The high protein diet and our microbiome

Biome Basics

Our gut contains trillions of bacteria that have a weight of over 1kg!

Bacteria perform different functions for us – help to break down foods, manufacture vitamins, amino acids, calm our immune system, influence our mood and may even affect our ability to cope with stress. Traditionally our gut microbiome was much more diverse before the development of antibiotics as well as before the development of specific types of food additives.

It’s a partnership

Fibre passes into your large bowel and feeds your gut bacteria, then good bacteria such as Bifidobacterium create short chain fatty acid compounds such as butyrate. Butyrate is food for your endothelial cells that line your gut and helps maintain the barrier between the endothelial cells and the contents of the gut. Butyrate helps the body make more T regulatory cells that reduce inflammation and has also been associated with a reduced risk of bowel cancer.

Western diets

Westerners typically eat less than the recommended amount of fibre and are high in protein. Having higher levels of protein in the diet has been shown to increase diversity, while perhaps not in a favourable way. Very high animal protein diets have been shown to reduce the beneficial species Bifidobacterium and increase the pathogenic Clostridia. A large participant prospective study found that high total protein intake, especially animal protein, is associated with a significantly increased risk of irritable bowel disease. Additionally, bacteria that thrive when the host eats red meat can create higher levels of trimethylamine-N-oxide (TMAO), a pro-atherogenic compound that increases the risk of cardiovascular disease.

Artificial sugars, processed meats and emulsifiers have all been implicated with detrimental effects on the gut microbiome. Recent evidence suggests that consumption of all types of artificial sweeteners is actually more likely to induce glucose intolerance than consumption of pure glucose and sucrose. Artificial sweeteners have been found to unfavourably change our gut microbiome to promote weight gain. Processed meats have been found to reduce gut diversity and emulsifiers (contained in most breads) have been shown to decrease the protective barrier between our endothelial cells and the contents of the bowel in animal studies.

What do we eat?

The Heart foundation recommends 25-30g fibre a day. Fruit, vegetables, legumes, wholegrains and nuts are all good sources of fibre.

Some particularly good types of fibre: Beta glucan found in oats and barley has a dual advantage of promoting good gut bacteria as well as binding to cholesterol to preventing it from being absorbed. Inulin promotes friendly bacteria and reduces triglyceride levels. This is found in good levels in onion, leek, garlic, artichoke, endive, asparagus, bananas and dandelion greens. Resistant starch found in grains, seeds and legumes is also great for the gut as it helps to produce butyrate.

Probiotics: Fermented Food

Fermented foods such as sauerkraut and kimchi in some cases have been found to treat and prevent inflammatory bowel disease. Why? It could be that not only are they a source of good bacteria and fibre but they are also a source of sulforophane. Sulforophane is produced from the breakdown of raw cruciferous vegetables and has been shown to provide antioxidant and anti-inflammatory properties. The richest source of sulforophane is from broccoli sprouts. If you ever want to learn more about sprouting broccoli seeds. Please talk to me!


Eating foods rich in polyphenols such as fruit, seeds, vegetables, cocoa and red wine have been found to increase levels of Bifidobacterium and Lactobacillus. Which is exciting, because all of these foods are fun to eat/drink.

In summary:

Personally I’d avoid artificial sweeteners. Eat a high fibre diet rich in fruits, vegetables, legumes and wholegrains. Include some probiotics in your diet like kimchi or sauerkraut. If you require a higher protein diet, try pea protein shakes as these seem to still promote beneficial strains of gut bacteria as well as having the added benefit of increasing those lovely short chain fatty acids for good health.

When modifying your diet to increase fibre:

  • For breakfast – you could try oats with some fruits and seed meal like linseed meal.

  • For lunch, throw some artichoke and legumes in your Mediterranean salad or cook up a lentil and barley soup.

  • Good snack ideas are fruit, nuts or seeds. Maybe a frozen and blended banana sprinkled with some cacao nibs.

  • Use a variety of vegetables and perhaps some kimchi/sauerkraut with your evening meal

For advice on a healthy high fibre diet come and talk to me! at Blue Lime Nutrition

Jane Whitbread


Influence of diet on the gut microbiome and implications for human health. 2017

Rasnik K. Singh, Hsin-Wen Chang, Di Yan, Kristina M. Lee, Derya Ucmak, Kirsten Wong, Michael Abrouk, Benjamin Farahnik, Mio Nakamura, Tian Hao Zhu, Tina Bhutani and Wilson Liao, J Transl Med. 15: 73.

Dr Michael Mosley 'the clever guts diet' 2017 Simon & Schuster, Australia

Beneficial Effects of Kimchi, a Korean Fermented Vegetable Food, on Pathophysiological Factors Related to Atherosclerosis. Feb 2018. Kim, Hyun Ju; Noh, Jeong Sook; Song, Yeong Ok; Journal of medicinal food Vol. 21, Iss. 2: 127-135.

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