The Psychobiotic Revolution by Ted Dinan

It may be possible to relieve anxiety and depression solely by manipulating bacteria in the gut.

Psychobiotics are defined as live bacteria and their food (probiotics & prebiotics) which, when ingested, confer mental health benefits through interactions with commensal gut bacteria. Ninety percent of what we lug around with us is not human. It’s microbial, and it’s vital to our health, our moods, even the decisions we make. There are roughly 15 trillion cells in our body—and over 100 trillion bacteria, most of them in the gut and most of them supporting such essential functions as digestion, immunity, metabolism, even mental health in ways that are only now being understood. The body is an ecosystem of interdependent parts relaying messages to each other, explains Ted Dinan, a psychiatrist at the University of Cork, Ireland. So influential are the thousands of species of gut flora on health that Dinan aims to harness the power of microbes to treat depression. Recently, he coined a term for the live organisms in the gut that are psychoactive and of potential benefit to those suffering from a variety of psychiatric illnesses—psychobiotics. Not only can researchers now discern which strains of gut bacteria affect the nervous system, they can also map the exact pathways through which specific gut bacteria influence the brain. Although there are many preparations of bacteria now being marketed as probiotics, “the vast majority do nothing for us,” Dinan insists. “Most don’t make it past the stomach acid. But a few have enormous implications for the future of psychiatric medication.”

It’s long been known that the stress system is intimately involved in depression. People suffering from major depression frequently have elevated levels of the hormone cortisol, released in response to stress. In a recent study, a probiotic cocktail of Lactobacillus helveticus andBifidobacterium longum was found to reduce cortisol levels. Many physiological and psychological processes associated with depression can be traced to a deficiency in the neurotransmitter GABA. Lack of GABA in the brain may bring on the negative ruminations long linked with depression. Researchers have identified gut microbes that actively secrete GABA. Chief among them are strains of Lactobacillus and Bifidobacterium. Interestingly, consuming dark chocolate leads to an increase in both bacterial families. The rich reservoir of polyphenols in chocolate acts as a prebiotic, enhancing the growth of beneficial bacteria already in the gut.

A number of microbes are capable of producing other neurotransmitters, such as norepinephrine, serotonin, and dopamine. Taking Bifidobacterium infantis as a probiotic, for example, alters levels of serotonin—just like Prozac. At MIT, a team of biologists has shown that a specific strain of Lactobacillus reuteri, delivered in either yogurt or in supplement form, improves mood, appearance, and general health by increasing levels of oxytocin, the hormone that kicks in when you cuddle, hug, or have sex. Other microbes act directly on nerve-cell receptors to influence brain states. Lactobacillus acidophilus—commonly found in yogurt, sauerkraut, and kimchi—improves the functioning of cannabinoid receptors in the spinal cord. The receptors are critical to regulating pain. “It might be time to start thinking about treating depression from the bottom up instead of the top down,” says neuroscientist Jane Foster of McMaster University, who leads a team studying depression. “The evidence is there that the brain is responding to the gut. Let’s make that the therapeutic pathway.”

B. infantis, L. reuteri, and several other strains of gut bacteria also work throughout the immune system by attacking inflammation, a hallmark of depression. The microbes also influence appetite, sending satiety signals to the brain by increasing levels of the hormone leptin and suppressing ghrelin. Psychobiotics affect the brain through several distinct pathways. The primary route is via the vagus nerve, a central conduit that relays messages from the intestines to the brain and touches many organs in between. Neurotransmitters produced by gut microbes activate the vagus nerve in specific ways, some by altering the neural response to reward. Lactobacillus rhamnosus, a strain of bacteria that reduces anxiety and depression, acts on the brain only via the vagus nerve. In the brain, it beefs up production of GABA receptors. Several strains of gut flora improve mood by way of the endocrine system, which is responsible for our response to stress. Some, like B. infantis and L. reuteri, work on the immune system, where they suppress proinflammatory cytokines. The L. helveticus and B. longum cocktail operates through the neuroendocrine system to lower cortisol. Further, it curbs inflammation. Some microbes are crucial digestively for fermenting fibrous food; the process yields short-chain fatty acids that enter the bloodstream and, once in the brain, regulate appetite. Therapeutic psychobiotics are a long way from reaching the market; still, it’s possible to unleash some of the power of microbes. There are active agents in yogurt that reduce anxiety and fear, studies show. Eating fermented foods—kefir, sauerkraut—also supplies psychobiotics. Take a cue from Stanford microbiologist Justin Sonnenburg, a pioneer in the therapeutic use of gut bacteria, who ferments his own kimchi. “These microbes,” he says, “could change public health.”

Scientifically Validated Psychobiotics

B. longum (1714)  – Reduce stress and inflammation. Found in yogurt, kefir and sauerkraut.
B. infantis (35624) (Same as B. longum) .Found in yogurt, kefir and sauerkraut.
L. helveticus .Found in yogurt, kefir and sauerkraut.

B. breve (1205)  – Reduces anxiety and prevents candida
B. animalis – Treats IBS and colitis
B. animalis lactis – Enhances PMN phagocytic capacity and NK cell tumoricidal activity boosting immune system.

