We have 100 trillion different bacteria in our bodies, up to two pounds of which are lurking in our intestines.[1] You probably know these microbes impact your digestion and your immunity—but did you realize the balance of bacteria in your gut can impact your level of pain, both physically and emotionally?

The microbes that live in your gut can either help keep you healthy and happy, or make you susceptible to conditions such as type 2 diabetes, obesity, inflammatory bowel disease, colon cancer, and autoimmune disorders such as rheumatoid arthritis.[2] Every day, your healthy and unhealthy strains of bacteria are in a constant battle with each other for domination of your entire body system, including your brain.

Many of my patients, when they experience either physical or emotional pain, hold it in their gut. Often patients will experience their stress in the form of stomach cramps, lower backache, diarrhea, or constipation. Others have more subtle symptoms that indicate bacterial imbalance, such as bad breath, a white pasty tongue, yeast infections (or general itchiness), or plantar warts. I’ve even treated patients with a heartbreaking history of childhood abuse or trauma that developed into lifelong irritable bowel syndrome and even ulcerative colitis.[3] Early traumas can change us on a genetic level, trigger autoimmune conditions, alter our bacterial balance, and leave our entire brain-gut connection vulnerable for a lifetime.[4]

Feelings of stress and emotional strain often “get us in the gut,” for good reason: Similar to the spinal cord, we have about 100 billion neurons in the small intestine alone. Almost every known neurotransmitter (and their receptors) can be found in this “second brain.”[5] The gut, not the brain, is also the body’s largest producer of serotonin, our primary happiness hormone.[6] However, without enough healthy digestive bacteria, neither your gut nor your brain can properly produce enough serotonin for regular bowel and brain functions,[7] which is why changing the balance of the bacteria in your gut can significantly impact the amount of pain you feel, both physically and emotionally.

In a recent article published in Gastroenterology, Dr. Kirsten Tillisch, associate professor of medicine in the digestive diseases division at UCLA’s David Geffen School of Medicine, did a brain scan study that showed this effect very clearly.[8]

Dr. Tillisch’s group studied 36 women, aged 18 to 55. One group ate a yogurt that contained a mix of several probiotics (Bifidobacterium animalis subsp Lactis, Streptococcus thermophiles, Lactobacillus bulgaricus, and Lactococcus lactis subsp Lactis) twice a day for four weeks. A second group had yogurt without probiotics, and a third group had nothing. The researchers took fMRI scans of the women’s brains before and after the 4-week period; both while resting and while looking at scary and upsetting photographs. The women who had eaten the probiotic yogurt showed a greater decrease in activity in their insula and somatosensory cortex (parts of the brain associated with emotions and physical sensations) while they were looking at the scary pictures.[9] Their experience indicated that these may be brain changes that could turn down the dial on stressful emotions that heighten sensations of physical pain–and vice versa. Then, during the resting brain scan, the women who had taken the probiotics showed increased connections in the prefrontal cortex, the area of higher-level thinking; versus the women who hadn’t had the probiotics (they had increased connections in more reactive, primal parts of their brain). By strengthening the prefrontal cortex, not only could probiotics help interrupt transmission of pain signals from the spinal cord,[10] they could also support more highly evolved executive functions to help you regulate your emotions and better manage your perception of pain.

I’ve seen this again and again–when my patients eat more probiotic, anti-inflammatory foods, they feel calmer and more emotionally steady, and experience an immediate release in pain, especially in their lower back. I’m not surprised: another study found that drinking yogurt with probiotics decreased inflammatory C-reactive protein levels by almost 30 percent in nine weeks.[11]

Help your good bugs fight pain:

Eat your veggies. People who eat tons of fresh produce have different microbes than those who eat more fat and carbohydrates. Your microbes use fruits’ and veggies’ fibers as food, fermenting these “prebiotics” in your intestine, producing beneficial short-chain fatty acids. While the RDA for fiber is 25–38 grams per day, most Americans only eat 12–18 grams per day.[12] Sautee spinach and broccoli with your eggs and slice up a tomato. Grab dried figs, goji berries, and walnuts as an on-the-go snack.

Eat fermented foods. Look for yogurts or kefir with Lactobacillus, Streptococcus, and Bifidobacterium. Other probiotic foods include miso, tempeh, kombucha drinks, kimchi (a Korean cabbage dish), and sauerkraut. (Careful: Most processed pickles are not fermented—some even have high fructose corn syrup, which feeds the bad bugs in your gut!)

If you drink dairy, use only raw milk. Grass-fed cows naturally create milk with more beneficial fat-burning, immunity-boosting conjugated linoleic fatty acids.[13] Many believe pasteurization kills the beneficial bacteria in raw milk and removes many nutrients, while still leaving behind bloat-inducing lactose, a form of sugar. Look for raw milk from Jersey, Guernsey, or Normande cows or goat’s milk, which all contain a protein (A2) that may cause less systemic inflammation.[14]

And, of course, take probiotics. A high potency probiotic can help to bolster the good guys in your gut. I use Life 9 Probiotics by Young Living Essential Oils. Store in the fridge to protect potency, then follow those probiotics with prebiotics such as asparagus, bananas, steel-cut oats, manuka honey, or lentils. Keep a bowl of crisp apples on your desk—good bugs gobble up the prebiotic pectin in their flesh.

If you really want to do your homework on this subject to make a greater positive impact on your gut, I recommend reading Dr. Emeran Mayer’s book The Mind-Gut Connection: How the Hidden Conversation Within Our Bodies Impacts Our Mood, Our Choices and Our Overall Health!