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In PART 1 we looked at a glossary of terms to build a bit of an understanding of wording and terms relating to the human microbiome.
In PART 2 we delve into some of the nitty gritty, in a little more detail.....
We often think of of your internal "bugs" as harmful “germs,” but there are many commensal (“good”) bacteria, yeast and fungi that help the body function properly – in fact life on earth couldn’t exist without them! The gut, skin, urogenital, and oral systems, as well as the blood and airways - host trillions of different types of "bugs" - his is often called the human microbiota. Although there are also some beneficial yeast and fungi that help make-up this microbiota - I will generally refer to them all as 'bacteria' in this blog.
Bacteria have only one cell, shaped like a sphere, rod or spiral. One is called a bacterium, and is so small that millions of them could fit on the head of a pin! [i] Most of these bacteria reside in our gut and is called the human gut microbiota, (formerly known as “gut flora”). The stomach and proximal small intestine - though certainly not sterile - contain relatively few bacteria in healthy people. [ii] The large intestine or colon contains most of our gut microbiota.
This myriad of bacteria symbiotically living within us, forms a biological society that profoundly influences our health. The intestinal microbiota can be regarded as an organism in itself, and includes the incredible amount of approximately 100 trillion bacteria, belonging to more than 1,000 species, and weighing between 1.5 - 2kg. The gut microbiota consists of 10 times as many cells as there are human cells in the body.
The genetic information in this microbiota, is known as the metagenome or microbiome, and is even more diverse than the entire human genome. Some research has suggested that one can even be identified (like a finger-print) by our gut microbiome! An individual’s profile of microbiota is continually influenced by a variety of factors including but not limited to, genetics, age, sex, diet, and lifestyle.[iii] Although known for decades to natural medicine practitioners, the gut is starting to be seen by conventional medicine and allopathic practitioners, as more than just a biological system with the sole purpose of digestion – ie: breaking down foods, synthesizing and absorbing certain nutrients – it is also being considered as a key player in regulating inflammation, immunity (60-80%) and many other systems within the human body.
Although, each of our microbiota and hence microbiome’s are unique and different, there are several beneficial species that are common to most humans. It is important to note that this diversity maintains our health and wellness, and a shift away from our “normal” gut microbiota diversity, is called dysbiosis.
Dysbiosis has been linked to gastrointestinal disorders like: irritable bowel syndrome (IBS) and inflammatory bowel (IBD), plus metabolic disorders such as: metabolic syndrome and obesity, as well as neuropsychological disorders including: attention deficit disorders (ADD/ADHD) and autism spectrum disorders, depression and anxiety.[iii]
In addition to the impact on our immune systems, our digestive systems are the second largest part of our neurological system ie: the enteric nervous system. This is why the gut is often referred to as our second brain! Early 19th and 20th century studies recognised the bi-directional communication between the brain and the gut, and showed that emotional states can alter the function of the gastrointestinal (GI) tract.[iv],[v],[vi] A decade or two ago, the notion within conventional medicine, that the manipulation of the intestinal microbiota could provide therapeutic value to human depressive and fatigue states was blatantly disregarded and often referred to as pseudo-science or outlandish. However, in the ensuing years, many of the mechanisms first proposed by many natural medicine practitioners and researchers, have been examined experimentally [vii],[viii]
The benefit of a healthy gut, with the presence of commensal organisms - is illustrated most effectively during early brain development and function. Research has indicated just how sensitive a foetus is to any changes in a mother’s microbiota. If a baby is born via Cesarean section, it misses the opportunity to ingest the mother’s bacteria as it travels down the vaginal canal. Studies show that those born via C-section, must work much harder to regain and maintain the same diversity in their microbiome, as those born vaginally. Hence the practice of 'vaginal seeding' or 'microbirthing' has become more popular for C-section babies, over the last few years. This involves giving the baby a swab of its mother's vaginal fluids – as it would have received during a vaginal birth – within the first few hours after the birth.[ix]
http://www.huffingtonpost.co.uk/toni-harman/childbirth-and-microbirth_b_5955652.html
Care would always need to be taken however to prevent the spread of undesirable or harmful organisms, like Group B streptococcus (GBS) - by seeding or natural birth during delivery. Viruses like both the herpes simplex virus type 1 (HSV-1) or type 2 (HSV-2), can commonly cause genital infection, which, when acquired or reactivated during pregnancy, carries with it the risk of transmission to the foetus or neonate.
Continued in PART 3 - GUT INSULTS....
SOURCES:
[ii] Quigley E.M.M. (2014). Review: "Gut Microbes - Importance in Health and Disease”. World Digestive Health Day 2014. The South African Gastroenterology Review, pp 14-18.
[iii] Zhou L., Jane A Foster J.A. (2015). Review: Psychobiotics and the gut–brain axis: in the pursuit of happiness. Neuropsychiatric Disease and Treatment 2015:11 715–723.
[iv] Beaumont W. (1833). Experiments and Observations on the Gastric Juice and the Physiology of Digestion. Plattsburg: F.P. Allen.
[v] Pavlov I. (1910). The Work of Digestive Glands. London: Griffen. [English translation from Russian by W. H. Thompson].[vi] Cannon W.B. (1909). The influence of emotional states on the functions of the alimentary canal. Am J Med Sci.137:480–487.
[vii] Logan A.C., Katzman M. (2005). Major depressive disorder: probiotics may be an adjuvant therapy. Med Hypotheses, 64:533–538. 75.
[viii] Bested A.C., Logan A.C., Selhub E.M. (2013). Intestinal microbiota, probiotics and mental health: from Metchnikoff to modern advances. Part III - convergence toward clinical trials. Gut Pathog, 5:4.
[ix] Quote: Dietert, R. (2014). Professor of Immunotoxicology - Cornell University. [online] http://www.huffingtonpost.co.uk/toni-harman/childbirth-and-microbirth_b_5955652.html
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