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The Dirty on Good Bacteria

How Probiotics Can Boost Your Physical and Mental Health

There’s been a lot of buzz about probiotics and their benefits for digestion – and rightfully so. Dozens of studies tout the power of probiotics to relieve constipation, diarrhea and various other gastrointestinal irritations. But the benefits don’t stop there. A growing body of research shows that probiotics may also boost mental health by combating depression, anxiety and other conditions.

Balancing the Good Bacteria with the Bad

When we think of bacteria in the body, we often think of colds and infections (and race to the doctor for antibiotics). But probiotics are a beneficial type of bacteria, or live microorganisms, that are essential for good health.

How do we get an ideal balance of good and bad bacteria? Population of the bacteria in the gut starts from birth. By the age of 1, the guts of babies born via vaginal births who were breastfed contain a healthy complement of bacteria, fungi, viruses and other microbes. If the gut bacteria are not colonized properly, the individual may have an impaired ability to respond to stress for life. Children who are born via Cesarean section or who are not breastfed – two practices that are becoming increasingly common – may have increased risk of allergies, impaired immunity and other problems because of imbalances in the gut microflora.

A healthy gut absorbs nutrients and disperses them throughout the body, and also helps us filter out dangerous bacteria, chemicals and toxins. Over time, the balance of bacteria in the gut can shift, often as a result of antibiotic overuse, chronic stress, insomnia, diseases, the environment and inflammatory diets, leading to a number of health problems.

Health Benefits of Probiotics

Probiotic foods and supplements can help restore optimal health in the gut and have been shown in several studies to have the following health benefits:

  • Relief for digestive problems such as diarrhea, constipation, gas, bloating and irritable bowel syndrome
  • Improved immune function
  • Fewer antibiotic-associated gastrointestinal problems
  • Prevention and treatment of eczema and other skin conditions in youth
  • Reduced incidence of yeast infections and urinary tract infections
  • Protection against food allergies and autoimmune disorders such as Crohn’s disease, ulcerative colitis and rheumatoid arthritis
  • Decreased risk of common childhood illnesses such as colds, ear infections, strep throat and diarrhea

Although science is starting to take a closer look at the benefits of probiotics, more research is needed to determine which types of probiotic strains are most beneficial for specific health conditions.

Probiotics: Not Just for the Gut

A growing body of research suggests that the bacteria in the gut also can have a significant impact on our moods and behavior. We can think of the human body as having two brains: the one in our heads and one in our gut. The gut brain, also known as the enteric nervous system, uses over 100 million neurons and more than 30 neurotransmitters, including the feel-good chemical serotonin (95 percent of the serotonin in the body is found in the gut).

The gut sends signals to the brain via the vagus nerve, which is why we have sensations like “butterflies in the stomach” and why psychiatric diagnoses such as depression and anxiety often co-occur with bowel disorders. While more research is needed in this area, the connection between the brain and the gut may make probiotics an exciting new treatment option for a variety of disorders, including:

Stress/Depression/Anxiety – In a study published in the Proceedings of the National Academy of Sciences, bacteria-fed mice had significantly lower levels of the stress hormone corticosterone and displayed significantly less behavior linked with stress, anxiety and depression than mice fed plain broth. The researchers also showed that regular feeding with the Lactobacillus strain caused changes in the expression of receptors for the neurotransmitter GABA; in other words, probiotics can have a direct effect on brain chemistry.

Autism – Limited studies have implicated abnormal gut flora in autism spectrum disorders. In a 2006 study by researchers at Reading University, parents reported significant improvements in concentration and behavior among autistic children taking probiotics, but the study results were compromised because parents refused to stop giving the probiotics to their children.

ADHD – Few controlled studies have evaluated the connection between probiotics and ADHD. In one study of 75 children with ADHD, the majority had little or no friendly bacteria in their gut, coupled with an overgrowth of harmful bacteria and/or yeast. The study author concluded that by taking probiotics, the symptoms of ADHD may be reduced.

Obesity – A study in Microbiology found that specially engineered probiotics can alter fat composition and metabolism, with implications for treating obesity, diabetes and related conditions. Other studies have echoed these findings.

Sources of Probiotics

Probiotic foods aren’t as common in the standard American diet as they are in some Asian and Northern European cultures. But if you know what to look for, you can incorporate a number of probiotic foods into your diet, such as:

  • Fermented dairy products, such as yogurt, kefir, buttermilk and goat’s cheese (as long as they contain live cultures)
  • Pickled foods like kimchi and sauerkraut (fermented cabbage) that contain active cultures
  • Miso paste (a seasoning paste made from fermented soybeans)
  • Tempeh (fermented beans)

If you suffer from gastrointestinal irritation, food sensitivities, frequent colds or infections or any other conditions mentioned here (or if your diet is high in processed foods or you are taking antibiotics or have high levels of stress), consider taking a probiotic supplement to restore balance in the gut. Probiotic supplements are generally quite safe and carry few side effects (except for those with impaired immune function or serious illnesses such as pancreatitis). Choose a supplement made by a well-known company that comes in the form of a double-walled capsule so it can get past the acidic stomach.

Your brain gets all the attention, but your gut may be what holds the key to overall health and wellness. Talk to your doctor about whether probiotics could improve your physical and mental health.