What is the gut microbiome and what does it do?
Nutritionists love talking about the gut microbiome, it’s one of our favourite topics (that, and chewing!). But what exactly is it, and why is it so important to your health? In this article I’m going to reveal all and share some of the surprising reasons why we’re a bit obsessed with your gut microbes.
What is the gut microbiome?
The gut microbiome is a community of microbes that live in your gut. This includes your mouth, throat, stomach, small intestine, and large intestine (aka the colon or large bowel).
There are microbiomes all over your body. They’re in your nose, lungs, vagina or penis, urinary tract, and on the skin. The gut microbiome is the largest and most diverse group that we know about.
It’s a huge community of trillions of different bacteria, yeast, viruses, and fungi. And as with any community there’s a mixture of friendly residents and others that are okay in small amounts but harmful if their numbers get out of hand.
5 surprising things your gut microbiome can do
Your gut microbes work hard, extracting nutrients and energy from food [1] and producing metabolites that help maintain the gut lining.
But their microbial powers extend out beyond the digestive tract. Here are five surprising things your gut microbiome can do:
Regulate mental wellbeing. Research shows that gut microbes produce and modulate the activities of mood chemicals like serotonin, GABA (gamma amino butyric acid), dopamine, and glutamate [2].
They also produce short-chain fatty acids that act as signalling molecules between the gut and the brain, transmitting messages that influence mood, behaviour, and mental wellbeing. Short chain fatty acids are highly anti-inflammatory and we know that inflammation can be a factor in poor mental health.
Influence oestrogen levels. Your gut microbiome contains a subset of bacteria called the estrobolome. Among other activities, they produce an enzyme called beta-glucuronidase that “unpacks” oestrogen previously detoxified by the liver and sends it back into general circulation.
When the microbiome is well balanced, the estrobolome helps maintain healthy oestrogen levels. But when the microbiome is out of balance (a condition known as ‘dysbiosis’), the estrobolome produces too much beta-glucuronidase which leads to too much oestrogen being reabsorbed [3].
Cause vaginal and urinary tract infections [4]. An overgrowth of unfriendly microbes in the gut can spread to the urinary tract and vagina, leading to infection. If a client is dealing with recurrent vaginal or bladder infections, one of the first things I ask about is their gut health. In some cases, I will suggest a microbiome test to investigate possible dysbiosis. We have access to labs that provide in depth testing of the microbiome in the gut, AND also in the vagina and urinary tract.
Influence your weight. Although the link between gut microbes and weight gain isn’t fully understood yet, research shows that they have an effect on hunger and satiety signals, and influence nutrient metabolism and energy expenditure [5].
Regulate immune function. Do you pick up every bug that’s going round? Your gut bacteria may need help! An estimated 80% of your immune system lives in the gut where it interacts with the gut microbiome. Gut bacteria and their metabolites help to develop immune cells and regulate the immune response [6]. If your gut bacteria are out of balance, your immune defences are compromised.
Why diversity matters to your gut bacteria
One of the most important factors in gut health is diversity. Imagine a garden that only has one type of plant in the flowerbeds. It would be dull and boring to look at and wouldn’t entice many birds and insects.
It’s the same with your gut microbiome. A vibrant, healthy microbiome contains a diverse range of species living alongside one another and producing lots of helpful metabolites.
To maintain this kind of microbial diversity we need to eat a diverse diet. Gut bugs love to feast on fibre and molecules called polyphenols from colourful fruits, vegetables, herbs, and spices. Eating a wide range of plant foods encourages the friendly microbes to thrive and helps keep the less-friendly ones in check.
If you’re dealing with uncomfortable gut symptoms, poor immune health, or think your microbiome might need an MOT, get in touch today. Book your FREE 15-minute discovery call to find out how a tailor-made nutrition programme can work for you.
You might also enjoy reading
Gut goodness! Tips to create healthy digestion
References
Hou, K., Wu, Z., Chen, X., Wang, J., Zhang, D., Xiao, C., Zhu, D., Koya, J. B., Wei, L., Li, J., & Chen, Z. 2022. Microbiota in health and diseases. Signal Transduction and Targeted Therapy, 7(1), 1-28. doi.org/10.1038/s41392-022-00974-4
Bhatia, N. Y., Jalgaonkar, M. P., Hargude, A. B., Sherje, A. P., Oza, M. J., & Doshi, G. M. 2023. Gut-Brain Axis and Neurological Disorders-How Microbiomes Affect our Mental Health. CNS & Neurological Disorders Drug Targets, 22(7), 1008–1030. doi.org/10.2174/1871527321666220822172039
Hu, S., Ding, Q., Zhang, W., Kang, M., Ma, J., & Zhao, L. 2023. Gut microbial beta-glucuronidase: A vital regulator in female estrogen metabolism. Gut Microbes, 15(1), 2236749. doi.org/10.1080/19490976.2023.2236749
Fu, C., Zhao, Y., Zhou, X., Lv, J., Jin, S., Zhou, Y., Liu, F., & Feng, N. 2024. Gut microbiota and interstitial cystitis: Exploring the gut-bladder axis through mendelian randomization, biological annotation and bulk RNA sequencing. Frontiers in Immunology, 15, 1395580. doi.org/10.3389/fimmu.2024.1395580
Aoun, A., Darwish, F., & Hamod, N. 2020. The Influence of the Gut Microbiome on Obesity in Adults and the Role of Probiotics, Prebiotics, and Synbiotics for Weight Loss. Preventive Nutrition and Food Science, 25(2), 113. doi.org/10.3746/pnf.2020.25.2.113
Wiertsema, S. P., Garssen, J., & J Knippels, L. M. 2021. The Interplay between the Gut Microbiome and the Immune System in the Context of Infectious Diseases throughout Life and the Role of Nutrition in Optimizing Treatment Strategies. Nutrients, 13(3), 886. doi.org/10.3390/nu13030886
