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ADHD and your gut health are an incredibly important connection. That’s because bacteria are almost literally everywhere around us. From desert sands to Antarctic ice, from the depths of the ocean to the upper atmosphere. They’re also in you!

100 trillion microbes, from more than 1,000 species, happily inhabiting your ears, nose and mouth, hanging out under your arms and between your toes—and riotously thriving in the warm, wet and well-stocked precincts of your bowels.

Your gastrointestinal (GI) tract is “tract housing” for a complex, ever-changing population of bacteria called gut microbiota. A microbiota is any group of microbes that occupy a specific habitat.

Are Bacteria Bad for Us?

Many of us still think of all bacteria as being bad. And we think of antibiotics as the medical militia that can stop those marauding germs from taking over.

True, there are a lot of bacteria that can sicken us.

But many species of bacteria are partners in good health—including so-called “friendly” gut bacteria. In fact, there are three to four pounds of these microorganisms in the gut, providing many important functions critical for maintaining our health.

Without those bacteria, you simply wouldn’t be alive.

Among their many metabolic talents, friendly gut bacteria:

  • help propel digesting food through the intestines
  • ease food cravings and regulate appetite
  • keep the lining of the intestines strong and intact (instead of weak and leaky)
  • stop bad bacteria from multiplying
  • thwart carcinogens
  • activate the gut-based immune system (70% of your total immune system)
  • stabilize intestinal pH (acid/alkaline balance), allowing beneficial bacteria to flourish
  • break down and rebuild hormones
  • manufacture essential fatty acids, B-vitamins and vitamin K
  • boost the absorption of vitamins and minerals

Given their health-sustaining power, it’s no surprise that scientific studies have found friendly bacteria can help prevent, control or reverse a wide range of conditions.

These include high cholesterol, prediabetes and diabetes, gum disease and cavities, colds, flu and pneumonia, colic, irritable bowel syndrome, eczema, vaginal infection, chronic constipation, rheumatoid arthritis, cirrhosis, overweight, canker and cold sores, chronic kidney disease, inflammatory bowel disease, allergies and asthma, high blood pressure, and the list goes on.

The Connection Between Gut Bacteria and ADHD

Along with these metabolic and medical benefits, scientists have recently discovered another way gut microbiota influence our lives. This mass of microscopic creatures affects the brain, playing a central role in how we think and feel.

And they may be affecting your ADHD child’s brain, and therefore his behavior.

Some strains of bacteria—including one called Clostridia—generate a chemical called HPHPA that can affect the brain, making your ADHD child more agitated and aggressive.

A simple test—the Organic Acids Test—can detect if HPHPA is overwhelming your child’s gut.

And, if it is, a straightforward integrative treatment can normalize gut flora, decrease HPHPA, and improve behavior.

Researchers in the field have discovered that communication between the gut and the brain—the “gut-brain axis,” as they’ve dubbed it—is a two-way process whose goal is keeping your body in a state of balance, or homeostasis.

Examples of homeostasis include a body temperature that’s not too hot or too cold, a heartbeat that’s not too fast or too slow, and a rate of digestion that’s not too speedy or too sluggish.

Gut microbiota also directly balance or imbalance the brain through neurotransmitters. These chemicals are produced in neurons (brain cells), and relay messages between neurons.

They fall into two main categories. There are inhibitory or calming neurotransmitters; and there are excitatory or stimulating neurotransmitters.

The inhibitory neurotransmitters include serotonin and GABA: they calm you down, playing key roles in stabilizing mood, appetite and sleep. The excitatory neurotransmitters include norepinephrine and epinephrine: they rev you up, and play key roles in attention, energy and sleep.

And then there’s dopamine, a neurotransmitter that plays key roles in both inhibition and excitation. Balanced levels of dopamine are a must for focus and motivation. Imbalanced dopamine is common in ADHD.

How Do Friendly Bacteria Make Us Happier?

Exactly how do gut microbiota influence communication between the gut and the brain? Or, as scientists like to ask: What is their mechanism of action? Turns out there are quite a few.

Gut microbiota affect the brain through:

  • The vagus nerve: It starts at the brainstem and ends at the colon, home to most gut microbiota.
  • Neurotransmitters: Neurotransmitters like serotonin influence emotions and mood. Neurotransmitters are also sent from the brain to the gut, and the gut to the brain.
  • Hormones: The gut microbiota also help regulate hormones, which affect the hypothalamic-pituitary-adrenal axis, a part of the endocrine (hormone-generating) system, which holds responsibility for the body’s stress response.
  • The immune system: Bacterial imbalance in the gut generates cytokines, messengers in the immune system that tell other immune cells to handle infection, inflammation and injury. Cytokines can do a lot of collateral damage, inflaming the rest of the body—including the brain.
  • Toxic byproducts of bacteria: These molecular byproducts, like HPHPA, can leak out of the gut into the bloodstream, enter the brain, and imbalance brain function. And it’s this mechanism of action that can worsen the symptoms of ADHD—when an overgrowth of Clostridia bacteria generates the toxin HPHPA, which bashes the brain.

The Connection Between Probiotics, Gut Health and ADHD

Several studies are establishing the link between the microbiota and the mind. They all involve supplementing the diet with a probiotic—a friendly, gut-inhabiting microorganism found in fermented food like yogurt, or in a probiotic supplement.

Ingested in adequate amounts, these live organisms produce a beneficial effect in patients suffering from behavioral, emotional or mental problems.

One study involving 20 children with ADHD, half taking Ritalin and half taking a probiotic and other nutritional supplements, like fish oil.1

The researchers were astonished by the results: The probiotics and other supplements worked as well as Ritalin! The children on both regimens had more impulse control and were more attentive.

Other research shows less stress, anxiety and depression, along with better problem-solving skills. In another study, seventy people were divided into groups, with some eating a probiotic-rich yogurt or taking a probiotic supplement.2

After six weeks, those eating the probiotic-rich yogurt had 85% less stress, anxiety and depression than the non-probiotic groups, and those taking the supplement had 51% less, reported researchers in the medical journal Nutritional Neuroscience.

In a study from the British Journal of Nutrition, researchers found that taking probiotics for 30 days decreased anger and hostility, depression and anxiety, and increased problem-solving ability.3

While the science of probiotics helping ADHD children’s brains is still ongoing, the evidence so far is compelling. I discuss this and many other natural and medicinal ways to help treat ADHD in my award-winning book, Finally Focused.

Yours in health,

James M. Greenblatt, MD
Founder, Medical Director, Psychiatry Redefined