B. bifidum along with L. acidophilus and L. casei for eight weeks has been proven to alleviate depression.

L. acidophilus – Treats SIBO. High amounts found in yogurt, kefir and sauerkraut. This Bacteria is also used to treat anxiety.

L. bulgaricus / L. helveticus – Improves immune function and moderate the response to emotional stimuli.  Found in kefir & yogurt.

L. rhamnosus – Reduce anxiety and depression.
L. rhamnosus GG (LGG) – Treats IBS.

S. boulardi – Treats IBS, Colitis and Crohn’s.
L. reuteri  – Reduces antibiotics and Reduces hunger.
L. plantarum  – Reduces IBS, support bowel, improve memory – Found in pickles and kimchi.
L. casei  – Mood enhancer, reduces anxiety & good for chronic fatigue syndrome – Found in yogurt.
L. paracasei  – Counter effects of alcohol and antibotics.
S. thermophilus – Syngerstic with L. delbruekii – for treating anxiety. Found in kefir and yogurt.

Rhizopus Microsporus & Klebsiella Pneumoniae Subsp. Ozaenae found in Tempeh has the following bioactive compounds and functional properties:

Antioxidant genestein, daidzein, tocopherol, superoxide dismutase

Prevents oxidative stress causing non-communicable disease such as hyperlipidemia, diabetes, cancer (breast and colon), prevents the damage of pancreatic beta cell

Astuti, 2015

Leuconostoc mesenteroides, Lactobacillus plantarum, Pediococcus pentosaceus, and Lactobacillus brevisfound in Sauerkraut has the following bioactive compounds and functional properties:

Vitamin C		Treats and prevents Scurvy	Peñas et al., 2013
Glucosinolates		Activation of natural antioxidant enzymes	Martinez-Villaluenga et al., 2012

B. Subtilis found in Natto has the following bioactive compounds and functional properties:

Nattokinase, antibiotics, Vitamin K

Antitumor and  Immunomodulating

Nagai, 2015

L. Kimchii, E.Faecalis, Lb.Brevis, P. Cerevisiae and Lb. Plantarum – Species found in fermented root vegetable dish Kimchi has been the follwoing bioactive compounds and functional properties:

Isocyanate and sulphide indole-3-carbinol		Prevention of cancer, detoxification of heavy metals in liver, kidney, and small intestine	Kwak et al., 2014
Ornithine		Anti-obesity efficacy	Park et al., 2012
Vitamin A, Vitamin C, fibers		Suppression of cancer cells	Han et al., 2015
Capsaicin, Allicin		Prevention of cancer, suppression of Helicobacter pylori	Lim and Im, 2009
Chlorophyll		Helps in prevention of absorbing carcinogen	Ferruzzi and Blakeslee, 2007
S-adenosyl-l-methionine (SAM)		Treatment of depression	Lee and Lee, 2009
HDMPPA (an antioxidant)		Therapeutic application in human atherosclerosis

Kombucha Probiotics: Bacteria & Yeast

The specific bacteria and yeast strains in the kombucha are what make it act the way it does, and what produce the fizz and flavor of kombucha. Not all kombucha cultures will contain the exact same strains, but these are some that have been recorded in studies:

• Acetobacter is an aerobic (requiring oxygen) bacteria strain that produces acetic acid and gluconic acid. It is always found in kombucha. Acetobacter strains also build the scoby mushroom. Acetobacter xylinoides and acetobacter ketogenum are two strains that you might find in kombucha.
• Saccharomyces includes a number of yeast strains that produce alcohol and are the most common types of yeast found in kombucha. They can be aerobic or anaerobic (requires an oxygen-free environment). They include Saccharomycodes ludwigii, Saccharomycodes apiculatus, Schizosaccharomyces pombe, Zygosaccharomyes, and Saccharomyces cerevisiae.
• Brettanomyces is another type of yeast strain, either aerobic or anaerobic, that are commonly found in kombucha and produce alcohol or acetic acid.
• Lactobacillus : A type of aerobic bacteria that is sometimes, but not always, found in kombucha. It produces lactic acid and slime.
• Pediococcus : These anaerobic bacteria produce lactic acid and slime. They are sometimes, but not always, found in kombucha.
• Gluconacetobacter kombuchae is an anaerobic bacteria that is unique to kombucha. It feeds on nitrogen that is found in tea and produces acetic acid and gluconic acid, as well as building the scoby.
• Zygosaccharomyces kombuchaensis is a yeast strain that is unique to kombucha. It produces alcohol and carbonation as well as contributing to the mushroom body.

Kombucha also contains a variety of other nutrients, particularly various acids and esters that give the drink its characteristic tang and fizz. Included in these components is gluconic acid, which is the primary difference between the makeup of kombucha and the makeup of apple cider vinegar. The actual bacteria, sugar, and acid content of kombucha depend on many factors, including the initial culture, the type of tea used, the type of sugar used, the strength of the tea, the type of water, the brewing time, the culturing temperature, and more. Due to the nature of kombucha, it is not possible to state an exact microbial composition for Kombucha.  While different SCOBYs may vary in their exact makeup, what is common to all kombuchas is gluconic acid, acetic acid, and fructose.