GI Microflora Imbalances

Many digestive disorders are caused by unfavourable alterations in the beneficial bacterial flora of the gastrointestinal (GI) tract. The result is a significant disruption of intestinal lining integrity due to a proliferation of pathogens such as E. coli, Clostridium perfringens, H. pylori, etc. This imbalance in microflora, or dysbiosis, is most commonly caused by the use of antibiotics that can wipe out both good and bad bacteria. Other causative factors are GI infections (e.g., traveller’s diarrhea), certain drugs such as acid-suppressing medications, chronic indigestion, chronic constipation, stress and diet. A primary role of beneficial microflora is to help protect the gut lining. Once these microflora become imbalanced, the host’s immune capabilities become compromised thus leading to more serious digestive disorders. Some examples of microflora imbalances in digestive disorders follow.

Most microbial imbalance studies have been conducted on patients with more severe GI disorders. A definite imbalance in gut microbiota composition exists in patients with inflammatory bowel disease (IBD) compared with healthy individuals. One such study[1] investigated the microflora of fecal samples obtained from patients with active Crohn’s disease (A-CD), active ulcerative colitis (A-UC), infective colitis (IC), and healthy subjects (HS). The results demonstrated that the anti-inflammatory commensal beneficial species Faecalibacterium prausnitzii (FP) along with bifidobacteria species were significantly diminished in active disease and colitis patients compared to healthy subjects. In a separate study[2] Willing et al used biopsy samples collected from mucosal surface during colonoscopy. The authors demonstrated that individuals with ileal CD had significantly lower numbers of FP and increased numbers of E coli compared to healthy subjects.

Irritable bowel syndrome (IBS) is one of the most common GI disorders and the intestinal microflora of 25 IBS patients and gender-matched healthy volunteers were compared[3] by monitoring fecal samples for Lactobacillus, Bifidobacterium, Bacteroides, C. perfringens, Enterobacteriaceae and Enteroccocus.  Compared with the control group (see following image), IBS patients showed a significant decrease in Bifidobacterium numbers for the IBS patients but a significant increase in both Enterobacteriaceae and C. perfringens. There were no significant differences in the other microflora between the two groups. In a related study, both fecal and mucosal brush samples were used to demonstrate a 2-fold decrease in the level of bifidobacteria in IBS patients compared to healthy subjects[4].


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Similar imbalances have been reported in adolescent celiac patients versus healthy counterparts[5]). In this study the ratio of Lactobacillus–Bifidobacterium to Bacteroides–E. coli was significantly reduced in celiac patients with either active or inactive disease compared with controls. A pathogenic bacterium called Helicobacter pylori (H. pylori) is a prime contributor to gastric and duodenal ulcer formation but non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin and ibuprofen are also major factors.

A prime factor in considering intervention treatment to help treat and prevent this microflora imbalance is to introduce special ingredients into a formulation capable of significantly increasing the numbers of beneficial microflora while suppressing growth of non-beneficial counterparts.




[1] Sokol H et al (2009) Low counts of Faecalibacterium prausnitzii in colitis microbiota, Inflammatory Bowel Disease 15:1183-1189

[2] Willing B et al (2006) Twin studies reveal specific imbalances in the mucosa-associated microbiota of patients with ileal Crohn’s disease, Inflammatory Bowel Disease 15:653-660.

[3] Si JM et al (2004) Intestinal microecology and quality of life in irritable bowel syndrome patients, World Journal of Gastroenterology, 10(12):1802-1805.

[4] Kerckhoffs APM et al (2009) Lower bifidobacteria counts in both duodenal mucosa-associated and fecal microbiota in irritable bowel syndrome patients, World Journal of Gastroenterology 15(23):2887-2892.

[5] Nadal I et al (2007) Imbalance in the composition of the duodenal microbiota of children with coeliac disease, Journal of Medical Microbiology 56:1669-1674.

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