top of page
  • ahwcweb

Food Effects on the Microbiome

Other than choosing whether or not to smoke, our eating habits are the single most powerful lifestyle influence affecting our quality of life and longevity. Diet is not only about what you eat – it also includes how we eat.

Many, if not most of us, have learned the fast paced, western society way of eating. We gobble our food down, and then look for more sensory enjoyment even if we don’t need the calories. We have become a nation overfed and under nourished.

How can we lose weight, improve health, reduce inflammation, and still fill our plate, not feel deprived, avoid skimpy portions and hunger pains? It all starts with real foods, prepared in a simple way free from added fats and sugars. In our western fast-paced society we have gotten use to what Michael Pollen calls “food-like substances” in his documentary, In Defense of Food. Food-like substances are the rattly, crinkly, packaged foods.

Highly processed foods do not have all the nutrition necessary to properly digest them, so they borrow from body stores to provide for the deficiency. Then the body has another challenge of actually absorbing the nutrients because the little hairs in the intestinal tract, called microvilli, are matted down by white refined flours, sugar, greasy and high fat foods, so that the little hairs cannot do their job of collecting and absorbing the nutrients. Thus, our gut also becomes compromised. You see, it is like a domino effect and the situation continues to get worse.

The raw fact is, we are only as healthy as our gut, or intestinal tract, is healthy. How can we get the little-hair guy to stand up and swim? It all starts with real whole, plant foods. These contain fiber and water, which work together to clean up the intestinal tract. Fiber acts like a broom in the intestinal tract to sweep up the gooey trash that has been hanging around and water pushes the fiber on through the tract so the little guys can stand up again.

But that is not all, there’s more! Whole, plant foods also have all the nutrition buzz words you hear about, vitamins, minerals, antioxidants, phytochemicals, etc. These empower the body to heal, repair, and fight off disease and illness.

If you want to improve gut health, fruits, grains, vegetables, legumes (beans, peas, lentils), nuts and seeds are all important foods to include to heal the body.

Your gut provides a home for trillions of bacteria with more than 2,000 known species of gut bacteria. The contributions of the gut microflora influence nutrient uptake, metabolism, body clocks, detoxification, immune responses, inflammation, and our mental health!(1)

The proper balance and diversity of gut bacteria is necessary for favorable immune responses and optimal health. Too much of either unfriendly or friendly bacteria triggers strong immune and inflammatory processes.

Beneficial bacteria release useful byproducts that protect our health and lower risk for colon cancer, atherosclerosis, and inflammatory conditions. They protect against infections, release neurotransmitters such as dopamine and serotonin, and improve our quality of sleep.(2)

Unfriendly gut bacteria release toxins and inflammatory agents that disrupt the gut barriers and thus contribute to the development of conditions such as atherosclerosis, hypertension, allergies, diabetes, obesity, inflammatory bowel diseases (Crohn’s, celiac, ulcerative colitis), lung problems, anxiety, and depression.(3)

We all have our own unique genetics, environmental, lifestyle, and dietary factors to which we are exposed. We cannot change our genetics, but we can change environmental, lifestyle and dietary factors in such a way as to encourage good bacteria and reduce unwanted bacteria.

Diets high in whole plant foods; fruits, vegetables, legumes and whole grains, and low in added sugar and saturated and trans fats (i.e., hydrogenated fats) stimulate the proliferation of beneficial and anti-inflammatory bacteria.(4) Liberal amounts of raw fruits and vegetables are particularly useful in building healthy gut microflora.(5)

In contrast, a low nutrient, high calorie Western diet (rich in sugar, animal products, salt, processed foods, and refined carbohydrates) is linked to more disease-causing bacteria.(6,7)

Carbohydrates have gotten a bad reputation due to the refining process and the ensuing inflammation created by refined grains, starches, sugars which feed unfriendly bacteria. But carbohydrates in their whole form, with fiber and nutrients intact make important contributions to gut health. Beyond fiber, whole grains, starches, and legumes contain resistant starches that reduce inflammation and lower the risk of chronic diseases, improve insulin sensitivity, potentially reversing insulin resistance also known as metabolic syndrome.(8,9,10) Plant foods, such as asparagus, artichokes, barley, rye, lentils, onions, chicory, garlic, leeks, and bananas provide the gut with prebiotics; non-digestible carbohydrate that feed good bacteria and assist in the formation of probiotics.

