How Diet Determines Disease

by | Aug 1, 2022

Recent studies have suggested that the composition of gut bacteria is linked with diseases such as inflammatory bowel disease, psoriasis, atopic dermatitis, autoimmune arthritis, obesity, type 2 diabetes, cardiovascular disease, and cancer. So how can we alter the gut bacteria in our favor? By changing our diets, because diet determines disease! But not just by getting the ideal amounts of protein, fat, carbs, fiber, vitamins and minerals. No. By making unique food choices and doing so often. Read on to learn why.

How Diet Determines Disease

The Gut Microbiome 

Just as a refresher, let’s go over the gut microbiome. You can refer to our previous post to learn more about it here. The gut microbiome is the collection of bacteria living in the intestines. The composition of bacteria varies between each person, but some key bacterial species are usually present in most people. Our diet is believed to explain at least 20% of the bacterial variations in humans. 

Examples of the Microbiome’s Impact on Disease

The following associations have been made between gut bacteria and these specific diseases:

People with obesity have an altered Bacteriodetes: Firmicutes ratio. They tend to have a greater abundance of Firmicutes (bad bacteria) than Bacteriodetes (good bacteria). Studies even show that transplanting bacteria from obese mice to lean mice causes obesity in lean mice (1).

IBD (Inflammatory Bowel Disease) including Ulcerative Colitis and Chron’s Disease
People with IBD have been found to have less bacterial diversity (fewer types of bacteria) and lower total amounts of Bacteriodes and Firmicutes. This means those bacteria are making less butyrate. Butyrate is an important anti-inflammatory in keeping gut inflammation in check (1).

Type 2 Diabetes
Individuals with type 2 diabetes have reduced amounts of Akkermansia muciniphila, a specific bacterial strain. Improving these levels may help improve blood sugar regulation.

Atherosclerosis (hardening of arteries)
People with heart disease have been found to have enhanced bacterial metabolism of choline and phosphatidylcholine in the gut, which produces an atherogenic compound called trimethylamine-N-oxide (TMAO) (1).

Alzheimer’s Disease
Those with Alzheimer’s disease may have greater amounts of bacteria producing amyloid and lipopolysaccharides (LPS), both of which increase the progression of Alzheimer’s disease (1). 

This is just a brief list of how some diseases are impacted by the gut microbiome. Researchers are just beginning to scratch the surface of this topic. But so far, we know enough to understand that our gut is related in some way to every aspect of our health. 

How Can We Alter Our Gut Microbiome? 

After reading through that list, you’re probably wondering how you can improve your gut microbiome to prevent (or improve) disease! Many factors impact the gut microbiome. A few of these include antibiotics, lifestyle factors (yes, being sedentary vs active makes a difference), smoking, probiotic supplements, and, of course, DIET. Hence, changing up any of these can make a difference. Today we’ll focus on diet. 

We’re not about to suggest a fad diet that excludes certain food groups from your diet because one study found that the exclusion of certain nutrients such as following a gluten-free diet or a Low-FODMAP diet reduced microbe diversity in the gut (2). If you must follow a gluten-free (GF) or Low-FODMAP diet, then that’s okay. You’ll just want to make sure after you’ve finished the Low-FODMAP diet that you’re including a wide variety of foods in your diet. If your GF, then you’ll also just want to make sure you’re eating a variety of foods as well all the time.

How to Improve Your Diet

How to improve your diet really depends on what your diet is like right now. Our answer is different for each person we meet with because we’re all starting from a unique place. However, we can offer some general direction, and that begins with variety. Increase the variety in your diet. Why?

One study found that the microbiome composition is more strongly linked with food choices than with the nutrient profile (macronutrients, vitamins, and minerals). This means that two different meal plans made up of different foods but the same amounts of protein, fat, and carbohydrates, vitamins and minerals, would have completely different impacts on the gut microbiome. 

If you were striving for the perfect diet to include the right amount of protein, fat, carbs, fiber, vitamins, and minerals, you might resort to having a meal replacement shake 3 times per day. What happens if you do this versus trying to get those nutrients from unique foods? Well, one study had a couple of people actually do this. They had a meal replacement shake daily for 10 days and the results showed that this diet pattern did NOT support a healthy gut microbiome despite offering all of the main nutrients (3). 

So, what do we recommend? Vary your diet! A diverse diet – meaning a diet rich in different plant foods – is associated with greatest microbial diversity (2). This is likely due to the variety of fibers and the 25,000+ phytochemicals found in different plant foods. Ready for an interesting fact? The microbe diversity in children ages 6-12 is much greater than in healthy adults because these young ones are more likely to be trying and exploring new foods. Adults are more likely to get stuck in a pattern of eating the same foods all the time, which is harmful for a healthy gut (2).


It’s okay to do meal prep, but try to include a wide variety of vegetables, fruits, grains, protein sources, nuts, and seeds in your daily diet. An easier way to know if you’re getting a variety? Aim for a rainbow of colors of food throughout your day. You can even print out a chart to check off your daily colors of the rainbow.  As you do this, treat the grocery store as your pharmacy for your colorful prescriptions. Enjoy loading your cart with a rainbow of colors!

Questions? Comments? Reach out to us!




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