Exploring Gut Bacterial Metabolites
One of the reasons our gut microbiome has such a powerful impact on our health, is due to their production of metabolites. A metabolite is an intermediate or end product of metabolism. Within Biomesight, we are focused specifically on the metabolic byproducts of our gut bacteria. Metabolomics is a very complex area of research - which metabolites are produced is a factor of our diet, our microbial communities and also our individual genetics.
If you're not an existing user, you might not have seen our metabolite sections. Please log in with these demo credentials (username: firstname.lastname@example.org password: Password1).
The first thing to note is that all of these sections are currently in beta - we expect them to remain in beta for some time yet as the research in these areas are ongoing and we have no healthy ranges for overall metabolite producers, except for Butyrate (Short chain fatty acids) and Hydrogen Sulfide (H2S). We manually review peer-reviewed research papers and catalogue it's contents. We don't release a new section until we have at least what we consider a reasonable starting point for each metabolite. But if you were to refer to any of these research papers, you will note that normally a small subset of bacteria is investigated in the studies. The lists are likely therefore far from comprehensive. Many metabolites are measured in vitro and output are compared using different input substrates. The reality is far more complex. Depending on which bacteria dominate, the substrate would be transformed into different intermediate products and again depending on the community, that substrate could be further transformed.
In the last few months we've added several metabolite sections to Biomesight.
Short Chain Fatty Acids (SCFAs): Butyrate, acetate and propionate make up around 95% of the SCFAs produced by gut bacteria. Sufficient butyrate in particular is essential for not just our gut health, but also our overall health and energy levels. Our guide level of 40% is based on Dr Hawrelak's research and clinical experience. Acetate and Propionate have also been linked to various benefits.
Neurotransmitters: The gut microbiota has been found to communicate with the brain through several different mechanisms. This includes the production of neurotransmitters or modulation of host neurotransmitter catabolism, innervation via the vagus nerve, or activation of the HPA axis. These microbial molecules do not act directly on the brain, which is isolated and protected by a membrane called the blood-brain barrier. It appears that neurotransmitters produced by gut bacteria act on the cells lining the gastrointestinal wall in order to have them transmit their message to the central nervous system through the neurons of the gastrointestinal tract that are connected to the brain.
We have included acetylcholine, dopamine, GABA, serotonin, histamine and norepinephrine as these are the primary neurotransmitters produced by gut bacteria. Many of our users would note that with the exception of GABA, their levels seem very low compared to the average. An average can hide a lot of detail though and low levels are actually more common than high levels. A chart showing the sample distribution would be more useful but we wanted to keep the balance between being informative but still giving a simple to understand interpretation. If you were to expand the list of bacteria, you'll see that bacteria such as Escherichia (a proteobacteria) feature in many of these lists. The recommended levels for Escherichia is lower than the Biomesight average. It is better to use the rating against each metabolite as a guide as this will highlight when your values actually fall outside of the typical ranges.
The histamine section in particular would benefit from an additional degraders section - as bacteria can both degrade and produce histamine. Note that the foods we eat can also contain high amounts of histamine.
Intolerance: While many intolerances are predetermined genetically (e.g. through lack of enzyme production), some are also impacted by our gut microbiota. Many gut bacteria produce enzymes relevant to degrading substrates ingested both through diet as well as those produced as byproducts of metabolizing other substrates. Intolerance should not be confused with allergies. Intolerances are milder reactions based on lack of enzymes and not an immune reaction. We focus on bacteria that produce enzymes that break down lactose and oxalates.
Toxins: Pathogenic gut bacteria produce small amounts of end or intermediate substances with various degrees of toxicity to humans. This section includes colibactin, d-lactate, hydrogen sulfide (H2S), methane and ethanol.
Detoxification: Gut bacteria affect the body's detoxification pathways through the production of enzymes causing toxins bound in the liver to be freed up and reabsorbed in the colon. We specifically focus on beta-glucuronidase producers. When beta-glucuronidase is in excess, the bonds between toxins and glucuronic acid are broken, and toxins and hormones that were meant to be excreted are then reabsorbed into the body.
Nutrients: Our gut bacteria produce many nutrients, many of which are plentiful in our diets. This section focuses on 2 beneficial nutrients, equol and Vitamin K2 MK7, that are uniquely produced by our gut bacteria. These nutrients are not present in foods (unless fermented or added) and cannot be synthesized by the human body itself.