The microbiome is a collection of microbes, mainly made up of bacteria, that live in and on the human body. Far from being a scary concept, these organisms are essential for optimum health. A large percentage of the microbiome is located in the gut where it delivers far reaching benefits.

Here is how the microbiota impact the body:

Mood

Much the same way as eating sweet foods makes you feel temporarily happy, gut bacteria can influence emotions (1). Anxiety, stress and negative emotions can be driven by dysbiosis (a state where “bad” organisms outnumber beneficial ones) (2). Conversely, periods of stress can deplete beneficial bacteria and encourage the growth of harmful ones (2).

Skin

As the body’s largest organ, the skin forms a protective barrier between the outside world and the body. Some specific nutrients used to nourish this important organ, including biotin, are produced by beneficial bacteria in the gut (3), directly affecting skin health. On the other end of the spectrum, reduced diversity in beneficial gut bacteria are associated with skin conditions such as eczema (4), dermatitis (5) and acne (6) amongst others.

Digestive health

The majority of beneficial bacteria found in the human body reside in the gut (7). Although babies are initially sterile (host no bacteria), microbes colonise the gut during birth and breastfeeding (7). Following colonisation, these gut bacteria enter a mutually beneficial relationship with the host whereby the bacteria have somewhere to live and the host benefits from their presence through increased nutrient availability (8). This mutually beneficial relationship is especially evident when it comes to digestive health. Short chain fatty acids and certain vitamins are provided by beneficial bacteria to the host through the breakdown of otherwise undigestible materials such as fibre (8). Short chain fatty acids in specific help to nourish the gut lining, improve blood flow and encourage healthy repair (9). Significant changes in the gut microbiota have been noted in digestive disorders such as irritable bowel syndrome and inflammatory bowel diseases, whereby certain beneficial bacteria are missing or they have been outnumbered by pathogenic ones (10). Even without a diagnosed disease, microbiota can influence areas of digestive health such as stool frequency or gut motility, gas and bloating (10).

The immune system

Microbiota play an important role in the development of the immune system from early childhood since they assist with the maturation of our defence system as well as train and educate it (11). Beneficial bacteria also discourage the entrance of potentially harmful organisms by producing specific substances to keep them out (12).

Bones

Calcium absorption and bone density are influenced by gut bacteria according to the latest research (13). Studies indicate that short chain fatty acids produced through the fermentation of fibres by beneficial bacteria may increase the rate at which calcium is absorbed and retained in bone (14). Animal models also suggest a link between improved bone density, beneficial bacteria and a high fibre diet (13).

If you would like to find out more about the particular types of bacteria in the human microbiome and even get your gut tested please visit Mapmygut.com

References

  1. Holzer P (2016) Neuropeptides, Microbiota, and Behavior. International Review of Neurobiology, 131: 67-89.
  2. Panduro A, Rivera-Inigues I, Sepulveda-Villegas M, Roman S (2017) Genes, emotions and gut microbiota: The next frontier for the gastroenterologist. World Journal of Gastroenterology, 23: 3030-3042.
  3. Said HM (2002) Biotin: the forgotten vitamin. The American Journal of Clinical Nutrition, 75: 179-180.
  4. Marrs T, Flohr C (2016) The role of skin and gut microbiota in the development of atopic eczema. British Journal of Dermatology, doi: 10.1111/bjd.14907.
  5. Nermes M, Kantele JM, Atosuo TJ, Salminen S, Isolauri E (2011) Interaction of orally administered Lactobacillus rhamnosus GG with skin and gut microbiota and humoral immunity in infants with atopic dermatitis. Clinical & Experimental Allergy, 41: 370-377.
  6. Bowe W, Patel NB, Logan AC (2014) Acne vulgaris, probiotics and the gut-brain-skin axis: from anecdote to translational medicine. Beneficial Microbes, 5: 185-199.
  7. Weller HM (2007) Bacteroides: the good, the bad, and the nitty-gritty. Clinical Microbiology Reviews, 20: 593-621.
  8. Read MN, Holmes AJ (2017) Towards an integrative Understanding of Diet–Host–Gut Microbiome interactions. Frontiers in Immunology, doi: 10.3389/ mmu.2017.00538.
  9. Morowitz MJ, Carlisle E, Alverdy JC (2011) Contributions of Intestinal Bacteria to Nutrition and Metabolism in the Critically Ill. Surgical Clinics of North America, 91: 771-785.
  10. Marchesi JR, Adams DH, Fava F, Hermes GDA, Hirschfield GM, Hold G, Quraishi MN, Kinross J, Smidt H,Tuohy KM, Thomas LV, Zoetendal EG, Hart A (2016) The gut microbiota and host health: a new clinical frontier. Gut, 65: 330-339.
  11. Sirisinha S (2016) e potential impact of gut microbiota on your health: Current status and future challenges. Asian Pacific Journal of Allergy and Immunology, 34: 249-264.
  12. Stecher B (2015) The Roles of inflammation, nutrient availability and the commensal microbiota in enteric pathogen infection. Microbiology Spectrum, doi: 10.1128/microbiolspec.MBP-0008-2014.
  13. Weaver CM (2015) Diet, Gut microbiome, and bone health. Current Osteoporosis Reports, 13: 125-130.
  14. Wallace TC, Marzorati M, Spence L, Weaver CM, Williamson PS (2017) New frontiers in fibers: innovative and emerging research on the Gut microbiome and bone health. The Journal of the American College of Nutrition, 36: 218-222.