Pesticide residues on food have the potential to harm friendly gut bacteria.(12) Glyphosates are used to spray most of our grain products for easier harvesting. But glyphosates do not treat our gut very well and have been linked to leaky gut syndrome and autoimmune diseases. Buying organic foods can reduce pesticide residues and glyphosates. If organic food is not available, soak plant produce briefly in a 10% salt rinse (use 1 part salt to 9 parts water). Pesticides found in meat, dairy, and fish cannot be reduced.

Artificial sweeteners reduce the number of good bacteria in your gut and encourage insulin resistance.(13) This is true of aspartame, saccharin, and sucralose. If too much stevia extract is used it can also adversely affect gut bacteria.(14) But using the stevia plant instead of the extract has no adverse effects.

Allowing 4-6 hours between meals without snacking improves gut microbiome. Two meals instead of three meals has also been shown to improve gut flora, while snacking or “grazing” disturbs the gut flora balance.(15)

Here is the good news: The composition of gut bacteria changes quickly—within three to ten days. For better or worse. In other words, even a short-term change in the diet to mostly animal products or mostly plant products rapidly alters the community of gut microbes. Eating an animal-based diet or consuming fast foods for several days, reduces useful byproducts from fermentation of carbohydrates. While a consistent, mostly plant-based diet lowers the risk of diarrhea and other intestinal infections and inflammatory bowel diseases due to the improve composition and variety of friendly gut bacteria. Give it a try and see for yourself the difference it will make!

We would be happy to work with you to pull all the pieces together in a way that will work for you. Schedule an appointment.

In our Start a New YOU! ® Program, we help participants take workable, doable, sustainable steps to improve health. We guarantee the Start a New YOU! ® Program will work for you if you work the program!

Schedule a free interview today to see if the Start a New YOU!® Online Program is right for you by calling 479-363-6585 or click below to schedule an appointment online.

To avoid being charged for the interview, please state the reason for the appointment is “free interview offer.”


  1. Baylor College of Medicine. “Dietary quality influences microbiome composition in human colonic mucosa.” ScienceDaily. 15 July

  2. Patterson E. Gut microbiota, obesity and diabetes. Postgrad Med J. 2016 May 92(1087):286-300. doi: 10.1136/postgradmedj-2015-133285.

  3. Singh RK. Influence of diet on the gut microbiome and implications for human health. Journal of Translational Medicine volume 15, Article number: 73 (2017).

  4. Tomova A. The Effects of Vegetarian and Vegan Diets on Gut Microbiota. Front. Nutr. 17 April

  5. Karon A. A Western Diet Linked to lower microbiome diversity. Internal Medicine News. March 29,

  6. Zinöcker MK. The Western Diet–Microbiome-Host Interaction. Nutrients. 2018 Mar: 10(3):

  7. Singh RK. Influence of diet on the gut microbiome and implications for human health. Journal of Translational Medicine. Volume 15, Article number: 73 (2017).

  8. Robertson MD. Insulin-sensitizing effects of dietary resistant starch and effects on skeletal muscle and adipose tissue metabolism. Am J Clin Nutr. 2005 Sep: 82(3):559-67.

  9. Birt D. Resistant Starch: Promise for Improving Human Health. Adv Nutr. 2013 Nov; 4(6): 587–601.

  10. Kieffer D.A. Resistant starch alters gut microbiome and metabolomic profiles concurrent with amelioration of chronic kidney disease in rats. J Physiol Renal Physiol. 2016 May 1; 310(9): F857–F871.

  11. Nicola Wilck, Salt-responsive gut commensal modulates TH17 axis and disease. Nature. 2017; DOI: 10.1038/nature24628

  12. Suez J. Artificial sweeteners induce glucose intolerance by altering the gut microbiota. Nature. 2014 Oct 9; 514(7521):181-6.

  13. Javier F. Effects of Sweeteners on the Gut Microbiota: A Review of Experimental Studies and Clinical Trials. Advances in Nutrition, Volume 10, Issue suppl_1, January 2019, Pages S31–

  14. Dandun Hu. Gut flora shift caused by time-restricted feeding might protect the host from metabolic syndrome, inflammatory bowel disease and colorectal cancer. Translational Cancer Research. Vol: 7:5. Oct. 2018.

  15. David LA. Diet rapidly and reproducibly alters the human gut microbiome. Nature. 2014 Jan 23; 505(7484):559-63.

  16. Thaiss et al. Trans-kingdom control of microbiota diurnal oscillations promotes metabolic homeostasis. Cell, 2014 DOI: 10.1016/j.cell.2014.09.048


bottom of page