Walking through the mall on one of my rare outings without my kids, I stopped in front of my favorite soap store. The store has a famously strong smell of vanilla, lemongrass, bergamot, and even a bit of patchouli to compliment the “Vegan” and “Cruelty-Free” artfully written on the walls. In bright, bold font, their newest ad reminded me to “Care For [My] Microbiome” with their skincare line. Microbiome, gut flora, gut bacteria – these are all buzzwords that have been floating around the internet for years and have become even more prevalent in the age of Goop. But what even is a microbiome? And what does that have to do with our health?
The Human Microbiome
Our human microbiome is made up of trillions of microorganisms unique to different parts of our body. When we talk about our microbiome in terms of our gut health, we’re talking about the microorganisms that live in our digestive system. We have a whole ecosystem of bacteria, fungi, viruses, and other microorganisms that live together and compete against one another inside our intestines. Researchers have sought to answer how our microbiome impacts our health for decades. And at the core of many of our health discussions in the United States is our weight. One study even went so far as to feed capsules of poop from thin people to change the microbiome of fat participants and promote weight loss. We can observe apparent differences in the microbiomes between thin and fat folks but have yet to figure out why. These studies and many others continue as we compare individuals’ microbiomes and health statuses.
High-Fat Diets and Microbiome
The National Institute of Health funded this extensive study on the connections between our western “High-Fat Diet,” our microbiome, and our weight. Essentially, scientists fed a combination of diets to groups of mice to observe the impact on their gut microbiome, their weight, and a group of signs called “metabolic syndrome.” These include high blood pressure, high blood sugar, and high cholesterol. In the mice on a High-Fat Diet, researchers found a “rapid loss” of a particular bacteria they call “SFB” (segmented filamentous bacteria). In our microbiome, SFB help to regulate immune cells in our intestines that control how much fat we absorb from our food. The study found that the sugar in the high-fat diet killed off much of the SFB, which researchers believe may have caused the mice’s weight gain and signs of metabolic disorder. But the results went further. The High-Fat Diet contained sucrose (the sugar in fruits and vegetables) and maltodextrin (the sugar in processed foods, candies, and soda). When they replaced the sugar with starches and supplemented the mice with an SFB probiotic, the mice did not gain weight or develop any additional symptoms.
The Bigger Picture
Is that enough to answer our question? Unfortunately, no. In a Q and A for Mayo Clinic, gastroenterology experts Dr. Kanika Sehgal and Dr. Sahil Shanna discuss the limitations of this study and others like it. They share that when studies use human participants, the results are inconsistent. Drs. Sehgal and Khanna point to a more complex relationship between weight and our microbiome that include “a plethora of factors including, but not limited to, diet composition, energy content, fasting and eating patterns, and the use of prebiotics, probiotics, and antibiotics.” They would like future studies to include lifestyle and activity factors and identify the strains of bacteria involved. The exact nature of the relationship between our weight and our microbiome is yet to be discovered. Still, with national attention on weight and a multi-trillion-dollar wellness industry, we continue to investigate.
So What?
So what does that mean for us? Before asking your thin friends for stool samples, remember that health is complex and dynamic and that weight is only one part of our whole picture. Our microbiomes may very well contribute to our weight and metabolism. As of right now, there’s no magical poop pill or face wash that can cure our ailments. Instead, consider health-centered nutrition recommendations and be mindful of how our choices might impact the trillions of organisms that we depend on and that depend on us.
The National Eating Disorders Association provides a helpline for support, resources, and treatment options for folks or their loved ones who may be suffering from an eating disorder. If you are in crisis and need help immediately, text “NEDA” to 741741 to be connected with a volunteer at the Crisis Text Line. NEDA’s hotline is available to call or text Mon-Thurs 3pm-6pm ET and Friday 1pm-5pm ET at (800)931-2237.
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