Are gut bacteria making you depressed, overweight, and hypothyroid?
We all carry trillions of bacteria in our guts, with as many as a thousand different strains. The composition of these strains, or our “bacterial fingerprint,” can influence whether we are prone to depression, anxiety, obesity, or Hashimoto’s hypothyroidism. “Bad” gut bacteria has been associated with low thyroid function and autoimmune Hashimoto’s.
Some gut bacteria can make you fat
Studies have shown people (and mice) who are overweight have much higher levels of particular strains of bacteria than thinner subjects. When thin mice are inoculated with bacteria from heavy mice, they gain weight. This is because these fat-promoting bacteria have been shown to encourage overeating, promote weight gain, prevent the burning of fat, and make obese people better at deriving calories from food than thin people.
In a nutshell, your “bacterial fingerprint” plays a role in how much fat you carry and how easy or difficult it is for you to lose weight. Although diet and exercise are important, these findings help to explain why solely relying on the “eat less and exercise more” approach to weight loss is outdated.
Effect of gut bacteria on depression and anxiety
The composition of your gut bacteria can also play a role in whether you suffer from depression and anxiety. For instance, having plenty of beneficial bacteria, such as the Bifidobacteria strain, can promote production of serotonin, the “feel-good” chemical that prevents depression.
On the other hand, too much of “bad” bacterial strains can promote depression and anxiety. This is because the gut is linked to the brain by the vagus nerve, a large nerve that sends messages back and forth between the brain and digestive system. The effects of harmful bacteria in the gut travel to the brain, impacting brain function and mood.
In one study, subjects who took probiotics containing Lactobacillus and Bifidobacterium reported less anxiety, depression, and anger and an improved ability to solve problems. In another study, mice given a Lactobacillus strain cruised through a maze that normally created high anxiety and showed lower levels of the stress hormone cortisol compared to their probiotic-deprived counterparts.
Gut bacteria and Hashimoto’s hypothyroidism
Gut bacteria influence Hashimoto’s hypothyroidism in several ways. For one, certain strains of bacteria have been associated with triggering Hashimoto’s, an autoimmune disease in which the immune system attacks the thyroid gland. An overgrowth of bad bacteria can also promote Hashimoto’s hypothyroidism by promoting intestinal permeability, or leaky gut. This is a condition in which the gut wall becomes inflamed and porous, allowing inflammatory compounds into the bloodstream. Also, 20 percent of thyroid hormone is converted by intestinal bacteria to a form the body can use. A poor balance of bacteria can hinder this conversion.
Cultivating good gut bacteria
Although researchers are still unsure exactly how to banish obesity, depression, and anxiety with probiotics, it’s clear you need to enhance your bacterial fingerprint for optimal health.
Birthing and baby feeding affect gut bacteria
The balance of good and bad bacteria starts at birth—vaginal deliveries and breastfeeding have been shown to improve a child’s chances of starting off with a healthy bacterial colony compared to C-sections and bottle feeding.
Chronic stress and gut bacteria
Chronic stress can throw your bacterial harmony out of balance, as can diets filled with sweets and sugars, processed foods, and fast foods. These foods damage and inflame the intestinal walls, promoting overgrowth of bad bacteria and yeasts.
Cultured food and fiber promotes good gut bacteria
You can promote bacterial harmony by focusing on an anti-inflammatory, whole foods diet that includes cultured and fermented foods, such as kefir, sauerkraut, kimchi, and fermented vegetables. If you use store-bought cultured foods, make sure they are the real deal and not simply made with vinegar, or pasteurized, which would kill good bacteria..
A healthy colony of good gut bacteria also relies on plenty of soluble fiber in the diet. Eating plenty of produce will give you just what you need in that respect.
Probiotics for obesity, depression, and anxiety
Fortunately, we have powerful probiotics today that can help you cultivate your inner garden. Probiotics should be stable enough to survive the hot and acidic environment of the stomach and contain ample amounts of beneficial strains. Ask my office for advice on a probiotic that’s right for you.
