As a clinical nutritionist with a keen interest in the microbiota, I often find myself advocating for the inclusion of legumes in our daily diets. The trillions of microbes, including bacteria, in your gut impact your health and happiness.Once of the most exciting new areas of science is the microbiome – our family of gut bacteria that reside within our intestines. There are literally trillions of these bacteria and research is now flooding in to link these with a wide variety of health problems – not only poor digestion (IBS, inflammatory bowel disease etc.), but others that we would not expect such as cancer, dementia and emotional health and wellbeing.
Our gut bacteria react poorly to some of the foods we eat and thrive with others. We are now starting to understand that certain gut bacteria positively or negatively affect both our physical health and our mood – anxiety/depression etc. Our diet can influence the balance of our gut bacteria.
What Are Legumes?
You may have heard the term “legumes” thrown around in health circles, but what exactly does it mean? Legumes are a type of plant characterised by their fruit or seeds that grow in pods. Common varieties include dried beans, peas, chickpeas, lentils, broad beans, lupins, soybeans, and even peanuts. Each of these legumes presents a treasure trove of nutrients that can significantly enhance your diet. These remarkable plant-based foods not only offer an extensive array of nutritional benefits but also play a crucial role in maintaining a healthy gut microbiome. In this article, we will explore the multifaceted advantages of legumes and why they should occupy a staple position on your plates.
Our programs start on an 8-week basis. Why? Because there is evidence that when a patient includes those types of legumes in their diet for that time, they will be able to modulate their microbiome, and as a result, many of the initial symptoms will reduce or disappear.”
The Nutritional Benefits of Legumes
1. Gut Health
One of the most compelling reasons to incorporate legumes into your meals is their high fibre content. Fibre is essential for maintaining gut health, as it aids in digestion and promotes regular bowel movements. Legumes are also an excellent source of resistant starch, a form of carbohydrate that acts as a prebiotic, nourishing the beneficial bacteria in our gut. While initially increasing your legume intake may lead to some gastrointestinal discomfort, this can frequently indicate positive changes within your gut environment. Gradually increasing your consumption can help mitigate these symptoms.
2. Plant-Based Protein Source
Legumes are exceptionally rich in protein, making them a fantastic alternative to animal-based proteins. Unlike many animal sources, legumes contain negligible saturated fat. This quality makes them an ideal choice for anyone seeking a plant-based diet without compromising on protein intake.
3. Rich Nutrient Profile & Interaction
Legumes are abundant proteins and in B vitamins, folate, potassium, zinc, calcium, iron, and magnesium—nutrients that are essential for optimal health. This nutrient density makes legumes an invaluable addition to your diet, supporting various bodily functions and overall well-being. While gut microbiota can release metabolites that can affect host physiology either positively or negatively, the selection of quality of protein and suitable food processing conditions are important to have a positive effect of dietary protein on gut microbiota and human health.
Recent studies indicate that gut microbiota play a crucial role in linking protein metabolism to the immune response of the host. These gut microbes participate in the digestion, absorption, metabolism, and transformation of dietary proteins within the gastrointestinal system. They convert amino acids into various metabolites, which in turn are involved in numerous physiological processes that affect both health and disease in the host. The composition of dietary protein can significantly influence the gut microbiota and the metabolites produced. Key factors such as the source, concentration, and balance of amino acids in dietary protein are essential in shaping the structure and function of gut microbes. It is advisable to maintain a proper balance between protein and carbohydrates, or to adopt a low-protein diet, rather than exceeding protein requirements. Excessive amounts of undigested protein can lead to an overgrowth of harmful microorganisms, increasing the risk of metabolic disorders. This summary highlights the interaction between dietary protein and gut microbiota composition and function, aiming to clarify how gut microbes may impact gastrointestinal health.
4. Complex Carbohydrates and Glycemic Control
Unlike simple carbohydrates that can spike blood sugar levels, legumes are low on the glycemic index (GI) scale and offer complex carbohydrates. This characteristic allows for a slower, more sustained release of energy, which is particularly beneficial for individuals managing diabetes.
5. Versatility in Cooking
The culinary flexibility of legumes is one of their most attractive qualities. Whether you’re blending chickpeas into creamy hummus, adding lentils to soups and stews for an added protein boost, or roasting black beans for a crunchy snack, the possibilities are virtually endless. Their adaptability makes it easy to incorporate them into any meal. Using spices: Adding certain spices like cumin, coriander, fennel seeds, or ginger can help break down the complex carbohydrates in legumes and make them easier to digest. Soaking: Soaking legumes overnight before cooking can help reduce their phytic acid content, which is known to interfere with nutrient absorption.
