Archive for July, 2011

Probiotics produce neurotransmitters

I’m sure you have heard of smart drugs and nutrients that improve brain function by altering neurotransmitter levels in your brain.

Well two new research papers reveal that probiotic bacteria in your gut can do the same thing naturally.

This is fantastic news because the main flaw with smart drugs is balancing the dose. If its being done in your gut by the food you eat your body can take care of balancing neurochemicals naturally.

This video is not on the latest research which you can read about below.

From Kurzweilai.net blog:

Professor Mark Lyte and associates at Texas Tech University Health Sciences Center have come up with a radical concept: that you may be able to fine-tune your mental and emotional states by the right combination of probiotics!

Probiotics are “good” bacteria that normally reside in your gut and are available OTC in any drug store or health food store. Lyte suggests that they can generate neurochemicals that affect your brain — even improve your psychological health, and that neurochemicals generated by the brain can also affect these bacteria.

We recently reported on evidence that gut microbes do in fact influence neurological function (along with aiding digestion and inhibiting pathogens). But Lyte and associates take it a step further.

probiotics

“This paper proposes a new field of microbial endocrinology, where microbiology meets neuroscience,” Lyte said. “There is already evidence to suggest that the connection between gut microbes and the nervous system represents a viable route for influencing neurological function. A recent study in mice, for example, showed that the presence of neurochemicals such a serotonin in the bloodstream was due to direct uptake from the gut.”

“Neurochemicals such as GABA may be viewed as a common shared language enabling interkingdom signaling between prokaryotes (e.g., probiotic bacteria) and eukaryotes (e.g., vertebrates),” Lyte said in a BioEssays paper. For example, lactobacilli and bifidobacteria produce GABA, which is known to reduce stress and anxiety (GABA may also reduce inflammation in colitis and intestinal bowel disease), he said.

probiotic

“GABA is already potentially present in some fermented foods,” Gregor Reid of the Department of Microbiology and Immunology, University of Western Ontario points out. “So should there not be some clinical evidence available already to suggest that eating these foods improves mental health?…. Lactobacillus acidophilus NCFM induce opioid effects, yet there is no evidence that pain relief is associated with ingestion of this organism in any probiotic formulation. This may be because nobody has investigated this formally, or the levels of the molecules necessary are too low.”

In the paper, Lyle lists several neurochemicals (normally produced by the brain) that are also produced by various probiotics in the gut:

Lactobacillus, Bifidobacterium GABA
Escherichia, Bacillus, Saccharomyces Norepinephrine
Candida, Streptococcus, Escherichia, Enterococcus Serotonin
Bacillus, Serratia Dopamine
Lactobacillus Acetylcholine
If Lyte’s hypothesis is confirmed, microbial endocrinology may emerge as an exciting new approach to treating patients with psychological problems.

brain

So do physical gastrointestinal problems have psychological counterparts? (Gives new meaning to “gut feeling.”) Also, what is the role of the “second brain” (neurons embedded in the walls of the long tube of our gut, or alimentary canal, contains some 100 million neurons) in this?

And will we see a new class of “psychohackers” experimenting with creating their own treatments and modifying their own neurochemicals to reduce depression and anxiety or induce happiness?

Ref.: M. Lyte, Probiotics function mechanistically as delivery vehicles for neuroactive compounds: Microbial Endocrinology in the design and use of probiotics, BioEssays, 2011; [DOI: 10.1002/bies.201100024]

Ref.: G. Reid, Neuroactive probiotics, BioEssays, 2011; [DOI: 10.1002/bies.201100074]

(GABA) is already potentially present in some fermented foods, should there not be some clinical evidence available already to suggest that eating these foods improves mental health?

Experiments with mice have determined that behavior and brain chemistry varies depending on the type of bacteria in the gut, report Stephen Collins at McMaster University and Premysl Bercik at the Farncombe Family Digestive Health Research Institute.

Working with healthy adult mice, the researchers showed that disrupting the normal bacterial content of the gut with antibiotics produced changes in behavior; the mice became either anxious or less cautious. This change was accompanied by an increase in brain-derived neurotrophic factor (BDNF), which has been linked to depression and anxiety.

When oral antibiotics were discontinued, bacteria in the gut returned to normal, “accompanied by restoration of normal behavior and brain chemistry,” Collins said.

gut

The findings are important because several common types of gastrointestinal disease, including irritable bowel syndrome, are frequently associated with anxiety or depression. In addition there has been speculation that some psychiatric disorders, such as late onset autism, may be associated with an abnormal bacterial content in the gut.

Bercik suggested that these results lay the foundation for investigating the therapeutic potential of probiotic bacteria and their products in the treatment of behavioral disorders, particularly those associated with gastrointestinal conditions such as irritable bowel syndrome.

The research appears in the online edition of the journal Gastroenterology.

Gut bacteria and stress

Another recent study with mice has also demonstrated a connection between gut bacteria in the digestive system and stress response.

Researchers at Ohio State University showed that gut bacterial colonies in mice decrease and immune biomarkers increase in response to stress. They ran a series of experiments using an aggressive mouse as a stressor for docile mice.

At the end of the stress experiments, blood samples and material from inside each animal’s intestine were taken from stressed animals along with samples from a control group. The blood samples were analyzed to detect the levels of two immune biomarkers used to gauge stress: a cell-signalling cytokine molecule and a protein called MCP-1 that summons macrophages, or scavenger cells, to the site of an infection.

The intestinal samples were used to determine the relative proportion of at least 30 types of bacteria residing there.

Compared to the control mice, the stressed animals showed two marked differences: the proportion of one important type of bacteria in the gut (Bacteroides) fell by 20 to 25 percent while another type (Clostridium) increased a similar amount. Also, levels of the two biomarkers jumped 10-fold in the stressed mice, compared to controls.

The researchers concluded that exposure to social stressors “significantly affect gut bacterial populations” while increasing circulating cytokines that regulate inflammatory responses.

Ref.: Bailey MT et al., Exposure to a social stressor alters the structure of the intestinal microbiota: implications for stressor-induced immunomodulation, Brain, Behavior, and Immunity, 2011

Archives