Where's Waldo? Searching for Missing Gut Bacteria

Molecular profiling indicates that patients with ulcerative colitis and Irritable Bowel Syndrome have notably low levels of the Bacteroides species in the gut.

Bacteroides cells colonising the gut. Image by Kathyrn Cross and Nikki Horn, IFR

Scientists on the Norwich Research Park have identified some bacteria that are low in abundance in the gut of Irritable Bowel Syndrome (IBS) and ulcerative colitis (UC) patients compared to healthy adults. This finding could be relevant to preventing or managing these conditions to maintain health.

Using molecular profiling techniques Institute of Food Research scientists have identified significant abnormalities in the fecal bacteria of UC and IBS patients. Previous studies have shown a reduced microbial diversity associated with UC and IBS but have not identified which groups of bacteria are missing.

“A better understanding of which bacteria or bacterial populations are relevant to ulcerative colitis and IBS is important if microbial interventions are to be used in preventing or managing these conditions,” said Dr. Arjan Narbad from the Institute of Food Research.

One group of bacteria was most notably reduced; the Bacteroides species. Previous studies have suggested a protective role of Bacteroides species in gut disorders. Reduction in some of these species in IBS and UC patients suggests a possible loss of a protective role by these bacteria.

IBS and UC are two very different disorders of the gastrointestinal tract which share common symptoms such as pain and changed bowel habits. The exact causes of them are not clear but it is generally accepted that populations of bacteria in the gut are an important factor in their development.

It is not yet known exactly how the species identified by Dr Narbad and his team protect against gastrointestinal conditions and further investigation is required.

Source: Institute of Food Research