SS · I’m still not sure exactly what the microbiome is…?
LY · The microbiome is the microbes living inside us; bacteria, fungi, viruses… , their genome and the stuff they produce (sam this is really important otherwise you could talk about microbiota to keep the definition shorter. The microbes by themselves are the microbiota). Scientists have demonstrated that bacteria living with us are extremely important to keeping healthy. Bacteria live (pluriel)in the skin, the mouth, and the vagina… with the largest majority of bacteria living in the gut. Bacteria are important in the digestion of food, to produce certain vitamins, and to transform certain carbs into molecules capable of influencing the immune system. They improve your sensitivity to insulin; and they improve your glucose tolerance. Diversity (a lot of different bacteria strains) is the key. they are tiny creatures living with and helping you a lot. But, they are fragile and you have to take care of them.
SS · How should we care for them?
LY · Eat a lot of fibre. Food has a huge impact on the microbiome. Your bacteria will be able to transform the fibres from food such as whole grains, certain root vegetables, leafy greens, the skin of fruit, cocoa nibs and nuts into small healthy molecules supporting the immune system and feeding the gut cells. By contrast, avoid refined sugar, artificial sweeteners and white flour.
SS · Judging by the multitude of constipation ads in this country, Americans are pretty bad at getting enough fibre.
LY · That’s a huge problem. American people have a huge deficit in fibre. Trials have shown that the fiber gap (the difference between the amount of fibre you have should get and the amount you do get per day) is basically 20 g/day because of the use of white flour everywhere and concluded that it will be impossible to change the taste of American people and go back to whole flour to make American people eat enough fibre. What they propose is to add fiber supplementation to flour. For sure the best thing to do is go back to whole food and not refined flour, but they believe the American people will not be able to do that.
SS · Talking of which, they call the gut the second brain.
LY · Actually it’s amazing. Scientists discovered that the bacteria you have in your gut produce neuromediators like serotonin and GABA and their precursors. Those molecules are able to modify anxiety, modify the mood, and balance the function of the brain… The reason why researchers call the gut the second brain is really whats happening in the gut will influence how your brain works; at the molecular level.
Some food like fermented food (yogurt, kefir) rich in bacteria and like whole grains, roots, veggies (rich in food for bacteria) are now named ‘psychobiotics’ based on their ability to ameliorate our mood, capacity to focus etc.
SS · What about probiotics?
LY · Probiotics are living bacteria. If you buy yogurt or kefir, be careful and check if they have living bacteria and importantly, avoid ones containing flavor or sugar and take some with whole milk.
On the other side there is also what we call prebiotics which is all the stuff your bacteria can eat – fibre is a prebiotic, raw honey is a prebiotic, cocoa nibs also. Whole grains are prebiotic. Roots like parsnip and Jerusalem artichoke, leeks, onions, asparagus. Blueberries; nuts, seeds, – they feed your own bacteria, have by that way a positive impact on your health and are delicious. Clinical trials show that feeding your own bacteria with a large variety of plant is an efficient option to have a diverse microbiome. If you have to take antibiotics, having probiotics also is a very good idea. Ask to your physician each time he recommends you take antibiotics.
SS · Kimchi is really popular in New York at the moment. I have Korean friends who eat kimchi daily and credit that for the fact that in four years of living in New York City they have never been unwell.
LY · Kimchi are fermented food with probiotics and healthy product of fermentation. But if you take probiotics and continue to eat unhealthily the new bacteria will die. There is a paper showing that french fries can really disturb your microbiome.
SS · How can our lifestyle support our microbiome?
LY · I think sleep is really important because to have a good circadian rhythm is really important for your immune system and for your bacteria.
Eating right; and i think it’s very difficult to define what is eating right because there is so many food crazes and food fads that it becomes difficult for people to know what is eating right. If I should give only one recommendation it really is to focus on fibre because you will find fibre in very healthy stuff, and also to decrease sugar and saturated fat. Avoid artificial sweeteners at all cost.
Reducing stress; I think is really important, because if you are too nervous you will produce a lot of cortisol, and you will change your immune system – that will influence on your gut bacteria – that’s very important.
Exercise; thats also very important. There is also data showing that patients who exercise a lot have a better immune system.
There is also avoiding smoking and stuff like that, but i think that’s so obvious now.
Good food is preventive medicine. Stay simple but feed your gut bacteria.