Neuroscientist Dr. David Perlmutter points out that of the thousands of bacteria that make up the human microbiome, only a few have been rigorously studied for their impact on health.
Photo credit: Shutterstock
In a blog post, he identifies five key species that support brain health and immunity: from Lactobacillus plantarum, present in fermented foods like kimchi, to Bifidobacterium longum, involved in the balance of gut flora.
Lactobacillus plantarum
Found in kimchi, sauerkraut and other fermented vegetables, Lactobacillus plantarum is one of the most studied bacteria when it comes to gut health. It stands up well in the acidic environment of the stomach and is associated with regulating the immune response and reducing inflammation at the digestive level.
One of the important roles of this bacterium is to protect the intestinal wall. Basically, it helps the gut stay “tight” so that harmful bacteria and inflammatory substances don't get into the bloodstream—which is associated with a lower risk of inflammatory problems throughout the body.
Some studies show that L. plantarum can reduce inflammation and regulate immune system reactions, including in autoimmune conditions. There are also indications that it helps break down proteins, which is relevant for people with food sensitivities.
In addition, L. plantarum helps the body use nutrients such as omega-3 fatty acids, vitamins and antioxidant compounds in food more efficiently by supporting their digestion and absorption in the gut.
Lactobacillus acidophilus
Commonly found in yogurt and other fermented dairy products, Lactobacillus acidophilus is one of the most well-known probiotic bacteria. At the intestinal level, it helps maintain the balance between beneficial and harmful bacteria, having direct effects on the immune system.
In women, it is associated with the reduction of Candida albicans, responsible for the occurrence of vaginal candidiasis.
Several clinical studies show that L. acidophilus can help lower cholesterol. Also, in the small intestine, it produces substances with an antibacterial effect, which limit the development of harmful microorganisms.
Lactobacillus brevis
Present in fermented foods such as sauerkraut and pickled cucumbers, Lactobacillus brevis is associated with the activation of the body's defense mechanisms, including cells directly involved in fighting infections.
There is data showing its effectiveness in the management of bacterial vaginosis, which is why this bacteria is included in some intimate health products. It also limits the growth of harmful bacteria in the gut.
Research shows that L. brevis can increase levels of BDNF (brain-derived neurotrophic factor), a substance involved in forming new neurons and strengthening existing connections. This mechanism is associated with the maintenance of long-term cognitive health.
Bifidobacterium lactis
Also known as B. animalis, this bacteria is commonly found in fermented dairy products. Studies show that B. lactis can reduce the frequency of digestive disorders and support immune function.
There is evidence that it helps fight some food-borne bacteria, including Salmonella, and may reduce the risk of episodes of acute diarrhoea. Clinical research also indicates a reduction in gastrointestinal infections when taken regularly, as well as faster recovery from exposure to harmful bacteria.
For people with sensitive digestion, B. lactis is one of the bacteria most commonly used to maintain intestinal balance.
Bifidobacterium longum
One of the first bacteria to colonize the human body after birth, Bifidobacterium longum plays an important role in shaping the microbiome and how the immune system develops and regulates itself.
Studies show that B. longum helps people who have problems with lactose, reduces episodes of diarrhea and can moderate some food reactions. In the intestine, it limits the growth of harmful bacteria and contributes to the protection of cells through its antioxidant effect.
Animal experiments also indicate an effect on emotional state: the presence of B. longum was linked to lower levels of anxiety, supporting the idea that gut flora directly influence the brain. Like L. acidophilus, it is also involved in maintaining cholesterol within normal limits.
Introducing these five bacteria into your daily diet can be done simply by regularly consuming fermented foods such as plain yogurt, kefir, sauerkraut or kimchi. For those who choose supplements, there are formulas that combine them in one capsule.
The gut microbiome plays a key role in digestion, immunity and brain function. A diet rich in fiber, fermented foods and probiotics helps maintain the balance of beneficial bacteria, with visible effects on focus, mood and inflammation in the body. When this balance is lost, metabolic problems can occur, as well as mental health disorders such as anxiety or depression.
