Bacteria in the Human Body

The human Gastrointestinal (GI) Tract has over 500 different species of bacteria.[5]
Source of GI Tract Microbes
The GI Tract in fetal development is sterile but in the newborn baby is quickly colonized by multiple species of microbes from the mother and the general environment.[3]

A Newborn's first microbial exposures are thought to be important in development of a broad array and stable microbial communities in the GI Tract. The fetus develops in a sterile environment where the first bacterial exposure occurs at birth. The mode of birth can affect what microbes colonize the baby's Gastrointestinal (GI) Tract. A Vaginal Delivery exposes the newborn to vaginally-derived microbes. Babies delivered by Cesarean section (C-Section) are not exposed to these vaginal microbes.[3]

Following birth, Microbes are encountered everywhere. They may be ingested in food, water, as Probiotic Supplements, even in the air.

The GI Tract is highly complex as it must allow beneficial microbes to colonize certain areas of the GI while defending against those that are pathogenic. This must occur while maintaining a barrier against infection while remaining permeable to nutrients. Any disruption in the Microbial Balance, or Dysbiosis, can cause an Inflammatory Response in the GI and/or throughout the entire body. Also, an Inflammatory Response in the body can cause Dysbiosis.

Dysbiosis is of concern in Inflammatory Bowel Diseases (IBD), as alterations in Microbial Balance can affect Symptoms and can Exacerbate the Disease.

About Dysbiosis / Microbial Imbalance

Dysbiosis is an imbalance of the body's microbes. The human body is covered by a variety of bacterial species. The most heavily covered is the Gastrointestinal (GI) Tract. Dysbiosis of intestinal microbiota is often characterized by a decrease in beneficial species of yeasts and bacteria, with a concomitant increase in species that are pathogenic, such as Clostridium difficile (C. diff).

What Causes Microbial Imbalance?

Dysbiosis can be the result of many factors: [1] [2]
- Alcohol / Drinking
- Antibiotic Treatment
---- Especially with Powerful / Broad Spectrum Antibiotics and/or Long Duration Treatment
- Diabetes, especially if poorly controlled
- Diet, especially diets high in carbohydrates / sugar, or high in fat
- Chronic Constipation
- Diarrhea
- Genetic Factors (ex. NOD2, ATG16L1, Defensins)
- Irritable Bowel Syndrome
- Illness, Infection, Inflammation
- Inflammatory Bowel Disease
- Medication
- Smoking [7]
- Unknown Cause

Effects of Microbial Imbalance in IBD

A proper microbial balance is very important to multiple body systems. When Dysbiosis occurs and this balance is disrupted it can have many different health effects:
Certain 'Beneficial " Microbes line the Gastrointestinal Tract.
- They provide a barrier so pathogenic organisms cannot invade the GI lining and invade the body
- Beneficial microbes release "Antibiotic-Like" substances that can kill or prevent colonization by other microbes
---- Certain microbes produce Toxins that can be extremely dangerous to health and can even be fatal
- They assist in the digestion of food and secrete certain Vitamins. Dysbiosis can cause Nutritional Effects and may lead to Vitamin and Mineral Deficiencies
- The presence of Microbes is imperative for normal Immune System Function


Treatment for Dysbiosis can include: no treatment, Antibiotics, Anti-Inflammatory Medications, Diet, Probiotics, Fecal Transplantation Therapy (FMT), and TNF-alpha inhibitors (ex. Cimzia, Humira, Remicade).


[pos]1a[/pos][1] Chiba M, Abe T, Tsuda H, Sugawara T, Tsuda S, Tozawa H, Fujiwara K, Imai H. Lifestyle-related disease in Crohn’s disease: Relapse prevention by a semi-vegetarian diet. World J Gastroenterol. 2010; 16(20):2484-2495. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2877178/

[pos]2a[/pos][2] Szabo G, Bala S, Petrasek J and Gattu A. Gut-Liver Axis and Sensing Microbes. Digestive Diseases: Pathomechanisms of Alcohol Induced Damage. 2010;28:737–744. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3211517

[pos]3a[/pos][3]. Dominguez-Bello MG, Costello EK, Contreras M, Magris M, Hidalgo G, Fierer N, Knight R. Delivery mode shapes the acquisition and structure of the initial microbiota across multiple body habitats in newborns. PNAS. 2010; 107(26): 11971-11975. http://www.pnas.org/content/107/26/11971.full.pdf+html

[pos]4a[/pos][4]. Usha Vyas and Natarajan Ranganathan, “Probiotics, Prebiotics, and Synbiotics: Gut and Beyond,” Gastroenterology Research and Practice, vol. 2012, Article ID 872716, 16 pages, 2012. doi:10.1155/2012/872716. http://www.hindawi.com/journals/grp/2012/872716

[pos]5a[/pos][5]. Chassaing B, Darfeuille-Michaud A. The Commensal Microbiota and Enteropathogens in the Pathogenesis of Inflammatory Bowel Diseases. Gastroenterology. 2011; 140(6): 1720-1728. http://download.journals.elsevierhea...8511001612.pdf

[pos]6a[/pos][6]. Craven M, Egan CE, Dowd SE, McDonough SP, Dogan B, et al. (2012) Inflammation Drives Dysbiosis and Bacterial Invasion in Murine Models of Ileal Crohn’s Disease. PLoS ONE 7(7): e41594. doi:10.1371/journal.pone.0041594. http://www.plosone.org/article/fetch...esentation=PDF

[pos]7a[/pos][7]. Wang H, Zhao J-X, Hu N, Ren J, Du M, Zhu M-J. Side-stream smoking reduces intestinal inflammation and increases expression of tight junction proteins. World J Gastroenterol. 2012; 18(18): 2180–2187. http://www.ncbi.nlm.nih.gov/pmc/arti...JG-18-2180.pdf

[pos]8a[/pos][8]. Xavier RJ, Podolsky DK. Unravelling the pathogenesis of inflammatory bowel disease. Nature. 2007; 448: 427-434. http://content.ebscohost.com/pdf19_2...U9%2Fi84Xs3wAA

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