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Worst Foods for Gut Health
Updated on November 22, 2023
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Worst Foods for Gut Health

Your gut is an important part of your body. It is responsible for digesting food, absorbing nutrients, and eliminating waste. It also supports immune function and protects you from disease.

Worst Foods for Gut Health 2

The gut is a very complex organ, and scientists are still learning a lot about it. However, we do know that there are foods that can improve your gut health and others that can harm your gut.

Taking charge of your gut health and ensuring you're strengthening healthy gut bacteria and maintaining balance is important. Some food can throw that balance off and put you at risk of digestive issues, mental health problems, and even an increased risk of infection.

Eating right and adjusting your diet is crucial to overall health.

Meet the Expert

Elise Harlow is a registered dietitian with a Master of Science in Nutritional Sciences. She is the founder of an online nutrition consulting and coaching business.

Elise helps people use the power of food to lead healthier lives. She works with various clients, including those who want to achieve a healthier weight, improve their gut health, lower cholesterol, manage their blood sugar, or balance their hormones.

Foods That Are Bad for Your Gut Bacteria

Your gut is home to trillions of bacteria, both good and bad. This microbiome is essential for keeping your digestive system functioning properly. 

To have a healthy gut, there needs to be a balance of healthy bacteria. Unfortunately, poor dietary choices can lead to an imbalance in the gut flora. 

Some foods can increase harmful gut bacteria. Others can decrease the beneficial bacteria in your gut.

If you want your good gut bacteria to thrive, below are some foods you should limit or avoid. The same foods should be avoided if you're trying to treat small intestinal bacterial overgrowth (SIBO).

1. Alcoholic drinks

Excessive drinking is associated with dysbiosis.1 Gut dysbiosis occurs when the bacteria in your digestive tract are out of balance. 

This can lead to different health issues, including:

  • Acid reflux
  • Anxiety
  • Chronic fatigue
  • Constipation
  • Cramps
  • Diarrhea
  • Gas and bloating 
  • Skin disorders, including acne, psoriasis, and rashes

If you want to drink alcohol, do so in moderation and only occasionally.

2. Artificial sweeteners

We all know that artificial sweeteners are much sweeter than regular sugar. But did you know that they can also make gut bacteria imbalanced?

There is a type of gut bacteria called Clostridium which thrive on sugar. When we eat artificial sweeteners, these bacteria consume them and produce toxins that can make us sick.2

This is why it's important to be aware of the types of artificial sweeteners we're consuming. 

Common artificial sweeteners to watch out for include:

  • Splenda Naturals Stevia Sweetener and Truvia (stevia)
  • Splenda (sucralose)
  • Sweet'N Low, Sugar Twin, and Necta Sweet (saccharin)
  • Sunett (acesulfame K)

Aspartame is another sweetener with negative effects on gut bacteria.

3. Red meats

Red meat may be bad for gut health. Research shows it can have a negative effect on gut bacteria. This is especially true if you eat red meat with a diet high in fat and sugar.3

Red meat is high in saturated and trans fats, which can promote the growth of bad bacteria.4

Examples of red meat include:

  • Beef
  • Pork
  • Lamb
  • Venison
  • Boar
  • Rabbit

4. Processed foods

A diet rich in processed food is bad for gut bacteria. Processed food tends to be high in sugar, which can feed harmful gut bacteria.5

In addition, many processed foods are low in fiber, which is important for a healthy gut.

A diet high in processed food can also cause weight gain. This puts a strain on the gut.

Examples of processed foods include:

  • Deli meats
  • Cereal
  • High-sugar drinks
  • Prepacked and frozen meals
  • Microwavable meals
  • Instant noodles

5. Sugary soft drinks

The sugar in soft drinks and soda feeds harmful bacteria in the gut.6

As mentioned earlier, research shows that artificial sweeteners are linked to negative changes in gut flora. In addition, sugary drinks can also contribute to weight gain, which can further impact gut health.

6. Foods with antibiotics

Antibiotics target all bacteria, good and bad. When you introduce them to your gut, they wipe out all gut bacteria.

This happens when you’re taking antibiotic medication. But they can also get into your gut when you eat foods from animals that were either treated with antibiotics or given feed containing them.

The overuse of antibiotics in livestock, as well as the use of herbicides and pesticides, can disrupt the delicate balance of gut microbes. This can lead to problems like antibiotic resistance and inflammatory bowel disease.7

"Even though the amount you get in food is much less than if you were prescribed antibiotics, it may still negatively affect your gut microbiota."

Elise Harlow, M.S., R.D.N.

