DO phytonutrients really work? Meg Smart DVM , PhD

"Processed foods represent nature stripped away with little bits added  back as fortification” (Prescott and Logan 2016)

While doing research for the advanced on line nutrtion course  for Dogs naturally magazine I came across a review section on the role of a healthy gut microbiome in the production of active phyto chemicals from the relatively indigestable phytonnutrients found in the cell wall of  inggested plants (The Secret Life of  Your MIcrobiome Prescott S.L. and Logsn A,l.2017 New Society Publishers).I felt that this was important as I feel just feeding a natural source of phytonutrients to pets that are  nutririnally  and/ or environmentally stressed and sufferiing for symptoms of  chronic inflammation (diabetis,allergies, obesity, auto immunity), may not be effective unless the  associated disfunctional gut mircobiome is corrected. Life is far removed  from the benefits derived from nature. Urbanization results in diets filled with sugar, rich foods, and beverages, ultra- processed, fast foods. Our moods and that of our children are being controlled by antidepressants, anti-anxiety, attention deficit and sleep enhancing medications. 30,000 dietary supplements emphasize our need for a fix. All market propaganda promising us a better life. Stress related problems are on the rise especially in children. We see these problem in our pets as a reflection of ourselves.

Phytochemicals and the microbiome

Phytochemical (nutrients) are natural chemicals found in the plant’s cell wall that give plants their taste, vivid colours and textures. They  are also chemical compounds produced by plants to help them thrive and thwart competitors, predators, and pathogens. Phytochemicals have been used as poisons and others have been used in traditional medicine.They are classified into the major categories such as carotenoids and polyphenols which include phenolic acid, flavonoids, and stilbenes/lignans,.Most are divided into groups based on a similar chemical structure such as anthrocyanins,flavones, and isoflavones. Flavanols  are further classifies as Catechins, epicatechins and proathocyanidins. .The structure is often complex.  An example of a beneficial phytochemical is salicin commonly known as aspirin.  found in the bark of the white willow. .

The adsorption of the phytonutrients is poor and microbial transformation of phytonutrients’ plays a significant role in the bioavailability. Microbes including Lactobacillus and Bifidobacterium help to convert the phytonutrients’ to metabolites. These metabolites are better absorbed and transported to the cells where needed.

For example in animal studies about half of the polyphenols transformed by the gut microbes arrive in the brain. Foods rich in polyphenols promote the growth of beneficial bacteria and contribute to microbial diversity. Examples of vital nutrients are quercetin (green leafy vegetables) resveratrol (grapes) and tannins from .Pomegranates. They also stimulate the growth of lactobacillus and Bifidobacterium.

Question: Is  a healthy gut microbiome required to transform the phytonutrients found in supplements containing herbs, mushrooms etc. into biologically active metabolites? Most of these types of holistic supplements do not mention that a healthy gut microbiome is required.

The relationship between the polyphenols and the microbiome is very complex. The microbiome changes associated with the westernized diet leads to less bioavailability of certain polyphenols. Microbial Dysbiosis in this case is not favourable to nutrient bioavailability. The polyphenols,  importance in increasing the energy expenditure by keeping the body lean and resistant to obesity, appeared much less bioavailable. This cycle was broken by adding a blend of flavonoids. Research has found antimicrobial polyphenols in certain herbs support the growth of beneficial microorganisms and suppress or repel the harmful microorganisms. 

Extracted poly saccharides are not as effective prebiotics as those found in the whole plant. Inulin is an excellent prebiotic found in thousands the plants but when it is purified the associated phytonutrients are lost. Purified prebiotics can help to restore the gut microbial ecology but they fail to prevent damage to the mucous layer which protects the intestinal lining. This can only be repaired by adding fibre rich whole foods. The plant cell wall is exactly where the phytonutrients are most abundant.

Polyphenol metabolites appear to stimulate the conversion of Omega-3 fatty acid alpha linolenic acid to the more biologically active omega 3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This indicates the beneficial microbes work on polyphenols making new biologically active chemical.

“Proc"""essed foods represent nature stripped away with little bits added  back as fortification” Prescott and Logan 

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