How Probiotics Can Make Us Feel Worse

Though often hailed as gut-health heroes, new research reveals that probiotics also have a dark side—proving that even beneficial bacteria can become troublesome when overconsumed.

How Probiotics Can Fuel Gas, Bloating, and Brain Fog

Probiotics, often considered a remedy for gut health, can ironically hurt various aspects of digestive well-being.

When someone has an overgrowth of bacteria in the small intestines, it’s typically a strain of Lactobacillus bacteria, Dr. Amy Myers, a functional medicine doctor and bestselling author of “The Autoimmune Solution,” explained in a 2020 interview with Josh Axe, a doctor of natural medicine, chiropractic physician, and clinical nutritionist. Lactobacillus has been studied extensively for its health benefits, which is why it is often included in many probiotic supplements, she added.

However, some people already have excessive Lactobacillus in their small intestine due to impaired motility, autoimmunity, or thyroid disease. Adding more Lactobacillus probiotics can worsen their bloating and other symptoms. These probiotics also tend to increase histamine, exacerbating SIBO.

A 2018 study revealed a link between probiotics and brain fog, gas, and bloating. Over two-thirds of 30 patients with brain fog had D-lactic acidosis, a buildup of lactic acid from probiotics, and more SIBO than those without brain fog. Discontinuing the Lactobacillus probiotics resolved their symptoms.

A 2018 study published in the American Journal of Gastroenterology revealed a connection between patients with SIBO symptoms who had recently consumed probiotics and positive tests for methane gas. The researchers examined 101 subjects who had been using probiotics for at least one month. The subjects’ positive breath tests suggested that probiotics might promote the overgrowth of methane-producing bacteria, potentially contributing to bad breath.

A 2018 Digestive Diseases and Sciences study found probiotic use may increase SIBO. Researchers gave 19 subjects Align probiotics containing Bifidobacterium infantis for two weeks. Methane gas breath levels were significantly higher with probiotics, indicating positive SIBO tests.

Dr. Myers said probiotics with Bifidobacterium and Lactobacillus species may worsen SIBO, advising certain people to avoid these.

Alternative Methods for a Healthy Gut

The U.S. Food and Drug Administration (FDA) may regulate probiotics as a dietary supplement, food ingredient, or drug, depending on how the probiotic is marketed, according to the National Center for Complementary and Integrative Health. If a probiotic is sold as a drug for disease treatment, then it must meet stricter requirements and be proven safe and effective through clinical trials. If it is sold as a supplement, which is often the case, prior FDA approval is not required.

Commercial probiotics can fail to address gastrointestinal distress, and while GI medications may provide temporary relief, they can sometimes add unwanted side effects.

Spore-Forming Probiotics

New research highlights soil-based, also known as spore-forming, probiotics as a promising alternative to traditional Lactobacillus probiotics commonly found on store shelves. According to Dr. Myers, these spore-based probiotics are superior and better tolerated by those with SIBO.

Spore-forming probiotics have a unique advantage over other types of probiotics because they can survive the harsh conditions of the gastrointestinal tract. They usually do not require refrigeration and can be safe at room temperature. The spore-forming Bacillus species, Bacillus coagulans, provides significant health benefits, including regulating immunity, preventing constipation, and reducing cholesterol levels, according to a 2020 Journal of Functional Foods article.

While shopping for probiotics, consumers can look for shelf-stable probiotic gummies, which usually contain Bacillus coagulans and sometimes Bacillus subtilis, another beneficial microbe found in fermented soybean foods, according to a 2021 review in the Annals of Microbiology journal.

Herbal Allies: Marshmallow Root, Licorice Root, and Slippery Elm

Although a 2023 Microorganisms study discusses the general health benefits of Lactobacillus probiotics, it also notes the advantages of traditional herbs for stomach issues. Herbs like marshmallow root, licorice root, and slippery elm have soothing properties that can help conditions like intestinal permeability, otherwise known as leaky gut. These healing herbs are often found in teas and other herbal products.

Soothing foods like coconut milk, honey, collagen, and whey protein can also help. They can help seal the gut’s tight junction proteins that keep cells intact and keep proteins from entering the bloodstream. This calms inflammation and improves SIBO symptoms.

Gut-Healing Smoothie Recipe

Mr. Axe recommends a smoothie recipe containing anti-inflammatory and gut-soothing ingredients to support gastrointestinal health.

Ingredients

1 to 2 cups full-fat coconut milk or almond milk 2 cups kale 2 cups spinach ½ avocado 2 frozen bananas, cut into chunks 1 teaspoon freshly grated ginger ½ tablespoon chia or flax seeds ½ tablespoon bee pollen 1 tablespoon hemp hearts 1 tablespoon raw honey or Manuka honey 2 tablespoons collagen protein or whey protein

Directions

Place all ingredients in a blender and blend on high until smooth (about 2 to 3 minutes). Serve over ice.