The Gut-Protein Connection, Transforming Gut Health in Midlife
Protein isn't just about building muscles; it's about building a strong and healthy gut.
Protein is one of the primary building blocks for all cells in the human body, including your gut cells. Even gut probiotics are made of protein.
Research has shown that both the amino acid balance and digestibility of dietary protein are primary factors contributing to gut microbes' composition, structure, and function. [1]
If you live in Australia, you’d think that protein malnutrition couldn’t exist. But many people in their midlife aren't eating enough protein, especially with trendy vegan and vegetarian diets on the rise.
Not only is there a problem with quantity, but protein quality also matters.
You are what you eat.
Fascinatingly, early research shows that low protein diets, like many restrictive diets today, cause the gut lining to become leaky [2].
"Leaky gut," also known as increased intestinal permeability, is a condition where the lining of the small intestine becomes damaged or compromised, allowing substances such as toxins, bacteria, and undigested food particles to leak into the bloodstream.
Typically, the cells lining the intestines are tightly packed together, forming a barrier that regulates the passage of nutrients and other substances into the bloodstream.
When the integrity of this barrier is compromised, gaps or "leaks" develop between the cells, allowing larger molecules to pass through. This allows bacteria to spread to the liver, the spleen, and other organs, creating inflammation throughout the body and brain.
Symptoms of leaky gut include:
1. Digestive Issues:
Chronic diarrhea
Constipation
Gas and bloating
Abdominal pain or discomfort
Irritable bowel syndrome (IBS) symptoms
2. Food Sensitivities:
Increased sensitivity to certain foods
Development of food intolerances
3. Nutritional Deficiencies:
Malabsorption of nutrients leading to deficiencies, such as vitamin B12, iron, and magnesium
Unexplained weight loss or inability to gain weight despite adequate caloric intake
4. Skin Problems:
Skin conditions such as acne, eczema, or psoriasis
Itchy skin or rashes
5. Autoimmune Symptoms:
Symptoms related to autoimmune conditions such as rheumatoid arthritis, lupus, or Hashimoto's thyroiditis
Joint pain and inflammation
Fatigue and weakness
6. Brain Fog and Mood Changes:
Cognitive symptoms such as brain fog, difficulty concentrating, or memory issues
Mood swings, anxiety, or depression
7. Fatigue and Low Energy:
Persistent fatigue or low energy levels
Difficulty maintaining energy throughout the day
8. Immune System Dysfunction:
Frequent infections or illnesses
Allergies or sensitivities to environmental triggers
A leaky gut can lead to a whole host of metabolic and autoimmune diseases such as obesity, type 2 diabetes, hypothyroidism, rheumatoid arthritis, multiple sclerosis, hashimoto's, inflammatory bowel disease, graves' disease, vitiligo, and many more.
Misguided culture has led us to believe that foods like beans and legumes are good protein sources. But, to equal 85g of salmon, you would have to eat 1.5 cups of black beans, while vegans and vegetarians would have to eat this amount multiple times daily to meet their protein needs.
Unfortunately, this quantity of beans often leads to uncomfortable side effects such as gas, bloating, and excessive flatulence. These are all key signs that beans and legumes aren’t good for our gut. Can you imagine consuming 5 cups of beans every day? Or attempting to reach the same protein intake with soy or tofu?
Bean and legumes also contain anti-nutrients like phytates (phytic acid), lectins, saponins, protease inhibitors, and oligosaccharides, which can interfere with the digestion and absorption of vitamins and minerals.
Even if one were to consume such quantities, the protein obtained may not be of sufficient quality due to various factors. The anti-nutritional components of plant proteins limit their digestive ability, and researchers speculate this could be why they can negatively affect the microbiome. [3,4,5]
This isn't to discount the nutritional value of certain beans and soy, which can provide protein and essential nutrients. However, the human digestive system, particularly that of omnivores, struggles to adapt to consuming such large amounts to meet protein needs.
Not long ago, the world thought the only way to keep your microbiome healthy was to eat fibre and probiotics. While these factors remain helpful, protein intake and quality play a significant role in the amount and diversity of your microbiome.
For example, when animals are undernourished in protein, they have a decrease in healthy bacteria amounts, including Lactobacillus bacteria. When given high-quality protein, the numbers and ratios of beneficial bacteria increase.
Other studies show that the ratios of gut bacteria are improved if animals are given milk protein, fish protein, or other animal protein instead of soy protein. [6]
Research shows that animal proteins, like meat, dairy (if you can handle it), and fish, are winners for gut health. They boost beneficial bacteria and pump out those good-for-you compounds like short-chain fatty acids.
Beneficial compounds made in the gut called postbiotics also increase with a higher protein in the diet. For example, more short-chain fatty acids are produced when you eat adequate quality protein.
Keeping your protein intake at around 1.4-2.0g per kg of body weight is now considered ideal, contrary to the RDA of 0.8g/kg. I wrote about this in "Unlock Peak Wellness In Midlife With 5 Key Reasons To Boost Your Protein Intake."
Here's a quick look at what that might look like:
In conclusion, the role of protein in gut health cannot be overstated. It serves as a fundamental building block for gut cells and probiotics alike, influencing the integrity and function of the gut lining.
However, the quantity and quality of protein intake are equally important. Insufficient protein intake, often seen in restrictive diets like vegan or vegetarian diets, can lead to protein malnourishment and compromise gut health.
Research indicates that high-quality animal proteins like meat, dairy (if tolerated) and fish protein are beneficial for gut health, promoting the growth of beneficial bacteria and enhancing the production of beneficial compounds like short-chain fatty acids.
Bottom line: Protein isn't just for bodybuilders. It's a gut game-changer too.