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Foods Bad for Leaky Gut

A leaky gut is a condition in which the lining of the intestines becomes damaged. This causes bacteria and toxins to "leak" into the bloodstream. It can lead to inflammation, autoimmune disease, and other health problems.

If you’re not sure, you can always take a leaky gut test to find out.

Certain foods can help you treat a leaky gut and restore your digestive health. But there are also foods you need to avoid to reduce symptoms. Below are some foods you can avoid:

1. High-lactose dairy products

Approximately 65 percent of the human population struggles with lactose intolerance. They don't have enough lactase, an enzyme needed to properly break down lactose. 

High-lactose dairy can cause leaky gut in people with lactose intolerance. You can take a food intolerance test to see if you have it.

High-lactose dairy foods include:

  • Whole Milk
  • Ice cream
  • Butter
  • Cheese

2. Non-organic foods

Fruits and vegetables that contain pesticides are considered non-organic foods. Eating them may cause inflammatory gut bacteria to thrive.

Switching to an organic diet is one of the best ways to improve gut health naturally. Organic food is free of harmful pesticides and chemicals that can disrupt the delicate balance of the gut microbiome. 

3. Foods high in gluten

Gluten-rich foods contain lectins, which may lead to leaky gut symptoms. This is especially true for people with gluten intolerance.8

Foods high in gluten include:

  • Bread
  • Baked goods
  • Cereal
  • Pasta
  • Crackers
  • Beer
  • Gravy
  • Commercial soups

4. Allergenic foods

If you have food allergies and continue to consume the food you are allergic to, this can cause intestinal damage and inflammation.

Foods that are common allergy triggers include:

  • Peanuts
  • Milk
  • Eggs
  • Chocolate
  • Wheat
  • Soy
  • Shellfish

5. High FODMAP foods

FODMAP is an acronym for "Fermentable Oligosaccharides, Disaccharides, Monosaccharides, and Polyols." They're made of sugars that are poorly digested by the small intestine.

People with irritable bowel syndrome (IBS) can eat low-FODMAP foods to determine which ones trigger their IBS symptoms.

According to Harlow, a low FODMAP diet is a temporary elimination diet that helps people with IBS identify specific food triggers. Once they know their triggers, they can avoid eating these foods.

"It's likely they will need to permanently reduce their intake of some high FODMAP foods, but not all of them."

Elise Harlow, M.S., R.D.N.

Examples of FODMAP foods include processed foods, fruit juices, sweeteners (like agave and honey), condiments, jam, relish, and hummus.

"There are studies that people who follow a low FODMAP diet long-term may negatively affect their gut microbiome," Harlow adds.

Foods That Are Bad for Gut Health

A healthy digestive system is important for many reasons. First, it helps the body absorb nutrients from food. It also gets rid of waste products that the body doesn't need.

Finally, healthy digestion ensures overall health by preventing harmful bacteria and toxins from getting into the bloodstream.

To keep your digestion healthy, here are foods you should avoid:

1. Fried foods

Fried foods are high in saturated and trans fats. These fats can be harmful to your gut health.

They also tend to be high in salt, which can promote the growth of harmful bacteria in your gut. This can lead to infections and other digestive problems.9

Some fried foods include:

  • Mozzarella sticks
  • Doughnuts/beignets
  • Samosas
  • Fried chicken
  • Deep fried food

2. Refined grains

There are a few reasons why refined grains are bad for gut health.

For one, they lack the fiber that keeps our digestive system moving. They are also stripped of other nutrients that can benefit gut health, such as polyphenols and antioxidants.

Finally, many refined grain products contain additives and chemicals. They can further damage the gut lining and disrupt the delicate balance of good and bad bacteria.10

Examples of refined grains include:

  • White bread
  • White flour
  • De-germed cornmeal
  • Instant grains
  • Fruit juices
  • Refined starches

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Looking for the best microbiome kit on the market? Look no further! Our review round-up page has all the information you need to make an informed decision.

Updated on November 22, 2023
Elise Harlow
Elise Harlow, M.S., R.D.N.
Medical Reviewer
Elise Harlow is a registered dietitian with a Master of Science in Nutritional Sciences. She is the founder of an online nutrition consulting and coaching business.

Elise helps people use the power of food to lead healthier lives. She works with various clients, including those who want to achieve a healthier weight, improve their gut health, lower cholesterol, manage their blood sugar, or balance their hormones.
Kelly Jamrozy
Kelly Jamrozy
Content Contributor
Kelly has experience working with clients in a variety of industries, including legal, medical, marketing, and travel. Her goal is to share important information that people can use to make decisions about their health and the health of their loved ones. From choosing the best treatment programs to improving dental and vision health to finding the best method for helping anyone who is struggling with health issues, she hopes to share what she learns through informative content.
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