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Health & Wellness

Foods that Promote a Healthy Microbiome: Polyphenols

By June 5, 2018No Comments

links between polyphenols in foods for healthy microbiome | Annex Naturopathic Clinic | Toronto Naturopathic Doctors

In one of my previous articles, I explained how the health of our microbiome can influence the health of our bodies.

When we have a well-balanced microbiome, it keeps our bodies in balance through regulating our immune system, encouraging efficient energy production, improving digestive health and promoting healthy detoxification.

So how do we encourage the growth and maintenance of a healthy microbiome?

A healthy diet plays an integral role at keeping our microbiome well balanced and functioning efficiently.

While there are a wide variety of foods that play a role that keep our probiotic flora healthy, this blog is going to focus on the intensely important bioactive compounds called polyphenols.

Polyphenols are antioxidant nutrients abundantly found in plants – they can be easily detected as they are primarily responsible for the blue, red and purple colours of fruits and vegetables.

A diet rich in polyphenols have been found to be crucial for good health.

These compounds are utilized by the body to combat inflammation, protecting us against chronic diseases such as cardiovascular disease, cancer and neurodegenerative disease.

Interestingly, there is a growing body of research that indicates that that these protective effects of polyphenols are dependent on proper colonic microbial flora.

Recent research have found that polyphenols can actually influence the health and colonization of the colonic (large intestinal) microbiome! Only 5-10% of ingested polyphenols are absorbed directly through the small intestine, and the rest (larger polyphenol molecules) appeared to bypass absorption and travel down to the colon to act as fuel for our intestinal probiotics.

It has been shown that polyphenols could actually change the ratio between specific bacteria, encouraging the growth of host-friendly bacteria, while down-regulating the growth of not-so-favourable bacteria.

Polyphenols, can reduce the growth and combat bad/pathogenic bacteria through repressing the formative genes, reducing the toxins produced by these bacteria, restricting their mobility, and through direct destruction.

The interesting thing is that these effects appear to come from not the polyphenols from food, but what they become after being ingested by the bacteria.

Polyphenols from fruit are like the “prebiotics” – giving bacteria energy so they can produce energy that benefits us, the host.

When ingested by beneficial bacteria, polyphenols from food are transformed in to smaller, more biologically active substances that can now be absorbed and better utilized by the body (and bacteria)

This means that it’s not just enough to eat a diet full of polyphenol-rich fruits and vegetables, you have to make sure your digestive health and microbiome is healthy and working efficiently in order to benefit from these foods.

If you have digestive health concerns, it’s crucial to seek out a medical professional (like a naturopathic doctor) who can help guide you through the path to optimal health.

colourful foods rich in polyphenols | Annex Naturopathic Clinic | Toronto Naturopathic Doctors

Foods rich in polyphenols

All colourful fruits and vegetables
– particularly berries, dark leafy green veggies that contain red, blues and purple foods (think swiss chard, curly kale, etc)

Aromatic, colourful herbs and spices

– consider green tea

Medicinal herbs
– ask a naturopath

Red wine
– look for organic wines and limit consumption to avoid detrimental effects of increased alcohol consumption

Dark Chocolate
– opt for >70%, low sugar
– or cacao (raw chocolate)

There are a tremendous variety of different antioxidants like polyphenols that are each beneficial to our health.

Just like our microbiome, it’s important to have diversity within our antioxidant pool, available for our bodies to utilize.

Having a diverse and large pool of antioxidants available will combat exogenous chemicals we are exposed to that are poor for our health, and encourages a healthy, diversified microbiome.

The diversity of antioxidants comes from the diversity of our diet so don’t just stick to only polyphenol rich foods; include them in a diet containing a wide variety of fruits and vegetables, switching things up on the regular, to keep the antioxidant pool strong.


If you’re curious to learn more about this subject or would like to consult with one of our NDs feel free to book a visit or contact us.

Yours in Health,

Annex Naturopathic Clinic
800 Bathurst St Suite 301,
Toronto, ON M5R 3M8


Annex Naturopathic Clinic is a clinic in Toronto that offers integrative healthcare solutions from Drs. Marnie Luck, ND, and Tanya Lee, ND