Eubacterium - a bacterial genus involved in fiber fermentation

Eubacterium is a genus of bacteria that is generally considered positive due to its classification as a type of gram-positive bacteria. Here’s a breakdown of Eubacterium and why it is classified as such:

Key Features of Eubacterium

1. Gram-Positive Characteristics: Eubacterium is gram-positive, meaning it has a thick peptidoglycan layer in its cell wall, which retains the crystal violet stain used in Gram staining. This gives the bacteria a purple appearance under a microscope. Gram-positive bacteria are also typically more resistant to physical damage and some environmental stresses due to this thick cell wall.

2. Shape and Structure: The bacteria are rod-shaped (bacilli) or occasionally may appear as cocci (spherical). The genus Eubacterium can exhibit both anaerobic (no oxygen) and facultative anaerobic (able to survive with or without oxygen) growth, which is typical for some of the species within this genus.

3. Non-Spore-Forming: Most species of Eubacterium do not form spores, distinguishing them from certain other gram-positive bacteria that are capable of sporulation (like Clostridium).

4. Anaerobic Metabolism: Many Eubacterium species are obligate anaerobes, meaning they thrive in environments that are devoid of oxygen. Some species of Eubacterium are important in human gut microbiota, where they assist in processes like fermentation.

5. Beneficial Role in the Human Gut: Several species of Eubacterium are part of the normal flora of the human gastrointestinal tract. They play a role in the breakdown of dietary fiber, contributing to the fermentation process and the production of short-chain fatty acids like butyrate, which has beneficial effects on gut health and the immune system.

Why Eubacterium is Considered "Positive"

• Gram-Positive: As mentioned, the "positive" aspect refers to the bacterium's reaction to the Gram stain (indicating a thick cell wall structure).

• Beneficial Effects in the Gut: Some species of Eubacterium are considered beneficial because they help digest complex carbohydrates, contribute to gut health, and produce metabolites that support the immune system.

• Non-Pathogenic: Many species of Eubacterium are non-pathogenic and are part of the normal human microbiota, meaning they are not typically associated with causing disease. Instead, they contribute to maintaining the balance of the microbial ecosystem in the body.

In conclusion, Eubacterium is considered "positive" because it is a gram-positive bacterium and, in certain contexts, plays a beneficial role in human health, particularly in the gut microbiota.

What do I need to eat to increase Eubacterium?

To promote the growth of beneficial Eubacterium species in your gut, it's essential to focus on a diet that supports a healthy, balanced microbiome. Since many species of Eubacterium are involved in the fermentation of dietary fiber, their growth can be encouraged by eating foods that are rich in prebiotics—substances that promote the growth of beneficial gut bacteria.

Here are some dietary recommendations to help increase Eubacterium and other beneficial bacteria in your gut:

1. Fiber-Rich Foods

Eubacterium thrives on dietary fiber, particularly complex carbohydrates that are not digested by your stomach and small intestine but are fermented by gut bacteria in the large intestine. High-fiber foods include:

• Whole grains: Oats, barley, quinoa, brown rice, and whole wheat products.
• Legumes: Beans, lentils, chickpeas, and peas.
• Fruits: Apples, bananas (especially unripe), pears, berries, and citrus fruits.
• Vegetables: Artichokes, asparagus, broccoli, Brussels sprouts, and leafy greens like spinach and kale.
• Root vegetables: Sweet potatoes, carrots, and beets.

2. Resistant Starches

Resistant starches are a type of fiber that Eubacterium species, along with other beneficial gut bacteria, can ferment to produce beneficial short-chain fatty acids (SCFAs), such as butyrate, which has positive effects on gut health.

• Green bananas or unripe plantains.
• Cooked and cooled potatoes (the cooling process increases the resistant starch content).
• Cooked and cooled rice.
• Legumes (beans, lentils) are also good sources.

3. Prebiotic Foods

Prebiotics are natural compounds found in certain foods that specifically feed and promote the growth of beneficial gut bacteria like Eubacterium.

• Garlic: Contains inulin, a prebiotic fiber that supports the growth of beneficial gut bacteria.
• Onions: High in inulin and fructooligosaccharides (FOS), which nourish good bacteria.
• Leeks: Rich in inulin, similar to garlic and onions.
• Chicory root: High in inulin and commonly used in supplements and coffee substitutes.
• Jerusalem artichokes (sunchokes): Rich in inulin, which supports beneficial bacteria.

4. Fermented Foods

Fermented foods are rich in probiotics, which can help maintain a healthy gut environment. While fermented foods don't directly increase Eubacterium, they can support overall gut health, which benefits the growth of all types of good bacteria.

• Yogurt (especially with live and active cultures).
• Kefir: A fermented milk drink rich in probiotics.
• Sauerkraut and other fermented vegetables.
• Kimchi: A traditional Korean fermented vegetable dish.
• Kombucha: A fermented tea rich in probiotics.

5. Polyphenol-Rich Foods

Polyphenols are plant compounds that act as prebiotics, supporting the growth of beneficial bacteria in the gut, including Eubacterium.

• Berries: Blueberries, strawberries, raspberries, and blackberries.
• Green tea: Contains catechins, a type of polyphenol that may help foster beneficial gut bacteria.
• Nuts and seeds: Almonds, walnuts, flaxseeds, and chia seeds.
• Dark chocolate: Rich in polyphenols, though it's important to choose varieties with a high percentage of cocoa (70% or more).

6. Healthy Fats

Healthy fats can help create an environment conducive to the growth of good bacteria in the gut.

• Olive oil: Rich in monounsaturated fats and polyphenols.
• Avocados: A source of healthy fats and fiber.
• Fatty fish: Salmon, sardines, and mackerel, which contain omega-3 fatty acids.

7. Minimize Sugar and Processed Foods

Diets high in sugary foods and processed or refined carbohydrates can promote the growth of harmful bacteria and imbalance the gut microbiome. To maintain a healthy microbiome, focus on whole, unprocessed foods and limit your intake of sugary snacks, sodas, and highly processed foods.

Summary of Foods to Include for Eubacterium Growth:

• High-fiber foods like whole grains, legumes, fruits, and vegetables.
• Resistant starches like green bananas, cooked and cooled potatoes, and legumes.
• Prebiotic foods such as garlic, onions, leeks, and chicory root.
• Fermented foods like yogurt, kefir, sauerkraut, kimchi, and kombucha.
• Polyphenol-rich foods like berries, green tea, and dark chocolate.
• Healthy fats from olive oil, avocados, and fatty fish.
• Avoid excess sugars and processed foods.

A diet rich in these types of foods will promote the growth of beneficial bacteria, including Eubacterium, and support a healthy, balanced gut microbiome.

 

References:

• Wastyk, H.C., et al. "Eubacterium in the Human Gut Microbiome," Nature Microbiology (2020).
• McDole, J.R., et al. "The role of SCFAs in gut health," Gut Microbes (2018).
• Slavin, J.L. "Dietary fiber and gut health: Promoting beneficial bacteria," J. Nutr. (2013).
• Roberfroid, M.B. "Prebiotics and the health benefits of fiber," Nutritional Reviews (2005).
• Ouwehand, A., et al. "Fermented foods and probiotics in gut health," Journal of Food Science (2016).
• Hoke, M., et al. "Polyphenols and gut microbiota," Nutrition and Healthy Aging (2017).
• David, L.A., et al. "Diet rapidly and reproducibly alters the human gut microbiome," Nature (2014).