Interest in the microbiome and its impact on health and disease has grown significantly over the last decade. While research is still in its infancy, much has been discovered about this mysterious microbial world. The following of which gives a little insight into what has been revealed so far.

#1 Microbes Outnumber Human Cells By 10:1 (False)

It’s widely reported that there are 10 times more microbial cells in the human body than human body cells. Refuting this claim, a recent study (1) has reported that the number of cells in the gut microbiota are in fact similar to the number of human body cells.

#2 The Gut Microbiome Differs Between Males And Females (True)

The ratio of human cells to bacterial cells, the types of bacteria residing in the gut, the speed at which the microbiome matures, and responses to supplementation have all been shown to differ between the two sexes. Research into these important sex differences in the gut microbiota may well have a powerful impact on health practices. As in life, when it comes to our guts, one sex doesn’t prevail over the other. Rather it’s about acknowledging how lifestyle factors and medical treatments can be tailored with sex differences in mind so as to optimise the health and wellbeing of the individual.

#3 The Womb Is A Sterile Environment (False)

For a long time it was thought that the womb was sterile, however research (2) has shown evidence of microbes in meconium (the first poo of the newborn), suggesting that the microbiome may well develop sometime during fetal development.

#4 All Bacteria Are Dangerous (False)

Bacteria are frequently portrayed as enemies. However, in the right context, such as their role in keeping your gut lining functioning optimally, bacteria can be heroes, playing an essential role in immunity, homeostasis, neurodevelopment, metabolism as well as preventing ‘bad’ bacteria from moving in.

#5 A Wide Diversity Of Gut Microbes Is Vital To Good Health (True)

Over time humans and microbes have coevolved, an ancient symbiotic partnership where bacteria and animals have learnt to converse. They provide signals to us, and we in turn signal back. It’s a vigorous and resilient setup allowing bacteria to interact with us by modulating our metabolism and immune system. However, when there is a shift in this dynamic, such as in a loss of diversity, the team is no longer working optimally and negative health outcomes can ensue (3)(4). Fortunately, there are ways to alter gut diversity by making considered choices about the food we eat and our lifestyle choices.

#6 Antibiotics Can Affect The Microbiome Putting Health At Risk (True)

Whilst antibiotics are essential for health care, their ill-considered use may pose more of a risk to the future health of patients than previously thought. For example, in a perturbed microbiota – as occurs through antibiotic use (6) – the signals ancestral microbes use to talk to body cells are abnormal which can lead to negative long-term physiological outcomes such as inflammatory bowel disease (IBD), irritable bowel syndrome (IBS), obesity and type 2 diabetes, to name a few. Another example of how antibiotics can put our health at risk is the increased risk of developing antibiotic-resistant bacteria; a problem at both the individual and societal level (7). Being mindful of the ways in which we might inadvertently disturb the balance of our gut microbiome is important to achieving good health.

#7 Individuals Differ More In Their Microbiome Than They Do In Their Genome (True)

Human individuals are 99.9% identical to each other in terms of their genome, however the microbiome of each individual can be 80-90% different from one another. So when you’re wondering what makes you unique compared to others, refer to your microbiome.

#8 Another Person’s Poo Can Save Your Life (True)

A fecal transplant is when feces from a donor with a healthy microbiome are transplanted into another person in order to restore balance of bacteria in their gut. Whilst a stomach churning concept, inserting poo from a healthy person into a patient suffering from a serious illness, such as an antibiotic resistant C. difficile (5), can be the difference between life and death.

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References

(1) Sender R, Fuchs S, Milo R. Revised Estimates for the Number of Human and Bacteria Cells in the Body. PLoS Biol. 2016 Aug 19;14(8):e1002533. doi: 10.1371/journal.pbio.1002533. PMID: 27541692; PMCID: PMC4991899.

(2) Stinson, Lisa F et al. “The Not-so-Sterile Womb: Evidence That the Human Fetus Is Exposed to Bacteria Prior to Birth.” Frontiers in microbiology vol. 10 1124. 4 Jun. 2019, doi:10.3389/fmicb.2019.01124

(3) Mosca, Alexis et al. “Gut Microbiota Diversity and Human Diseases: Should We Reintroduce Key Predators in Our Ecosystem?.” Frontiers in microbiology vol. 7 455. 31 Mar. 2016, doi:10.3389/fmicb.2016.00455

(4) Bull, Matthew J, and Nigel T Plummer. “Part 1: The Human Gut Microbiome in Health and Disease.” Integrative medicine (Encinitas, Calif.) vol. 13,6 (2014): 17-22.

(5) Brandt, Lawrence J. “Fecal transplantation for the treatment of Clostridium difficile infection.” Gastroenterology & hepatology vol. 8,3 (2012): 191-4.

(6) Langdon, A., Crook, N. & Dantas, G. The effects of antibiotics on the microbiome throughout development and alternative approaches for therapeutic modulation. Genome Med 8, 39 (2016). https://doi.org/10.1186/s13073-016-0294-z

(7) Llor, Carl, and Lars Bjerrum. “Antimicrobial resistance: risk associated with antibiotic overuse and initiatives to reduce the problem.” Therapeutic advances in drug safety vol. 5,6 (2014): 229-41. doi:10.1177/2042098614554919