Remember the old saying you are what you eat? It turns out, it would be more appropriate to say you are what you digest and metabolize. Human digestion is outsourced to the community of microbes housed in our GI tract called the microbiome. These microbes determine your blood sugar levels with meals (glycemic response), calories you derive from food, and modulate your food cravings, making some people more prone to obesity, diabetes and other medical conditions.
Did you know you need the right bacteria to benefit from the anti-cancer effect of broccoli? Cruciferous vegetables like broccoli contain glucosinolates which are metabolized by gut bacteria into an anti-cancer metabolite called sulphoraphane - that is if you have the right bacteria. Since one person may benefit more than another based on the microbes present in the gut, the next time your child says I won’t eat my broccoli because I don’t have the right bacteria, science is on her side. However, replacing those missing bacteria isn’t so far away. Proof of concept is a lab in Singapore engineered bacteria that derived the anti-cancer benefits from broccoli and shrink tumors in mice
“Twenty years ago, sequencing the first human genome was a colossal event that took 13 years and $1 billion dollars, and now we can sequence DNA for under $100 in less than a day”
There are various examples of how we digest and metabolize our food differently. Is red meat good or bad for you? It partly depends on your gut microbes – some microbiomes will produce higher levels of a pro-inflammatory compound called TMAO that has been linked to heart disease. What happens to the fiber you eat? Again, it depends on if you have bacteria that ferment more butyric acid (the main fuel source for the cells lining your colon) or compounds like propionic acid which are pro-inflammatory.