maintenance. However, this system is composed of organs that are extremely complex. Among the different parts, the intestine is viewed as an incredible surface of contact with the environment and is colonised by hundreds of trillions of gut microbes. The role of the gut barrier has been studied for decades, but the exact mechanisms involved in the protection of the gut barrier are various and complementary. Among them, the integrity of the mucus barrier is one of the first lines of protection of the gastrointestinal tract. In the past, this 'slimy' partner was mostly considered a simple lubricant for facilitating the progression of the food bolus and the stools in the gut. Since then, different researchers have made important progress, and currently, the regulation of this mucus barrier is gaining increasing attention from the scientific community. Among the factors influencing the mucus barrier, the microbiome plays a major role in driving mucus changes. Additionally, our dietary habits (ie, high-fat diet, low-fibre/high-fibre diet, food additives, pre- probiotics) influence the mucus at different levels. Given that the mucus layer has been linked with the appearance of diseases, proper knowledge is highly warranted. Here, we debate different aspects of the mucus layer by focusing on its chemical composition, regulation of synthesis and degradation by the microbiota as well as some characteristics of the mucus layer in both physiological and pathological situations.

Reference

Paone, P., & Cani, P. D. (2020). Mucus barrier, mucins and gut microbiota: the expected slimy partners?. Gut, 69(12), 2232–2243. https://doi.org/10.1136/gutjnl-2020-322260

Gastroenterology Report
2019, February 13
DOI: https://doi.org/10.1093/gastro/goy052

Fight them or feed them: how the intestinal mucus layer manages the gut microbiota

Abstract

The intestinal tract is inhabited by a tremendous number of microorganisms, termed the gut microbiota. These microorganisms live in a mutualistic relationship with their host and assist in the degradation of complex carbohydrates. Although the gut microbiota is generally considered beneficial, the vast number of microbial cells also form a permanent threat to the host. Thus, the intestinal epithelium is covered with a dense layer of mucus to prevent translocation of the gut microbiota into underlying tissues. Intestinal mucus is an organized glycoprotein network with a host-specific glycan structure. While the mucus layer has long been considered a passive, host-designed barrier, recent studies showed that maturation and function of the mucus layer are strongly influenced by the gut microbiota. In return, the glycan repertoire of mucins can select for distinct mucosa-associated bacteria that are able to bind or degrade specific mucin glycans as a nutrient source. Because the intestinal mucus layer is at the crucial interface between host and microbes, its breakdown leads to gut bacterial encroachment that can eventually cause inflammation and infection. Accordingly, a dysfunctional mucus layer has been observed in colitis in mice and humans. Moreover, the increased consumption of a low-fiber Western-style diet in our modern society has recently been demonstrated to cause bacteria-mediated defects of the intestinal mucus layer. Here, I will review current knowledge on the interaction between gut bacteria and the intestinal mucus layer in health and disease. Understanding the molecular details of this host-microbe interaction may contribute to the development of novel treatment options for diseases involving a dysfunctional mucus layer, such as ulcerative colitis.

Reference

Schroeder B. O. (2019). Fight them or feed them: how the intestinal mucus layer manages the gut microbiota. Gastroenterology report, 7(1), 3–12. https://doi.org/10.1093/gastro/goy052

Frontiers in immunology
2022, September 13
DOI: https://doi.org/10.3389/fimmu.2022.953196

Diet, microbiota, and the mucus layer: The guardians of our health

Abstract

The intestinal tract is an ecosystem in which the resident microbiota lives in symbiosis with its host. This symbiotic relationship is key to maintaining overall health, with dietary habits of the host representing one of the main external factors shaping the microbiome-host relationship. Diets high in fiber and low in fat and sugars, as opposed to Western and high-fat diets, have been shown to have a beneficial effect on intestinal health by promoting the growth of beneficial bacteria, improve mucus barrier function and immune tolerance, while inhibiting pro-inflammatory responses and their downstream effects. On the contrary, diets low in fiber and high in fat and sugars have been associated with alterations in microbiota composition/functionality and the subsequent development of chronic diseases such as food allergies, inflammatory bowel disease, and metabolic disease. In this review, we provided an updated overview of the current understanding of the connection between diet, microbiota, and health, with a special focus on the role of Western and high-fat diets in shaping intestinal homeostasis by modulating the gut microbiota.

