Dear Doctors: It seems like every new health discovery is connected to the gut microbiome these days. I'm 68 years old, and this is new to me. I understand about probiotics, and I even take one, but now I'm seeing ads for prebiotics and postbiotics. What are they? Do I need to take them?
Dear Reader: When it comes to the gut microbiome, we're all on a learning curve, no matter our age.
Targeted study of our microbial companions dates back to the 17th century, but it's the recent leaps forward in genomic sequencing technology that have made present-day discoveries possible. Emerging research continues to show that the composition, diversity and behaviours of the trillions of bacteria, fungi, yeasts, viruses and other microbes that colonise our bodies play a pivotal role in human health and well-being.
We agree with you that we're hearing about new breakthroughs at what feels like a dizzying pace. In the last few years alone, reputable studies have linked the gut microbiome to blood sugar control, Type 1 diabetes, a variety of neurodegenerative diseases, some chronic gastrointestinal disorders, immunity and immune disorders, mood, depression and mental health. These findings have ignited intense interest in the gut and its microscopic residents.
They have also spurred the emergence of a vast and somewhat chaotic marketplace of products -- and a new vocabulary to go with them. This includes terms like "probiotics", as well as the "prebiotics" and "postbiotics" that you're asking about. At the root of these new terms is the word "biotics", which refers to the living components of an ecosystem. In this instance, the living components are the colonies of intestinal microflora, and their ecosystem is the gut.
The word probiotic was coined in 1965. At that time, it described a substance that is produced by one organism and benefits another organism. Today, probiotics refers to the intestinal flora themselves. Someone takes probiotics in an effort to introduce certain species of beneficial microbes into their gut. This can be via supplements or by eating certain foods in which bacteria and other microflora naturally occur.
The trillions of microorganisms in the gut need something to eat, and that's where prebiotics come into play. The word prebiotics refers to those components of food that, because they are not digestible, reach the large intestine intact. There, they act as food for the microflora of the gut.
Most recently, the word postbiotics has entered the gut microbiome conversation. This refers to the waste products that result from the digestion of prebiotics and probiotics. They include nutrients such as vitamin K and certain B vitamins, and also short chains of proteins that can help control the growth of potentially harmful bacteria.
Retail shelves are stocked with supplements in each of these categories. But whether or not they're helpful remains unclear. What we do know is that our gut microbiomes are primarily shaped by what we eat. The best way to maintain yours is with a diet that includes naturally fermented foods, a wide range of fresh fruit and vegetables, grains and legumes, and limits added sugars and processed foods. Universal Features Syndicate
Dr Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health.
