In Vitro Assessment of the Effects of Human Milk Oligosaccharides on the Microbiota in Irritable Bowel Syndrome

Irritable Bowel Syndrome (IBS) affects 1 in 5 people at some point in their life, this has huge implications on not only patients but the economy. The syndrome is characterised by pain, irregular bowel movements and general discomfort making IBS difficult to diagnose and treat. However, there is now strong evidence implicating the gut microbiome in the onset and alleviation of many gastrointestinal diseases.

The objective of the present study was to assess the potential for using Human Milk Oligosaccharides (HMO) as a new prebiotic to manipulate the microbiome and their functionality to alleviate symptoms and signs of IBS. 

Batch culture fermentation models were used to assess 6 individual HMOs in IBS (n=4) and healthy donors (n=2). Batch culture models were aseptically inoculated with a basal culture medium in the presence of the HMOs with the temperature kept constant (37°C) and the pH regulated (6.8). These models were run for 48 hours and samples were taken at 0, 8, 24 and 48 hours from each culture. The samples were then analysed using a number of different techniques; flow cytometry coupled with fluorescent in-situ hybridization (FISH) for microbial composition and NMR spectroscopy for metabolite profiling, as well as gas chromatography (GC) for short chain fatty acids (SCFA) analysis.

There is a clear change in microbial composition when introducing HMOs into the culture in both healthy and IBS subjects throughout the fermentation compared to not. Furthermore, there is a significant difference between SCFAs in healthy compared to IBS subject samples. After performing multivariate statistics on the NMR data, preliminary modelling revealed a number of differences between the metabolic profiles.