Reference

Suriano, F., Nyström, E. E. L., Sergi, D., & Gustafsson, J. K. (2022). Diet, microbiota, and the mucus layer: The guardians of our health. Frontiers in immunology, 13, 953196. https://doi.org/10.3389/fimmu.2022.953196

International journal of molecular sciences
2021, September 23
DOI: https://doi.org/10.3390/ijms221910224

Gut Microbiota and Dietary Factors as Modulators of the Mucus Layer in Inflammatory Bowel Disease

Abstract

The gastrointestinal tract is optimized to efficiently absorb nutrients and provide a competent barrier against a variety of lumen environmental compounds. Different regulatory mechanisms jointly collaborate to maintain intestinal homeostasis, but alterations in these mechanisms lead to a dysfunctional gastrointestinal barrier and are associated to several inflammatory conditions usually found in chronic pathologies such as inflammatory bowel disease (IBD). The gastrointestinal mucus, mostly composed of mucin glycoproteins, covers the epithelium and plays an essential role in digestive and barrier functions. However, its regulation is very dynamic and is still poorly understood. This review presents some aspects concerning the role of mucus in gut health and its alterations in IBD. In addition, the impact of gut microbiota and dietary compounds as environmental factors modulating the mucus layer is addressed. To date, studies have evidenced the impact of the three-way interplay between the microbiome, diet and the mucus layer on the gut barrier, host immune system and IBD. This review emphasizes the need to address current limitations on this topic, especially regarding the design of robust human trials and highlights the potential interest of improving our understanding of the regulation of the intestinal mucus barrier in IBD.

Reference

Fernández-Tomé, S., Ortega Moreno, L., Chaparro, M., & Gisbert, J. P. (2021). Gut Microbiota and Dietary Factors as Modulators of the Mucus Layer in Inflammatory Bowel Disease. International journal of molecular sciences, 22(19), 10224. https://doi.org/10.3390/ijms221910224

Microorganisms
2018, August 02
DOI: https://doi.org/10.3390/microorganisms6030078

The Interaction of the Gut Microbiota with the Mucus Barrier in Health and Disease in Human

Abstract

Glycoproteins are major players in the mucus protective barrier in the gastrointestinal and other mucosal surfaces. In particular the mucus glycoproteins, or mucins, are responsible for the protective gel barrier. They are characterized by their high carbohydrate content, present in their variable number, tandem repeat domains. Throughout evolution the mucins have been maintained as integral components of the mucosal barrier, emphasizing their essential biological status. The glycosylation of the mucins is achieved through a series of biosynthetic pathways processes, which generate the wide range of glycans found in these molecules. Thus mucins are decorated with molecules having information in the form of a glycocode. The enteric microbiota interacts with the mucosal mucus barrier in a variety of ways in order to fulfill its many normal processes. How bacteria read the glycocode and link to normal and pathological processes is outlined in the review.

Reference

Corfield A. P. (2018). The Interaction of the Gut Microbiota with the Mucus Barrier in Health and Disease in Human. Microorganisms, 6(3), 78. https://doi.org/10.3390/microorganisms6030078

Biochemical Society Transactions
2022, October 31
DOI: https://doi.org/10.1042/bst20201201

Relationship between mucosa-associated gut microbiota and human diseases

Abstract

The mucus layer covering the gastrointestinal (GI) tract plays a critical role in maintaining gut homeostasis. In the colon, the inner mucus layer ensures commensal microbes are kept at a safe distance from the epithelium while mucin glycans in the outer mucus layer provide microbes with nutrients and binding sites. Microbes residing in the mucus form part of the so-called 'mucosa-associated microbiota' (MAM), a microbial community which, due to its close proximity to the epithelium, has a profound impact on immune and metabolic health by directly impacting gut barrier function and the immune system. Alterations in GI microbial communities have been linked to human diseases. Although most of this knowledge is based on analysis of the faecal microbiota, a growing number of studies show that the MAM signature differs from faecal or luminal microbiota and has the potential to be used to distinguish between diseased and healthy status in well-studied conditions such as IBD, IBS and CRC. However, our knowledge about spatial microbial alterations in pathogenesis remains severely hampered by issues surrounding access to microbial communities in the human gut. In this review, we provide state-of-the-art information on how to access MAM in humans, the composition of MAM, and how changes in MAM relate to changes in human health and disease. A better understanding of interactions occurring at the mucosal surface is essential to advance our understanding of diseases affecting the GI tract and beyond.

Reference

Juge N. (2022). Relationship between mucosa-associated gut microbiota and human diseases. Biochemical Society transactions, 50(5), 1225–1236. https://doi.org/10.1042/BST20201201