3 Surprising Ways Your Gut Microbes Affect Your Health

Our gastrointestinal tracts are filled with up to seven pounds of bacteria, fungi, protozoa, viruses and helminths, collectively called our gut microbiota. Together, they function like another organ, and we’re learning more and more about how they affect almost every aspect of our health. Besides helping us digest fats, proteins and carbohydrates and regulating our gut function, they have surprising effects on other parts of the body. Read on to learn three ways your gut microbes can help or hurt your health, outside of your gut.

They Influence your Mood 

There are several ways gut microbes can affect your mental and emotional health. Evidence suggests that they can stimulate the vagus nerve, which is actually a massive complex of nerves that connects the entire digestive system to the brain and influences feelings of satiety, stress and mood (Silva et al., 2020). They can help metabolize or recycle hormones like estrogen and thyroid hormones (Lipski, 2020) or alter signaling of the hypothalamic-pituitary-adrenal (HPA) axis (Silva et al., 2020). They also produce their own neurotransmitters like dopamine, serotonin, GABA and norepinephrine, and make short-chain fatty acids (SCFAs) that trigger gut cells to release serotonin into the bloodstream (Silva et al., 2020). Out of balance, the microbiome can cause cravings and mood swings, as overgrowths of microbes like Candida albicans eat up the glucose in your food and cause blood sugar dips (Van Ende et al., 2019).

They strengthen your immune system 

Immune components called dendritic cells (DCs) poke little “arms” between intestinal cells, sample intestinal contents and decide, based on receptors on the outsides of the microbes and the presence of other chemicals, whether they are friend or foe. If they deem a microbe potentially harmful, they take parts of the microbe called antigens and present them to other immune cells, which then mount an immune response (Rescigno et al., 2001). Non-harmful gut microbes keep this process primed, like a fire drill in preparation for a real fire, so the immune system can have a quick and robust response to pathogens (Park et al., 2023). Research shows that “germ-free” animals, grown in a sterile environment so they don’t have any gut microbes, have significantly less dendritic cells and areas of the gut, called Peyer’s patches, where immune cells process antigens (Haverson et al., 2007). The more different types of helpful microbes the immune system is exposed to, the more ready it will be for different types of pathogens, and the less likely it will be to react to non-harmful substances like foods or bodily tissues, as seen in autoimmune disorders (Wu & Wu, 2012). 

They make vital nutrients

While we know that a healthy gut microbiome can help us break down, and thus get more nutrients from our foods, the microbes themselves also synthesize many essential nutrients for humans. For example, there are two forms of vitamin K: K1 and K2. K1 comes from eating vegetables like raw leafy greens, but K2 is more bioavailable, or easily used by the body, and is produced by gut bacteria. It’s important to get enough vitamin K to prevent cardiovascular disease and keep calcium in your bones and teeth, and up to half of your daily Vitamin K requirement is provided by healthy gut bacteria (Morowitz et al. 2011). B vitamins help with a whole host of your body’s processes, and prevent fatigue and tiredness throughout the day. B12 can be produced by gut microbes, but the main way B12 is absorbed is through a process that requires going through the stomach and small intestine, so about 2-3% of gut microbial B-12 is absorbed (Carmel, 2014). However, we only need a small amount of daily B12 to prevent Alzheimer’s and neurological issues, so getting a little from your gut may be helpful. Folate (B9) is produced by certain gut microbes, including Bifidobacterium bifidum and B. infantis, and studies have shown that administering these strains increases folate in stool (LeBlanc et al., 2013). Other B vitamins, thiamine, niacin, riboflavin, pantothenic acid (B5), pyridoxine (B6) and biotin are all produced by various gut microbes (LeBlanc et al., 2013). Lacking a robust variety of microbial strains in your gut could mean that you’re missing out on these extra boosts of nutrients. 

For these reasons and many more, it’s important to make sure your gut microbiome is on point. Alimental’s Gut-Skin Axis Restoration Program provides the resources you need, so check it out here.

References

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development in jejunal mucosa after colonization with selected commensal gut bacteria: A study in germ-free pigs. Veterinary Immunology and Immunopathology, 119(3-4), 243–253. https://doi.org/10.1016/j.vetimm.2007.05.022

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(2013). Bacteria as vitamin suppliers to their host: A gut microbiota perspective. Current Opinion in Biotechnology, 24(2), 160–168. https://doi.org/10.1016/j.copbio.2012.08.005

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