6. Economic and Sustainable
Legumes are an economical choice for anyone aiming to maintain a healthy diet. Beyond their affordability, many legumes boast a long shelf life, making them an excellent and convenient pantry staple. According to the 2019 EAT-Lancet report, incorporating at least 50 grams (about ¼ cup) of legumes into your daily diet is essential for promoting personal health and sustainable eating practices. These nutrient-rich foods are foundational in traditional diets around the globe, contributing to low greenhouse gas emissions and minimal water usage. Additionally, legumes enrich the soil through nitrogen fixation, providing a sustainable protein source. However, challenges such as erratic crop yields and lower profitability compared to other crops can hinder their wider adoption.
7. High in Fibre
Most individuals fail to meet the recommended daily fibre intake (25g for women, 30g for men). Legumes are an excellent source of both soluble and insoluble fibre, which can help improve satiety, manage cholesterol levels, and diminish the risk of diseases such as colon cancer.
The alimentary habits are crucial in the conformation of gut microbiota. The Mediterranean diet is widely recognized for its health benefits and has been associated with a lower risk of colon cancer. On the other hand, inflammation is a process commonly associated with cancer, and the intestinal microbiota interacts with the host to maintain normal function and health, particularly in processes of immunity and defense. The above image , we are focusing in particular on two groups of substances (fibre, protein fractions) present in legumes whose mechanisms of action to prevent colon cancer or inflammation are likely to be mediated by the intestinal microbiota functional composition.
8. Chronic Disease Prevention
The mineral content of legumes varies significantly, influenced by factors such as their inherent mineral composition, mineral interactions, and the presence of phytic and tannic acids. Recognized as low glycemic index (GI) foods, legumes have demonstrated promising effects in lowering cholesterol levels. This evidence positions legumes as functional foods with potential health benefits.
Regularly incorporating legumes into your diet is associated with numerous health advantages, such as reduced cholesterol levels, lower blood pressure, and a decreased risk of chronic diseases like heart disease. Research indicates that consuming approximately 50 grams of legumes daily may also correlate with a lower risk of mortality.
The human gastrointestinal tract hosts a diverse microbiota, comprising bacteria, fungi, archaea, protozoans, and viruses. Notably, more than 90% of these microorganisms belong to four primary phyla: Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. The major “enterotypes” are primarily represented by the genera Bacteroides, Ruminococcus, and Prevotella. Dysbiosis, or an imbalance in this microbiota, has been associated with various disorders, including digestive issues (such as Crohn’s disease and irritable bowel syndrome), metabolic conditions (like obesity and diabetes), and other health challenges (including allergies and autism).
9. Cancer Protection
Research indicates that the intake of legumes, particularly soybeans, may harbour protective effects against certain types of cancer, including prostate and breast cancer.
The Impact of Diet on Lipid Peroxidation Biomarkers in Colon Health
A research has focused on lipid peroxidation biomarkers that indicate oxidative stress and inflammation in colon tissues, which are essential for understanding and ultimately intervening in the onset and progression of colon cancer. It has been exploreed how dietary changes may influence the expansion of specific gut bacteria, potentially driving tumor development in the colonic epithelium or creating environments conducive to tumor growth. Recent findings shed light on these mechanisms.
For the first time, the results reveal a significant protective effect against colon tumorigenesis from a diet rich in fish and spinach, while also confirming the potential carcinogenic effects of a diet high in red and processed meats. These dietary effects correlate with variations in critical colorectal cancer (CRC) biomarkers, including apoptosis, inflammation, intestinal permeability, and oxidative stress.
Moreover, the fecal microbiota transplant experiment has established a clear causal link between diet-altered microbiota and CRC risk. This underscores the protective role of a gut microbiome associated with a plant- and vegetable-based diet (PVD) and the detrimental effects linked to a meat-based diet (MBD). Notably, we observed a negative correlation between non-carcinogenic biological amines (NCBAs) and specific bacterial genera from the Lachnospiraceae and Prevotellaceae families, which are prevalent in the PVD diet. This suggests a relationship between shifts in bacterial populations and metabolic profiles.
Despite previous studies indicating that colon cancer risk factors can be influenced by the fecal microbiome, our findings bolster the understanding of how diet shapes microbiota and impacts colon cancer risk.
10. Weight Management
With their high protein and fibre content, legumes can aid in weight management. The satiety provided by these foods helps to curtail hunger, while their fibrous nature means that not all of it is broken down during digestion—potentially resulting in lower overall calorie intake.
My Thoughts
Incorporating legumes into your daily diet not only enriches your nutritional intake but also fosters a thriving gut microbiome, filled with the symbiotic bacteria essential for optimal health. The diverse range of legumes mirrors the trillions of beneficial bacteria that exist within our microbiota, thereby highlighting the interconnectedness of our dietary choices and gut health. By embracing a variety of legumes, you empower yourself to make decisions that support both your health and the environment.
For tailored advice on how to effectively include legumes in your diet, do not hesitate to book a consultation with our expert gut health dietitians today!
For more insights into Dietary Protein and Gut Microbiota Composition and Function and recent research, check out the detailed findings in this article
Images credits:
- https://www.eurekaselect.com/article/90389
