Irritable Bowel Syndrome (IBS) is a common intestinal disorder that affects anywhere from seven to ten out of 100 people in the world. The etiopathogenesis of IBS is not completely understood, but several pathophysiological changes are known. Recently, it was discovered that some patients with IBS have an altered microbiome, accompanied with dysbiosis. IBS, among other causes, may have roots in the microbiome.

Studies have been conducted on patients with IBS, and in general, they show a decrease in the proportion of Bifidobacterium and Lactobacillus, but an increase in Enterobacter. Certain types of IBS, such as IBS with diarrhea (IBS-D) and IBS with constipation (IBS-C) also show certain trends in the microbiome. Those with IBS-D had a greater reduction of Lactobacillus than patients with IBS-C. Another strong indicator of the role of the microbiota in IBS is the low-grade inflammation it can cause. More studies have been conducted to investigate the connection between IBS and the microbiome and have found a twofold increase in the ratio of Firmicutes to Bacteroidetes in IBS patients as well as an association between abdominal pain and low amounts of Bifidobacteria. A healthy microbiome must be maintained in order to prevent abdominal diseases such as IBS.

PASSOS, Maria do Carmo Friche, & MORAES-FILHO, Joaquim Prado. (2017). INTESTINAL MICROBIOTA IN DIGESTIVE DISEASES. Arquivos de Gastroenterologia, Epub July 06, 2017.